LRBA is essential for urinary concentration and body water homeostasis.

Protein kinase A (PKA) directly phosphorylates aquaporin-2 (AQP2) water channels in renal collecting ducts to reabsorb water from urine for the maintenance of systemic water homeostasis. More than 50 functionally distinct PKA-anchoring proteins (AKAPs) respectively create compartmentalized PKA signaling to determine the substrate specificity of PKA. Identification of an AKAP responsible for AQP2 phosphorylation is an essential step toward elucidating the molecular mechanisms of urinary concentration. PKA activation by several compounds is a novel screening strategy to uncover PKA substrates whose phosphorylation levels were nearly perfectly correlated with that of AQP2. The leading candidate in this assay proved to be an AKAP termed lipopolysaccharide-responsive and beige-like anchor protein (LRBA). We found that LRBA colocalized with AQP2 in vivo, and Lrba knockout mice displayed a polyuric phenotype with severely impaired AQP2 phosphorylation. Most of the PKA substrates other than AQP2 were adequately phosphorylated by PKA in the absence of LRBA, demonstrating that LRBA-anchored PKA preferentially phosphorylated AQP2 in renal collecting ducts. Furthermore, the LRBA-PKA interaction, rather than other AKAP-PKA interactions, was robustly dissociated by PKA activation. AKAP-PKA interaction inhibitors have attracted attention for their ability to directly phosphorylate AQP2. Therefore, the LRBA-PKA interaction is a promising drug target for the development of anti-aquaretics.

Using Data-Dependent and -Independent Hybrid Acquisitions for Fast Liquid Chromatography-Based Untargeted Lipidomics.

Untargeted lipidomics using liquid chromatography (LC) coupled with tandem mass spectrometry (MS) is essential for large cohort studies. Using a fast LC gradient of less than 10 min for the rapid screening of lipids decreases the annotation rate, because of the lower coverage of the MS/MS spectra caused by the narrow peak width. A systematic procedure is proposed in this study to achieve a high annotation rate in fast LC-based untargeted lipidomics by integrating data-dependent acquisition (DDA) and sequential window acquisition of all-theoretical mass spectrometry data-independent acquisition (SWATH-DIA) techniques using the updated MS-DIAL program. This strategy uses variable SWATH-DIA methods for quality control (QC) samples, which are a mixture of biological samples that were analyzed multiple times to correct the MS signal drift. In contrast, biological samples are analyzed using DDA to facilitate the structural elucidation of lipids using the pure spectrum to the maximum extent. The workflow is demonstrated using an 8.6 min LC gradient, where the QC samples are analyzed using five different SWATH-DIA methods. The use of both DDA and SWATH-DIA achieves a 1.7-fold annotation coverage from publicly available benchmark data obtained using a fast LC-DDA-MS technique and offers 95.3% lipid coverage, as compared to the benchmark data set from a 25 min LC gradient. This study demonstrates that harmonized improvements in analytical conditions and informatics tools provide a comprehensive lipidome in fast LC-based untargeted lipidomics, not only for large-scale studies but also for small-scale experiments, contributing to both clinical applications and basic biology.

Differential treatment responses to immune checkpoint inhibitor (ICI) therapy in a case of multiple primary malignancies: the programmed death ligand-1 (PD-L1) negative ureteral and lung metastasis from a clear cell renal cell carcinoma appearing after robotic-assisted partial nephrectomy progressed after ICI therapy, while synchronous PD-L1-positive primary lung squamous cell carcinoma responded very well to ICI therapy: a case report.

