Angiotensin II-induced Expression Research Articles

MicroRNA‑219 overexpression serves a protective role during liver fibrosis by targeting tumor growth factor β receptor 2.

Progressive liver fibrosis is the primary cause of liver cirrhosis and hepatocellular carcinoma, and leads to considerable morbidity and mortality. Recent studies have demonstrated that microRNAs (miRNAs or miRs) are associated with fibrotic processes in liver disorders, although the exact role of miR-219 remains unclear and the relevant mechanisms remain to be completely understood. To the best of our knowledge, the present study was the first to demonstrate the functional implications of miR-219 expression during liver fibrosis. The present study reported that miR-219 exhibited significantly reduced expression in serum from patients and that its expression was negatively associated with clinical stage. It was also demonstrated that miR-219 attenuated angiotensin II-induced expression of pro-fibrotic markers, including α-smooth muscle actin, atlastin GTPase 1 and collagen. Additionally, a CCl4-induced mouse liver injury model was used to demonstrate that miR-219 strongly suppressed liver fibrosis in vivo. Furthermore, the present study identified tumor growth factor β receptor 2 (TGFBR2) as a direct target gene of miR-219. In conclusion, the results of the present study revealed that miR-219 may regulate pro-fibrotic markers by directly targeting the TGFBR2 gene and the miR-219/TGFBR2 signaling pathway may be a potential therapeutic target for liver fibrosis.

Abstract P146: Transient Neonatal High Oxygen Exposure Accelerates Adult Cardiac Baseline and Ang Ii-induced Prooxidative and Proinflammatory Responses

Objective: Preterm birth is associated with disequilibrated early life oxidant-antioxidant and proinflammatory conditions that can be carried into adulthood and contribute to the development of organ dysfunction. Neonatally high O 2 -exposed rats, a model of prematurity-related prooxidative conditions, exhibit adult hypertension, early cardiac dysfunction and fibrosis, and premature angiotensin (ANG) II-induced heart failure. We hypothesized that neonatal high O 2 exposure will exaggerate baseline and ANG II-induced cardiac prooxidative and proinflammatory gene expression in adult rats. Design and Methods: Sprague-Dawley pups were kept in 80% O 2 (H group) or room air (NNI group) from day 3-10 of life. Twelve-weeks-old H and NNI rats were infused with ANG II (100 ng.kg -1 .min -1 ) or saline (NaCl) for 4 weeks (n = 4 per group). RNA extracted from hearts was used in arrays to assess expression of oxidative stress and inflammatory genes. Data is expressed as fold change (F.C.) compared to control NNI+NaCl. Results: H+NaCl exhibited increased baseline Cd68 expression (F.C: 1.47; P<0.05 vs control), tendancy of increased Nfkb1 and Tnf expression (1.52 and 1.48), and a tendancy of decreased Il1b and Il18 expression (0.72 and 0.78). H+ANGII versus NNI+ANGII exhibited similar increase in Tnf ( 2.12 vs 2.13; P<0.05 vs control), greater increase in Cd14 , Cd68 , and Nfkb1 (2.5 vs 1.78, 2.13 vs 1.94, 2.0 vs 1.7; P<0.05 vs controls), and a greater tendancy of increase in Tgfb1 , Myd88 , Cybb , and Gstp1 (2.68 vs 1.82, 2.37 vs 1.31, 1.91 vs 0.98, 2.45 vs 1.61) expression. NNI+ANGII versus H+ANGII exhibited greater increase in expression of genes involved in early inflammatory process, including Ccl2 , Icam1 , and Vcam1 (2.07 vs 1.56, 1.88 vs 1.36, 2.34 vs 1.29; P<0.05 vs control). Conclusions: Neonatal high O 2 exposure accelerates baseline and ANG II-induced cardiac prooxidative and proinflammatory responses in adult rats, which could account for early cardiac abnormalities and premature ANG II-induced heart failure in this model.

Exendin-4 alleviates angiotensin II-induced senescence in vascular smooth muscle cells by inhibiting Rac1 activation via a cAMP/PKA-dependent pathway.

