Investigation of the safety and feasibility of AAV1/SERCA2a gene transfer in patients with chronic heart failure supported with a left ventricular assist device - the SERCA-LVAD TRIAL.

The SERCA-LVAD trial was a phase 2a trial assessing the safety and feasibility of delivering an adeno-associated vector 1 carrying the cardiac isoform of the sarcoplasmic reticulum calcium ATPase (AAV1/SERCA2a) to adult chronic heart failure patients implanted with a left ventricular assist device. The SERCA-LVAD trial was one of a program of AAV1/SERCA2a cardiac gene therapy trials including CUPID1, CUPID 2 and AGENT trials. Enroled subjects were randomised to receive a single intracoronary infusion of 1 × 1013 DNase-resistant AAV1/SERCA2a particles or a placebo solution in a double-blinded design, stratified by presence of neutralising antibodies to AAV. Elective endomyocardial biopsy was performed at 6 months unless the subject had undergone cardiac transplantation, with myocardial samples assessed for the presence of exogenous viral DNA from the treatment vector. Safety assessments including ELISPOT were serially performed. Although designed as a 24 subject trial, recruitment was stopped after five subjects had been randomised and received infusion due to the neutral result from the CUPID 2 trial. Here we describe the results from the 5 patients at 3 years follow up, which confirmed that viral DNA was delivered to the failing human heart in 2 patients receiving gene therapy with vector detectable at follow up endomyocardial biopsy or cardiac transplantation. Absolute levels of detectable transgene DNA were low, and no functional benefit was observed. There were no safety concerns in this small cohort. This trial identified some of the challenges of performing gene therapy trials in this LVAD patient cohort which may help guide future trial design.

Yin-Yang 1 transcription factor modulates ST2 expression during adverse cardiac remodeling post-myocardial infarction.

BACKGROUND: The cardioprotective effects of metformin remain poorly defined. Interleukin (IL)-33/ST2L signaling is a novel cardioprotective pathway, which is antagonized by the soluble isoform sST2. No data exist about the regulation of ST2 expression. This study aimed to evaluate the pathophysiological implication of Yin-Yang 1 (Yy1) transcription factor in cardiac remodeling and the expression of the soluble ST2 isoform. METHODS AND RESULTS: Myocardial infarction (MI) was induced in Wistar rats randomly receiving metformin or saline solution by permanent ligation of the left anterior coronary artery. In addition, a model of cardiomyocyte "biochemical strain" was used. Metformin administration improved post-MI cardiac remodeling, an effect that was associated with increased IL-33 and reduced sST2 levels in the myocardium. The anti-remodeling effects of metformin were also associated with a decrease in the transcription factor Yy1 intranuclear level and lower levels of phosphorylated HDAC4 within the cytoplasmic space. These effects were also observed in a cardiomyocyte biochemical strain model, where Yy1 silencing or HDAC4 inhibition blocked sST2 production in cardiomyocytes. Metformin blocked the HDAC4 phosphorylation induced by MI, preventing its export from the nucleus to the cytosol. The presence of dephosphorylated HDAC4 in the nucleus acted as a co-repressor of Yy1, repressing sST2 expression. CONCLUSION: The transcription factor Yy1 regulates sST2 expression, and repression of Yy1 by metformin results in lower levels of sST2 that are associated with favorable myocardial remodeling. The manipulation of YY1 or its co-repressor HDAC4 emerge as new targets to modulate ST2/IL33 signaling and prevent adverse cardiac remodeling.

Tracing the Pathway from Drift-Wave Turbulence with Broken Symmetry to the Production of Sheared Axial Mean Flow.

This study traces the emergence of sheared axial flow from collisional drift-wave turbulence with broken symmetry in a linear plasma device-the controlled shear decorrelation experiment. As the density profile steepens, the axial Reynolds stress develops and drives a radially sheared axial flow that is parallel to the magnetic field. Results show that the nondiffusive piece of the Reynolds stress is driven by the density gradient, results from spectral asymmetry of the turbulence, and, thus, is dynamical in origin. Taken together, these findings constitute the first simultaneous demonstration of the causal link between the density gradient, turbulence, and stress with broken spectral symmetry and the mean axial flow.

Prevalence of AAV1 neutralizing antibodies and consequences for a clinical trial of gene transfer for advanced heart failure.

