DOI: 10.5061/dryad.v6wwpzh6q
title: Secretin targets interstitial cells of Cajal to regulate intestinal motility

description: Secretin plays an important role in gastrointestinal (GI) physiology by
 stimulating bicarbonate and bile secretion to neutralize acidic chyme and
 aid in lipid absorption. Secretin also slows intestinal motility, an
 effect attributed to vagal afferent pathways. In this study, we show
 evidence for a novel function of secretin involving a non-neural mechanism
 mediated by interstitial cells of Cajal (ICC). Secretin receptors (SCTR)
 were found to be abundantly expressed by ICC in the deep muscular plexus
 (ICC-DMP) of the small intestine. Secretin reduced small intestinal
 contractions in the presence of tetrodotoxin (TTX) and suppressed
 cholinergic transmission. Ca2+ imaging demonstrated that the inhibitory
 effects of secretin occur through inhibition of Ca2+ transients in
 ICC-DMP, an effect previously linked to inhibition of intestinal
 contractions. SCTRs are linked to function via Gas, secretin increased
 cAMP levels in ICC-DMP, and responses were inhibited by a selective PKA
 antagonist. Our data suggest that PKA activation is in some way linked to
 inhibition of IP3 receptors, as the robust increase in Ca2+ transients in
 ICC-DMP due to uncaging of IP3 was blocked by secretin. Conclusions from
 these experiments outline a new concept for ICC-DMP: these cells serve as
 a focus point in which signaling from the enteric nervous system and
 hormones converge and integrate mechanisms regulating intestinal motility.
 In the case of secretin, this may result in slowing of intestinal transit
 to enhance digestion and absorption of nutrients.
description: # Secretin targets interstitial cells of Cajal to regulate intestinal
 motility Dataset DOI: [10.5061/dryad.v6wwpzh6q](10.5061/dryad.v6wwpzh6q)
 ## Description of the data and file structure All experimental data
 associated files collected for the paper are organized below:  ### Files
 and variables #### File: README.docx **Description:** Copy of file list as
 a Word table #### File: STMAPS.zip **Description:** The folder contains
 all data associated with calcium imaging experiments.  **Sub-folders:**
 ###### *STMAPS_3Hz_EFS:*
 COLOR_11-6-23_40x_gc6_IM_nicard200nM_EFS3hzcontinuous_20secCNTRL_sct100nM_5min_STMapCell1-1000frames COLOR_11-6-23_40x_gc6_IM_nicard200nM_EFS3hzcontinuous_20secCNTRL_STMapcell1-1000frames ###### *STMAPS_10Hz_EFS:* 81424_40x_gc6kit_dmp_mrs25001uM_lnna100uM_2xstim10sec_1min10sec_10hz10sec_secondBest_STMap1-1after copy 81424_40x_gc6kit_dmp_mrs25001uM_lnna100uM_2xstim10sec_1min10sec_10hz10sec_secondBest_STMap1-1before copy 81424_40x_gc6kit_dmp_mrs25001uM_lnna100uM_2xstim10sec_1min10sec_10hz10sec_secretin100nM3min_STMap1-1after copy 81424_40x_gc6kit_dmp_mrs25001uM_lnna100uM_2xstim10sec_1min10sec_10hz10sec_secretin100nM3min_STMap1-1before