A5052048835- Ion Transport and Channel Regulation
- Ion channel regulation and function
- Drug Transport and Resistance Mechanisms
- Helicobacter pylori-related gastroenterology studies
- Erythrocyte Function and Pathophysiology
- Metabolism, Diabetes, and Cancer
- Pancreatic function and diabetes
- Receptor Mechanisms and Signaling
- Amino Acid Enzymes and Metabolism
- NF-κB Signaling Pathways
- Physiological and biochemical adaptations
- Diet and metabolism studies
- Gastrointestinal motility and disorders
- Neuroscience and Neuropharmacology Research
- Biochemical Analysis and Sensing Techniques
- Protein Kinase Regulation and GTPase Signaling
- Neurobiology and Insect Physiology Research
- Nitric Oxide and Endothelin Effects
- Peroxisome Proliferator-Activated Receptors
- Cystic Fibrosis Research Advances
- Magnesium in Health and Disease
- Genetics and Physical Performance
- Inhalation and Respiratory Drug Delivery
- Adipose Tissue and Metabolism
- Metabolism and Genetic Disorders
University of California, Riverside
2007-2020
University of California, Davis
1995-1997
Medical University of South Carolina
1997
Mount Desert Island Biological Laboratory
1992-1996
Yale University
1992-1996
University of Toronto
1992
Duke University
1985-1990
Duke University Hospital
1985-1990
Duke Medical Center
1985-1990
By mediating the coupled movement of Na, K, and Cl ions across plasma membrane most animal cells, bumetanide-sensitive Na-K-Cl cotransporter (NKCC) plays a vital role in regulation ionic balance cell volume. The transporter is central element process vectorial salt transport secretory absorptive epithelia. A cDNA encoding cotransport protein was isolated from shark rectal gland library by screening with monoclonal antibodies to native cotransporter. 1191-residue predicted sequence has 12...
The Na-K-Cl cotransporter (NKCC) is present in most animal cells where it functions cell volume homeostasis and epithelial salt transport. We developed six monoclonal antibodies (designated T4, T8, T9, T10, T12, T14) against a fusion protein fragment encompassing the carboxy-terminal 310 amino acids of human colonic NKCC. These T selectively recognized putative NKCC proteins diverse variety tissues. Western blot analysis membranes isolated from 23 types identified single bands immunoreactive...
We determined the relationship between activation state and phosphorylation of Na-K-Cl cotransport protein in tubules isolated from shark rectal gland, a prototypic chloride-secreting epithelium. In response to cAMP-dependent secretagogues (e.g. vasoactive intestinal peptide, adenosine, forskolin) or osmotically induced changes cell volume, (assessed measurements loop diuretic binding) increased 5-10 fold. The was temporally associated with comparable increase (3-9 fold) phosphorylation....
By moving chloride into epithelial cells, the Na-K-Cl cotransporter aids transcellular movement of across both secretory and absorptive epithelia. Using cDNA probes from recently identified elasmobranch (sNKCC1) (Xu, J. C., Lytle, C. Zhu, T. T., Payne, A., Benz, E., Forbush, B., III(1994) Proc. Natl. Acad. Sci. 91, 2201-2205), we have human homologue. screening libraries a colonic carcinoma line, T84 cell, sequence 4115 bases overlapping clones. The deduced protein is 1212 amino acids in...
The effect of cytoplasmic Cl concentration ([Cl]i) on the activation state ([3H]benzmetanide binding rate) and phosphorylation (32P incorporation) Na-K-Cl cotransporter was evaluated in secretory tubules isolated from dogfish shark rectal gland. Reduction [Cl]i at relatively constant cell volume (by removal extracellular or Na by addition bumetanide) increased phosphorylation. Raising K ([K]o) 4 to 80 mM, a maneuver that elevated above normal, reduced basal cotransport activity rendered it...