Adeno-associated virus serotype 1 (AAV1) has many advantages as a gene therapy vector, but the presence of pre-existing neutralizing antibodies (NAbs) is an important limitation. This study was designed to determine: (1) characteristics of AAV NAbs in human subjects, (2) prevalence of AAV1 NAbs in heart failure patients and (3) utility of aggressive immunosuppressive therapy in reducing NAb seroconversion in an animal model. NAb titers were assessed in a cohort of heart failure patients and in patients screened for a clinical trial of gene therapy with AAV1 carrying the sarcoplasmic reticulum calcium ATPase gene (AAV1/SERCA2a). AAV1 NAbs were found in 59.5% of 1552 heart failure patients. NAb prevalence increased with age (P=0.001) and varied geographically. The pattern of NAb titers suggested that exposure is against AAV2, with AAV1 NAb seropositivity due to crossreactivity. The effects of immunosuppression on NAb formation were tested in mini-pigs treated with immunosuppressant therapy before, during and after a single AAV1/SERCA2a infusion. Aggressive immunosuppression did not prevent formation of AAV1 NAbs. We conclude that immunosuppression is unlikely to be a viable solution for repeat AAV1 dosing. Strategies to reduce NAbs in heart failure patients are needed to increase eligibility for gene transfer using AAV vectors.

A calcium-sensitive promoter construct for gene therapy.

Targeting diseased cells is a challenging issue in both pharmacological and biological therapeutics. Gene therapy is emerging as a novel approach for treating rare diseases and for illnesses for which there is no other alternative. An important limitation of gene therapy has been the off-target effects and therefore efforts have been focused on increasing the specificity of gene transfer to the targeted organ. Here, we describe a promoter containing six nuclear factor of activated T cells (NFAT) consensus sequences, which is as efficient as the cytomegalovirus (CMV) promoter to drive expression in vascular smooth muscle cells both in vitro and in vivo. In contrast to the CMV promoter it is activated in a Ca(2+)-dependent manner after endoplasmic reticulum depletion and allows the transgene expression only in proliferative/diseased cells. Overexpression of sarco/endoplasmic reticulum (SR/ER) Ca(2+) ATPase 2a under the control of this NFAT promoter inhibits restenosis after angioplasty in rats. In conclusion, this promoter may be useful for gene therapy in vascular proliferative diseases and other diseases involving upregulation of the NFAT pathway.

Efficient transduction of vascular smooth muscle cells with a translational AAV2.5 vector: a new perspective for in-stent restenosis gene therapy.

Coronary artery disease represents the leading cause of mortality in the developed world. Percutaneous coronary intervention involving stent placement remains disadvantaged by restenosis or thrombosis. Vascular gene therapy-based methods may be approached, but lack a vascular gene delivery vector. We report a safe and efficient long-term transduction of rat carotid vessels after balloon injury intervention with a translational optimized AAV2.5 vector. Compared with other known adeno-associated virus (AAV) serotypes, AAV2.5 demonstrated the highest transduction efficiency of human coronary artery vascular smooth muscle cells (VSMCs) in vitro. Local delivery of AAV2.5-driven transgenes in injured carotid arteries resulted in transduction as soon as day 2 after surgery and persisted for at least 30 days. In contrast to adenovirus 5 vector, inflammation was not detected in AAV2.5-transduced vessels. The functional effects of AAV2.5-mediated gene transfer on neointimal thickening were assessed using the sarco/endoplasmic reticulum Ca(2+) ATPase isoform 2a (SERCA2a) human gene, known to inhibit VSMC proliferation. At 30 days, human SERCA2a messenger RNA was detected in transduced arteries. Morphometric analysis revealed a significant decrease in neointimal hyperplasia in AAV2.5-SERCA2a-transduced arteries: 28.36±11.30 (n=8) vs 77.96±24.60 (n=10) µm(2), in AAV2.5-green fluorescent protein-infected, P<0.05. In conclusion, AAV2.5 vector can be considered as a promising safe and effective vector for vascular gene therapy.

SERCA2a gene transfer prevents intimal proliferation in an organ culture of human internal mammary artery.