copy ***STMAPS_AT7867:*** 8-22-23_GC6fkit_SI_MYIM_20x_30sCNTRL_SCT100nMpuff_STMap2-before copy 8-22-23_GC6fkit_SI_MYIM_20x_30sCNTRL_SCT100nMpuff_STMap2-after copy 8-22-23_GC6fkit_SI_MYIM_20x_30sCNTRL_2ndSCT100nMpuffAT786710uM35min_STMap2-before copy 8-22-23_GC6fkit_SI_MYIM_20x_30sCNTRL_2ndSCT100nMpuffAT786710uM35min_STMap2-after copy ***STMAPS_8bromocAMP_DMP:*** COLOR_2-6-25_40xGkitgc6_SI_IM_nicard300nm_ttx1uM_washoutCNTRL_STMap1-color COLOR_2-6-25_40xGkitgc6_SI_IM_nicard300nm_ttx1uM_8bromo_500uM_3min_afterwash_STMap1-color ***STMAPS_ESI*** COLOR_10-23-23_GC6KI_40x_IM_cntrl30s sct1umpuff_ESI05_10uM30min_STMapIM3-1 copy COLOR_10-23-23_GC6KI_40x_IM_cntrl30s sct1umpuff_ESI05_10uM30min_STMapIM3-withSCT copy ***STMAPS_forskolin_DMP*** 12-8-23_Tissue1_gc6KI_40x_cntrl_dmp_STMap_1 copy 12-8-23_Tissue1_gc6KI_40x_fsk20nM_2min_dmp_STMap1 copy ***STMAPS_secretin_DMP*** 11-6-23_40x_gc6_IMMY_nicard200nM_sctpuff_35scntrl__STMapIM copy 11-6-23_40x_gc6_IMMY_nicard200nM_sctpuff_35scntrl__STMapIM-AFTER copy ***STMAPS_secretin_MY*** 11-6-23_40x_gc6_IMMY_nicard200nM_sctpuff_35scntrl__STMapIM-BEFORE copy 11-6-23_40x_gc6_IMMY_nicard200nM_sctpuff_35scntrl__STMapMY1-AFTER copy ***STMAPS_Secretin_nominalCalcium_DMP_MY*** color_1-23-23_gc6f_SI_IM_cntrl_STMap copy color1-23-23_gc6f_SI_IM_cntrl0ca_STMap copy color_1-23-23_gc6f_SI_IM_0ca_secretin100nM3min_STMap-1 copy color_1-23-23_gc6f_SI_MY_cntrl_STMap copy color_1-23-23_gc6f_SI_MY_cntrl0ca_STMap copy color_1-23-23_gc6f_SI_MY_0ca_secretin100nM3min_STMap-1 copy ***STMAPS_secretin_TTX_DMP*** 12-11-24_AREA3_40x_kitGC_duod_IMMY_TTX1uM_Cntrl_STMapIM1 copy 12-11-24_AREA3_40x_kitGC_duod_IMMY_TTX1uM_secretin100nM5min_STMapIM1 copy GC6kit_Small Intestine_100nM Nicardipine_1uM TTX 15 min_20x_STMapIM1 copy GC6kit_Small Intestine_100nM Nicardipine_1uM TTX \_Secritin 100nM 3 Min_20x_STMapIM1 copy ***STMAPS_secretin_TTX_MY*** 12-11-24_AREA3_40x_kitGC_duod_IMMY_TTX1uM_Cntrl_STMapMY1-500frames 12-11-24_AREA3_40x_kitGC_duod_IMMY_TTX1uM_secretin100nM5min_STMapMY1-500frames GC6kit_Small Intestine_100nM Nicardipine_1uM TTX 15 min_20x_STMapMY1 copy GC6kit_Small Intestine_100nM Nicardipine_1uM TTX \_Secritin 100nM 3 Min_20x_STMapMY1 copy ***STMAPS_CagedIP3_*** DMP COLOR_4-9-24_Area7_60x_gc6kit_cagedIp3_SI_dmp_20sCNTRL_10pwrPulse_x10_50sec_repeat_cntrl_STMap COLOR_4-9-24_Area6_60x_gc6kit_cagedIp3_SI_dmp_27sCNTRL_10pwrPulse_x10_53sec_repeat_sct100nM_4min_STMap ***STMAPS_Thapsigargin*** 10-31-23_40x_si_nicard200nM_IMMY_30scntrl_thapsigargin10uM20min_sctpuff1uM_STMapIM-BEFORE copy 10-31-23_40x_si_nicard200nM_IMMY_30scntrl_thapsigargin10uM20min_sctpuff1uM_STMapIM-AFTER copy 10-31-23_40x_si_nicard200nM_IMMY_30scntrl_thapsigargin10uM20min_sctpuff1uM_STMapMY-BEFORE copy 10-31-23_40x_si_nicard200nM_IMMY_30scntrl_thapsigargin10uM20min_sctpuff1uM_STMapMY-AFTER copy #### File: PRISM_FILES.zip