We mapped the cellular and subcellular distribution of Na-K-Cl co-transporter (NKCC) in adult gerbil inner ear by immunostaining with a monoclonal antibody (MAb T4) generated against human colon NKCC. Heavy immunolabeling was seen basolateral plasma membrane marginal cells stria vascularis dark vestibular system. Subpopulations fibrocytes cochlear spiral ligament limbus underlying neurosensory epithelium also stained moderate to strong intensity, apparently along their entire plasmalemma....
Na-K-Cl cotransport activity in duck erythrocytes increases ∼10-fold response to osmotic cell shrinkage, norepinephrine, fluoride, or calyculin-A (an inhibitor of type-1 and -2a phosphatases). To assess whether all four stimuli promote phosphorylation the protein this is catalyzed by same kinase, cotransporter was isolated from immunoprecipitation its pattern evaluated. Each stimulus evoked proportionate phosphorylation. No two combination greater activation than did more potent acting...
The colon is believed to absorb NaCl via the coupled operation of apical Na/H exchanger-3 (NHE3) and Cl/HCO 3 exchanger SLC26A3 (DRA). Efficient coupling requires that NHE3 DRA operate in close proximity within common luminal cytosolic microenvironments. Thus we examined whether these proteins coexist along margin surface enterocytes by quantitative immunofluorescence microscopy consecutive segments from nonfasted mice rats. cecocolonic profiles expression were roughly inverse; was highest...
HNF4α has been implicated in colitis and colon cancer humans but the role of different isoforms expressed from two promoters (P1 P2) active is not clear. Here, we show that P1-HNF4α primarily differentiated compartment mouse colonic crypt P2-HNF4α proliferative compartment. Exon swap mice express only P1- or have gene expression profiles, interacting proteins, cellular migration, ion transport epithelial barrier function. The also exhibit altered susceptibilities to experimental (DSS)...
Na-K-2Cl cotransporter (NKCC) and K-Cl (KCC) play key roles in cell volume regulation epithelial Cl − transport. Reductions either or cytosolic concentration ([Cl ] i ) stimulate a corrective uptake of KCl water via NKCC, whereas swelling triggers loss KCC. The dependence these transporters on [Cl was evaluated model duck red blood cells. Replacement with methanesulfonate elevated the set point at which NKCC activates KCC inactivates. insensitive to ionic strength. Reducing constant driving...
Basolateral Na-K-Cl cotransport activity in primary cultures of dog tracheal epithelial cells is stimulated by β-adrenergic agents, such as isoproterenol, and apical UTP, which acts through an P<sub>2</sub>-purinergic receptor. While at least part the stimulatory effect isoproterenol appears to involve direct activation cotransporter via cAMP-dependent protein kinase, stimulation UTP entirely secondary Cl<sup>-</sup> efflux a resultant decrease intracellular [Cl<sup>-</sup>]...
In the duck red blood cell, Na-K-2Cl cotransport exhibits two modes of ion movement: net and obligate cation exchange. high-K cells, predominant exchange is K/K (or K/Rb). high-Na it becomes Na/Na Na/Li). Both represent partial reactions in which a fully loaded carrier releases part its cargo, rebinds fresh ions, returns back across membrane loaded. Net occurs when unloads completely empty. This mode has fixed stoichiometry 1Na:1K:2Cl under all conditions tested. The requirements exchanges...
To test whether the peroxisome proliferator-activated receptor gamma (PPARgamma) ligand rosiglitazone (Ro) has therapeutic activity in IL-10(-/-) mouse model of inflammatory bowel disease (IBD), and to identify cellular targets molecular mechanisms Ro action.The progression spontaneous chronic colitis mice was compared 5-week-old fed a standard diet with or without for 12 weeks. The possible effect also tested over 6-week interval older established IBD.Treatment slowed onset IBD mice. Crypt...
