scholarly journals Reg-II Is an Exocrine Pancreas Injury-Response Product That Is Up-Regulated by Keratin Absence or Mutation

2007 ◽  
Vol 18 (12) ◽  
pp. 4969-4978 ◽  
Author(s):  
Bihui Zhong ◽  
Pavel Strnad ◽  
Diana M. Toivola ◽  
Guo-Zhong Tao ◽  
Xuhuai Ji ◽  
...  
Keyword(s):  
Gene Expression ◽  
Exocrine Pancreas ◽  
Pancreatic Injury ◽  
Recovery Phase ◽  
Wild Type ◽  
Peptide Antibody ◽  
Keratin Filament ◽  
Candidate Protein ◽  
Cytoplasmic Filament

The major keratins in the pancreas and liver are keratins 8 and 18 (K8/K18), but their function seemingly differs in that liver K8/K18 are essential cytoprotective proteins, whereas pancreatic K8/K18 are dispensable. This functional dichotomy raises the hypothesis that K8-null pancreata may undergo compensatory cytoprotective gene expression. We tested this hypothesis by comparing the gene expression profile in pancreata of wild-type and K8-null mice. Most prominent among the up-regulated genes in K8-null pancreas was mRNA for regenerating islet-derived (Reg)-II, which was confirmed by quantitative reverse transcription-polymerase chain reaction and by an anti-Reg-II peptide antibody we generated. Both K8-null and wild-type mice express Reg-II predominantly in acinar cells as determined by in situ hybridization and immunostaining. Analysis of Reg-II expression in various keratin-related transgenic mouse models showed that its induction also occurs in response to keratin cytoplasmic filament collapse, absence, or ablation of K18 Ser52 but not Ser33 phosphorylation via Ser-to-Ala mutation, which represent situations associated with predisposition to liver but not pancreatic injury. In wild-type mice, Reg-II is markedly up-regulated in two established pancreatitis models in response to injury and during the recovery phase. Thus, Reg-II is a likely mouse exocrine pancreas cytoprotective candidate protein whose expression is regulated by keratin filament organization and phosphorylation.

scholarly journals The effect of neurogenin3 deficiency on pancreatic gene expression in embryonic mice

2006 ◽  
Vol 37 (2) ◽  
pp. 301-316 ◽  
Author(s):  
Andreas Petri ◽  
Jonas Ahnfelt-Rønne ◽  
Klaus Stensgaard Frederiksen ◽  
David George Edwards ◽  
Dennis Madsen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Microarray Analysis ◽  
Molecular Mechanisms ◽  
Homeobox Gene ◽  
Specific Gene ◽  
Wild Type ◽  
Specific Gene Expression ◽  
And Function ◽  
Deficient Mice

To understand the molecular mechanisms regulating pancreatic endocrine development and function, pancreatic gene expression was compared between Ngn3-deficient mice and littermate controls on embryonic days 13 and 15. Microarray analysis identified 504 genes with significant differences in expression. Fifty-two of these showed at least twofold reduction in Ngn3 knockouts compared to controls. Many of them were previously described to be involved in endocrine development and function. Among the genes not previously characterized were Rhomboid veinlet-like 4, genes involved in tetrahydrobiopterin biosynthesis and the Iroquois-type homeobox gene Irx1, the latter was selected for further investigation. In situ hybridisation demonstrated that two Iroquois genes, Irx1 and Irx2, were expressed in pancreatic endoderm of wild-type, but not Ngn3 mutant embryos. Furthermore, ectopic Ngn3 induced prominent Irx2 expression in chicken endoderm. Co-labelling established that Irx1 and Irx2 mRNA is located to glucagon-, but not insulin- or somatostatin-producing cells in mice and chicken. These data suggest that Irx1 and Irx2 serve an evolutionary conserved role in the regulation of α-cell-specific gene expression.

scholarly journals Mutations in SIX1 associated with Branchio-oto-renal Syndrome (BOR) differentially affect otic expression of putative target genes

2021 ◽  
Author(s):  
Tanya Mehdizadeh ◽  
Himani Datta Majumdar ◽  
Sahra Ahsan ◽  
Andre Luiz Pasqua Tavares ◽  
Sally A Moody
Keyword(s):  
Gene Expression ◽  
Target Genes ◽  
Otic Vesicle ◽  
Wild Type ◽  
Single Nucleotide ◽  
Putative Target ◽  
Individual Effects ◽  
Factor Interactions ◽  
Ability To Drive