Vascular aging has been implicated in the progression of diabetes and age-related cardiovascular disorders. Glucagon-like peptide-1 (GLP-1) is an incretin hormone capable of cytoprotective actions in addition to its glucose-lowering effect. The present study was undertaken to examine whether Exendin-4, a specific ligand for the GLP-1 receptor, could prevent angiotensin (ANG) II-induced premature senescence in vascular smooth muscle cells (VSMCs) and to determine the underlying mechanism involved. Senescence-associated β-galactosidase (SA β-gal) assay showed that ANG II induced premature senescence of VSMCs. Pretreatment with Exendin-4 significantly attenuated ANG II-induced generation of H2O2 and the subsequent VSMC senescence. These effects were, however, reversed in the presence of exendin fragment 9-39, a GLP-1 receptor antagonist, or PKI14-22. Moreover, a marked increase in the levels of p53 and p21 induced by ANG II was blunted by the treatment with Exendin-4. Nevertheless, Exendin-4 failed to decrease ANG II-induced expression of NAD(P)H oxidase 1 (Nox1), NAD(P)H oxidase 4 (Nox4), p22(phox), or p47(phox) in VSMCs. Mechanistically, Exendin-4 blocked ANG II-induced Rac1 activation through the cAMP/PKA signaling cascade. Specifically, NSC23766, a Rac1 inhibitor, abrogated the suppressive effects of Exendin-4 on ANG II-induced premature senescence and H2O2 generation, respectively. Thus Exendin-4 confers resistance to ANG II-induced superoxide anion generation from NAD(P)H oxidase and the resultant VSMC senescence by inhibiting Rac1 activation via a cAMP/PKA-dependent pathway. These findings demonstrate that GLP-1 as well as its analogs (GLP-1-related reagents) may hold therapeutic potential in the treatment of diabetes with cardiovascular disease.

Efonidipine, a Ca2+-Channel Blocker, Enhances the Production of Dehydroepiandrosterone Sulfate in NCI-H295R Human Adrenocortical Carcinoma Cells

Steroid biosynthesis is initiated with transportation of cholesterol along with steroidogenic acute regulatory protein (StAR) into the mitchondria and is achieved with several steroidogenic enzymes. It has been reported that Ca(2+) channel blockers (CCBs), such as azelnidipine, efonidipine and nifedipine, suppress the biosynthesis of aldosterone and cortisol, but the overall effects of CCBs on steroid biosynthesis remain to be clarified. The present study was designed to evaluate the effects of CCBs on the expression of steroidogenic enzymes and the production of adrenal androgen, dehydroepiandrosterone sulfate (DHEA-S) that has anti-atherosclerotic actions. NCI-H295R human adrenocortical carcinoma cells and HepG2 human hepatoma cells were cultured for 24 hours with or without a CCB (amlodipine, efonidipine, nifedipine, azelnidipine R(-)-efonidipine, verapamil or diltiazem). HepG2 hepatoma cells were used to confirm the effects of CCBs on the expression of StAR. In fact, efonidipine and nifedipine increased the expression of StAR in HepG2 cells. Efonidipine and nifedipine, but not other examined CCBs, also increased the N(6), 2'-O-dibutyryladenosine 3',5'-cyclic monophosphate (dbcAMP)-induced StAR mRNA, which reflects the action of adrenocorticotropic hormone, and efonidipine and R(-)-efonidipine enhanced the dbcAMP-induced DHEA-S production in NCI-H295R adrenocortical carcinoma cells. Therefore, efonidipine and nifedipine might increase the expression of StAR and, in turn, efonidipine enhanced the dbcAMP-induced DHEA-S production, independent of Ca(2+) channel blockade. These results indicate that such effects are not associated with Ca(2+) influx. Moreover, only efonidipine enhanced the angiotensin II-induced expression of StAR mRNA (P < 0.01 vs. angiotensin II alone). In conclusion, efonidipine might exert an additional action beyond anti-hypertensive actions.