When Na-K-2Cl cotransport is activated in duck red blood cells by either osmotic cell shrinkage, norepinephrine, fluoride, or calyculin A, phosphorylation of the transporter occurs at a common set serine/threonine sites. To examine kinetics and regulation activating kinase, phosphatase activity was inhibited abruptly with A subsequent changes were determined. Increases fractional incorporation 32P into uptake 86Rb closely correlated, suggesting that event rate determining activation process....
The Na-K-Cl cotransporter mediates the coupled transport of Na, K, and Cl across plasma membrane many animal cell membranes. It is inhibited by loop diuretics such as furosemide, bumetanide, benzmetanide. We have developed a panel monoclonal antibodies directed against 195-kDa shark rectal gland cotransport protein. Four representative (J3, J4, J7, J25), each which recognizes discrete structural domain, were selected for detailed characterization. When radiolabeled diuretic bound to prior...
The Na-K-2Cl cotransporter isoform1 (NKCC1) is present in many animal cells where it plays prominent roles regulating cell volume and maintaining intracellular Cl(-) concentration ([Cl(-)]i) above electrochemical equilibrium. We show here that NKCC1 active cultured oligodendrocytes. Expression of the rat spinal cord increased during development from postnatal day 6 through 21 parallel with myelin basic protein. In oligodendrocytes, 39% total K+ (86Rb+) influx represented activity. Activation...
SUMMARY To examine the evolution of endurance-exercise behaviour, we have selectively bred four replicate lines laboratory mice (Mus domesticus) for high voluntary wheel running (`high runner' or HR lines),while also maintaining non-selected control (C) lines. By generation 16,HR ran ∼2.7-fold more than C mice, mainly by faster(especially in females), a differential maintained through subsequent generations, suggesting an evolutionary limit unknown origin. We hypothesized that would higher...
In mucosal tissues, epithelial M cells capture and transport microbes across the barrier to underlying immune cells. Previous studies suggested that high affinity ligands targeting may be used deliver vaccines; here, we show particle composition dispersion buffer ionic strength can independently influence their uptake in vivo. First, addition of a poloxamer 188 nanoparticle formulations increased intranasally administered nanoparticles vivo, but effect was dependent on presence...
Glucagon is important for regulating lipid metabolism in part through its inhibition of fatty acid synthesis adipocytes. Acetyl-CoA carboxylase 1 (ACC1) the rate-limiting enzyme synthesis. has been proposed to activate cAMP-dependent protein kinase A (PKA), which phosphorylates ACC1 attenuate lipogenic activity ACC1. Because AMP-activated (AMPK) also inhibits by phosphorylation ACC1, we examined involvement AMPK and upstream glucagon-elicited signaling adipocytes vitro vivo. LC-MS-MS...
Abstract: Near-infrared nanoconstructs present a potentially effective platform for site-specific and deep tissue optical imaging phototherapy. We have engineered polymeric nanocapsule composed of polyallylamine hydrochloride (PAH) chains cross-linked with sodium phosphate doped indocyanine green (ICG) toward such endeavors. The ICG-doped nanocapsules were coated covalently polyethylene glycol (5000 daltons) through reductive amination. administrated the constructs by tail vein injection to...
Significance This work identifies a mechanism by which atheroprone oscillatory shear and atheroprotective pulsatile differentially regulate microRNA (miR) biogenesis in the vascular endothelium. Nonphosphorylated nucleolin facilitates maturation of miR-93 miR-484, turn target Krüpple-like factor 2 endothelial nitric oxide synthase mRNAs. The translational significance these findings is provided identification elevated levels miR-484 sera from patients with coronary artery disease.
Endothelial cells of the blood-brain barrier (BBB) are characterized by extensive tight junctions and asymmetric distribution specific enzymes transport systems. Maintenance BBB endothelial phenotype depends on astrocyte-endothelial interactions. We showed previously that cultured cerebral microvascular (CMEC) exhibit robust Na-K-Cl cotransport activity. In present study, we evaluated expression protein in CMEC quantitative Western blot analysis found a approximately 170 kDa was recognized...