Description: Analysis files for all experimental data. Sub-folders: **SECRETIN_CONTRACTION_mouse** All secretin contraction analysis small intestine with and without TTX (1uM). **CONTRACTION_secretin_MONKEY** All secretin contraction analysis small intestine with and without TTX (1uM) in monkey. **DRYAD_RNAScope** Analysis for RNAScope Sctr immunohistochemistry. **IMAGING__Secretin** Analysis for imaging with and without Secretin (100nM) in ICC-DMP and ICC-MY GCaMP6f-kitiCre. **EFS_IMAGING__Secretin** Analysis for imaging with and without Secretin (100nM) in ICC-DMP GCaMP6f-kitiCre for EFS experiments. **SECRETIN_CONTRACTION_mouse_CCh** All secretin contraction analysis small intestine with CCh. **DRYAD__CAGEDIP3** Analysis for Caged IP3 imaging with and without secretin (100nM) in ICC-DMP GCaMP6f-kitiCre. **nominalCa_IMAGING__Secretin** Analysis for imaging with and without Secretin (100nM) in ICC-DMP GCaMP6f-kitiCre for nominal Ca2+ experiments. **CONTRACTION_DREADD_Gs_SI** All contraction analysis in small intestine DREADD-Gs-KitiCre mice. **CONTRACTION_FORSKOLIN_8bromocAMP** All forskolin and 8-bromo-cAMP contraction analysis small intestine with and without TTX (1uM). **DRYAD_cAMP_IMAGING_** Analysis for imaging with and without Forskolin (20nM) and 8-bromo-cAMP (500nM) in ICC-DMP GCaMP6f-kitiCre. **DRYAD_IMAGING_KitiCre-CAMPER** Analysis for imaging with and without Secretin (100nM), Forskolin (1uM) and DMSO vehicle in ICC-DMP kitiCre-CAMPER. **CONTRACTION_AT7867** All secretin contraction analysis small intestine with AT7867(10uM) in the presence of TTX(1uM). **AT7867_IMAGING__Secretin** Analysis for imaging with and without Secretin (100nM) in the presence of AT7867 (10uM) ICC-DMP GCaMP6f-kitiCre in the presence of TTX(1uM). **CONTRACTION_ESI-05_** All secretin contraction analysis small intestine with ESI-05(10uM) in the presence of TTX(1uM). **ESI_IMAGING__Secretin** Analysis for imaging with and without Secretin (100nM) in the presence of ESI-05 (10uM) ICC-DMP GCaMP6f-kitiCre in the presence of TTX(1uM). **CONTRACTION_Secretin_5nM10nM** All secretin contraction analysis small intestine for 5nM and 10nM concentrations in the presence of TTX(1uM). **CONTRACTION_Secretin_washout** All secretin contraction analysis small intestine with washout data in the presence of TTX(1uM). #### File: IMMUNO.zip **Description:** Data images of immunohistochemistry data. ***Sub-folders:*** ***CAMPER-Kiticre*** Immunohistochemistry, Small intestine, 20x. Mscfr-594; GFP-488; DAPI ***DREADDGs-kiticre*** Immunohistochemistry, small intestine, 20x, 60x. Mscfr-594; GFP-488; DAPI ***RNAScope_SCTR*** RNAScope Sctr immunohistochemistry, small intestine, 20x, 60x. Mscfr-488; RNA probe (Sctr)-594 ## Code/software Fiji software is needed to visualize images and STMAPS:  [Fiji: ImageJ, with "Batteries Included"](https://fiji.sc/)