Name: preparation of pancreatic acinar cells for the purpose of calcium imaging, cell injury measurements, and adenoviral infection
Uploaded: 2013-07-05T12:00:00
Description: Watch this Scientific Journal Video about Preparation of Pancreatic Acinar Cells for the Purpose of Calcium Imaging, Cell Injury Measurements, and Adenoviral Infection at JoVE.com

This work was supported by a National Institutes of Health Grant DK083327, and DK093491 (to S.Z.H.).

1. Preparing Pancreatic Acinar Cells for Calcium Imaging
<ol>
	<li>Prepare HEPES incubation buffer containing 20 mM HEPES, 95 mM NaCl, 4.7 mM KCl, 0.6 mM MgCl2, 1.3 mM CaCl2, 10 mM glucose, 2 mM glutamine, and 1 &times; minimum Eagle's medium non-essential amino acids. Adjust the final solution to pH 7.4 with NaOH.</li>
	<li>Prepare a BSA incubation buffer by adding BSA (1% w/v final) to 25 ml of the HEPES incubation buffer (described above).</li>
	<li>Prepare a collagenase digestion buffer by...

<ol>
	<li>Toescu, E. C., Lawrie, A. M., Petersen, O. H., Gallacher, D. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatial+and+temporal+distribution+of+agonist-evoked+cytoplasmic+Ca2++signals+in+exocrine+acinar+cells+analysed+by+digital+image+microscopy.">Spatial and temporal distribution of agonist-evoked cytoplasmic Ca2+ signals in exocrine acinar cells analysed by digital image microscopy.</a> Embo J. 11, 1623-1629 (1992).</li><li>Ito, K., Miyashita, Y., Kasai, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Micromolar+and+submicromolar+Ca2++spikes+regulating+distinct+cellular+functions+in+pancreatic+acinar+cells.">Micromolar and submicromolar Ca2+ spikes regulating distinct cellular functions in pancreatic acinar cells.</a> Embo J. 16, 242-251 (1997).</li><li>Husain, S. Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+ryanodine+receptor+mediates+early+zymogen+activation+in+pancreatitis.">The ryanodine receptor mediates early zymogen activation in pancreatitis.</a> Proc. Natl. Acad. Sci. U.S.A. 102, 14386-14391 (2005).</li><li>Raraty, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calcium-dependent+enzyme+activation+and+vacuole+formation+in+the+apical+granular+region+of+pancreatic+acinar+cells.">Calcium-dependent enzyme activation and vacuole formation in the apical granular region of pancreatic acinar cells.</a> Proc. Natl. Acad. Sci. U.S.A. 97, 13126-13131 (2000).</li><li>Orabi, A. I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dantrolene+mitigates+caerulein-induced+pancreatitis+in+vivo+in+mice.">Dantrolene mitigates caerulein-induced pancreatitis in vivo in mice.</a> Am. J. Physiol. Gastrointest. Liver Physiol. 299, G196-G204 (2009).</li><li>Shah, A. U., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protease+Activation+during+in+vivo+Pancreatitis+is+Dependent+upon+Calcineurin+Activation.">Protease Activation during in vivo Pancreatitis is Dependent upon Calcineurin Activation.</a> Am. J. Physiol. Gastrointest. Liver Physiol. , (2009).</li><li>Muili, K. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pharmacologic+and+genetic+inhibition+of+calcineurin+protects+against+carbachol-induced+pathologic+zymogen+activation+and+acinar+cell+injury.">Pharmacologic and genetic inhibition of calcineurin protects against carbachol-induced pathologic zymogen activation and acinar cell injury.</a> Am. J. Physiol. Gastrointest. Liver Physiol. , (2012).</li><li>Orabi, A. I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ethanol+enhances+carbachol-induced+protease+activation+and+accelerates+Ca2++waves+in+isolated+rat+pancreatic+acini.">Ethanol enhances carbachol-induced protease activation and accelerates Ca2+ waves in isolated rat pancreatic acini.</a> J. Biol. Chem. 286, 14090-14097 (2011).</li><li>Nathanson, M. H., Padfield, P. J., O'Sullivan, A. J., Burgstahler, A. D., Jamieson, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanism+of+Ca2++wave+propagation+in+pancreatic+acinar+cells.">Mechanism of Ca2+ wave propagation in pancreatic acinar cells.</a> J. Biol. Chem. 267, 18118-18121 (1992).</li><li>Reed, A. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low+extracellular+pH+induces+damage+in+the+pancreatic+acinar+cell+by+enhancing+calcium+signaling.">Low extracellular pH induces damage in the pancreatic acinar cell by enhancing calcium signaling.</a> J. Biol. Chem. 286, 1919-1926 (2011).