The responses of cells to chemical signals are relatively well characterized and understood. Cells also respond mechanical in the form externally applied force forces generated by cell-matrix cell-cell contacts. Many features cell function that generally considered be under control stimuli, such as motility, proliferation, differentiation survival, can altered changes stiffness substrate which adhered, even when their environment remains unchanged. examples from clinical whole animal studies...

The extracellular Ca2+-sensing receptor (CaSR) plays an essential role in Ca2+ homeostasis by regulating the rate of parathyroid hormone (PTH) secretion and calcium reabsorption kidney. Activation renal CaSR is thought to inhibit paracellular divalent cation cortical ascending limb (cTAL) both directly indirectly via a decrease NaCl transport. However, patients with autosomal dominant hypocalcemia (ADH), caused gain-of-function mutations, defect tubular loss has not been described so far....

Mutational replacements of specific residues in the GTP-binding pocket 21-kDa ras proteins (p21ras) reduce their GTPase activity. To test possibility that cognate regions G protein α chains participate GTP binding and hydrolysis, we compared signaling functions normal mutated (termed αs) Gs, stimulatory regulator adenylyl cyclase. αs were expressed an αs-deficient S49 mouse lymphoma cell line, cyc-. which leucine replaces glutamine 227 (corresponding to 61 p21ras) constitutively activates...

The α subunits of G s and i link different sets hormone receptors to stimulation inhibition, respectively, adenylyl cyclase. A chimeric /α cDNA was constructed that encodes a polypeptide composed the amino terminal 60% an chain carboxyl 40% . introduced via retroviral vector into S49 cyc - cells, which lack endogenous Although less than half hybrid is derived from , its ability mediate β-adrenoceptor cyclase matched normal expressed same in cells. This result indicates acid sequences contain...

Ammonia is both produced and transported by renal epithelial cells, it regulates ion transport. Recent studies have identified a family of putative ammonium transporters; mRNA for two members this family, Rh B-glycoprotein (RhBG) C-glycoprotein (RhCG), expressed in the kidney. The purpose study was to determine cellular location RhBG RhCG protein mouse We generated RhBG- RhCG-specific anti-peptide antibodies. Immunoblot analysis confirmed that proteins were localization with...

In many cases, the biologic responses of cells to extracellular signals and specificity cannot be explained solely on basis interactions known signaling proteins. Recently, scaffolding adaptor proteins have been identified that organize in contribute nature pathways. an effort identify might system(s) activated by Ca2+ receptor (CaR), we used a bait construct representing intracellular C terminus human CaR yeast two hybrid system screen kidney cDNA library. We clone C-terminal 1042 amino...

Angiotensinogen, angiotensin-converting enzyme, and renin constitute the components of renin-angiotensin system. The mammalian renal proximal tubule contains angiotensinogen, angiotensin receptors. Previous immunohistochemical studies describing presence in could not distinguish synthesized from trapped glomerular filtrate. In present study, we examined activity mRNA rabbit cells primary culture microdissected tubules. Renin was lysates culture. Cellular content cultured increased by...

Mechanical properties of cells and extracellular matrices are critical determinants function in contexts including oncogenic transformation, neuronal synapse formation, hepatic fibrosis stem cell differentiation. The size heterogeneity biological specimens the importance measuring their mechanical under conditions that resemble environments vivo present a challenge for quantitative measurement. Centimeter-scale tissue samples can be measured by commercial instruments, whereas at subcellular...

Increased Na/H antiporter activity has been demonstrated after in vivo chronic metabolic acidosis as well vitro acid preincubation of cultured rabbit renal tubule cells. To study the underlying molecular mechanisms this adaptive increase activity, present studies examined effect low pH media on and mRNA abundance was increased by 60% a mouse cortical cell line (MCT), 90% an opossum kidney (OKP) 24 h (low [HCO3]) media. The ethylisopropylamiloride sensitivity antiporters were different these...

The mechanical properties of tissues and cells including renal glomeruli are important determinants their differentiated state, function, responses to injury but not well characterized or understood. Understanding glomerular mechanics is for understanding diseases attributable abnormal expression assembly structural proteins hemodynamics. We use atomic force microscopy (AFM) a new technique, capillary micromechanics, measure the elastic rat glomeruli. Young's modulus was 2,500 Pa, it reduced...

