195 research outputs found
Differential Expression of Pancreatic Protein and Chemosensing Receptor mRNAs in NKCC1-null Intestine
AIM: To investigate the intestinal functions of the NKCC1 Na+-K+-2Cl cotransporter (SLC12a2 gene), differential mRNA expression changes in NKCC1-null intestine were analyzed.
METHODS: Microarray analysis of mRNA from intestines of adult wild-type mice and gene-targeted NKCC1-null mice (n = 6 of each genotype) was performed to identify patterns of differential gene expression changes. Differential expression patterns were further examined by Gene Ontology analysis using the online Gorilla program, and expression changes of selected genes were verified using northern blot analysis and quantitative real time-polymerase chain reaction. Histological staining and immunofluorescence were performed to identify cell types in which upregulated pancreatic digestive enzymes were expressed.
RESULTS: Genes typically associated with pancreatic function were upregulated. These included lipase, amylase, elastase, and serine proteases indicative of pancreatic exocrine function, as well as insulin and regenerating islet genes, representative of endocrine function. Northern blot analysis and immunohistochemistry showed that differential expression of exocrine pancreas mRNAs was specific to the duodenum and localized to a subset of goblet cells. In addition, a major pattern of changes involving differential expression of olfactory receptors that function in chemical sensing, as well as other chemosensing G-protein coupled receptors, was observed. These changes in chemosensory receptor expression may be related to the failure of intestinal function and dependency on parenteral nutrition observed in humans with SLC12a2 mutations.
CONCLUSION: The results suggest that loss of NKCC1 affects not only secretion, but also goblet cell function and chemosensing of intestinal contents via G-protein coupled chemosensory receptors
Myo-Inositol Reduces β-Catenin Activation in Colitis
AIM
To assess dietary myo-inositol in reducing stem cell activation in colitis, and validate pβ-cateninS552 as a biomarker of recurrent dysplasia.
METHODS
We examined the effects of dietary myo-inositol treatment on inflammation, pβ-cateninS552 and pAkt levels by histology and western blot in IL-10-/- and dextran sodium sulfate-treated colitic mice. Additionally, we assessed nuclear pβ-cateninS552 in patients treated with myo-inositol in a clinical trial, and in patients with and without a history of colitis-induced dysplasia.
RESULTS
In mice, pβ-cateninS552 staining faithfully reported the effects of myo-inositol in reducing inflammation and intestinal stem cell activation. In a pilot clinical trial of myo-inositol administration in patients with a history of low grade dysplasia (LGD), two patients had reduced numbers of intestinal stem cell activation compared to the placebo control patient. In humans, pβ-cateninS552 staining discriminated ulcerative colitis patients with a history of LGD from those with benign disease.
CONCLUSION
Enumerating crypts with increased numbers of pβ-cateninS552 - positive cells can be utilized as a biomarker in colitis-associated cancer chemoprevention trials
A Cytosolic Multiprotein Complex Containing p85\u3cem\u3eα\u3c/em\u3e is Required for \u3cem\u3eβ\u3c/em\u3e-Catenin Activation in Colitis and Colitis-Associated Cancer
Wnt/β-catenin signaling is required for crypt structure maintenance. We previously observed nuclear accumulation of Ser-552 phosphorylated β-catenin (pβ-CatSer-552) in intestinal epithelial cells (IEC) during colitis and colitis-associated cancer. Data here delineate a novel multiprotein cytosolic complex (MCC) involved in β-catenin signaling in the intestine. The MCC contains p85α, the class IA subunit of PI3K, along with β-catenin, 14-3-3ζ, Akt, and p110α. MCC levels in IEC increase in colitis and colitis-associated cancer patients. IEC-specific p85α-deficient (p85ΔIEC) mice develop more severe dextran sodium sulfate colitis due to delayed ulcer healing and reduced epithelial β-catenin activation. In colonic IEC, p85α deficiency did not alter PI3K signaling. In vitro shRNA depletion of individual complex members disrupts the MCC and reduces β-catenin signaling. Despite worse colitis, p85ΔIEC mice have reduced tumor burden after azoxymethane/dextran sodium sulfate treatment. Together the data indicate that the β-catenin MCC is needed for mucosal repair and carcinogenesis. This novel MCC may be an attractive therapeutic target in preventing cancer in colitis patients
Adolescent Experiences with Self-Asphyxial Behaviors and Problematic Drinking in Emerging Adulthood
Self-asphyxial behavior to achieve a euphoric high (The Choking Game; TCG), occurs most often during early adolescence. Participants in TCG often engage in other risky behaviors. This study investigated the relationship between prior experience with TCG and problematic drinking behaviors in emerging adulthood. Emerging adults, 18 to 25 years old (N = 1248), 56% female, and 78% Caucasian completed an online survey regarding knowledge of and prior engagement in TCG and current drinking behaviors. Participants who personally engaged in TCG during childhood/adolescence or were familiar with TCG reported significantly more problematic drinking behaviors during emerging adulthood. Those present when others engaged in TCG but resisted participation themselves reported significantly less current problematic drinking behaviors than those who participated, but significantly more current problematic drinking behaviors than those never present. Emerging adults with increased social familiarity with TCG during adolescence endorsed greater problematic drinking behaviors. Results suggest resistance skills may generalize across time/activities