BACKGROUND: Renal cell carcinoma (RCC) and non-small cell lung cancer (NSCLC) are representative malignancies that respond well to immune checkpoint inhibitors (ICIs). Research has been conducted to identify biomarkers, such as programmed death ligand-1 (PD-L1), that would allow the response to ICI therapy to be predicted; however, the complex tumor immune system consisting of both host and tumor factors may also exert an influence. CASE PRESENTATION: Computed tomographic imaging (CT) incidentally revealed a left renal mass, and a left pulmonary nodule with multiple lymph node metastases (LNMs). Firstly, video-assisted thoracic surgery revealed a lung tumor invading the chest wall. Histologically, the findings of the tumor were consistent with squamous cell carcinoma (SCC), and immunohistochemistry (IHC) showed positive PD-L1 expression. The renal tumor was excised by robotic-assisted partial nephrectomy (RAPN). Histologically, the renal tumor showed the features of clear cell carcinoma (CCC). Four months after the RAPN, CT revealed left hydronephrosis caused by an enhancing ureteral tumor. Then, multiple right lung metastases appeared, and the left lung tumor increased. Following treatment including atezolizumab, the primary lung SCC and the multiple LNMs almost disappeared completely, while the ureteral and right lung metastases showed progression. The ureteral metastasis was resected by left open nephroureterectomy. Histology of the ureteral tumor revealed features consistent with CCC. Histological examination of the multiple right lung metastases that were resected by partial lobectomy via a small thoracic incision also revealed features consistent with CCC. Two months after nephroureterectomy, a solitary left lung metastasis was treated by nivolumab and ipilimumab. Six months after nephroureterectomy, the patient died of RCC. Further studies of specimens revealed that the tumor cells in the primary RCC and the ureteral and lung metastases showed negative results of IHC for PD-L1. CONCLUSIONS: The responses to ICI therapy of concomitant RCC and NSCLC were quite different. The PD-L1 expression status in individual tumors in cases of multiple primary malignancies (MPMs) may directly predict the response of each malignancy to ICI therapy, because the host immune system, which may affect the response to ICI therapy, could be the same in MPMs.

[A Case of pagetoid Carcinoma of the Breast with Pathological Complete Response by Neoadjuvant Chemotherapy].

We herein report a 63-year-old woman who presented with about 20 mm-sized mass in the right breast and the right nipple with erosion. Preoperative examinations revealed a diagnosis of HER2-type pagetoid carcinoma with axillary lymph node metastasis. After neoadjuvant chemotherapy(pertuzumab, trastuzumab, and docetaxel, followed by adriamycin and cyclophosphamide), a pathological complete response was achieved. The patient was treated with anti-HER2 therapy without recurrence.

Development of RIKEN Plant Metabolome MetaDatabase.

The advancement of metabolomics in terms of techniques for measuring small molecules has enabled the rapid detection and quantification of numerous cellular metabolites. Metabolomic data provide new opportunities to gain a deeper understanding of plant metabolism that can improve the health of both plants and humans that consume them. Although major public repositories for general metabolomic data have been established, the community still has shortcomings related to data sharing, especially in terms of data reanalysis, reusability and reproducibility. To address these issues, we developed the RIKEN Plant Metabolome MetaDatabase (RIKEN PMM, http://metabobank.riken.jp/pmm/db/plantMetabolomics), which stores mass spectrometry-based (e.g. gas chromatography-MS-based) metabolite profiling data of plants together with their detailed, structured experimental metadata, including sampling and experimental procedures. Our metadata are described as Linked Open Data based on the Resource Description Framework using standardized and controlled vocabularies, such as the Metabolomics Standards Initiative Ontology, which are to be integrated with various life and biomedical science data using the World Wide Web. RIKEN PMM implements intuitive and interactive operations for plant metabolome data, including raw data (netCDF format), mass spectra (NIST MSP format) and metabolite annotations. The feature is suitable not only for biologists who are interested in metabolomic phenotypes, but also for researchers who would like to investigate life science in general through plant metabolomic approaches.

Publisher Correction: A cheminformatics approach to characterize metabolomes in stable-isotope-labeled organisms.

In the originally published Supplementary Information for this paper, the files presented as Supplementary Tables 3, 4, and 7 were duplicates of Supplementary Tables 5, 6, and 9, respectively. All Supplementary Table files are now correct online.

A cheminformatics approach to characterize metabolomes in stable-isotope-labeled organisms.

We report a computational approach (implemented in MS-DIAL 3.0; http://prime.psc.riken.jp/) for metabolite structure characterization using fully 13C-labeled and non-labeled plants and LC-MS/MS. Our approach facilitates carbon number determination and metabolite classification for unknown molecules. Applying our method to 31 tissues from 12 plant species, we assigned 1,092 structures and 344 formulae to 3,604 carbon-determined metabolite ions, 69 of which were found to represent structures currently not listed in metabolome databases.

[A Case in Which a Laparotomy Transition, in a Patient with Sigmoid Colon Cancer, Prevented Peritoneal Metastasis from Being Missed].

