The Hippo pathway regulates the development and homeostasis of many tissues and in many species. It controls the activity of two paralogous transcriptional coactivators, YAP and TAZ (YAP/TAZ). Although previous studies have established that aberrant YAP/TAZ activation is detrimental to mammalian brain development, whether and how endogenous levels of YAP/TAZ activity regulate brain development remain unclear.
View Article and Find Full Text PDFThe tight junction (TJ) and barrier function of colonic epithelium is highly sensitive to ionizing radiation. We evaluated the effect of lysophosphatidic acid (LPA) and its analog, Radioprotein-1, on γ-radiation-induced colonic epithelial barrier dysfunction using Caco-2 and m-IC cell monolayers in vitro and mice in vivo. Mice were subjected to either total body irradiation (TBI) or partial body irradiation (PBI-BM5).
View Article and Find Full Text PDFThe apical junctional complex (AJC), which includes tight junctions (TJs) and adherens junctions (AJs), determines the epithelial polarity, cell-cell adhesion and permeability barrier. An intriguing characteristic of a TJ is the dynamic nature of its multiprotein complex. Occludin is the most mobile TJ protein, but its significance in TJ dynamics is poorly understood.
View Article and Find Full Text PDFThe role of reactive oxygen species (ROS) in osmotic stress, dextran sulfate sodium (DSS) and cyclic stretch-induced tight junction (TJ) disruption was investigated in Caco-2 cell monolayers and restraint stress-induced barrier dysfunction in mouse colon Live cell imaging showed that osmotic stress, cyclic stretch and DSS triggered rapid production of ROS in Caco-2 cell monolayers, which was blocked by depletion of intracellular Ca by 1,2-bis-(-aminophenoxy)ethane-,,','-tetraacetic acid. Knockdown of Ca1.3 or TRPV6 channels blocked osmotic stress and DSS-induced ROS production and attenuated TJ disruption and barrier dysfunction.
View Article and Find Full Text PDFEthanol is metabolized into acetaldehyde in most tissues. In this study, we investigated the synergistic effect of ethanol and acetaldehyde on the tight junction integrity in Caco-2 cell monolayers. Expression of alcohol dehydrogenase sensitized Caco-2 cells to ethanol-induced tight junction disruption and barrier dysfunction, whereas aldehyde dehydrogenase attenuated acetaldehyde-induced tight junction disruption.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
October 2016
Psoriasis is a chronic inflammatory skin disease with a clear genetic contribution, characterized by keratinocyte proliferation and immune cell infiltration. Various closely interacting cell types, including innate immune cells, T cells, and keratinocytes, are known to contribute to inflammation. Innate immune cells most likely initiate the inflammatory process by secretion of IL-23.
View Article and Find Full Text PDFBackground: Alcohol consumption is one of the major risk factors for colorectal cancer. However, the mechanism involved in this effect of alcohol is unknown.
Methods: We evaluated the effect of chronic ethanol feeding on azoxymethane and dextran sulfate sodium (AOM/DSS)-induced carcinogenesis in mouse colon.
The goals of this study were to evaluate the effects of ionizing radiation on apical junctions in colonic epithelium and mucosal barrier function in mice in vivo. Adult mice were subjected to total body irradiation (4 Gy) with or without N-acetyl-l-cysteine (NAC) feeding for 5 days before irradiation. At 2-24 h postirradiation, the integrity of colonic epithelial tight junctions (TJ), adherens junctions (AJ), and the actin cytoskeleton was assessed by immunofluorescence microscopy and immunoblot analysis of detergent-insoluble fractions for TJ and AJ proteins.
View Article and Find Full Text PDFBackground: Disruption of epithelial tight junctions (TJ), gut barrier dysfunction and endotoxemia play crucial role in the pathogenesis of alcoholic tissue injury. Occludin, a transmembrane protein of TJ, is depleted in colon by alcohol. However, it is unknown whether occludin depletion influences alcoholic gut and liver injury.
