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 adding 1.1 mg/ml (200 Units/ml) type-4 collagenase and 1 mg/ml soybean trypsin inhibitor to 6 ml of BSA incubation buffer (described above).</li>
	<li>Acid-wash 22x22 mm coverslips by immersing in two parts HNO3 and one part HCl for 2 hr. Then decant using DI water and store in 70% ethanol.</li>
	<li>Euthanize one mouse by CO2 asphyxiation. Orient the animal in the supine position, and prepare the abdominal surface by cleaning with 70% ethanol. Perform a laparotomy to expose the abdominal cavity. Dissect out the pancreas and immediately rinse in a small weigh boat containing 6 ml of collagenase digestion buffer.</li>
	<li>Dissect away any large pieces of fat or visible blood vessels, then remove 5 ml of collagenase digestion buffer and add it back to the 15 ml conical tube.</li>
	<li>Using fine dissection scissors mince the pancreas in the small weighing boat containing 1 ml of collagenase digestion buffer. Mince until the resulting solution appears evenly dispersed.</li>
	<li>Transfer the minced product to a 125 ml Erlenmeyer plastic flask, and add the remaining 5 ml of collagenase digestion buffer to the container. Make sure the tissue is fully submerged in buffer.</li>
	<li>Place the flask in a 37 &deg;C water bath and shake at 90 rpm for 30 min. During this short period of downtime, prepare calcium activating agonists (e.g. caerulein, carbachol) and rinse the 22x22 mm acid-washed coverslips with DI water. Dry, and then place on top of a flat surface lined by laboratory film.</li>
	<li>After the 30 min digest is complete, transfer the suspension back to the 15 ml conical tube and allow the cells to settle. Carefully pipette out the collagenase digestion buffer and replace with 6 ml of BSA incubation buffer. Vigorously shake the tube by hand for 10 sec in order to disperse the cells into smaller clusters. Immediately upon shaking, remove any large, floating debris from the unsettled media.</li>
	<li>Allow the remaining cells to settle, and exchange the media with fresh BSA incubation buffer.</li>
	<li>Repeat step 1.11 twice, until the suspension is comprised of only small clusters which are only finely visible to the naked eye. The cells should resemble those depicted in Figure 1A (top row).</li>
	<li>Remove the BSA incubation buffer and replace with HEPES incubation buffer.</li>
	<li>Prepare a 750 &mu;M, 100X stock of Fluo-4AM in 10% DMSO.</li>
	<li>Load the cells in the 15 ml conical tube containing the cell suspension and BSA-free HEPES incubation buffer. To do this, add an appropriate volume (1:100 dilution) of the stock solution to the cell suspension. Then plate 500 &mu;l of this suspension onto each 22x22 mm coverslip.</li>
	<li>Keep coverslips in the dark at room temperature. Take the first Ca2+ measurements 30 min after loading. The dye is automatically removed from the medium upon starting the perfusion, which should occur 30 min after dye loading.</li>
</ol>
2. Measuring Calcium in Pancreatic Acinar Cells
<ol>
	<li>Rinse each perfusion set-up with DI water and fill with an appropriate amount of buffer or agonist. Prime each syringe with buffer or agonist to insure proper flow. Clamp syringes to a ring stand approximately 1-2 feet above the microscope stage.</li>
	<li>Use fine tweezers to carefully grasp from its edge one coverslip containing cell suspension. Tilt the coverslip 45&deg;, and allow the excess buffer to run off. Place the coverslip on top of the rubber gasket with the cells on top of the coverslip, and assemble the chamber (Figures 2A and 2B).</li>
	<li>Secure the perfusion chamber to the stage and insert the tubing which contains buffer into the first inlet of the chamber (Figure 2C). Turn the syringe containing buffer on and allow the buffer to perfuse over the entire surface of the coverslip. Once the buffer has reached the opposite end of the chamber, insert a vacuum line into the vacuum inlet. Insert any other tubes (containing agonist, inhibitors, etc.) into their appropriate position along the chamber.</li>
	<li>Visualize the cells using either a 200X or 400X, 1.4 numerical aperture objective and an argon laser to excite the Fluo-4AM dye at a wavelength of 488 nm (Figure 1A, bottom). The power settings of the laser should be adjusted such that the photomultiplier tube (PMT) is not saturated by the emitted light. In addition, the voltage across the PMT needs to be optimized for maximum light detection.</li>
	<li>Long-pass emission signals of &gt; 515 nm are collected at frame speeds of 2-5 sec/frame for visualizing slow oscillatory patterns and 0.2-0.3 sec/frame for visualizing faster, global calcium waves (Figures 3 and 4).</li>
	<li>After imaging is complete, close the syringes and remove all tubing. Disassemble the chamber and repeat steps 2.2-2.4.</li>
	<li>Collect data as numerical values of fluorescence intensity over time and transfer to Image J (software package provided as freeware by the National Institutes of Health and can be found at <a href="http://rsb.info.nih.gov/ij/" target="_blank">http://rsb.info.nih.gov/ij/</a>).</li>
	<li>View real-time cellular images and identify regions of interest (ROIs; i.e. apical, basolateral, nuclear, etc.)</li>