</li><li>Amsterdam, A., Jamieson, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+and+functional+characterization+of+isolated+pancreatic+exocrine+cells.">Structural and functional characterization of isolated pancreatic exocrine cells.</a> Proc. Natl. Acad. Sci. U.S.A. 69, 3028-3032 (1972).</li><li>Van Acker, G. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumor+progression+locus-2+is+a+critical+regulator+of+pancreatic+and+lung+inflammation+during+acute+pancreatitis.">Tumor progression locus-2 is a critical regulator of pancreatic and lung inflammation during acute pancreatitis.</a> J. Biol. Chem. 282, 22140-22149 (2007).</li><li>Ito, K., Miyashita, Y., Kasai, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinetic+control+of+multiple+forms+of+Ca(2+)+spikes+by+inositol+trisphosphate+in+pancreatic+acinar+cells.">Kinetic control of multiple forms of Ca(2+) spikes by inositol trisphosphate in pancreatic acinar cells.</a> J. Cell Biol. 146, 405-413 (1999).</li><li>Leite, M. F., Burgstahler, A. D., Nathanson, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ca2++waves+require+sequential+activation+of+inositol+trisphosphate+receptors+and+ryanodine+receptors+in+pancreatic+acini.">Ca2+ waves require sequential activation of inositol trisphosphate receptors and ryanodine receptors in pancreatic acini.</a> Gastroenterology. 122, 415-427 (2002).</li><li>Paredes, R. M., Etzler, J. C., Watts, L. T., Zheng, W., Lechleiter, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+calcium+indicators.">Chemical calcium indicators.</a> Methods. 46, 143-151 (2008).</li><li>Schild, D., Jung, A., Schultens, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Localization+of+calcium+entry+through+calcium+channels+in+olfactory+receptor+neurones+using+a+laser+scanning+microscope+and+the+calcium+indicator+dyes+Fluo-3+and+Fura-Red.">Localization of calcium entry through calcium channels in olfactory receptor neurones using a laser scanning microscope and the calcium indicator dyes Fluo-3 and Fura-Red.</a> Cell Calcium. 15, 341-348 (1994).</li><li>Saluja, A. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Secretagogue-induced+digestive+enzyme+activation+and+cell+injury+in+rat+pancreatic+acini.">Secretagogue-induced digestive enzyme activation and cell injury in rat pancreatic acini.</a> Am. J. Physiol. 276, 835-842 (1999).</li><li>Husain, S. Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ryanodine+receptors+contribute+to+bile+acid-induced+pathological+calcium+signaling+and+pancreatitis+in+mice.">Ryanodine receptors contribute to bile acid-induced pathological calcium signaling and pancreatitis in mice.</a> Am. J. Physiol. Gastrointest. Liver Physiol. , (2012).</li><li>Gurda, G. T., Guo, L., Lee, S. H., Molkentin, J. D., Williams, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cholecystokinin+activates+pancreatic+calcineurin-NFAT+signaling+in+vitro+and+in+vivo.">Cholecystokinin activates pancreatic calcineurin-NFAT signaling in vitro and in vivo.</a> Mol. Biol. Cell. 19, 198-206 (2008).</li></ol>

The cell isolation method and subsequent assays depicted here represent powerful tools with which to study the physiological and pathophysiological features of the exocrine pancreas. The method for isolating dispersed pancreatic acinar cells was first described by Amsterdam and Jamieson in 1972 11. The methods presented here have been adapted from more recent isolation methods described by Van Acker and colleagues 12. Although these techniques are highly reproducible and easily learned, there...

Dynamic changes in cytosolic calcium are necessary for both physiological and pathological acinar cell events. These divergent effects of calcium are thought to result from distinct spatial and temporal patterns of calcium signaling 1. For example, enzyme and fluid secretion from the acinar cell are linked to calcium spikes from a restricted region of the apical pole where secretion takes place 2. In contrast, a global calcium wave followed by intense non-oscillatory calcium signals is associated with early pathological events which lead to acute pancreatitis 3,4. These include intra-acinar protease activation, reduced enzyme secretion, and acinar cell injury. Our lab uses isolated pancreatic acini to study these early pathological events which lead to disease both in vivo and in vitro 5-7. The methods detailed here describe isolation of primary acinar cells for the purpose of measuring cytosolic calcium levels and cell injury. A method for adenoviral infection of these cells is also provided.