Coronary restenosis, a major complication of percutaneous balloon angioplasty, results from neointimal proliferation of vascular smooth muscle cells (VSMCs). The sarco/endoplasmic reticulum calcium ATPase 2a isoform (SERCA2a), specific to contractile VSMCs, has been reported previously to be involved in the control of the Ca(2+)-signaling pathways governing proliferation and migration. Moreover, SERCA2a gene transfer was reported to inhibit in vitro VSMC proliferation and to prevent neointimal thickening in a rat carotid injury model. The aim of this study was to evaluate the potential therapeutic interest of SERCA2a gene transfer for prevention of in-stent restenosis using a ex vivo model of human left internal mammary artery (hIMA) intimal thickening. Left hIMAs, obtained at the time of aorto-coronary bypass surgeries, were subjected to balloon dilatation followed by infection for 30 min with adenoviruses encoding either human SERCA2 and green fluorescence protein (GFP) or control gene (ß-galactosidase, ß-gal) and GFP. Proliferation of subendothelial VSMCs and neointimal thickening were observed in balloon-injured hIMA maintained 14 days in organ culture under constant pressure and perfusion. SERCA2a gene transfer prevented vascular remodeling and significantly (P<0.01, n=5) reduced neointimal thickening in injured arteries (intima/media ratio was 0.07±0.01 vs 0.40±0.03 in ß-gal-infected arteries). These findings could have potential implications for treatment of pathological in-stent restenosis.

Prevalence of aging population in the Middle East and its implications on cancer incidence and care.

The Middle Eastern population is aging rapidly, and as aging is the main risk factor for cancer, the incidence and prevalence of that disease are increasing among all the populations in the region. These developments represent huge challenges to national and community-based health services. At the current state of affairs, most Middle Eastern countries require the cooperation of international agencies in order to cope with such new challenges to their health systems. The focus and emphasis in facing these changing circumstances lie in the education and training of professionals, mainly physicians and nurses, at the primary, secondary and tertiary levels of health services. It is imperative that these training initiatives include clinical practice, with priority given to the creation of multidisciplinary teams both at the cancer centers and for home-based services.

Sarcoplasmic reticulum and calcium cycling targeting by gene therapy.

Although progress in conventional treatments is making steady and incremental gains to reduce mortality associated with heart failure (HF), there remains a need to explore potentially new therapeutic approaches. HF induced by different etiologies such as coronary artery disease, hypertension, diabetes, infection or inflammation results generally in calcium cycling dysregulation at the myocyte level. Recent advances in understanding of the molecular basis of these calcium cycling abnormalities, together with the evolution of increasingly efficient gene transfer technology, has placed HF within the reach of gene-based therapy. Furthermore, the recent successful completion of a phase 2 trial targeting the sarcoplasmic reticulum calcium pump ushers in a new era for gene therapy for the treatment of HF.

War and first onset of suicidality: the role of mental disorders.

BACKGROUND: Suicide rates increase following periods of war; however, the mechanism through which this occurs is not known. The aim of this paper is to shed some light on the associations of war exposure, mental disorders, and subsequent suicidal behavior. METHOD: A national sample of Lebanese adults was administered the Composite International Diagnostic Interview to collect data on lifetime prevalence and age of onset of suicide ideation, plan, and attempt, and mental disorders, in addition to information about exposure to stressors associated with the 1975-1989 Lebanon war. RESULTS: The onset of suicide ideation, plan, and attempt was associated with female gender, younger age, post-war period, major depression, impulse-control disorders, and social phobia. The effect of post-war period on each type of suicide outcome was largely explained by the post-war onset of mental disorders. Finally, the conjunction of having a prior impulse-control disorder and either being a civilian in a terror region or witnessing war-related stressors was associated with especially high risk of suicide attempt. CONCLUSIONS: The association of war with increased risk of suicidality appears to be partially explained by the emergence of mental disorders in the context of war. Exposure to war may exacerbate disinhibition among those who have prior impulse-control disorders, thus magnifying the association of mental disorders with suicidality.

Delivery of gelfoam-enabled cells and vectors into the pericardial space using a percutaneous approach in a porcine model.

Intrapericardial drug delivery is a promising procedure, with the ability to localize therapeutics with the heart. Gelfoam particles are nontoxic, inexpensive, nonimmunogenic and biodegradable compounds that can be used to deliver therapeutic agents. We developed a new percutaneous approach method for intrapericardial injection, puncturing the pericardial sac safely under fluoroscopy and intravascular ultrasound (IVUS) guidance. In a porcine model of myocardial infarction (MI), we deployed gelfoam particles carrying either (a) autologous mesenchymal stem cells (MSCs) or (b) an adenovirus encoding enhanced green fluorescent protein (eGFP) 48 h post-MI. The presence of MSCs and viral infection at the infarct zone was confirmed by immunoflourescence and PCR. Puncture was performed successfully in 16 animals. Using IVUS, we successfully determined the size of the pericardial space before the puncture, and safely accessed that space in setting of pericardial effusion and also adhesions induced by the MI. Intrapericardial injection of gelfoam was safe and reliable. Presence of the MSCs and eGFP expression from adenovirus in the myocardium were confirmed after delivery. Our novel percutaneous approach to deliver (stem-) cells or adenovirus was safe and efficient in this pre-clinical model. IVUS-guided delivery is a minimally invasive procedure that seems to be a promising new strategy to deliver therapeutic agents locally to the heart.