	<li>Acquire fluorescence intensities for these ROIs and represent as fluorescence intensity/baseline fluorescence intensity (i.e. F/F0).</li>
	<li>Generate tracings by plotting F/F0 vs. time. In addition to tracings, representative images are commonly provided and displayed using pseudocolor.</li>
</ol>
3. Preparation of Pancreatic Acinar Cells for Cell Injury Assays
<ol>
	<li>Warm DMEM F-12 media (without phenol red) to 37 &deg;C.</li>
	<li>Add BSA (0.1% w/v final), and HCl (50 &mu;M final) to the DMEM F-12 media.</li>
	<li>Aliquot 50 ml of DMEM into a conical tube.</li>
	<li>Prepare a collagenase buffer by adding 0.5 mg/ml (12 U/ml) of collagenase type IV to 10 ml of supplemented DMEM F-12 media.</li>
	<li>Euthanize one mouse by CO2 asphyxiation. Orient the animal in the supine position, and prepare the abdominal surface by cleaning with 70% ethanol. Perform a laparotomy to expose the abdominal cavity. Dissect out the pancreas and immediately rinse in a small weighing boat containing 6 ml of collagenase buffer.</li>
	<li>Mince the tissue using fine dissection scissors for 3-5 min or until the resulting solution appears evenly dispersed.</li>
	<li>Transfer the minced tissue to a 125 ml Erlenmeyer flask with 5 ml of additional collagenase buffer, then place into a 37 &deg;C water bath with shaking at 90 rpm for 5 min.</li>
	<li>Remove from the shaker, allow cells to briefly settle, and exchange with 5 ml of fresh collagenase buffer. Then incubate for an additional 35 min in a 37 &deg;C water bath with shaking at 90 rpm.</li>
	<li>Vigorously resuspend the digest using a transfer pipette until the suspension appears homogeneous with no obvious cell clumps. Then gently pipette the cell suspension through a pre-wet nylon mesh into a conical flask.</li>
	<li>Vigorously pipette an additional 3 ml of fresh DMEM F-12 media (with collagenase) through the mesh, in order to force through any remaining cells.</li>
	<li>Add another 6-10 ml of DMEM F-12 media and allow the cells to settle for 2-3 min. Repeat this step twice, and remove the supernatant after the final wash.</li>
	<li>Add fresh DMEM F-12 media, resuspend the cells, and plate 500 &mu;l of cell suspension into each well of a 48-well tissue culture plate. The cells should resemble those depicted in Figure 1B.</li>
	<li>Allow the plate to sit in a 37 &deg;C water bath at 90 rpm for 5 min before adding agonists.</li>
	<li>Stimulate the cells with varying agonists for 2-4 hr.</li>
	<li>Tilt the plate at an angle to allow the cells to settle and carefully pipette out an aliquot of media (usually 100 &mu;l) and flash freeze in liquid nitrogen.</li>
	<li>Flash freeze the remaining cell suspension. Flash freezing is not essential for LDH measurements. As an alternative samples can be kept on ice if they will be assayed the same day or stored in -20 &deg;C for long term storage.</li>
</ol>
4. Measuring Lactate Dehydrogenase Leakage
<ol>
	<li>Measure lactate dehydrogenase (LDH) leakage primarily using the reagents and instructions supplied in the Promega CytoTox 96 Non-Radioactive Cytotoxicity Assay kit (see Table of specific reagents and materials).</li>
	<li>Reconstitute the LDH substrate (that is provided in the kit) with 12 ml of assay buffer (also provided).</li>
	<li>Thaw frozen cell suspension and media samples in a water bath at room temperature.</li>
	<li>Plate 50 &mu;l of each media sample in a 96-well plate.</li>
	<li>To the cell suspension, add the necessary volume of 10X lysis buffer so that the final concentration is 1X. Vortex briefly and incubate at 37 &deg;C for 60 min.</li>
	<li>Centrifuge lysed samples at 250 x g for 4 min to pellet cell debris.</li>
	<li>For cell lysates, plate 50 &mu;l of a 1:10 dilution into each well of a 96 well plate.</li>
	<li>Add 50 &mu;l of reconstituted substrate to each well, incubate the plate in the dark at room temperature for 30 min.</li>
	<li>Stop the reaction by adding 50 &mu;l of the stop solution (provided in the kit) to each well.</li>
	<li>Measure absorbance at 490 nm.</li>
	<li>Use the following formulae to calculate %LDH leakage. The optical densities below are corrected by subtracting out a blank OD reading from a well containing only PBS, substrate, and stop solution.</li>
</ol>
LDH in media = (Media OD492) x (media dilution factor) x (vol. of media)*Since it is usually unnecessary to dilute media samples, the dilution factor will most often equal1.
Total LDH = ((Lysate OD490) x (lysate dilution factor) x (vol. in cell suspension))+ ((Media OD490) x (dilution factor) x (vol. of media aliquoted for sampling))
<img alt="Equation 1" fo:src="/files/ftp_upload/50391/50391eq1highres.jpg" src="/files/ftp_upload/50391/50391eq1.jpg" />
5. Infecting Pancreatic Acinar Cells with Adenovirus
<ol>
	<li>Prepare pancreatic acinar cells as described in section 3.</li>
	<li>Following step 3.12, add 107 infectious units (IFUs) of adenovirus to the cell suspension and incubate for 30 min at 37 &deg;C.</li>
	<li>Evenly plate 2 ml of cell suspension in a 6-well plate.</li>
	<li>For most expression constructs, cells should be adequately infected within 18 hr; and for some luciferase constructs, just within 6 hr.</li>
</ol>