<table border="1">
 <tbody>
 <tr>
 <td>Name</td>
 <td>Company</td>
 <td>Catalogue Number</td>
 <td>Comments</td>
 </tr>
 <tr>
 <td>Mice</td>
 <td>NCI</td>
 <td>N/A</td>
 <td>Male 20-30 grams; virtually any strain should yield comparable results.</td>
 </tr>
 <tr>
 <td>HEPES</td>
 <td>American Bioanalytical</td>
 <td>AB00892</td>
 <td></td>
 </tr>
 <tr>
 <td>Sodium Chloride</td>
 <td>J.T. Baker</td>
 <td>3624-05</td>
 <td></td>
 </tr>
 <tr>
 <td>Potassium Chloride</td>
 <td>J.T. Baker</td>
 <td>3040-01</td>
 <td></td>
 </tr>
 <tr>
 <td>Magnesium Chloride</td>
 <td>Sigma</td>
 <td>M-8266</td>
 <td></td>
 </tr>
 <tr>
 <td>Calcium Chloride</td>
 <td>Fischer</td>
 <td>C79</td>
 <td></td>
 </tr>
 <tr>
 <td>Dextrose</td>
 <td>J.T. Baker</td>
 <td>1916-01</td>
 <td></td>
 </tr>
 <tr>
 <td>L-Glutamine</td>
 <td>Sigma</td>
 <td>G-8540</td>
 <td></td>
 </tr>
 <tr>
 <td>1X minimum Eagle's medium non-essential amino acid mixture</td>
 <td>Gibco</td>
 <td>11140-050</td>
 <td></td>
 </tr>
 <tr>
 <td>Sodium Hydroxide</td>
 <td>EM</td>
 <td>SX0593</td>
 <td></td>
 </tr>
 <tr>
 <td>Bovine Serum Albumin</td>
 <td>Sigma</td>
 <td>A7906</td>
 <td></td>
 </tr>
 <tr>
 <td>Collagenase</td>
 <td>Worthington</td>
 <td>4188</td>
 <td></td>
 </tr>
 <tr>
 <td>Soybean Trypsin Inhibitor</td>
 <td>Sigma</td>
 <td>T-9003</td>
 <td></td>
 </tr>
 <tr>
 <td>Carbon Dioxide</td>
 <td>Matheson Gas</td>
 <td> 124-38-9 </td>
 <td></td>
 </tr>
 <tr>
 <td>125 ml Erlenmeyer plastic flask</td>
 <td>Crystalgen </td>
 <td>26-0005</td>
 <td></td>
 </tr>
 <tr>
 <td>Dissection kit</td>
 <td>Fine Science Tools</td>
 <td>14161-10</td>
 <td></td>
 </tr>
 <tr>
 <td>70% Ethanol</td>
 <td>LabChem</td>
 <td>LC222102</td>
 <td></td>
 </tr>
 <tr>
 <td>P1000, P100, P10 pipettes</td>
 <td>Gilson</td>
 <td>FA10005P</td>
 <td></td>
 </tr>
 <tr>
 <td>Weighing boat</td>
 <td>Heathrow Scientific</td>
 <td>HS1420A</td>
 <td></td>
 </tr>
 <tr>
 <td>Plastic transfer pipettes</td>
 <td>USA Scientific</td>
 <td>1020-2500</td>
 <td></td>
 </tr>
 <tr>
 <td>15 ml conical tubes</td>
 <td>BD Falcon</td>
 <td>352095</td>
 <td></td>
 </tr>
 <tr>
 <td>50 ml conical tubes</td>
 <td>BD Falcon</td>
 <td>352070</td>
 <td></td>
 </tr>
 <tr>
 <td>1.5 ml micro-centrifuge tube</td>
 <td>Fisher</td>
 <td>05-408-129</td>
 <td></td>
 </tr>
 <tr>
 <td>0.65 ml micro-centrifuge tube</td>
 <td>VWR</td>
 <td>20170-293</td>
 <td></td>
 </tr>
 <tr>
 <td>22 x 22 mm glass coverslips</td>
 <td>Fisher</td>
 <td>032811-9</td>
 <td></td>
 </tr>
 <tr>
 <td>Nitric Acid</td>
 <td>Fischer</td>
 <td>A483-212</td>
 <td></td>
 </tr>
 <tr>
 <td>Hydrochloric Acid</td>
 <td>Fischer</td>
 <td>A142-212</td>
 <td></td>
 </tr>
 <tr>
 <td>Deionized water</td>
 <td>N/A</td>
 <td>N/A</td>
 <td></td>