Giant splenic cyst and solid pseudopapillary tumour of the pancreas managed with distal pancreatectomy and splenectomy.

Solid pseudopapillary tumours of the pancreas and giant splenic cysts are very rare entities, and their coexistence in a young female patient has not been previously reported in the literature. We present the case of a 27-year-old woman who presented with abdominal pain and two masses on abdominal imaging. A mass located in the right upper quadrant was biopsied, and histological and immunohistochemical analysis showed a solid pseudopapillary tumour of the pancreas. A giant cystic splenic lesion was also noted. The patient underwent a distal pancreatectomy and splenectomy in our referral centre. Margins were negative on histopathological examination. Negative surgical margins were achieved with distal pancreatectomy and splenectomy despite the large size of the pancreatic tumour. The management of solid pseudopapillary tumours of the pancreas is often challenging and the concomitant presence of a giant splenic cyst poses additional challenges to the surgical management of such tumours.

Apolipoprotein E deficiency abrogates insulin resistance in a mouse model of type 2 diabetes mellitus.

AIMS/HYPOTHESIS: Although it is known that lipid metabolism plays a role in insulin resistance in type 2 diabetes and in obesity, the mechanism is still largely unknown. Apolipoprotein E (ApoE) regulates plasma lipid levels and also plays a role in the uptake of lipids into various tissues. To investigate whether the suppression of whole-particle lipoprotein uptake into tissues affects insulin responsiveness and the diabetic condition, we examined the effect of an ApoE (also known as Apoe) gene deletion in MKR mice, a mouse model of type 2 diabetes. METHODS: ApoE ( -/- ), MKR, ApoE ( -/- )/MKR and control mice were placed on a high-fat, high-cholesterol diet for 16 weeks. Glucose tolerance, serum insulin, blood glucose, insulin tolerance, tissue triacylglycerol content and atherosclerotic lesions were assessed. RESULTS: ApoE ( -/- )/MKR and ApoE ( -/- ) mice showed significantly improved blood glucose, glucose tolerance and insulin sensitivity. Reduced triacylglycerol content in liver and reduced fat accumulation in liver and adipose tissue were found in ApoE ( -/- )/MKR and ApoE ( -/- ) mice compared with control and MKR mice. ApoE ( -/- ) and ApoE ( -/- )/MKR mice demonstrated similarly large atherosclerotic lesions, whereas MKR and control mice had small atherosclerotic lesions. CONCLUSIONS/INTERPRETATION: We demonstrated that ApoE deficiency abrogates insulin resistance in a mouse model of type 2 diabetes, suggesting that lipid accumulation in tissue is a major cause of insulin resistance in this mouse model.

Glycogen synthase kinase-3beta is a negative regulator of cardiomyocyte hypertrophy.

Hypertrophy is a basic cellular response to a variety of stressors and growth factors, and has been best characterized in myocytes. Pathologic hypertrophy of cardiac myocytes leads to heart failure, a major cause of death and disability in the developed world. Several cytosolic signaling pathways have been identified that transduce prohypertrophic signals, but to date, little work has focused on signaling pathways that might negatively regulate hypertrophy. Herein, we report that glycogen synthase kinase-3beta (GSK-3beta), a protein kinase previously implicated in processes as diverse as development and tumorigenesis, is inactivated by hypertrophic stimuli via a phosphoinositide 3-kinase-dependent protein kinase that phosphorylates GSK-3beta on ser 9. Using adenovirus-mediated gene transfer of GSK-3beta containing a ser 9 to alanine mutation, which prevents inactivation by hypertrophic stimuli, we demonstrate that inactivation of GSK-3beta is required for cardiomyocytes to undergo hypertrophy. Furthermore, our data suggest that GSK-3beta regulates the hypertrophic response, at least in part, by modulating the nuclear/cytoplasmic partitioning of a member of the nuclear factor of activated T cells family of transcription factors. The identification of GSK-3beta as a transducer of antihypertrophic signals suggests that novel therapeutic strategies to treat hypertrophic diseases of the heart could be designed that target components of the GSK-3 pathway.

