Kendrick, Michael L.

Anoctamin‐1 (Ano1) is a widely expressed protein responsible for endogenous Ca 2+ ‐activated Cl 2 currents. Ano1 is overexpressed in cancer. Differential expression of transcriptional variants is also found in other diseases. However, the mechanisms underlying regulation of Ano1 are unknown. This study identifies the Ano1 promoter and defines a mechanism for regulating its expression. Next‐generation RNA sequencing (RNA‐seq) analysis in human gastric muscle found a new exon upstream of the reported exon 1 and identified a promoter proximal to this new exon. Reporter assays in human embryonic kidney 293 cells showed a 6.7 ± 2.1fold increase in activity over empty vector. Treatment with a known regulator of Ano1 expression, IL‐4, increased promoter activity by 1.6 ± 0.02‐fold over untreated cells. The promoter region contained putative binding sites for multiple transcription factors including signal transducer and activator of transcription 6 (STAT6), a downstream effector of IL‐4. Chromatin immunoprecipitation (ChIP) experiments on T84 cells, which endogenously express Ano1, showed a 2.1 ± 0.12‐fold increase in binding of STAT6 to P0 after IL‐4 treatment. These results were confirmed by mutagenesis, expression, and RNA interference techniques. This work allows deeper understanding of the regulation of Ano1 in physiology and as a potential therapeutic target in a variety of diseases—Mazzone, A., Gibbons, S. J., Bernard, C. E., Nowsheen, S., Middha, S., Almada, L. L., Ordog, T., Kendrick, M. L., Reid Lombardo, KM., Shen, K. R., Galietta, L. J. V., Fernandez‐Zapico, M. E., and Farrugia, G., Identification and characterization of a novel promoter for the human ANO1 gene regulated by the transcription factor signal transducer and activator of transcription 6 (STAT6). FASEB J. 29, 152–163 (2015). www.fasebj.org

Abstract Background There is increasing evidence for specific cellular changes in the stomach of patients with diabetic ( DG ) and idiopathic ( IG ) gastroparesis. The most significant findings are loss of interstitial cells of Cajal ( ICC ), neuronal abnormalities, and an immune cellular infiltrate. Studies done in diabetic mice have shown a cytoprotective effect of CD 206+ M2 macrophages. To quantify overall immune cellular infiltrate, identify macrophage populations, and quantify CD 206+ and i NOS + cells. To investigate associations between cellular phenotypes and ICC . Methods Full thickness gastric body biopsies were obtained from non‐diabetic controls (C), diabetic controls ( DC ), DG , and IG patients. Sections were labeled for CD 45, CD 206, Kit, i NOS , and putative human macrophage markers ( HAM 56, CD 68, and EMR 1). Immunoreactive cells were quantified from the circular muscle layer. Key Results Significantly fewer ICC were detected in DG and IG tissues, but there were no differences in the numbers of cells immunoreactive for other markers between patient groups. There was a significant correlation between the number of CD 206+ cells and ICC in DG and DC patients, but not in C and IG and a significant correlation between i NOS + cells and ICC in the DC group, but not the other groups. CD 68 and HAM 56 reliably labeled the same cell populations, but EMR 1 labeled other cell types. Conclusions & Inferences Depletion of ICC and correlation with changes in CD 206+ cell numbers in DC and DG patients suggests that in humans, like mice, CD 206+ macrophages may play a cytoprotective role in diabetes. These findings may lead to novel therapeutic options, targeting alternatively activated macrophages.