Single nucleotide mutations in SIX1 are causative in some individuals diagnosed with branchiootic/branchio-oto-renal (BOR) syndrome. To test whether these mutations have differential effects on otic gene expression, we engineered four BOR mutations in Xenopus six1 and targeted mutant protein expression to the neural crest and cranial placode precursor cells in wild-type embryos. Changes in the otic expression of putative Six1 targets and/or co-factors were monitored by qRT-PCR and in situ hybridization. We found that each mutant had a different combination of effects. The V17E mutant reduced eya2, tspan13, zbtb16 and pa2g4 otic vesicle expression at a frequency indistinguishable from wildtype Six1, but reduced prdm1 more and spry1 less compared to wild-type Six1. For most of these genes, the R110W, W122R and Y129C mutants were significantly less repressive compared to wild-type Six1. Their individual effects varied according to the level at which they were expressed. The R110W, W122R and Y129C mutants also often expanded prdm1 otic expression. Since previous studies showed that all four mutants are transcriptionally deficient and differ in their ability to interact with co-factors such as Eya1, we propose that altered co-factor interactions at the mutated sites differentially interfere with their ability to drive otic gene expression.

scholarly journals Growth, photosynthesis, and gene expression in Chlamydomonas over a range of CO2 concentrations and CO2/O2 ratios: CO2 regulates multiple acclimation states

2005 ◽  
Vol 83 (7) ◽  
pp. 796-809 ◽  
Author(s):  
Peter Vance ◽  
Martin H Spalding
Keyword(s):  
Gene Expression ◽  
Doubling Time ◽  
Wild Type ◽  
Airlift Bioreactors ◽  
Cell Doubling Time ◽  
Glycolate Dehydrogenase ◽  
Type C ◽  
Induced Genes ◽  
Inducible Genes

Growth, photosynthesis, and induction of two low CO2-inducible genes of Chlamydomonas reinhardtii Dangeard strain CC125 were quantified in a range of physiologically relevant CO2 and O2 concentrations (5%–0.005% CO2 and 20% or 2% O2) using airlift bioreactors to facilitate the simultaneous measurement of both growth and in situ photosynthetic rates. Within these CO2 concentration ranges, O2 concentrations (20% vs. 2%) had no discernable effect on growth, photosynthetic rate, or induction of the periplasmic carbonic anhydrase (Cah1) and glycolate dehydrogenase (Gdh) genes in wild-type C. reinhardtii. These results failed to support the hypothesis that the CO2/O2 ratio plays any role in signaling for the up-regulation of limiting CO2-induced genes and (or) of the CO2-concentrating mechanism (CCM). The mRNA abundance of the Cah1 and Gdh genes appeared to be regulated in concert, suggesting co-regulation by the same signaling pathway, which, because of a lack of an O2 effect, seems unlikely to involve photorespiration or a photorespiratory metabolite. Instead, it appeared that the CO2 concentration alone was responsible for regulation of limiting CO2 acclimation responses. Based on growth, photosynthesis, and gene expression characteristics, three distinct CO2-regulated physiological states were recognized within the studied parameters, a high CO2 (5%–0.5%) state, a low CO2 (0.4%–0.03%) state, and a very low CO2 (0.01%–0.005%) state. Induction of Cah1 expression and Gdh up-regulation occurred at a CO2 concentration between 0.5% and 0.4% CO2, delineating the high from the low CO2 states. Photosynthetic characteristics also were distinct in the three CO2-regulated physiological states, e.g., the estimated K0.5(CO2) of the high CO2, low CO2, and very low CO2 states were 72, 10, and 0.9 µmol·L–1 CO2, respectively. In addition to a greater photosynthetic CO2 affinity, the very low CO2 state could be distinguished from the low CO2 state by an increased cell-doubling time and a smaller cell size.Key words: algae, Chlamydomonas, CO2, gene expression, induction, photorespiration, photosynthesis.

scholarly journals Effect of peripheral administration of cholecystokinin on food intake in apolipoprotein AIV knockout mice