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. Vd of organelles in parietal cells of 6 genetically engineered mouse strains was obtained to identify a stable histological phenotype of acid secretion. We confirmed that CAM to TV ratio fairly represented secretory activity in untreated and secretion-inhibited wild-type (WT) mice and in NHE2−/− mice as well, though the response was significantly attenuated in the latter. However, high CAM to TV ratios wrongly posed as active acid secretion in AE2−/−, GHKAα−/−, and NHE4−/− mice. Achlorhydric genotypes also had a significantly higher Vd of basolateral membrane than WT mice, and reduced Vd of mitochondria and canaliculi. The Vd of mitochondria, and ratio of the Vd of basolateral membranes/Vd of mitochondria were preferred predictors of the level of acid secretion. Alterations in acid secretion, then, cause significant changes not only in the Vd of secretory membranes but also in mitochondria and basolateral membranes
Radiation‐Induced Oral Mucositis Hamster Model Using a Linear Accelerator Enhances Clinical Relevance of Preclinical Studies for Treatment Strategy Investigation
Translational animal models for oral mucositis (OM) are necessary to simulate and assess the bioclinical effects and response in humans. These models should simulate high levels of radiation exposure that leads to oxidative stress and inflammatory‐initiated tissue changes. Hamster models have been extensively studied to observe pathological effects of radiation exposure and help in the development of effective treatments. To successfully evaluate the potential for treatment regimens with consistency and relevance, a radiation‐induced OM hamster model was developed using a clinical linear accelerator utilized by cancer patients daily. The dose exposure to the isolated, everted cheek pouch of a hamster, as well as the progression of injury, pro‐inflammatory marker, histological, and elasticity analyses of the buccal pouch were conducted to verify replicability and reproducibility of the injury model. The findings from this model demonstrated its ability to consistently induce injury and resolution over 28 days using an acute dose of 60 Gy. This model was developed to enhance clinical relevance when evaluating potential efficacious treatments and can now be utilized in efficacy studies to better evaluate developed therapeutics in a preclinical model that is easy to translate to clinical studies
Classification of TP53 mutations and HPV predict survival in advanced larynx cancer
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134126/1/lary25915-sup-0001-suppinfo.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134126/2/lary25915_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134126/3/lary25915.pd
Cancer stem cells: Mediators of tumorigenesis and metastasis in head and neck squamous cell carcinoma
BackgroundCancer stem cells (CSCs) represent a subpopulation of cells responsible for tumor growth. Their role in head and neck squamous cell carcinoma (HNSCC) tumorigenesis and metastasis remains uncertain.MethodsWound healing and an orthotopic animal model were used to study cells expressing the CSC phenotype (CD44high and aldehyde dehydrogenase [ALDH]+) and assess mobility, tumorigenesis, and metastasis. A prospective collection of 40 patient‐derived primary HNSCC specimens were analyzed for CSC‐proportion compared to clinical variables.ResultsCSCs exhibited significantly faster wound closure and greater tumorigenesis and regional metastasis in vivo than non‐CSCs. In primary patient tumors, size and advanced stage were correlated with elevated proportion of CSCs, however, not with survival.ConclusionHNSCC stem cells mediate tumorigenesis and regional metastasis in vivo. In primary patient tumors, CSC‐proportion was associated with tumor size and stage, but not with metastatic spread or survival. CSC burden alone may only represent a minor variable in understanding CSCs and metastasis. © 2014 Wiley Periodicals, Inc. Head Neck 37: 317–326, 2015Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110728/1/hed23600.pd
Beta-catenin cleavage enhances transcriptional activation
Nuclear activation of Wnt/β-catenin signaling is required for cell proliferation in inflammation and cancer. Studies from our group indicate that β-catenin activation in colitis and colorectal cancer (CRC) correlates with increased nuclear levels of β-catenin phosphorylated at serine 552 (pβ-Cat552). Biochemical analysis of nuclear extracts from cancer biopsies revealed the existence of low molecular weight (LMW) pβ-Cat552, increased to the exclusion of full size (FS) forms of β-catenin. LMW β-catenin lacks both termini, leaving residues in the armadillo repeat intact. Further experiments showed that TCF4 predominantly binds LMW pβ-Cat552 in the nucleus of inflamed and cancerous cells. Nuclear chromatin bound localization of LMW pβ-Cat552 was blocked in cells by inhibition of proteasomal chymotrypsin-like activity but not by other protease inhibitors. K48 polyubiquitinated FS and LMW β-catenin were increased by treatment with bortezomib. Overexpressed in vitro double truncated β-catenin increased transcriptional activity, cell proliferation and growth of tumor xenografts compared to FS β-catenin. Serine 552-> alanin substitution abrogated K48 polyubiquitination, β-catenin nuclear translocation and tumor xenograft growth. These data suggest that a novel proteasome-dependent posttranslational modification of β-catenin enhances transcriptional activation. Discovery of this pathway may be helpful in the development of diagnostic and therapeutic tools in colitis and cancer
Prenatal exome sequencing in anomalous fetuses: new opportunities and challenges
We investigated the diagnostic and clinical performance of exome sequencing (ES) in fetuses with sonographic abnormalities with normal karyotype, microarray and, in some cases, normal gene specific sequencing
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