View Article and Find Full Text PDFPrevious in vitro studies showed that glutamine (Gln) prevents acetaldehyde-induced disruption of tight junctions and adherens junctions in Caco-2 cell monolayers and human colonic mucosa. In the present study, we evaluated the effect of Gln supplementation on ethanol-induced gut barrier dysfunction and liver injury in mice in vivo. Ethanol feeding caused a significant increase in inulin permeability in distal colon.
View Article and Find Full Text PDFBackground: Acetaldehyde, the toxic ethanol (EtOH) metabolite, disrupts intestinal epithelial barrier function. Aldehyde dehydrogenase (ALDH) detoxifies acetaldehyde into acetate. Subpopulations of Asians and Native Americans show polymorphism with loss-of-function mutations in ALDH2.
View Article and Find Full Text PDFIn this study we characterized the effects of radiation injury on the expression and function of the autotaxin (ATX)-LPA2 GPCR axis. In IEC-6 crypt cells and jejunum enteroids quantitative RT-PCR showed a time- and dose-dependent upregulation of lpa2 in response to γ-irradiation that was abolished by mutation of the NF-κB site in the lpa2 promoter or by inhibition of ATM/ATR kinases with CGK-733, suggesting that lpa2 is a DNA damage response gene upregulated by ATM via NF-κB. The resolution kinetics of the DNA damage marker γ-H2AX in LPA-treated IEC-6 cells exposed to γ-irradiation was accelerated compared to vehicle, whereas pharmacological inhibition of LPA2 delayed the resolution of γ-H2AX.
View Article and Find Full Text PDFDisruption of intestinal epithelial tight junctions is an important event in the pathogenesis of ulcerative colitis. Dextran sodium sulfate (DSS) induces colitis in mice with symptoms similar to ulcerative colitis. However, the mechanism of DSS-induced colitis is unknown.
View Article and Find Full Text PDFAm J Physiol Gastrointest Liver Physiol
June 2014
The intestinal epithelium is subjected to various types of mechanical stress. In this study, we investigated the impact of cyclic stretch on tight junction and adherens junction integrity in Caco-2 cell monolayers. Stretch for 2 h resulted in a dramatic modulation of tight junction protein distribution from a linear organization into wavy structure.
View Article and Find Full Text PDFBackground & Objectives: Genetic variation in the DNA repair genes might be associated with altered DNA repair capacities (DRC). Reduced DRC due to inherited polymorphisms may increase the susceptibility to cancers. Base excision and nucleotide excision are the two major repair pathways.
View Article and Find Full Text PDFPurpose: Carcinogens causes DNA damage, including oxidative lesions that are removed efficiently by the base excision repair (BER) pathway. Variations in BER genes may reduce DNA repair capacity, leading to development of urological cancers.
Methods: This study included 195 prostate cancer (PCa) and 212 bladder cancer (BC) patients and 250 controls who had been frequency matched by age, sex, and ethnicity.
The DNA double strand break repair gene XRCC4, an important caretaker of genome stability and XRCC3 are suggested to play an imperative role in the development of carcinogenesis. However, no evidence has been provided showing that these genes are associated with risk of urinary bladder cancer (UBC). The study was designed to examine the polymorphisms associated with two genes namely XRCC4 G1394T (rs6869366), intron 3 (rs28360317), intron 7 rs1805377 and rs2836007 and XRCC3 (rs861539 and rs1799796), respectively and investigate their role as susceptible markers for UBC risk in North Indian cohort.
View Article and Find Full Text PDFMicroRNAs (miRNA) are a class of small noncoding RNA molecules that have been implicated in a wide variety of cellular functions through post-transcriptional regulations on target genes. Common genetic variants (single-nucleotide polymorphisms, SNPs) in pre-miRNA genes may alter their expression and/or maturation effecting thousands of target mRNAs, resulting in varied functional consequences. Three common SNPs (hsa-mir-146a G>C rs2910164, hsa-mir-196a2 C>T rs11614913, and hsa-mir-499 T>C rs3746444) in pre-miRNAs were investigated to evaluate their association with urinary bladder cancer risk.