 </tr>
 <tr>
 <td>18 x 18 mm coverslips</td>
 <td>Fischer</td>
 <td>021510-9</td>
 <td></td>
 </tr>
 <tr>
 <td>Laboratory film</td>
 <td>Parafilm</td>
 <td>PM-996</td>
 <td></td>
 </tr>
 <tr>
 <td>Fluo-4AM</td>
 <td>Invitrogen</td>
 <td>F14201</td>
 <td></td>
 </tr>
 <tr>
 <td>Dimethylsulfoxide</td>
 <td>Sigma</td>
 <td>D2650</td>
 <td></td>
 </tr>
 <tr>
 <td>Luer lock</td>
 <td>Becton Dickinson</td>
 <td>932777</td>
 <td></td>
 </tr>
 <tr>
 <td>60 ml syringe</td>
 <td>BD Bioscience</td>
 <td>DG567805</td>
 <td></td>
 </tr>
 <tr>
 <td>23 &frac34; gauge needle</td>
 <td>BD Bioscience</td>
 <td>9328270</td>
 <td></td>
 </tr>
 <tr>
 <td>PE50 tubing</td>
 <td>Clay Adam</td>
 <td>PE50-427411</td>
 <td></td>
 </tr>
 <tr>
 <td>Flat head screwdriver </td>
 <td>N/A</td>
 <td>N/A</td>
 <td></td>
 </tr>
 <tr>
 <td>DMEM F-12, no Phenol Red</td>
 <td>Gibco</td>
 <td>21041-025 </td>
 <td></td>
 </tr>
 <tr>
 <td>30.5 gauge needle</td>
 <td>BD Bioscience</td>
 <td>305106</td>
 <td></td>
 </tr>
 <tr>
 <td>5 CC syringe</td>
 <td>BD Bioscience</td>
 <td>309603</td>
 <td></td>
 </tr>
 <tr>
 <td>25 ml Erlenmeyer flask</td>
 <td>Fischer</td>
 <td>FB50025</td>
 <td></td>
 </tr>
 <tr>
 <td>Nylon mesh filter </td>
 <td>Nitex</td>
 <td>03-150/38</td>
 <td>150 &mu;m pore size</td>
 </tr>
 <tr>
 <td>48 well tissue culture plate</td>
 <td>Costar</td>
 <td>3548</td>
 <td></td>
 </tr>
 <tr>
 <td>96 well tissue culture plate </td>
 <td>Costar</td>
 <td>3795</td>
 <td></td>
 </tr>
 <tr>
 <td>6 well tissue culture plate</td>
 <td>Costar</td>
 <td>3506</td>
 <td></td>
 </tr>
 <tr>
 <td>Liquid nitrogen</td>
 <td>Matheson Gas</td>
 <td>7727-37-9</td>
 <td></td>
 </tr>
 <tr>
 <td>Cytotoxicity assay kit</td>
 <td>Promega</td>
 <td>G1782</td>
 <td></td>
 </tr>
 <tr>
 <td>Adeno-GFP</td>
 <td>N/A</td>
 <td>N/A</td>
 <td>Gift from J. Williams</td>
 </tr>
 <tr>
 <td></td>
 <td></td>
 <td></td>
 <td>Equipment</td>
 </tr>
 <tr>
 <td>Ring stand with clamps</td>
 <td>United Scientific</td>
 <td>SET462</td>
 <td></td>
 </tr>
 <tr>
 <td>Perifusion chamber</td>
 <td>N/A</td>
 <td>N/A</td>
 <td>Designed by S.Z.H and colleagues at Yale University</td>
 </tr>
 <tr>
 <td>Vacuum line</td>
 <td>Manostat</td>
 <td>72-100-000</td>
 <td></td>
 </tr>
 <tr>
 <td>Water bath with shaker</td>
 <td>Precision Scientific</td>
 <td>51220076</td>
 <td></td>
 </tr>
 <tr>
 <td>Confocal microscope</td>
 <td>Zeiss</td>
 <td>LSM 710</td>
 <td></td>
 </tr>
 <tr>
 <td>BioTek Synergy H1 plate reader</td>
 <td>BioTek</td>
 <td>11-120-534</td>
 <td></td>
 </tr>
 <tr>
 <td>Tissue culture hood</td>
 <td>Nuaire</td>
 <td>NU-425-600</td>
 <td></td>
 </tr>
 <tr>
 <td>Tissue culture Incubator</td>
 <td>Thermo</td>
 <td>3110</td>
 <td></td>
 </tr>
 </tbody>
</table>

