Ultrastructure of Highly Ordered Granules in Alveolar Type II Cells in Several Species.

Alveolar Type II cells from seven mammalian species were examined for a protein in the rough endoplasmic reticulum (RER), which showed a multilayered, repeating motif. Each motif, 100 nm in width, comprised two parallel outer dense layers, a less dense central layer, and often 1-3 faint layers on either side of the latter. Outer layers showed periodicities at 3-4 densities/100 nm of width, while layers on either side of the central layer showed 5-7 densities/100 nm of width.

A community survey on knowledge of the impact of environmental and epigenetic factors on health and disease.

Aim: An outreach effort was designed to survey breast cancer survivors, supporters and their families and friends with respect to their interest in, and knowledge of, the potential impact of the environment and epigenetics on health.

Methods: Two nearly identical questionnaires (one for adolescents and one for adults) were designed to gauge the perception of this community as to whether the environment impacts health and cancer risk through processes other than genetics. The questionnaires were filled out at casual social gatherings, fundraisers and wellness campaigns as well as in schools (730 participants).

Tumor response ratio predicts overall survival in breast cancer patients treated with neoadjuvant chemotherapy.

Background: Neoadjuvant chemotherapy (NAC) is commonly used to treat locally advanced breast cancer. Pathologic complete response (pCR) predicts improved overall survival (OS); however, prognosis of patients with partial response remains unclear. We evaluated whether tumor response ratio (TRR) is a better predictor of OS than current staging methods.

Oral cadmium in mice carrying 5 versus 2 copies of the Slc39a8 gene: comparison of uptake, distribution, metal content, and toxicity.

The highly conserved human and mouse SLC39A8 gene encodes the divalent cation/bicarbonate symporter ZIP8 expressed ubiquitously in most cell types. Our bacterial artificial chromosome-transgenic BTZIP8-3 line has 3 additional copies of the Slc39a8 gene in addition to its constitutive diploid pair found in wild-type (WT) mice. In liver, kidney, lung, testis, gastrointestinal tract, and brain, BTZIP8-3 mice are known to express ∼2.

Loss of NHE1 activity leads to reduced oxidative stress in heart and mitigates high-fat diet-induced myocardial stress.

Acute inhibition of the NHE1 Na(+)/H(+) exchanger protects against ischemia-reperfusion injury and chronic inhibition attenuates development of cardiac hypertrophy and failure. To determine the cardiac effects of chronic inhibition of NHE1 under non-pathological conditions we used NHE1-null mice as a model of long-term NHE1 inhibition. Cardiovascular performance was relatively normal in Nhe1(-/-) mice although cardiac contractility and relaxation were slightly improved in mutant mice of the FVB/N background.

Oral benzo[a]pyrene in Cyp1a1/1b1(-/-) double-knockout mice: Microarray analysis during squamous cell carcinoma formation in preputial gland duct.

Benzo[a]pyrene (BaP) is a prototypical polycyclic aromatic hydrocarbon (PAH) found in combustion processes. Cytochrome P450 1A1 and 1B1 enzymes (CYP1A1, CYP1B1) and other enzymes can activate PAHs to reactive oxygenated intermediates involved in mutagenesis and tumor initiation; also, CYP1 enzymes can detoxify PAHs. Cyp1(+/+) wild-type (WT) and Cyp1b1(-/-) knockout mice receiving oral BaP (12.

ZIP8 zinc transporter: indispensable role for both multiple-organ organogenesis and hematopoiesis in utero.

Previously this laboratory characterized Slc39a8-encoded ZIP8 as a Zn(2+)/(HCO(3)(-))(2) symporter; yet, the overall physiological importance of ZIP8 at the whole-organism level remains unclear. Herein we describe the phenotype of the hypomorphic Slc39a8(neo/neo) mouse which has retained the neomycin-resistance gene in intron 3, hence causing significantly decreased ZIP8 mRNA and protein levels in embryo, fetus, placenta, yolk sac, and several tissues of neonates. The Slc39a8(neo) allele is associated with diminished zinc and iron uptake in mouse fetal fibroblast and liver-derived cultures; consequently, Slc39a8(neo/neo) newborns exhibit diminished zinc and iron levels in several tissues.

Identification of a conserved anti-apoptotic protein that modulates the mitochondrial apoptosis pathway.

Here we identified an evolutionarily highly conserved and ubiquitously expressed protein (C9orf82) that shows structural similarities to the death effector domain of apoptosis-related proteins. RNAi knockdown of C9orf82 induced apoptosis in A-549 and MCF7/casp3-10b lung and breast carcinoma cells, respectively, but not in cells lacking caspase-3, caspase-10 or both. Apoptosis was associated with activated caspases-3, -8, -9 and -10, and inactivation of caspases 10 or 3 was sufficient to block apoptosis in this pathway.

Secretory pathway stress responses as possible mechanisms of disease involving Golgi Ca2+ pump dysfunction.