View Article and Find Full Text PDFRecent evidence indicates the involvement of microRNAs (miRNAs), in cell growth control, differentiation, and apoptosis, thus playing a role in tumorigenesis. Single-nucleotide polymorphisms (SNPs) located at miRNA-binding sites (miRNA-binding SNPs) are likely to affect the expression of the miRNA target and may contribute to the susceptibility of humans to common diseases. We genotyped SNPs hsa-mir196a2 (rs11614913), hsa-mir146a (rs2910164), and hsa-mir499 (rs3746444) in a case-control study including 159 prostate cancer patients and 230 matched controls.
View Article and Find Full Text PDFMatrix metalloproteinases (MMPs) contribute to tumor invasion and microenvironment, hence are associated with bladder cancer risk. We therefore, tested whether polymorphisms in MMP genes modify the risk of bladder cancer (BC) and whether smoke exposure modifies this risk. Genotyping was performed in 200 BC patients and 200 controls by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).
View Article and Find Full Text PDFBackground: Cyclooxygenase-2 (COX-2) is an enzyme involved in the synthesis of prostaglandins and thromboxanes, which are regulators of processes that are relevant to cancer development. It is involved in carcinogenesis, immune response suppression, apoptosis inhibition, angiogenesis, and tumor cell invasion and metastasis. The gene for COX-2, designated as prostaglandin-endoperoxide synthase 2 (PTGS-2), carries polymorphisms, such as -765G>C, 1195G>A in the promoter region, and 8473T>C in the 3'-untranslated region (UTR), which have been associated with susceptibility to malignant disease.
View Article and Find Full Text PDFPerturbations in the cell cycle and apoptotic genes have been implicated in human malignancies. Cell cycle (MDM2 and Cyclin D1) and apoptotic (Fas) genes that are differentially expressed in urinary bladder cancer (UBC) were investigated with the susceptibility to UBC in northern India. A total of 212 UBC patients and age- and sex-matched 250 controls were investigated for MDM2 G309T, Cyclin D1 G870A, and Fas A670G polymorphisms by polymerase chain reaction and restriction fragment length polymorphism.
View Article and Find Full Text PDFThe objective of the study was to investigate the association of Xeroderma Pigmentoum group C (XPC) Lys939Gln (A > C) and poly (AT) insertion deletion (PAT -/+) gene polymorphism with the risk of cervical cancer. We enrolled 220 cervical cancer patients and 237 healthy individuals. Polymorphism for XPC gene (Lys939Gln, PAT -/+) was genotyped by polymerase chain reaction and restriction fragment length polymorphism method.
View Article and Find Full Text PDFInterindividual variation in prostate cancer (PCa) susceptibility may be modulated in part through genetic polymorphisms in the DNA repair genes, especially the genes involved in the base excision repair and nucleotide excision repair pathway. Two of the common single-nucleotide polymorphisms X-ray repair cross-complementing group 1 (XRCC1) and Xeroderma pigmentosum group D (XPD) genes in PCa, which is one of the most common neoplasias in men all over the world, have been studied. In a case-control study of 171 PCa patients and 200 age-matched healthy controls, of similar ethnicity, genotyping was done to determine XPD exon 10 (G23592A), exon 23 (A35931C), and XRCC1 exon 6 (C26304T), exon 9 (G27466A), exon 10 (G23591A) gene polymorphisms by amplification refractory mutation-specific and polymerase chain reaction-restriction fragment length polymorphism methods, respectively.
View Article and Find Full Text PDFPurpose: To investigate the association between two Xeroderma pigmentosum group C polymorphism (XPC Lys939Gln and insertion/deletion PAT -/+ in intron 9) and bladder cancer (BC) susceptibility.
Materials And Methods: Genotyping was performed in 208 BC patients and 245 controls by PCR-RFLP method.
Results: XPC PAT +/+ genotype was associated with elevated risk of BC (p = 0.