Genetic and Pharmacologic Inhibition of the Ca2+ Influx Channel TRPC3 Protects Secretory Epithelia From Ca2+-Dependent Toxicity

doi:10.1053/j.gastro.2011.02.052

Gastroenterology

Volume 140, Issue 7, June 2011, Pages 2107-2115.e4

https://doi.org/10.1053/j.gastro.2011.02.052 Get rights and content

Background & Aims

Excessive Ca²⁺ influx mediates many cytotoxic processes, including those associated with autoimmune inflammatory diseases such as acute pancreatitis and Sjögren syndrome. Transient receptor potential (canonical) channel (TRPC) 3 is a major Ca²⁺ influx channel in pancreatic and salivary gland cells. We investigated whether genetic or pharmacologic inhibition of TRPC3 protects pancreas and salivary glands from Ca²⁺-dependent damage.

Methods

We developed a Ca²⁺-dependent model of cell damage for salivary gland acini. Acute pancreatitis was induced by injection of cerulein into wild-type and Trpc3^−/− mice. Mice were also given the Trpc3-selective inhibitor pyrazole 3 (Pyr3).

Results

Salivary glands and pancreas of Trpc3^−/− mice were protected from Ca²⁺-mediated cell toxicity. Analysis of Ca²⁺ signaling in wild-type and Trpc3^−/− acini showed that Pyr3 is a highly specific inhibitor of Tprc3; it protected salivary glands and pancreas cells from Ca²⁺-mediated toxicity by inhibiting the Trpc3-mediated component of Ca²⁺ influx.

Conclusions

TRPC3-mediated Ca²⁺ influx mediates damage to pancreas and salivary glands. Pharmacologic inhibition of TRPC3 with the highly selective TRPC3 inhibitor Pyr3 might be developed for treatment of patients with acute pancreatitis and Sjögren syndrome.

Section snippets

Materials and Methods

Detailed methods are given in Supplementary Materials and Methods. Only key methods are described in detail here.

Pyr3 Is a Selective Inhibitor of Trpc3

Previous work indicated that Pyr3 is a selective TRPC3 inhibitor because it did not or poorly inhibited other TRPC and TRP channels.²⁸ However, the specificity of Pyr3 for the native TRPC3 was not determined. We use pancreatic and parotid acini from Trpc3^−/− mice to test the selectivity of Pyr3. Preliminary experiments showed that maximal inhibition of receptor-stimulated Ca²⁺ signaling is observed with 3 μmol/L Pyr3, with 10 to 50 μmol/L Pyr3 inhibiting Ca²⁺ signaling to the same extent as 3

Discussion

The present study examined the potential use of a specific Trpc3 inhibitor in the treatment of the autoimmune inflammatory diseases acute pancreatitis and Sjögren syndrome. The first novel finding of the present study is the importance of Trpc3 for salivary secretion. Salivary secretion is a Ca²⁺-mediated process,¹⁸ and Ca²⁺ influx is essential to sustain the secretion. Salivary glands express several TRPC channels, including TRPC1, TRPC3, and TRPC6.²⁰ Deletion of Trpc3 in mice reduced salivary

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: Conflicts of interest The authors disclose no conflicts.

: Funding Supported by the Intramural Research Program of the National Institutes of Health National Institute of Dental and Craniofacial Research/Division of Intramural Research (S.M.), grant Z01-ES-101684 (to L.B.), the Science Research Program of the National Research Foundation of Korea, and the Ministry of Education, Science and Technology grants 2011-0001167 and 2010-0000315 (to D.M.S.).

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Basic—Liver, Pancreas, and Biliary TractGenetic and Pharmacologic Inhibition of the Ca2+ Influx Channel TRPC3 Protects Secretory Epithelia From Ca2+-Dependent Toxicity

Background & Aims

Methods

Results

Conclusions

Section snippets

Materials and Methods

Pyr3 Is a Selective Inhibitor of Trpc3

Discussion

Cell Calcium

Ageing Res Rev

Cell Calcium

Cell Calcium

Am J Pathol

Trends Pharmacol Sci

Cell Calcium

Gastroenterology

Cell Calcium

Cell Calcium

Curr Biol

Cell Calcium

Sleep Med Rev

FEBS Lett

J Biol Chem

Mol Cell

J Biol Chem

Cell Calcium

Cell Calcium

Crosstalk signaling between mitochondrial Ca2+ and ROS

Front Biosci

Pancreatitis: the neglected duct

Gut

Basic—Liver, Pancreas, and Biliary Tract
Genetic and Pharmacologic Inhibition of the Ca²⁺ Influx Channel TRPC3 Protects Secretory Epithelia From Ca²⁺-Dependent Toxicity