The Anti-Fibrotic Effect of Mycophenolic Acid–Induced Neutral Endopeptidase

Mycophenolic acid (MPA) appears to have anti-fibrotic effects, but the molecular mechanisms underlying this are unknown. We prospectively studied 35 stable kidney transplant recipients maintained on cyclosporine and azathioprine. We converted 20 patients from azathioprine to enteric-coated mycophenolate sodium (EC-MPS) and continued the remaining 15 patients on azathioprine. Exploratory mRNA expression profiling, performed on five randomly selected EC-MPS patients, revealed significant upregulation of neutral endopeptidase (NEP), which is an enzyme that degrades angiotensin II. We confirmed these microarray data by measuring levels of NEP expression in all subjects; in addition, we found that NEP gene expression correlated inversely with proteinuria. In an additional 33 patients, glomerular and tubular NEP protein levels from renal graft biopsies were significantly higher among the 13 patients receiving cyclosporine + EC-MPS than among the 12 patients receiving cyclosporine + azathioprine or 8 patients receiving cyclosporine alone. Glomerular NEP expression inversely correlated with glomerulosclerosis and proteinuria, and tubular NEP expression inversely correlated with interstitial fibrosis. Incubation of human proximal tubular cells with MPA increased NEP gene expression in a dose- and time-dependent manner. Moreover, MPA reduced angiotensin II-induced expression of the profibrotic factor plasminogen activator inhibitor-1, and a specific NEP inhibitor completely reversed this effect. Taken together, our data suggest that MPA directly induces expression of neutral endopeptidase, which may reduce proteinuria and slow the progression of renal damage in kidney transplant recipients.

Angiotensin II-Induced Expression of Brain-Derived Neurotrophic Factor in Human and Rat Adrenocortical Cells

Angiotensin II (Ang II) is a major regulator of steroidogenesis in adrenocortical cells, and is also an effective inducer of cytokine and growth factor synthesis in several cell types. In microarray analysis of H295R human adrenocortical cells, the mRNA of brain-derived neurotrophic factor (BDNF), a neurotrophin widely expressed in the nervous system, was one of the most up-regulated genes by Ang II. The aim of the present study was the analysis of the Ang II-induced BDNF expression and BDNF-induced effects in adrenocortical cells. Real-time PCR studies have shown that BDNF is expressed in H295R and rat adrenal glomerulosa cells. In H295R cells, the kinetics of Ang II-induced BDNF expression was faster than that of aldosterone synthase (CYP11B2). Inhibition of calmodulin kinase by KN93 did not significantly affect the Ang II-induced stimulation of BDNF expression, suggesting that it occurs by a different mechanism from the CYP11B2-response. Ang II also caused candesartan-sensitive, type-1 Ang II receptor-mediated stimulation of BDNF gene expression in primary rat glomerulosa cells. In rat adrenal cortex, BDNF protein was localized to the subcapsular region. Ang II increased BDNF protein levels both in human and rat cells, and BDNF secretion of H295R cells. Ang II also increased type-1 Ang II receptor-mediated BDNF expression in vivo in furosemide-treated rats. In rat glomerulosa cells, BDNF induced tropomyosin-related kinase B receptor-mediated stimulation of EGR1 and TrkB expression. These data demonstrate that Ang II stimulates BDNF expression in human and rat adrenocortical cells, and BDNF may have a local regulatory function in adrenal glomerulosa cells.

Stat3 Is Involved in Angiotensin II-Induced Expression of MMP2 in Gastric Cancer Cells

The expression of matrix metalloproteinase-2 (MMP2) has been linked with tumor invasion, angiogenesis, and metastasis. It has been reported that angiotensin II (Ang II) can induce MMP2 expression in gastric cancer cells. However, the molecular basis for Ang II regulates MMP2 expression in gastric cancer cells remains unclear. The aim of our study is to explore whether angiotensin II could induce MMP2 expression mediated through the Stat signaling pathway and its potential mechanism. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP)-binding assays was employed to determine the DNA-STAT binding activity. MMP2 and VEGF expression was analyzed with real-time PCR and Western blots. To examine the role of Stat3 in angiotensin II-induced MMP2 expression, A JAK-specific inhibitor and AG490 were used. Angiotensin II activated STAT-DNA binding activity in dose-dependent manners in gastric cancer cells. AG490 markedly inhibited angiotensin II-induced Stat3 activation and the expression of MMP2 and VEGF in gastric cancer cells. These results indicate that Stat3 may at least in part mediate angiotensin II-induced MMP2 mRNA expression in human gastric cancer cells. The activation of the JAK/Stat3 signaling pathway plays an important role in the progression of gastric cancer and that blockade of JAK/Stat3 signals may provide a novel therapeutic strategy for gastric cancer.