2012 ◽  
Vol 302 (11) ◽  
pp. G1336-G1342 ◽  
Author(s):  
Go Yoshimichi ◽  
Chunmin C. Lo ◽  
Kellie L. K. Tamashiro ◽  
Liyun Ma ◽  
Dana M. Lee ◽  
...  
Keyword(s):  
Gene Expression ◽  
Food Intake ◽  
Food System ◽  
Nucleus Tractus Solitarius ◽  
Wild Type ◽  
Post Hoc Analysis ◽  
Nodose Ganglia ◽  
Post Hoc ◽  
The Brain

Apolipoprotein AIV (apo AIV) and cholecystokinin (CCK) are satiation factors secreted by the small intestine in response to lipid meals. Apo AIV and CCK-8 has an additive effect to suppress food intake relative to apo AIV or CCK-8 alone. In this study, we determined whether CCK-8 (1, 3, or 5 μg/kg ip) reduces food intake in fasted apo AIV knockout (KO) mice as effectively as in fasted wild-type (WT) mice. Food intake was monitored by the DietMax food system. Apo AIV KO mice had significantly reduced 30-min food intake following all doses of CCK-8, whereas WT mice had reduced food intake only at doses of 3 μg/kg and above. Post hoc analysis revealed that the reduction of 10-min and 30-min food intake elicited by each dose of CCK-8 was significantly larger in the apo AIV KO mice than in the WT mice. Peripheral CCK 1 receptor (CCK1R) gene expression (mRNA) in the duodenum and gallbladder of the fasted apo AIV KO mice was comparable to that in WT mice. In contrast, CCK1R mRNA in nodose ganglia of the apo AIV KO mice was upregulated relative to WT animals. Similarly, upregulated CCK1R gene expression was found in the brain stem of apo AIV KO mice by in situ hybridization. Although it is possible that the increased satiating potency of CCK in apo AIV KO mice is mediated by upregulation of CCK 1R in the nodose ganglia and nucleus tractus solitarius, additional experiments are required to confirm such a mechanism.

Roles of Pax-6 in murine diencephalic development

Development ◽  
1997 ◽  
Vol 124 (8) ◽  
pp. 1573-1582 ◽  
Author(s):  
N. Warren ◽  
D.J. Price
Keyword(s):  
Gene Expression ◽  
Regional Differences ◽  
Third Ventricle ◽  
Regulatory Gene ◽  
Wild Type ◽  
Dorsal Midline ◽  
The Third ◽  
Normal Expression ◽  
In Situ Hybridizations

Pax-6 is one of the earliest regulatory genes to be expressed in the diencephalon. We tested whether normal Pax-6 protein is required for early diencephalic development by examining morphology, precursor proliferation and patterns of regulatory gene expression in the embryonic diencephalon of Small-eye mice (Pax-6 mutants). In Small-eye mice, diencephalic morphology was abnormal at all the embryonic ages studied (days 10.5, 12.5 and 14.5). Regional differences in diencephalic cell density were lost, the diencephalon/mesencephalon boundary was unclear and the third ventricle was enlarged. We estimated diencephalic proliferative rates after labelling with bromodeoxyuridine and found that they were abnormally low in mutants aged embryonic day 10.5. In older mutants, the diencephalon contained fewer cells than normal. In wild-type E14.5 diencephalon, Pax-6, Dlx-2 and Wnt-3 are expressed in discrete regions along the rostrocaudal and dorsoventral axes. In situ hybridizations for these genes in E14.5 Small-eye mice revealed discrete zones of diencephalic expression that had similar relative positions to those in wild-type mice. Some differences of detail in their expression were seen: Pax-6 had an expanded rostral domain of expression and an abnormally indistinct caudal boundary; Dlx-2 had a diffuse, rather than a sharp, caudal boundary of expression; the normally high dorsal midline expression of Wnt-3 was lost. We conclude that normal expression of Pax-6 is required for the correct regulation of diencephalic precursor proliferation. Pax-6 may also control some aspects of diencephalic differentiation, but its mutation in Small-eye mice does not preclude the development of a degree of diencephalic regionalization resembling that in normal mice.