We report a case of laparoscopic sigmoidectomy for sigmoid colon cancer where a laparotomy transition prevented peritoneal metastasis from being missed. Case: A 64-year-old woman was diagnosed with sigmoid colon cancer. Computed tomography revealed a large bowel obstruction and a 12 mm wide basal bulge in the gallbladder. A laparoscopic sigmoidectomy( D3 dissection)was first performed, and intra-abdominal observation revealed no disseminated nodules. A laparoscopic cholecystectomy was performed continuously but, due to strong adhesions, a laparotomy was administered. Three disseminated nodules were observed in the omentum during the laparotomy and a postoperative pathological examination revealed pT4aN1b(2/23)M1c1(P2), pStage Ⅳc. Adjuvant chemotherapy of 8 courses of CAPOX was performed and there has been no recurrence 20 months after surgery.

[A Case of SM Carcinoma of the Sigmoid Colon with Distant Metastasis in the Early Stage after Endoscopic MucosalResection].

INTRODUCTION: We report a case of submucosal(SM)adenocarcinoma of the sigmoid colon which developed distant metastasis 3 months after endoscopic mucosal resection(EMR). CASE: 54-year-old, male. Colonoscopy, which was performed due to positive fecal occult blood test, revealed 18 mm Isp sigmoid polyp. EMR was performed with en bloc resection. Pathological examination revealed adenocarcinoma(tub>por>sig), pT1b, Ly1c, V1a, pHM0, and pVM1. Therefore, laparoscopic sigmoidectomy(D2 dissection)was performed. Postoperative pathological examination revealed pT1b, pN2b(10/11), PN1b, pPM0, pDM0, pStage Ⅲb. Distant nodal involvement were found on computed tomography 3 months after EMR, although systemic chemotherapy(mFOLFOX6 plus panitumumab 18 courses and FOLFIRI plus bevacizumab 4 courses)was performed, the patient died of liver failure caused by liver metastasis 21 months after EMR. CONCLUSION: We present a case of T1 sigmoid adenocarcinoma which developed distant metastasis 3 months after EMR with literature review.

TAFRO syndrome as a cause of glomerular microangiopathy: a case report and literature review.

BACKGROUND: TAFRO syndrome is a systemic inflammatory disorder that manifests as thrombocytopenia (T), anasarca (A), fever (F), reticulin fibrosis (R), and organomegaly (O). Renal dysfunction is frequently complicated with TAFRO syndrome, however, it is challenging to perform kidney biopsy in patients with TAFRO syndrome in the presence of thrombocytopenia. Renal histology in TAFRO syndrome mainly shows membranoproliferative glomerulonephritis (MPGN)-like lesions or thrombotic microangiopathy (TMA)-like glomerulopathy. We review our case and previous reports of TAFRO syndrome with kidney biopsy findings and discuss the renal pathophysiology of TAFRO syndrome. CASE PRESENTATION: We describe a previously healthy 48- year-old woman with TAFRO syndrome. Kidney biopsy performed before the treatment showed diffuse global endocapillary proliferative changes with endothelial cell swelling, double contours of partial capillary walls, and mesangiolysis, consistent with TMA-like glomerulopathy. Glucocorticoid therapy including steroid pulse was ineffective and she developed anasarca, renal dysfunction and oliguria. Hemodialysis was required. However, the anti-Interleukin (IL)-6 receptor antibody (tocilizumab) therapy was very effective. An increase in urinary volume was achieved about 2 weeks after the tocilizumab therapy and hemodialysis was discontinued. To investigate the renal pathophysiology of TAFRO syndrome, we performed immunohistological staining of vascular endothelial growth factor (VEGF)-A, CD34, and D2-40, in our case and a normal control kidney. Glomerular VEGF-A was especially positive in podocytes both, in the control and in the case, with no significant difference and there was a significant increase of VEGF-A staining area in the cortical peritubular capillaries in the case. Both glomerular and renal cortical CD34 expression were significantly decreased in our case. D2-40 expression in cortex was not significantly different. CONCLUSIONS: We reviewed our case and other 10 previous reports about renal biopsy findings in TAFRO syndrome and found that glomerular microangiopathy was a common finding. IL-6-VEGF-axis-induced glomerular microangiopathy may play a crucial role in developing acute kidney injury in TAFRO syndrome and the anti-IL-6 receptor antibody therapy may be useful for TAFRO syndrome refractory to glucocorticoids. About the pathophysiology of VEGF in TAFRO syndrome, VEGF balance in the glomerulus and perhaps in the peritubular capillary system as well may be critical. Further investigation is needed.