In mammalian tissues, uptake of Ca(2+) and Mn(2+) by Golgi membranes is mediated by the secretory pathway Ca(2+) -ATPases, SPCA1 and SPCA2, encoded by the ATP2C1 and ATP2C2 genes. Loss of one copy of the ATP2C1 gene, which causes SPCA1 haploinsufficiency, leads to squamous cell tumors of keratinized epithelia in mice and to Hailey-Hailey disease, an acantholytic skin disease, in humans. Although the disease phenotypes resulting from SPCA1 haploinsufficiency in mice and humans are quite different, each species-specific phenotype is remarkably similar to those arising as a result of null mutations in one copy of the ATP2A2 gene, encoding SERCA2, the endoplasmic reticulum (ER) Ca(2+) pump.

Loss of the NHE2 Na+/H+ exchanger in mice results in dilation of folliculo-stellate cell canaliculi.

Genetic ablation of the NHE2 Na+/H+ exchanger causes gastric achlorhydria, absorptive defects in kidney and colon, and low fertility. Here we show that NHE2 is expressed in the pituitary, with the highest mRNA expression in pars distalis and lower expression in pars intermedia. In pars distalis of NHE2-null mice, prominent cyst-like dilatations of folliculo-stellate (FS) cell canaliculi developed with age, and there were increased FS cell area, accumulation of lipid in FS cell cytoplasm, redundancies in FS cell basement membrane, and other changes.

Loss of the AE3 anion exchanger in a hypertrophic cardiomyopathy model causes rapid decompensation and heart failure.

The AE3 Cl(-)/HCO(3)(-) exchanger is abundantly expressed in the sarcolemma of cardiomyocytes, where it mediates Cl(-)-uptake and HCO(3)(-)-extrusion. Inhibition of AE3-mediated Cl(-)/HCO(3)(-) exchange has been suggested to protect against cardiac hypertrophy; however, other studies indicate that AE3 might be necessary for optimal cardiac function. To test these hypotheses we crossed AE3-null mice, which appear phenotypically normal, with a hypertrophic cardiomyopathy mouse model carrying a Glu180Gly mutation in α-tropomyosin (TM180).

In utero and lactational exposure to a complex mixture of polychlorinated biphenyls: toxicity in pups dependent on the Cyp1a2 and Ahr genotypes.

Polychlorinated biphenyls (PCBs) are persistent toxic pollutants occurring as complex mixtures in the environment. Humans are known genetically to have > 60-fold differences in hepatic cytochrome P450 1A2 (CYP1A2) levels and > 12-fold differences in aryl hydrocarbon receptor (AHR) affinity, both of which could affect PCB pharmacokinetics. Thus, we compared Ahr(b1)_Cyp1a2(+/+) high-affinity AHR wild-type, Ahr(d)_Cyp1a2(+/+) poor affinity AHR wild-type, Ahr(b1)_Cyp1a2(-/-) knockout, and Ahr(d)_Cyp1a2(-/-) knockout mouse lines.

Hedgehog signaling regulates E-cadherin expression for the maintenance of the actin cytoskeleton and tight junctions.

In the stomach, strictly regulated cell adherens junctions are crucial in determining epithelial cell differentiation. Sonic Hedgehog (Shh) regulates epithelial cell differentiation in the adult stomach. We sought to identify whether Shh plays a role in regulating adherens junction protein E-cadherin as a mechanism for epithelial cell differentiation.

Oral N-acetylcysteine rescues lethality of hepatocyte-specific Gclc-knockout mice, providing a model for hepatic cirrhosis.

Background & Aims: Certain liver diseases have been associated with depletion of glutathione (GSH), the major antioxidant in the liver. A recent report about Gclc(h/h) mice with a hepatocyte-specific ablation of Gclc (the gene encoding the catalytic subunit of the rate-limiting enzyme in GSH synthesis) has shown an essential role of GSH in hepatic function. Gclc(h/h) mice develop severe steatosis and die of liver failure within one month, due to ~95% depletion of hepatic GSH; mitochondria are the major affected organelles, displaying abnormal ultrastructure and impaired functioning.

Organ-specific roles of CYP1A1 during detoxication of dietary benzo[a]pyrene.

Polycyclic aromatic hydrocarbons (PAHs) are widely distributed environmental toxicants derived from sources that include cigarette smoke, petroleum distillation, gas- and diesel-engine exhaust, and charcoal-grilled food. The gastrointestinal tract is the principal route of PAH exposures, even when inhaled. The most thoroughly studied prototype of PAHs is benzo[a]pyrene (BaP), well known to be toxic, mutagenic, and carcinogenic in various tissues and cell types.

CLIC5 mutant mice are resistant to diet-induced obesity and exhibit gastric hemorrhaging and increased susceptibility to torpor.