preparation of pancreatic acinar cells for the purpose of calcium imaging, cell injury measurements, and adenoviral infection

The pancreatic acinar cell is the main parenchymal cell of the exocrine pancreas and plays a primary role in the secretion of pancreatic enzymes into the pancreatic duct. It is also the site for the initiation of pancreatitis. Here we describe how acinar cells are isolated from whole pancreas tissue and intracellular calcium signals are measured. In addition, we describe the techniques of transfecting these cells with adenoviral constructs, and subsequently measuring the leakage of lactate dehydrogenase, a marker of cell injury, during conditions that induce acinar cell injury in vitro. These techniques provide a powerful tool to characterize acinar cell physiology and pathology.

An example of acinar cell calcium measurements in response to physiologic stimuli is provided in Figure 3. Acinar cells were loaded with the calcium dye Fluo-4 and perfused with the acetylcholine analogue carbachol (CCh; 1 &mu;M)) 8. Cells responded in the form of a calcium wave which initiates in the apical region and propagates to the basolateral region 3,9. Representative tracings shown in Figure 3B demonstrate the typical peak-plateau pattern commonly observed w...

Watch this Scientific Journal Video about Preparation of Pancreatic Acinar Cells for the Purpose of Calcium Imaging, Cell Injury Measurements, and Adenoviral Infection at JoVE.com

Preparation of Pancreatic Acinar Cells for the Purpose of Calcium Imaging, Cell Injury Measurements, and Adenoviral Infection

We describe a reproducible method of preparing mouse pancreatic acinar cells from a mouse for the purpose of examining acinar cell calcium signals and cellular injury with physiologically and pathologically relevant stimuli. A method for adenoviral infection of these cells is also provided.

The pancreatic acinar  cell is the main parenchymal cell of the exocrine pancreas and plays a primary  role in the secretion of pancreatic enzymes into ...

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Research

JoVE Journal

Biology

Isolation and Culture of Mouse Primary Pancreatic Acinar Cells

This protocol permits rapid isolation (in less than 1 hr) of murine pancreatic acini, making it possible to maintain them in culture for more than one week. More than 20 x 106 acinar cells can be obtained from a single murine pancreas. This protocol offers the possibility to independently process as many as 10 pancreases in parallel. Because it preserves acinar architecture, this model is well suited for studying the physiology of the exocrine pancreas in vitro in contrast to cell lines established from pancreatic tumors, which display many genetic alterations resulting in partial or total loss of their acinar differentiation.

In this publication, we describe a rapid and convenient procedure for isolating and culturing primary pancreatic acinar cells from the murine pancreas. This method constitutes a valuable approach to study the physiology of fresh primary normal/untransformed exocrine pancreatic cells.

This protocol permits rapid isolation (in less than 1 hr) of murine pancreatic acini, making it possible to maintain them in culture for more than one ...

Imaging Cell Membrane Injury and Subcellular Processes Involved in Repair

The ability of injured cells to heal is a fundamental cellular process, but cellular and molecular mechanisms involved in healing injured cells are poorly understood. Here assays are described to monitor the ability and kinetics of healing of cultured cells following localized injury. The first protocol describes an end point based approach to simultaneously assess cell membrane repair ability of hundreds of cells. The second protocol describes a real time imaging approach to monitor the kinetics of cell membrane repair in individual cells following localized injury with a pulsed laser. As healing injured cells involves trafficking of specific proteins and subcellular compartments to the site of injury, the third protocol describes the use of above end point based approach to assess one such trafficking event (lysosomal exocytosis) in hundreds of cells injured simultaneously and the last protocol describes the use of pulsed laser injury together with TIRF microscopy to monitor the dynamics of individual subcellular compartments in injured cells at high spatial and temporal resolution. While the protocols here describe the use of these approaches to study the link between cell membrane repair and lysosomal exocytosis in cultured muscle cells, they can be applied as such for any other adherent cultured cell and subcellular compartment of choice.

The process of healing injured cells involves trafficking of specific proteins and subcellular compartments to the site of cell membrane injury. This protocol describes assays to monitor these processes.