Molecular and Microscopic Analysis of Altered Gene Expression in Transgenic and Gene Targeted Mice

1996 ◽  
Vol 54 ◽  
pp. 12-13
Author(s):  
W. K. Jones ◽  
J. Robbins
Keyword(s):  
Gene Expression ◽  
Pulmonary Veins ◽  
Microscopic Analysis ◽  
Mouse Tissue ◽  
Adult Heart ◽  
Heavy Chains ◽  
Altered Gene Expression ◽  
Altered Gene ◽  
Pulmonary Myocardium

Two myosin heavy chains (MyHC) are expressed in the mammalian heart and are differentially regulated during development. In the mouse, the α-MyHC is expressed constitutively in the atrium. At birth, the β-MyHC is downregulated and replaced by the α-MyHC, which is the sole cardiac MyHC isoform in the adult heart. We have employed transgenic and gene-targeting methodologies to study the regulation of cardiac MyHC gene expression and the functional and developmental consequences of altered α-MyHC expression in the mouse.We previously characterized an α-MyHC promoter capable of driving tissue-specific and developmentally correct expression of a CAT (chloramphenicol acetyltransferase) marker in the mouse. Tissue surveys detected a small amount of CAT activity in the lung (Fig. 1a). The results of in situ hybridization analyses indicated that the pattern of CAT transcript in the adult heart (Fig. 1b, top panel) is the same as that of α-MyHC (Fig. 1b, lower panel). The α-MyHC gene is expressed in a layer of cardiac muscle (pulmonary myocardium) associated with the pulmonary veins (Fig. 1c). These studies extend our understanding of α-MyHC expression and delimit a third cardiac compartment.

scholarly journals Engineered Phage Endolysin Eliminates Gardnerella Biofilm without Damaging Beneficial Bacteria in Bacterial Vaginosis Ex Vivo

Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 54
Author(s):  
Christine Landlinger ◽  
Lenka Tisakova ◽  
Vera Oberbauer ◽  
Timo Schwebs ◽  
Abbas Muhammad ◽  
...  
Keyword(s):  
Bacterial Vaginosis ◽  
Bactericidal Activity ◽  
High Selectivity ◽  
Ex Vivo ◽  
Vaginal Microbiome ◽  
Wild Type ◽  
Wild Type Enzyme ◽  
Promising Alternative ◽  
First Time

Bacterial vaginosis is characterized by an imbalance of the vaginal microbiome and a characteristic biofilm formed on the vaginal epithelium, which is initiated and dominated by Gardnerella bacteria, and is frequently refractory to antibiotic treatment. We investigated endolysins of the type 1,4-beta-N-acetylmuramidase encoded on Gardnerella prophages as an alternative treatment. When recombinantly expressed, these proteins demonstrated strong bactericidal activity against four different Gardnerella species. By domain shuffling, we generated several engineered endolysins with 10-fold higher bactericidal activity than any wild-type enzyme. When tested against a panel of 20 Gardnerella strains, the most active endolysin, called PM-477, showed minimum inhibitory concentrations of 0.13–8 µg/mL. PM-477 had no effect on beneficial lactobacilli or other species of vaginal bacteria. Furthermore, the efficacy of PM-477 was tested by fluorescence in situ hybridization on vaginal samples of fifteen patients with either first time or recurring bacterial vaginosis. In thirteen cases, PM-477 killed the Gardnerella bacteria and physically dissolved the biofilms without affecting the remaining vaginal microbiome. The high selectivity and effectiveness in eliminating Gardnerella, both in cultures of isolated strains as well as in clinically derived samples of natural polymicrobial biofilms, makes PM-477 a promising alternative to antibiotics for the treatment of bacterial vaginosis, especially in patients with frequent recurrence.

scholarly journals RNA In Situ Hybridization for Detecting Gene Expression Patterns in the Abdomens and Wings of Drosophila Species

2021 ◽  
Vol 4 (1) ◽  
pp. 20
Author(s):  
Mujeeb Shittu ◽  
Tessa Steenwinkel ◽  
William Dion ◽  
Nathan Ostlund ◽  
Komal Raja ◽  
...  
Keyword(s):  
Gene Expression ◽  
In Situ Hybridization ◽  
Expression Patterns ◽  
Drosophila Species ◽  
Gene Expression Patterns ◽  
Probe Design ◽  
Tissue Preparation ◽  
Design And Synthesis ◽  
Rna In Situ Hybridization

RNA in situ hybridization (ISH) is used to visualize spatio-temporal gene expression patterns with broad applications in biology and biomedicine. Here we provide a protocol for mRNA ISH in developing pupal wings and abdomens for model and non-model Drosophila species. We describe best practices in pupal staging, tissue preparation, probe design and synthesis, imaging of gene expression patterns, and image-editing techniques. This protocol has been successfully used to investigate the roles of genes underlying the evolution of novel color patterns in non-model Drosophila species.

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