The Ca 2+ -sensing receptor (CaR) couples to multiple G proteins involved in distinct signaling pathways: Gα i inhibit the activity of adenylyl cyclase and activate ERK, q stimulate phospholipase C A 2 , Gβγ phosphatidylinositol 3-kinase. To determine whether also 12/13 we investigated pathway by which CaR regulates D (PLD), a known target. We established Madin-Darby canine kidney (MDCK) cell lines that stably overexpress wild-type (CaR WT ) or nonfunctional mutant R796W as negative control,...

We studied a nine-year-old boy with severe, recurrent infections. The patient was exposed in utero to azathioprine and prednisone. He had autoimmune hemolytic anemia, bronchiectasis, Hodgkin's disease. patient's circulating lymphocytes were normal number phenotype, but stimulation of the T-cell receptor by antigens, mitogens, monoclonal antibodies failed induce interleukin-2–receptor expression, interleukin-2 synthesis, or lymphocyte proliferation. early biochemical events necessary initiate...

The Ca(2+)-sensing receptor (CaR), a G protein-coupled receptor, is expressed in many epithelial tissues including the parathyroid glands, kidney, and GI tract. Although its role regulating PTH levels Ca(2+) metabolism are best characterized, it may also regulate salt water transport kidney as demonstrated by recent reports showing association of potent gain-of-function mutations CaR with Bartter-like, salt-wasting phenotype. To determine whether this interacts novel proteins that control...

Primary care providers do not routinely follow guidelines for the of patients with chronic kidney disease (CKD). Multidisciplinary efforts may improve disease. Pharmacist based interventions have effectively improved management hypertension. We performed a pragmatic, randomized, controlled trial to evaluate effect pharmacist quality improvement program on 1) outcomes CKD and 2) adherence in primary setting. Patients moderate severe receiving services at one thirteen community-based Veterans...

Soluble, circulating Klotho (sKlotho) is essential for normal health and renal function. sKlotho shed from the distal convoluted tubule (DCT), its primary source, via enzymatic cleavage. However, physiologic mechanisms that control production, trafficking, shedding are not fully defined. We previously found G protein‐coupled calcium‐sensing receptor (CaSR) co‐localizes with membrane‐bound αKlotho disintegrin/metalloprotease ADAM10 in DCT controls response to CaSR ligands pHo by activating...

The Ca2+-sensing receptor (CaR) stimulates a number of phospholipase activities, but the specific phospholipases and mechanisms by which CaR activates them are not defined. We investigated regulation A2(PLA2) in human embryonic kidney 293 cells that express either wild-type or nonfunctional mutant (R796W) CaR. PLA2activity was attributable to cytosolic PLA2(cPLA2) based on its inhibition arachidonyl trifluoromethyl ketone, lack bromoenol lactone, enhancement CaR-stimulated activity...

The extracellular Ca 2+ -sensing receptor (CaR) responds to polycations, including and neomycin. This is a physiological regulator of systemic metabolism may also mediate the toxic effects hypercalcemia. A number divalent cations, Pb , Co Cd Fe are kidney, brain, other tissues where CaR expressed. To determine which cations can activate CaR, we expressed human in HEK-293 cells measured activation phospholipase 2 (PLA ) mitogen-activated protein kinase p42ERK response potential agonists for...

The amiloride-sensitive, growth factor-activatable Na/H exchanger (NHE-1) is a ubiquitous mammalian protein that involved in the regulation of intracellular pH and cell volume. We have determined intron/exon boundaries transcription initiation sites characterized portion 5'-flanking regulatory region human NHE-1 gene. gene spans approximately 70 kilobases. coding divided into 12 exons 11 introns, one which 41.5 kilobases length. first exon contains entire 5'-noncoding region, 786 bases long,...

Sodium-proton antiporter activity can be modulated through changes Vmax and/or intracellular proton sensitivity of the antiporter. To characterize a parathyroid hormone (PTH)-induced decrease in continuous renal cell line (opossum kidney cells), extracellular sodium and dependence amiloride-inhibitable 22Na uptake was studied. The Km for at pH 6.32 28 mM unaltered by PTH, whereas decreased 26%. When set over range 5.87-7.57 potassium-nigericin method, increased as decreased. Hill analysis...