Pulmonary Apical Opacities on Thin-Section Computed Tomography: Relationship to Primary Spontaneous Pneumothorax in Young Male Patients and Corresponding Histopathologic Findings.

OBJECTIVE: The purpose of this study was to test the hypothesis that apical opacities on computed tomography (CT) are related to occurrence of primary spontaneous pneumothorax (PSP) in young male patients. METHODS: We compared the frequency of apical opacities on thin-section CT between 70 male patients with PSP (PSP group) and 74 male patients without a history of PSP (non-PSP group). We also evaluated histopathologic findings of 39 specimens from 37 surgical cases in the PSP group. RESULTS: Apical opacities were significantly more frequent in the PSP group than in the non-PSP group (right side, P = 0.01; left side, P = 0.005). Histopathologically, subpleural band-like alveolar collapse was seen in 35 specimens (89.7%), which was always accompanied by fibroelastosis and fibroblastic foci. CONCLUSIONS: Apical opacities on CT were significantly associated with PSP in young male patients. These apical opacities histopathologically correspond to fibrotic pleural thickening with subpleural alveolar collapse.

Compressive Lesions of the Optic Chiasm: Subjective Symptoms and Visual Field Diagnostic Criteria.

We investigated the diagnostic ability of a new criterion (simple temporal depression) for compressive lesions of the optic chiasm. The subjects were 124 eyes with compressive lesions of the optic chiasm. The controls were 84 eyes. The Humphrey (Carl Zeiss) visual field test was used for visual field testing. The simple temporal depression index was calculated as the ratio of the sums of the thresholds for one line on the nasal side and temporal side of the vertical meridian. The result of new index was 87% sensitivity and 99% specificity. This result suggested that our new criterion will assist the diagnosis in the future.

Mutant analysis of Cdt1's function in suppressing nascent strand elongation during DNA replication in Xenopus egg extracts.

The initiation of DNA replication is strictly regulated by multiple mechanisms to ensure precise duplication of chromosomes. In higher eukaryotes, activity of the Cdt1 protein is temporally regulated during the cell cycle, and deregulation of Cdt1 induces DNA re-replication. In previous studies, we showed that excess Cdt1 inhibits DNA replication by suppressing progression of replication forks in Xenopus egg extracts. Here, we investigated the functional regions of Cdt1 that are required for the inhibition of DNA replication. We constructed a series of N-terminally or C-terminally deleted mutants of Cdt1 and examined their inhibitory effects on DNA replication in Xenopus egg extracts. Our results showed that the region spanning amino acids (a. a.) 255-620 is required for efficient inhibition of DNA replication, and that, within this region, a. a. 255-289 have a critical role in inhibition. Moreover, one of the Cdt1 mutants, Cdt1 R285A, was compromised with respect to the licensing activity but still inhibited DNA replication. This result suggests that Cdt1 has an unforeseen function in the negative regulation of DNA replication, and that this function is located within a molecular region that is distinct from those required for the licensing activity.

Intrahepatic cholangiocarcinoma producing granulocyte colony-stimulating factor and parathyroid hormone-related protein.

A 78-year-old man was referred to our hospital with suspected liver abscess. Fever and inflammatory reaction resolved after percutaneous drainage and administration of antibiotics. However, leukocyte count was remarkably increased, and hypercalcemia was noted. The liver mass was also enlarged, as observed in the follow-up abdominal CT scans. Therefore, a percutaneous needle biopsy was performed, and the histopathological findings indicated the presence of adenocarcinoma. Additional blood examination revealed high serum levels of granulocyte colony-stimulating factor (G-CSF) and parathyroid hormone-related protein (PTHrP). Lastly, the patient was diagnosed with cholangiocarcinoma producing G-CSF and PTHrP. Chemoradiotherapy with S-1 was initiated, which was partially effective. However, the patient died 134 days after initiating the therapy. Only two cases of cholangiocarcinoma producing G-CSF and PTHrP have been reported to date. Here we reported an additional case of cholangiocarcinoma producing G-CSF and PTHrP.

Excess Cdt1 inhibits nascent strand elongation by repressing the progression of replication forks in Xenopus egg extracts.