Hydrogen sulfide (H2S) is produced endogenously by l-cysteine metabolism. H2S modulates several ion channels with an unclear mechanism of action. A possible mechanism is through reduction-oxidation reactions attributable to the redox potential of the sulfur moiety. The aims of this study were to determine the effects of the H2S donor NaHS on NaV1.5, a voltage-dependent sodium channel expressed in the gastrointestinal tract in human jejunum smooth muscle cells and interstitial cells of Cajal, and to elucidate whether H2S acts on NaV1.5 by redox reactions. Whole cell Na+ currents were recorded in freshly dissociated human jejunum circular myocytes and NaV1.5-transfected human embryonic kidney-293 cells. RT-PCR amplified mRNA for H2S enzymes cystathionine β-synthase and cystathionine γ-lyase from the human jejunum. NaHS increased native Na+ peak currents and shifted the half-point ( V1/2) of steady-state activation and inactivation by +21 ± 2 mV and +15 ± 3 mV, respectively. Similar effects were seen on the heterologously expressed NaV1.5 α subunit with EC50s in the 10−4 to 10−3 M range. The reducing agent dithiothreitol (DTT) mimicked in part the effects of NaHS by increasing peak current and positively shifting steady-state activation. DTT together with NaHS had an additive effect on steady-state activation but not on peak current, suggesting that the latter may be altered via reduction. Pretreatment with the Hg2+-conjugated oxidizer thimerosal or the alkylating agent N-ethylmaleimide inhibited or decreased NaHS induction of NaV1.5 peak current. These studies show that H2S activates the gastrointestinal Na+ channel, and the mechanism of action of H2S is partially redox independent.

AbstractBackgroundLaparoscopic insulinoma resection (LIR) for sporadic disease is increasingly supported as a feasible and safe operation in small series of patients. To determine whether LIR is an acceptable alternative to the open operation, it is necessary to compare LIR to historical controls. The purpose of this study was to identify the skills and technology needed for LIR and establish outcome standards.MethodsA database of patients with benign sporadic insulinoma who underwent an open procedure at the Mayo Clinic was reviewed for demographics, imaging, operative/pathology reports, and outcomes. Outcomes were compared to a world‐wide meta‐analysis of patients who had undergone LIR reported in the English literature between 1996 and 2009.ResultsTwo hundred fifteen patients underwent a primary open operation for benign sporadic insulinoma. Solitary tumors were found in 97%. Meta‐analysis identified 232 patients who underwent LIR. The open and LIR groups underwent comparable operations that included enucleations (64 vs. 68%) and distal pancreatectomies (28 vs. 35%) (p = 0.06). The mean estimated blood loss, operating time, and length of stay were comparable between the open and LIR groups (p = NS). Pancreatic fistula occurred more often in the LIR group (24 vs. 11%, p < 0.05). A curative operation was performed in 98% of control patients and in 99% of the LIR group (p = NS).ConclusionsMultiple insulinomas are rare and a focused resection guided by imaging may be performed. LIR is associated with an increased incidence of pancreatic fistula. Success of LIR will depend on accurate multimodality preoperative imaging, skilled use of lap‐US to replace palpation for localization, and safe methods to dissect the tumor adjacent to the pancreatic duct.

Abstract Background Outcomes for patients with hepatocellular carcinoma (HCC) without cirrhosis and factors associated with disease progression remain unclear. The goals of this single-institution study were to define the outcomes for such patients, and to determine factors associated with survival and disease progression. Methods This was a retrospective review of consecutive patients with HCC without cirrhosis who underwent hepatic resection between 1985 and 2003. Survival was estimated by the Kaplan–Meier method and risk factors were identified by Cox proportional hazards models. Results A total of 143 patients were enrolled, of whom 29·4 per cent had identifiable risk factors for chronic liver disease. Major resection (at least three segments) was undertaken in 63·6 per cent of patients. The operative mortality rate was 3·5 per cent. Median disease-free survival was 2·4 years. Multivariable analysis revealed presence of multiple tumours as the only independent predictor of tumour recurrence. Median overall survival was 3·3 years. Factors independently associated with decreased overall survival were multiple tumours, high histological grade, perioperative transfusion, male sex and age at least 66 years. Conclusion Patients with HCC but without cirrhosis have acceptable outcomes after resection. Specific risk factors for the development of HCC in these patients have yet to be defined.