Atorvastatin inhibits angiotensin II-induced T-type Ca 2+ channel expression in endothelial cells

Ca 2+ channels are involved in the regulation of vascular functions. Angiotensin II is implicated in the development of atherosclerosis and vascular remodeling. In this study, we demonstrated that angiotensin II preferentially increased the expression of α1G, a T-type Ca 2+ channel subunit, via AT 1 receptors in endothelial cells. Angiotensin II-induced expression of α1G was inhibited by pretreatment with atorvastatin and the MEK1/2 inhibitor, PD98059. The effect of atorvastatin was reversed by mevalonate and farnesyl pyrophosphate which implicates the activation of the small GTP-binding protein, Ras. Our data indicate that angiotensin II induces α1G expression in endothelial cells via AT 1 receptors, Ras and MEK. Angiotensin II-induced migration of endothelial cells in a wound healing model was inhibited by incubation with mibefradil, a T-type Ca 2+ channel blocker. Our data indicate that angiotensin II induces T-type Ca 2+ channels in endothelial cells, which may play a role in the development of vascular disorders.

Interleukin-1β enhances the angiotensin-induced expression of plasminogen activator inhibitor-1 through angiotensin receptor upregulation in human astrocytes

Plasminogen activator inhibitor-1 (PAI-1) regulates not only fibrinolysis but extracellular matrix remodeling, and angiotensin II is known to play an important role in controlling the expression of PAI-1 in astrocytes. We have studied the effect of interleukin-1β (IL-1β), one of major cytokines also active in the nervous system, on the angiotensin II-induced expression of PAI-1 in human astrocytes. Cultures of normal human astrocytes were stimulated with IL-1β and angiotensin II, and the expression of mRNAs for angiotensin II type 1 receptor (AT1) and PAI-1 was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) or real-time quantitative PCR. PAI-1 protein in astrocyte-conditioned medium was measured by enzyme-linked immunosorbent assay (ELISA). IL-1β enhanced the expression of AT1 in astrocytes in time- and concentration-dependent manners. After 24-h stimulation, 10 ng/ml IL-1β and 10 nM angiotensin II increased the levels of PAI-1 protein in astrocyte-conditioned medium by 1.9-fold and 1.8-fold of the basal value, respectively. There was no synergistic effect when the cells were stimulated simultaneously with IL-1β and angiotensin II. When the cells were stimulated, with angiotensin II, 16 h after the stimulation with IL-1β, the production of PAI-1 was enhanced by 1.4-fold as compared to the cells stimulated only with IL-1β. CV-11794, an AT1 antagonist, inhibited the enhanced PAI-1 production in response to angiotensin II. We conclude that IL-1β increases angiotensin II-induced PAI-1 secretion by astrocytes through the induction of AT1, and the enhanced secretion of PAI-1 may modulate functions of plasminogen activators in the nervous system.

Differential Regulation of Angiotensin II-induced Expression of Connective Tissue Growth Factor by Protein Kinase C Isoforms in the Myocardium

Protein kinase C (PKC) and angiotensin II (AngII) can regulate cardiac function in pathological conditions such as in diabetes or ischemic heart disease. We have reported that expression of connective tissue growth factor (CTGF) is increased in the myocardium of diabetic mice. Now we showed that the increase in CTGF expression in cardiac tissues of streptozotocin-induced diabetic rats was reversed by captopril and islet cell transplantation. Infusion of AngII in rats increased CTGF mRNA expression by 15-fold, which was completely inhibited by co-infusion with AT1 receptor antagonist, candesartan. Similarly, incubation of cultured cardiomyocytes with AngII increased CTGF mRNA expression by 2-fold, which was blocked by candesartan and a general PKC inhibitor, GF109203X. The role of PKC isoform-dependent action was further studied using adenoviral vector-mediated gene transfer of dominant negative (dn) PKC or wild type PKC isoforms. Expression of dnPKCalpha, -epsilon, and -zeta isoforms suppressed AngII-induced CTGF expression in cardiomyocytes. In contrast, expression of dominant negative PKCdelta significantly increased AngII-induced CTGF expression, whereas expression of wild type PKCdelta inhibited this induction. This inhibitory effect was further confirmed in the myocardium of transgenic mice with cardiomyocyte-specific overexpression of PKCdelta (deltaTg mice). Thus, AngII can regulate CTGF expression in cardiomyocytes through a PKC activation-mediated pathway in an isoform-selective manner both in physiological and diabetic states and may contribute to the development of cardiac fibrosis in diabetic cardiomyopathy.