Chronic erythropoietin treatment decreases post-infarct myocardial damage in rats without venous thrombogenic effect.

OBJECTIVES: Whereas administration of erythropoietin (EPO) acutely after myocardial infarction (MI) reduces infarct size and chronic EPO therapy attenuates post-MI remodeling, the safety of chronic EPO therapy following MI is unknown. Therefore, we examined the thrombogenic effects of a chronic EPO therapy after MI. METHODS: Rats underwent coronary occlusion followed by reperfusion. They were assigned to one of the following groups: EPO-A, single injection of EPO 5,000 U/kg at the time of reperfusion; EPO-C, injection of EPO 5,000 U/kg at the time of reperfusion followed by 300 U/kg/week; PBS-C, injection of vehicle only. After eight weeks of treatment they were exposed to a validated prethrombotic test based on partial stenosis of the inferior vena cava. RESULTS: As compared to the rats receiving vehicle only, the rats treated with EPO exhibited a significant reduction in MI size (28.7 +/- 2.1% and 25.8 +/- 1.9 vs. 39.8 +/- 3.0% in EPO-A, EPO-C and PBS-C, respectively; p < 0.05). Whereas the hematocrit was significantly increased in EPO-C (59.7 +/- 2.0% vs. 44.7 +/- 0.9% in EPO-A, p < 0.001), the proportion of rats in which a thrombus occurred was similar in all groups (p = 0.52). CONCLUSION: Chronic EPO therapy added to the single high dose of EPO injected acutely did not induce venous pro-thrombotic effect in rats.

Recirculating cardiac delivery of AAV2/1SERCA2a improves myocardial function in an experimental model of heart failure in large animals.

Abnormal excitation-contraction coupling is a key pathophysiologic component of heart failure (HF), and at a molecular level reduced expression of the sarcoplasmic reticulum (SR) Ca(2+) ATPase (SERCA2a) is a major contributor. Previous studies in small animals have suggested that restoration of SERCA function is beneficial in HF. Despite this promise, the means by which this information might be translated into potential clinical application remains uncertain. Using a recently established cardiac-directed recirculating method of gene delivery, we administered adeno-associated virus 2 (AAV2)/1SERCA2a to sheep with pacing-induced HF. We explored the effects of differing doses of AAV2/1SERCA2a (low 1 x 10(10) d.r.p.; medium 1 x 10(12) d.r.p. and high 1 x 10(13) d.r.p.) in conjunction with an intra-coronary delivery group (2.5 x 10(13) d.r.p.). At the end of the study, haemodynamic, echocardiographic, histopathologic and molecular biologic assessments were performed. Cardiac recirculation delivery of AAV2/1SERCA2a elicited a dose-dependent improvement in cardiac performance determined by left ventricular pressure analysis, (+d P/d t(max); low dose -220+/-70, P>0.05; medium dose 125+/-53, P<0.05; high dose 287+/-104, P<0.05) and echocardiographically (fractional shortening: low dose -3+/-2, P>0.05; medium dose 1+/-2, P>0.05; high dose 6.5+/-3.9, P<0.05). In addition to favourable haemodynamic effects, brain natriuretic peptide expression was reduced consistent with reversal of the HF molecular phenotype. In contrast, direct intra-coronary infusion did not elicit any effect on ventricular function. As such, AAV2/1SERCA2a elicits favourable functional and molecular actions when delivered in a mechanically targeted manner in an experimental model of HF. These observations lay a platform for potential clinical translation.

Differential effect of DPI 201-106 on the sensitivity of the myofilaments to Ca2+ in intact and skinned trabeculae from control and myopathic human hearts.

The effects of DPI, a new inotropic agent, were compared in trabeculae carneae from control and myopathic human hearts loaded with aequorin, a bioluminescent calcium indicator that emits light when it combines with calcium, and in saponin-skinned trabeculae carneae from the same hearts. The force-pCa curves in saponin-skinned fibers and the peak force-peak Ca2+ curves in aequorin-loaded preparations were not significantly different between the control and myopathic tissues. The force-pCa curve in the skinned and aequorin-loaded preparations from the same control hearts displayed no significant shifts with the addition of DPI. In contrast, a leftward shift was present in the force-calcium relationship in the presence of DPI in aequorin-loaded and skinned muscles from myopathic hearts, indicating an increase in the sensitivity of the myofilaments to calcium. These differences in the modulation of calcium activation between myopathic and control tissues indicate that pharmacological agents may produce differential effects in normal and diseased hearts.