Cdt1 is a protein essential for initiation of DNA replication; it recruits MCM helicase, a core component of the replicative DNA helicase, onto replication origins. In our previous study, we showed that addition of excess Cdt1 inhibits nascent strand elongation during DNA replication in Xenopus egg extracts. In the present study, we investigated the mechanism behind the inhibitory effect of Cdt1. We found that addition of recombinant Cdt1 inhibited nascent DNA synthesis in a reinitiation-independent manner. To identify the mechanism by which Cdt1 inhibits nascent strand elongation, the effect of Cdt1 on loading of Mcm4 and Rpa70 onto chromatin was examined. The results showed that Cdt1 suppressed the excessive Rpa70 binding caused by extensive, aphidicolin-induced DNA unwinding; this unwinding occurs between stalled DNA polymerases and advancing replication forks. These findings suggested that excess Cdt1 suppressed the progression of replication forks.

Fulminant Non-occlusive Mesenteric Ischemia After Head Trauma: Report of Two Cases.

There have been no case reports of non-occlusive mesenteric ischemia (NOMI) following head trauma. Our two patients with non-surgical traumatic intracerebral hemorrhage succumbed to NOMI one week after the injury. Both were women over age 80 years and were clinically improving before NOMI occurred. One patient had been eating since admission, while the other had not, which prompted the initiation of enteral nutrition on day 5. The patients shared many characteristics: 1) over age 80 years; 2) minor brain contusion; 3) constipation for a week; 4) minimal abdominal symptoms; 5) rapidly developing leukocytosis, hyperglycemia, hypernatremia, and elevated blood urea nitrogen; 6) massive diarrhea with a small amount of blood on the same day that laboratory data became abnormal; and 7) fever and shock developed shortly after diarrhea appeared. Because of the fulminant worsening of the condition, shock status, and old age, surgical intervention was considered high risk and not performed in either patient. In retrospect, if NOMI had been diagnosed earlier when the acute pancreatitis-like symptoms began, surgical intervention may have saved their lives. Clinicians should be aware that NOMI can occur after relatively minor head trauma, which can cause death if the diagnosis is delayed.

Subcortical hemorrhage caused by cerebral amyloid angiopathy compared with hypertensive hemorrhage.

OBJECTIVES: Most published reports on lobular hemorrhage in cerebral amyloid angiopathy (CAA) include patients diagnosed only by imaging studies. This study analyzed patients with subcortical hemorrhage histologically diagnosed as CAA or non-CAA (hypertensive). METHODS: This is a retrospective study analyzing data from 100 craniotomy cases. Tissue of hematoma cavity wall was collected for histological investigation in hematoma removal by surgery in patients with subcortical hemorrhage. Statistical analyses of blood pressure, hematoma location and volume, outcome, and mortality was performed in CAA and non-CAA groups. RESULTS: There were 47 CAA and 53 non-CAA cases, and average age was significantly older in the CAA group (p < 0.01). Blood pressure was significantly lower (p < 0.01) but hematoma volume was significantly greater (p < 0.05) in the CAA group. Rebleeding occurred in two CAA cases and one non-CAA case, but no re-operations were required. Average score of modified Rankin Scale, which is used to measure the degree of disability in patients who have had a stroke, at three months after surgery was not significantly different between the two groups (CAA: 3.94 ± 1.28, non-CAA: 3.58 ± 1.50). There were seven deaths in the CAA and six in the non-CAA group, and intraventricular hemorrhage highly complicated in the death cases in both groups. In the CAA group, average age of the fatal cases was significantly older than that of the surviving cases (p < 0.05) and six cases demonstrated dementia before onset of hemorrhage. CONCLUSIONS: Surgical removal of a subcortical hemorrhage caused by CAA is not contraindicated. However, age > 80 years, complication with intraventricular hemorrhage, hematoma volume ≥ 50 ml, and dementia before onset of hemorrhage contribute to high mortality, and craniotomy should be carefully considered for such patients. A limitation of this study is that comparison between CAA and non-CAA groups was performed in the patients with only surgically indicated ICH, and does not evaluate entire ICH cases with CAA. However, this study appropriately compared pathologically diagnosed CAA and non-CAA in patients with moderate to severe lobular ICH with surgical indications.

A lipidome landscape of aging in mice.