Mechanisms of angiotensin II-induced expression of B2 kinin receptors.

Although the primary roles of the kallikreinkinin system and the renin-angiotensin system are quite divergent, they are often intertwined under pathophysiological conditions. We examined the effect of ANG II on regulation of B(2) kinin receptors (B2KR) in vascular cells. Vascular smooth muscle cells (VSMC) were treated with ANG II in a concentration (10(-9)-10(-6) M)- and time (0-24 h)-dependent manner, and B2KR protein and mRNA levels were measured by Western blots and PCR, respectively. A threefold increase in B2KR protein levels was observed as early as 6 h, with a peak response at 10(-7) M. ANG II (10(-7) M) also increased B2KR mRNA levels twofold 4 h after stimulation. Actinomycin D suppressed the increase in B2KR mRNA and protein levels induced by ANG II. To elucidate the receptor subtype involved in mediating this regulation, VSMC were pretreated with losartan (AT(1) receptor antagonist) and/or PD-123319 (AT(2) receptor antagonist) at 10 microM for 30 min, followed by ANG II (10(-7) M) stimulation. Losartan completely blocked the ANG II-induced B2KR increase, whereas PD-123319 had no effect. In addition, expression of B2KR mRNA levels was decreased in AT(1A) receptor knockout mice. Finally, to determine whether ANG II stimulates B2KR expression via activation of the MAPK pathway, VSMC were pretreated with an inhibitor of p42/p44(mapk) (PD-98059) and/or an inhibitor of p38(mapk) (SB-202190), followed by ANG II (10(-7) M) for 24 h. Selective inhibition of the p42/p44(mapk) pathway significantly blocked the ANG II-induced increase in B2KR expression. These findings demonstrate that ANG II regulates expression of B2KR in VSMC and provide a rationale for studying the interaction between ANG II and bradykinin in the pathogenesis of vascular dysfunction.

Involvement of apoptosis signal-regulating kinase-1 on angiotensin II-induced monocyte chemoattractant protein-1 expression.

Monocyte chemoattractant protein 1 (MCP-1) could contribute to enhanced leukocyte recruitment and activation resulting in chronic tissue damage. However, little is known about the molecular mechanisms of cardiac MCP-1 expression. To elucidate these molecular mechanisms, angiotensin II-induced expression of MCP-1 was examined in cultured rat neonatal ventricular cardiomyocytes and fibroblasts by adenovirus gene transfer. MCP-1 mRNA increased 3.6-fold in cardiac fibroblasts at 3 hours after 100 nmol/L angiotensin-II stimulation (P<0.01), whereas MCP-1 mRNA in cardiomyocytes was unchanged. Angiotensin II significantly enhanced JNK, p38MAPK, and nuclear factor-kappaB (NF-kappaB) activities of cardiac fibroblasts. Wild-type ASK-1 increased MCP-1 expression of cardiac fibroblasts, whereas dominant negative mutant of ASK-1 (DN-ASK), dominant negative mutant of p38MAPK (DN-p38MAPK), and pyrrolidine dithiocarbamate significantly inhibited such expression. The increased MCP-1 mRNA expression in wild-type ASK-1 transfected fibroblasts was inhibited by cotransfection with adenovirus expressing DN-p38MAPK. On the contrary, the decreased MCP-1 mRNA expression in DN-ASK transfected cells was increased by cotransfection with adenovirus expressing constitutively active MKK6. Angiotensin II induced MCP-1 gene expression in cardiac fibroblasts. The angiotensin II-induced activation of ASK-1 followed by p38MAPK and NF-kappaB signaling in cardiac fibroblasts is partially involved in myocardial MCP-1 expression.