The ability of injured cells to heal is a fundamental cellular process, but cellular and molecular mechanisms involved in healing injured cells are poorly ...

Live Cell Imaging of Primary Rat Neonatal Cardiomyocytes Following Adenoviral and Lentiviral Transduction Using Confocal Spinning Disk Microscopy

Primary rat neonatal cardiomyocytes are useful in basic in vitro cardiovascular research because they can be easily isolated in large numbers in a single procedure. Due to advances in microscope technology it is relatively easy to capture live cell images for the purpose of investigating cellular events in real time with minimal concern regarding phototoxicity to the cells. This protocol describes how to take live cell timelapse images of primary rat neonatal cardiomyocytes using a confocal spinning disk microscope following lentiviral and adenoviral transduction to modulate properties of the cell. The application of two different types of viruses makes it easier to achieve an appropriate transduction rate and expression levels for two different genes. Well focused live cell images can be obtained using the microscope&#8217;s autofocus system, which maintains stable focus for long time periods. Applying this method, the functions of exogenously engineered proteins expressed in cultured primary cells can be analyzed. Additionally, this system can be used to examine the functions of genes through the use of siRNAs as well as of chemical modulators.

This protocol describes a method of live cell imaging using primary rat neonatal cardiomyocytes following lentiviral and adenoviral transduction using confocal spinning disk microscopy. This enables detailed observations of cellular processes in living cardiomyocytes.

Primary rat neonatal cardiomyocytes are useful in basic in vitro cardiovascular research because they can be easily isolated in large numbers in a single ...

Assessing the Secretory Capacity of Pancreatic Acinar Cells

Pancreatic acinar cells produce and secrete digestive enzymes. These cells are organized as a cluster which forms and shares a joint lumen. This work demonstrates how the secretory capacity of these cells can be assessed by culture of isolated acini. The setup is advantageous since isolated acini, which retain many characteristics of the intact exocrine pancreas can be manipulated and monitored more readily than in the whole animal. Proper isolation of pancreatic acini is a key requirement so that the ex&#160;vivo culture will represent the in&#160;vivo nature of the acini. The protocol demonstrates how to isolate intact acini from the mouse pancreas. Subsequently, two complementary methods for evaluating pancreatic secretion are presented. The amylase secretion assay serves as a global measure, while direct imaging of pancreatic secretion allows the characterization of secretion at a sub-cellular resolution. Collectively, the techniques presented here enable a broad spectrum of experiments to study exocrine secretion.

Isolated pancreatic acini retain their in&#160;vivo morphology and activity and offer powerful ways for monitoring and manipulating secretion. This work demonstrates how acini can be isolated from the mouse pancreas, and how their secretory capacities can be assessed.

Pancreatic acinar cells produce and secrete digestive enzymes. These cells are organized as a cluster which forms and shares a joint lumen. This work ...

Cytosolic Calcium Measurements in Renal Epithelial Cells by Flow Cytometry

A variety of cellular processes, both physiological and pathophysiological, require or are governed by calcium, including exocytosis, mitochondrial function, cell death, cell metabolism and cell migration to name but a few. Cytosolic calcium is normally maintained at low nanomolar concentrations; rather it is found in high micromolar to millimolar concentrations in the endoplasmic reticulum, mitochondrial matrix and the extracellular compartment. Upon stimulation, a transient increase in cytosolic calcium serves to signal downstream events. Detecting changes in cytosolic calcium is normally performed using a live cell imaging set up with calcium binding dyes that exhibit either an increase in fluorescence intensity or a shift in the emission wavelength upon calcium binding. However, a live cell imaging set up is not freely accessible to all researchers. Alternative detection methods have been optimized for immunological cells with flow cytometry and for non-immunological adherent cells with a fluorescence microplate reader. Here, we describe an optimized, simple method for detecting changes in epithelial cells with flow cytometry using a single wavelength calcium binding dye. Adherent renal proximal tubule epithelial cells, which are normally difficult to load with dyes, were loaded with a fluorescent cell permeable calcium binding dye in the presence of probenecid, brought into suspension and calcium signals were monitored before and after addition of thapsigargin, tunicamycin and ionomycin.

Calcium is involved in numerous physiological and pathophysiological signaling pathways. Live cell imaging requires specialized equipment and can be time consuming. A quick, simple method using a flow cytometer to determine relative changes in cytosolic calcium in adherent epithelial cells brought into suspension was optimized.

A variety of cellular processes, both physiological and pathophysiological, require or are governed by calcium, including exocytosis, mitochondrial ...