Role of the stress-activated protein kinases in endothelin-induced cardiomyocyte hypertrophy.

The signal transduction pathways governing the hypertrophic response of cardiomyocytes are not well defined. Constitutive activation of the stress-activated protein kinase (SAPK) family of mitogen-activated protein (MAP) kinases or another stress-response MAP kinase, p38, by overexpression of activated mutants of various components of the pathways is sufficient to induce a hypertrophic response in cardiomyocytes, but it is not clear what role these pathways play in the response to physiologically relevant hypertrophic stimuli. To determine the role of the SAPKs in the hypertrophic response, we used adenovirus-mediated gene transfer of SAPK/ERK kinase-1 (KR) [SEK-1(KR)], a dominant inhibitory mutant of SEK-1, the immediate upstream activator of the SAPKs, to block signal transmission down the SAPK pathway in response to the potent hypertrophic agent, endothelin-1 (ET-1). SEK-1(KR) completely inhibited ET-1-induced SAPK activation without affecting activation of the other MAP kinases implicated in the hypertrophic response, p38 and extracellular signal-regulated protein kinases (ERK)-1/ERK-2. Expression of SEK-1(KR) markedly inhibited the ET-1-induced increase in protein synthesis. In contrast, the MAPK/ERK kinase inhibitor, PD98059, which blocks ERK activation, and the p38 inhibitor, SB203580, had no effect on ET-1-induced protein synthesis. ET-1 also induced a significant increase in atrial natriuretic factor mRNA expression as well as in the percentage of cells with highly organized sarcomeres, responses which were also blocked by expression of SEK-1(KR). In summary, inhibiting activation of the SAPK pathway abrogated the hypertrophic response to ET-1. These data are the first demonstration that the SAPKs are necessary for the development of agonist-induced cardiomyocyte hypertrophy, and suggest that in response to ET-1, they transduce critical signals governing the hypertrophic response.

Role of intracellular calcium handling in force-interval relationships of human ventricular myocardium.

Experiments were performed in human working myocardium to investigate the relationship of intracellular calcium handling and availability to alterations in the strength of contraction produced by changes in stimulation rate and pattern. Both control and myopathic muscles exhibited potentiation of peak isometric force during the postextrasystolic contraction which was associated with an increase in the peak intracellular calcium transient. Frequency-related force potentiation was attenuated in myopathic muscles compared to controls. This occurred despite an increase in resting intracellular calcium and in the peak amplitude of the calcium transient as detected with aequorin. Therefore, abnormalities in contractile function of myopathic muscles during frequency-related force potentiation are not due to decreased availability of intracellular calcium, but more likely reflect differences in myofibrillar calcium responsiveness. Sarcolemmal calcium influx may also contribute to frequency-related changes in contractile force in myopathic muscles as suggested by a decrease in action potential duration with increasing stimulation frequency which is associated with fluctuations in peak calcium transient amplitude.

Cytosolic phospholipase A(2) regulates golgi structure and modulates intracellular trafficking of membrane proteins.

The Golgi complex and the trans-Golgi network are critical cellular organelles involved in the endocytic and biosynthetic pathways of protein trafficking. Lipids have been implicated in the regulation of membrane-protein trafficking, vesicular fusion, and targeting. We have explored the role of cytosolic group IV phospholipase A(2) (cPLA(2)) in membrane-protein trafficking in kidney epithelial cells. Adenoviral expression of cPLA(2) in LLC-PK(1) kidney epithelial cells prevents constitutive trafficking to the plasma membrane of an aquaporin 2-green fluorescent protein chimera, with retention of the protein in the rough endoplasmic reticulum. Plasma membrane Na(+)-K(+)-ATPase alpha-subunit localization is markedly reduced in cells expressing cPLA(2), whereas the trafficking of a Cl(-)/HCO(3)(-) anion exchanger to the plasma membrane is not altered in these cells. Expression of cPLA(2) results in dispersion of giantin and beta-COP from their normal, condensed Golgi localization, and in marked disruption of the Golgi cisternae. cPLA(2) is present in Golgi fractions from noninfected LLC-PK(1) cells and rat kidney cortex. The distribution of tubulin and actin was not altered by cPLA(2), indicating that the microtubule and actin cytoskeleton remain intact. Total cellular protein synthesis is unaffected by the increase in cPLA(2) activity. Thus cPLA(2) plays an important role in determining Golgi architecture and selective control of constitutive membrane-protein trafficking in renal epithelial cells.