Involvement of adrenoceptors in the angiotensin II-induced expression of inducible transcription factors in the rat forebrain and hypothalamus

Angiotensin II (Ang II) acts as a neuromodulator/neurotransmitter in specific brain nuclei involved in the regulation of blood pressure and volume homeostasis. It also induces a highly differentiated transcription factor expression in these nuclei. We investigated whether adrenoceptors, which modulate other central actions of angiotensin II like the vasopressin release, also play a role in the AT1 receptor-mediated expression of the transcription factors (TF) c-Fos, c-Jun and Krox-24 in the rat brain. Ang II, injected intracerebroventricularly, induced the expression of c-Fos, c-Jun and Krox-24 in the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei. Pretreatment with the α1-adrenoceptor antagonist, prazosin, significantly inhibited the Ang II-induced transcription factor expression in the SON and PVN. The α2-adrenoceptor antagonist, yohimbine, also reduced Ang II-stimulated transcription factors significantly in both nuclei. This inhibition was mainly localized in vasopressinergic magnocellular neurons in both nuclei. The β-adrenoceptor antagonist, propranolol, did not influence the Ang II-induced expression of TF. Our results show that both, Ang II-induced vasopressin release and transcription factor expression, involve the same neuronal connections in the brain, implicating that the signal transduction pathways leading to the two different effects are at least to a certain degree convergent.

Effect of taurine on angiotensin II-induced expression of immediate early response genes in primary cultured neonatal rat heart cells.

Taurine has been used successfully to treat patients with congestive heart failure2. Recently, it has been established that one of the important factors contributing to the development of cardiac hypertrophy and heart failure is angiotensin II3, 9, 14. Angiotensin II is a peptide hormone that plays a major role in the regulation of fluid balance, blood pressure and cardiac function. Its direct cardiac effects include modulation of Na+, H+ and Ca2+ transport, increasing heart rate and mechanical function, stimulation of protein synthesis and enhancing uptake and utilization of glucose3, 9.

Regional suppression by lesions in the anterior third ventricle of c-fos expression induced by either angiotensin II or hypertonic saline.

Angiotensin II (250 pmol) infused into the cerebral ventricles of male rats induces the expression of c-fos in the subfornical organ, supraoptic and paraventricular nuclei of the hypothalamus, as well as in the lateral parabrachial nucleus, locus coeruleus and the nucleus of the solitary tract in the brainstem. Electrolytic lesions of the anteroventral third ventricle, principally the subcommissural (ventral) median preoptic nucleus, inhibited the dipsogenic response to i.c.v. angiotensin II and also suppressed c-fos expression in supraoptic nucleus, paraventricular nucleus, lateral parabrachial nucleus, locus coeruleus and nucleus of the solitary tract but not in the subfornical organ or dorsal median preoptic nucleus. The stimulating effect of i.c.v. angiotensin II on corticosterone was also reduced. Median preoptic nucleus lesions also suppressed the expression of c-fos following i.v. infusions of 6 micrograms angiotensin II in supraoptic nucleus and paraventricular nucleus but not in subfornical organ, dorsal median preoptic nucleus, lateral parabrachial nucleus, locus coeruleus and nucleus of the solitary tract. Median preoptic nucleus lesions reduced the dipsogenic effects of an intragastric infusion of hypertonic (1.5 M) saline and suppressed c-fos expression in supraoptic nucleus and paraventricular nucleus compared to sham-lesioned rats. However, c-fos expression was unaltered in subfornical organ, dorsal median preoptic nucleus lesions had no effect on the increased corticosterone induced by hypertonic saline. Subfornical organ lesions did not alter dipsogenic responses to i.c.v. angiotensin II, nor was the i.c.v. angiotensin II-induced expression of c-fos suppressed in the basal forebrain. These experiments show that the ventral median preoptic nucleus (but not the subfornical organ), part of the anteroventral third ventricle, is critical for the expression of c-fos in more caudal areas of the brain following i.c.v. angiotensin II. c-fos expression in supraoptic nucleus and paraventricular nucleus following i.v. angiotensin II is also dependent on an intact median preoptic nucleus, suggesting that supraoptic nucleus and paraventricular nucleus activation may be dependent on the median preoptic nucleus, and that suppression following i.c.v. infusions is not due to mechanical obstruction to infused peptide. However, there is a clear separation of the effects of i.c.v. and i.v. angiotensin II on brainstem structures. The median preoptic nucleus (but not the subfornical organ) seems essential for activation following the former but not the latter, suggesting alternative mechanisms for the effect of i.v. angiotension II on the brainstem.(ABSTRACT TRUNCATED AT 400 WORDS)