Nephrotoxin Microinjection in Zebrafish to Model Acute Kidney Injury

The kidneys are susceptible to harm from exposure to chemicals they filter from the bloodstream. This can lead to organ injury associated with a rapid decline in renal function and development of the clinical syndrome known as acute kidney injury (AKI). Pharmacological agents used to treat medical circumstances ranging from bacterial infection to cancer, when administered individually or in combination with other drugs, can initiate AKI. Zebrafish are a useful animal model to study the chemical effects on renal function in vivo, as they form an embryonic kidney comprised of nephron functional units that are conserved with higher vertebrates, including humans. Further, zebrafish can be utilized to perform genetic and chemical screens, which provide opportunities to elucidate the cellular and molecular facets of AKI and develop therapeutic strategies such as the identification of nephroprotective molecules. Here, we demonstrate how microinjection into the zebrafish embryo can be utilized as a paradigm for nephrotoxin studies.

Renal injuries incurred from nephrotoxins, which include drugs ranging from antibiotics to chemotherapeutics, can result in complex disorders whose pathogenesis remains incompletely understood. This protocol demonstrates how zebrafish can be used for disease modeling of these conditions, which can be applied to the identification of renoprotective measures.

The kidneys are susceptible to harm from exposure to chemicals they filter from the bloodstream. This can lead to organ injury associated with a rapid ...

Cystometric and External Urethral Sphincter Measurements in Awake Rats with Implanted Catheter and Electrodes Allowing for Repeated Measurements

Lower urinary tract function is mainly assessed by means of cystometric bladder function analysis in rodents. Conventional cystometries are usually performed as terminal analysis under urethane anesthesia. It is well known that anesthetic drugs can influence bladder function. Hence, the aim of this technique is to perform cystometric measurements of the urinary bladder and external urethral sphincter in lightly restrained awake rats. For this purpose, a bladder catheter is implanted into the bladder dome. Subsequently, two electrodes are implanted bilateral to the external urethral sphincter and a ground electrode is sutured to a non-responsive skeletal muscle. The bladder catheter and the three electrodes are finally tunneled subcutaneously to the neck region and affixed to a harness. With this technique, the lower urinary tract can be measured at multiple time points in the same animal to assess lower urinary tract function. The main application of this technique is the follow-up of simultaneous urinary bladder and external urethral sphincter function in awake healthy rats and after induction of a disease or injury. Moreover, subsequent lower urinary tract monitoring can be performed during evaluation of the disease/injury and to monitor treatment efficacy.

This protocol first describes the surgical procedure of the permanent implantation of a urinary bladder catheter combined with external urethral sphincter electrodes, and second, the measurement of the function of the urinary bladder and external urethral sphincter in implanted awake animals.

Lower urinary tract function is mainly assessed by means of cystometric bladder function analysis in rodents. Conventional cystometries are usually ...

Micromanipulation Techniques Allowing Analysis of Morphogenetic Dynamics and Turnover of Cytoskeletal Regulators

Examining the spatiotemporal dynamics of proteins can reveal their functional importance in various contexts. In this article, it is discussed how fluorescent recovery after photobleaching (FRAP) and photoactivation techniques can be used to study the spatiotemporal dynamics of proteins in subcellular locations. We also show how these techniques enable straightforward determination of various parameters linked to actin cytoskeletal regulation and cell motility. Moreover, the microinjection of cells is additionally described as an alternative treatment (potentially preceding or complementing the aforementioned photomanipulation techniques) to trigger instantaneous effects of translocated proteins on cell morphology and function. Micromanipulation such as protein injection or local application of plasma membrane-permeable drugs or cytoskeletal inhibitors can serve as powerful tool to record immediate consequences of a given treatment on cell behavior at the single cell and subcellular level. This is exemplified here by immediate induction of lamellipodial cell edge protrusion by the injection of recombinant Rac1 protein, as established a quarter-century ago. In addition, we provide a protocol for determining the turnover of enhanced green fluorescent protein (EGFP)-VASP, an actin filament polymerase prominently accumulating at lamellipodial tips of B16-F1 cells, employing FRAP and including associated data analysis and curve fitting. We also present guidelines for estimating the rates of lamellipodial actin network polymerization, as exemplified by cells expressing EGFP-tagged &#946;-actin. Finally, instructions are given for how to investigate the rates of actin monomer mobility within the cell cytoplasm, followed by actin incorporation at sites of rapid filament assembly, such as the tips of protruding lamellipodia, using photoactivation approaches. None of these protocols is&#160;restricted to components or regulators of the actin cytoskeleton, but can easily be extended to explore in analogous fashion the spatiotemporal dynamics and function of proteins in various different subcellular structures or functional contexts.