Chloride intracellular channel 5 (CLIC5) and other CLIC isoforms have been implicated in a number of biological processes, but their specific functions are poorly understood. The association of CLIC5 with ezrin and the actin cytoskeleton led us to test its possible involvement in gastric acid secretion. Clic5 mutant mice exhibited only a minor reduction in acid secretion, Clic5 mRNA was expressed at only low levels in stomach, and Clic5 mutant parietal cells were ultrastructurally normal, negating the hypothesis that CLIC5 plays a major role in acid secretion.

Volume density, distribution, and ultrastructure of secretory and basolateral membranes and mitochondria predict parietal cell secretory (dys)function.

Acid secretion in gastric parietal cells requires highly coordinated membrane transport and vesicle trafficking. Histologically, consensus defines acid secretion as the ratio of the volume density (Vd) of canalicular and apical membranes (CAMs) to tubulovesicular (TV) membranes, a value which varies widely under normal conditions. Examination of numerous achlorhydric mice made it clear that this paradigm is discrepant when used to assess most mice with genetic mutations affecting acid secretion.

Massive fundic gland polyposis in a patient receiving protracted proton-pump inhibitor medication.

A case of massive fundic gland polyposis (MFGPsis) in a female patient receiving protracted proton-pump inhibitor (PPI) medication is described. At gross examination the majority of the polyps were overlapping, confluent, some of them having a "cauliflower-like" configuration. The fundic gland polyps (FGP) arose in the gastric acid secretory mucosa.

Oral benzo[a]pyrene-induced cancer: two distinct types in different target organs depend on the mouse Cyp1 genotype.

Benzo[a]pyrene (BaP) is a prototypical polycyclic aromatic hydrocarbon (PAH) found in combustion processes. Cytochrome P450 1A1 and 1B1 enzymes (CYP1A1 and CYP1B1) can both detoxify PAHs and activate them to cancer-causing reactive intermediates. Following high dosage of oral BaP (125 mg/kg/day), ablation of the mouse Cyp1a1 gene causes immunosuppression and death within ∼28 days, whereas Cyp1(+/+) wild-type mice remain healthy for >12 months on this regimen.

Fundic gland cysts in Atp4a-/- mice mimic fundic gland polyps in humans.

Background: Innumerable fundic gland polyps (FGPs) (that is massive FGP polyposis) may be found in the human stomach. Innumerable fundic gland cysts (FGCs) develop in mice lacking the gene Atp4a (Atp4a((-/-))), that encodes the enzyme ATPase. The aim was to monitor the evolution of FGCs in Atp4a((-/-)) mice.

Loss of parietal cell expression of Sonic hedgehog induces hypergastrinemia and hyperproliferation of surface mucous cells.

Background & Aims: Sonic Hedgehog (Shh) is expressed in the adult stomach, but its role as a gastric morphogen is unclear. We sought to identify mechanisms by which Shh might regulate gastric epithelial cell function and differentiation.

Methods: Mice with a parietal cell-specific deletion of Shh (HKCre/Shh(KO)) were created.

Deletion of the chloride transporter slc26a7 causes distal renal tubular acidosis and impairs gastric acid secretion.

SLC26A7 (human)/Slc26a7 (mouse) is a recently identified chloride-base exchanger and/or chloride transporter that is expressed on the basolateral membrane of acid-secreting cells in the renal outer medullary collecting duct (OMCD) and in gastric parietal cells. Here, we show that mice with genetic deletion of Slc26a7 expression develop distal renal tubular acidosis, as manifested by metabolic acidosis and alkaline urine pH. In the kidney, basolateral Cl(-)/HCO3(-) exchange activity in acid-secreting intercalated cells in the OMCD was significantly decreased in hypertonic medium (a normal milieu for the medulla) but was reduced only mildly in isotonic medium.

Ligand-specific function of transforming growth factor beta in epithelial-mesenchymal transition in heart development.

The ligand specificity of transforming growth factor beta (TGFbeta) in vivo in mouse cardiac cushion epithelial-to-mesenchymal transition (EMT) is poorly understood. To elucidate the function of TGFbeta in cushion EMT, we analyzed Tgfb1(-/-), Tgfb2(-/-), and Tgfb3(-/-) mice between embryonic day (E) 9.5 and E14.

Knock-in mouse lines expressing either mitochondrial or microsomal CYP1A1: differing responses to dietary benzo[a]pyrene as proof of principle.

In the past, CYP1A1 protein was known to be located in the endoplasmic reticulum (ER; microsomes). More recently, CYP1A1 was shown also to be targeted to the inner mitochondrial membrane; mitochondrial import is dependent on NH(2)-terminal processing that exposes a cryptic targeting signal. It is interesting that microsomal and mitochondrial CYP1A1 enzymes exhibit different substrate specificities, electron donors, and inducer properties.

Deletion of the chloride transporter Slc26a9 causes loss of tubulovesicles in parietal cells and impairs acid secretion in the stomach.

Slc26a9 is a recently identified anion transporter that is abundantly expressed in gastric epithelial cells. To study its role in stomach physiology, gene targeting was used to prepare mice lacking Slc26a9. Homozygous mutant (Slc26a9(-/-)) mice appeared healthy and displayed normal growth.