Understanding the molecular mechanisms of aging is crucial for enhancing healthy longevity. We conducted untargeted lipidomics across 13 biological samples from mice at various life stages (2, 12, 19 and 24 months) to explore the potential link between aging and lipid metabolism, considering sex (male or female) and microbiome (specific pathogen-free or germ-free) dependencies. By analyzing 2,704 molecules from 109 lipid subclasses, we characterized common and tissue-specific lipidome alterations associated with aging. For example, the levels of bis(monoacylglycero)phosphate containing polyunsaturated fatty acids increased in various organs during aging, whereas the levels of other phospholipids containing saturated and monounsaturated fatty acids decreased. In addition, we discovered age-dependent sulfonolipid accumulation, absent in germ-free mice, correlating with Alistipes abundance determined by 16S ribosomal RNA gene amplicon sequencing. In the male kidney, glycolipids such as galactosylceramides, galabiosylceramides (Gal2Cer), trihexosylceramides (Hex3Cer), and mono- and digalactosyldiacylglycerols were detected, with two lipid classes-Gal2Cer and Hex3Cer-being significantly enriched in aged mice. Integrated analysis of the kidney transcriptome revealed uridine diphosphate galactosyltransferase 8A (UGT8a), alkylglycerone phosphate synthase and fatty acyl-coenzyme A reductase 1 as potential enzymes responsible for the male-specific glycolipid biosynthesis in vivo, which would be relevant to sex dependency in kidney diseases. Inhibiting UGT8 reduced the levels of these glycolipids and the expression of inflammatory cytokines in the kidney. Our study provides a valuable resource for clarifying potential links between lipid metabolism and aging.

Role of survivin in acute lung injury: epithelial cells of mice and humans.

Survivin, an inhibitor of apoptosis, regulates cell division and is a potential target for anticancer drugs because many cancers express high survivin levels. However, whether survivin would be toxic to human lung cells and tissues has not been determined. This report clarified the involvement of survivin in acute lung injury. We used immunohistochemical analysis, immunoelectron microscopy, and real-time reverse transcription-quantitative polymerase chain reaction to study survivin expression and localization in injured mouse and human lungs. We also used cultured human lung epithelial cells (BEAS-2B and A549) to study survivin cytoprotection. Nuclei and cytoplasm of epithelial cells in day 3 and day 7 models of bleomycin-injured lung showed survivin-positive results, which is consistent with upregulated survivin mRNA expression. These nuclei also evidenced double positive findings for proliferating cell nuclear antigen and survivin. Day 7 models had similar Smac/DIABLO-positive and survivin-positive cell distributions. The cytoplasm and nuclei of epithelial cells in lesions with diffuse alveolar damage manifested strong survivin-positive findings. Bleomycin stimulation in both epithelial cell lines upregulated expression of survivin and apoptosis-related molecules. Suppression of survivin expression with small interfering RNA rendered human lung epithelial cells susceptible to bleomycin-induced damage, with markedly upregulated activation of caspase-3, caspase-7, poly (ADP-ribose) polymerase, and lactate dehydrogenase activity and an increased number of dead cells compared with mock small interfering RNA-treated cells. Overexpression of survivin via transfection resulted in these epithelial cells being resistant to bleomycin-induced cell damage, with reduced activation of apoptosis-related molecules and lactate dehydrogenase activity and fewer dead cells compared with results for mock-transfected cells. Survivin, acting at the epithelial cell level that depends partly on apoptosis inhibition, is therefore a key mediator of cytoprotection in acute lung injury. Understanding the precise role of survivin in normal lung cells is required for the development of therapeutic survivin.

AKAP9 regulation of microtubule dynamics promotes Epac1-induced endothelial barrier properties.

Adhesive forces at endothelial cell-cell borders maintain vascular integrity. cAMP enhances barrier properties and controls cellular processes through protein kinase A bound to A-kinase anchoring proteins (AKAPs). It also activates exchange protein directly activated by cAMP (Epac1), an exchange factor for Ras-related protein 1 (Rap1) GTPases that promotes cadherin- and integrin-mediated adhesion through effects on the actin cytoskeleton. We demonstrate that AKAP9 facilitates the microtubule polymerization rate in endothelial cells, interacts with Epac1, and is required for Epac1-stimulated microtubule growth. AKAP9 is not required for maintaining barrier properties under steady-state conditions. Rather, it is essential when the cell is challenged to make new adhesive contacts, as is the case when Epac activation enhances barrier function through a mechanism that, surprisingly, requires integrin adhesion at cell-cell contacts. In the present study, defects in Epac-induced responses in AKAP9-silenced cells were evident despite an intact Epac-induced increase in Rap activation, cortical actin, and vascular endothelial-cadherin adhesion. We describe a pathway that integrates Epac-mediated signals with AKAP9-dependent microtubule dynamics to coordinate integrins at lateral borders.