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	<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. 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No conflict of interest declared.

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 ...

preparation-pancreatic-acinar-cells-for-purpose-calcium-imaging-cell

Research

JoVE Journal

Biology

13.2K Görüntüleme.  Children's Hospital of Pittsburgh of UPMC. Biz fizyolojik ve patolojik ilgili uyaranlara ile asiner hücre kalsiyum sinyalleri ve hücresel hasarı incelemek amacıyla bir fare fare pankreas asiner hücre hazırlama tekrarlanabilir bir yöntem açıklanmaktadır. Bu hücrelerin, adenoviral enfeksiyon için bir yöntem de sağlanmaktadır.

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

Preparation of Drosophila S2 cells for Light Microscopy

The ideal experimental system would be cheap and easy to maintain, amenable to a variety of techniques, and would be supported by an extensive literature and genome sequence database. Cultured Drosophila S2 cells, the product of disassociated 20-24 hour old embryos1, possess all these properties. Consequently, S2 cells are extremely well-suited for the analysis of cellular processes, including the discovery of the genes encoding the molecular components of the process or mechanism of interest. The features of S2 cells that are most responsible for their utility are the ease with which they are maintained, their exquisite sensitivity to double-stranded (ds)RNA-mediated interference (RNAi), and their tractability to fluorescence microscopy as either live or fixed cells.
S2 cells can be grown in a variety of media, including a number of inexpensive, commercially-available, fully-defined, serum-free media2. In addition, they grow optimally and quickly at 21-24&deg;C and can be cultured in a variety of containers. Unlike mammalian cells, S2 cells do not require a regulated atmosphere, but instead do well with normal air and can even be maintained in sealed flasks.
Complementing the ease of RNAi in S2 cells is the ability to readily analyze experimentally-induced phenotypes by phase or fluorescence microscopy of fixed or live cells. S2 cells grow in culture as a single monolayer but do not display contact inhibition. Instead, cells tend to grow in colonies in dense cultures. At low density, S2 cultures grown on glass or tissue culture-treated plastic are round and loosely-attached. However, the cytology of S2 cells can be greatly improved by inducing them to flatten extensively by briefly culturing them on a surface coated with the lectin, concanavalin A (ConA)3. S2 cells can also be stably transfected with fluorescently-tagged markers to label structures or organelles of interest in live or fixed cells. Therefore, the usual scenario for the microscopic analysis of cells is this: first, S2 cells (which can possess transgenes to express tagged markers) are treated by RNAi to eliminate a target protein(s). RNAi treatment time can be adjusted to allow for differences in protein turn-over kinetics and to minimize cell trauma/death if the target protein is important for viability. Next, the treated cells are transferred to a dish containing a coverslip pre-coated with conA to induce cells to spread and tightly adhere to the glass. Finally, cells are imaged with the researcher's choice of microscopy modes. S2 cells are particularly good for studies requiring extended visualization of live cells since these cells stay healthy at room temperature and normal atmosphere.

Preparation of Drosophila S2 cells for Light Microscopy

Drosophila Schneider (S2) cells are an increasingly popular system for the discovery and functional analysis of genes. Our goal is to describe some of the microscopic techniques that make S2 cells such an increasingly important experimental system.

The ideal experimental system would be cheap and easy to maintain, amenable to a variety of techniques, and would be supported by an extensive literature ...

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 ...

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 ...