We describe how micro- and photomanipulation techniques such as FRAP and photoactivation enable the determination of motility parameters and the spatiotemporal dynamics of proteins within migrating cells. Experimental readouts include subcellular dynamics and turnover of motility regulators or of the underlying actin cytoskeleton.

Examining the spatiotemporal dynamics of proteins can reveal their functional importance in various contexts. In this article, it is discussed how ...

Analysis of Beta-cell Function Using Single-cell Resolution Calcium Imaging in Zebrafish Islets

Pancreatic beta-cells respond to increasing blood glucose concentrations by secreting the hormone insulin. The dysfunction of beta-cells leads to hyperglycemia and severe, life-threatening consequences. Understanding how the beta-cells operate under physiological conditions and what genetic and environmental factors might cause their dysfunction could lead to better treatment options for diabetic patients. The ability to measure calcium levels in beta-cells serves as an important indicator of beta-cell function, as the influx of calcium ions triggers insulin release. Here we describe a protocol for monitoring the glucose-stimulated calcium influx in zebrafish beta-cells by using GCaMP6s, a genetically encoded sensor of calcium. The method allows monitoring the intracellular calcium dynamics with single-cell resolution in ex vivo mounted islets. The glucose-responsiveness of beta-cells within the same islet can be captured simultaneously under different glucose concentrations, which suggests the presence of functional heterogeneity among zebrafish beta-cells. Furthermore, the technique provides high temporal and spatial resolution, which reveals the oscillatory nature of the calcium influx upon glucose stimulation. Our approach opens the doors to use the zebrafish as a model to investigate the contribution of genetic and environmental factors to beta-cell function and dysfunction.

Beta-cell functionality is important for blood-glucose homeostasis, which is evaluated at single-cell resolution using a genetically encoded reporter for calcium influx.

Pancreatic beta-cells respond to increasing blood glucose concentrations by secreting the hormone insulin. The dysfunction of beta-cells leads to ...

Imaging Calcium Dynamics in Subpopulations of Mouse Pancreatic Islet Cells

Pancreatic islet hormones regulate blood glucose homeostasis. Changes in blood glucose induce oscillations of cytosolic calcium in pancreatic islet cells that trigger secretion of three main hormones: insulin (from &#946;-cells), glucagon (&#945;-cells) and somatostatin (&#948;-cells). &#946;-Cells, which make up the majority of islet cells and are electrically coupled to each other, respond to the glucose stimulus as one single entity. The excitability of the minor subpopulations, &#945;-cells and &#948;-cells (making up around 20% (30%) and 4% (10%) of the total rodent1 (human2) islet cell numbers, respectively) is less predictable and is therefore of special interest.
Calcium sensors are delivered into the peripheral layer of cells within the isolated islet. The islet or a group of islets is then immobilized and imaged using a fluorescence microscope. The choice of the imaging mode is between higher throughput (wide-field) and better spatial resolution (confocal). Conventionally, laser scanning confocal microscopy is used for imaging tissue, as it provides the best separation of the signal between the neighboring cells. A wide-field system can be utilized too, if the contaminating signal from the dominating population of &#946;-cells is minimized.
Once calcium dynamics in response to specific stimuli have been recorded, data are expressed in numerical form as fluorescence intensity vs. time, normalized to the initial fluorescence and baseline-corrected, to remove the effects linked to bleaching of the fluorophore. Changes in the spike frequency or partial area under the curve (pAUC) are computed vs. time, to quantify the observed effects. pAUC is more sensitive and quite robust whereas spiking frequency provides more information on the mechanism of calcium increase.
Minor cell subpopulations can be identified using functional responses to marker compounds, such as adrenaline and ghrelin, that induce changes in cytosolic calcium in a specific populations of islet cells.

Here, we present a protocol for imaging and quantifying calcium dynamics in heterogeneous cell populations, such as pancreatic islet cells. Fluorescent reporters are delivered into the peripheral layer of cells within the islet, which is then immobilized and imaged, and per-cell analysis of the dynamics of fluorescence intensity is performed.

Pancreatic islet hormones regulate blood glucose homeostasis. Changes in blood glucose induce oscillations of cytosolic calcium in pancreatic islet cells ...