Effect of Cell Adhesion Molecule 1 Expression on Intracellular Granule Movement in Pancreatic α Cells.
Although glucagon secreted from pancreatic α cells plays a role in increasing glucose concentrations in serum, the mechanism regulating glucagon secretion from α cells remains unclear. Cell adhesion molecule 1 (CADM1), identified as an adhesion molecule in α cells, has been reported not only to communicate among α cells and between nerve fibers, but also to prevent excessive glucagon secretion from α cells. Here, we investigated the effect of CADM1 expression on the movement of intracellular secretory granules in α cells because the granule transport is an important step in secretion. Spinning disk microscopic analysis showed that granules moved at a mean velocity of 0.236 ± 0.010 μm/s in the mouse α cell line αTC6 that expressed CADM1 endogenously. The mean velocity was significantly decreased in CADM1-knockdown (KD) cells (mean velocity: 0.190 ± 0.016 μm/s). The velocity of granule movement decreased greatly in αTC6 cells treated with the microtubule-depolymerizing reagent nocodazole, but not in αTC6 cells treated with the actin-depolymerizing reagent cytochalasin D. No difference in the mean velocity was observed between αTC6 and CADM1-KD cells treated with nocodazole. These results suggest that intracellular granules in pancreatic α cells move along the microtubule network, and that CADM1 influences their velocity.
Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan.|School of Pharmacy, Aichi Gakuin University, Nagoya, Japan.
Satoru
S
Yokawa
School of Pharmacy, Aichi Gakuin University, Nagoya, Japan.
Tadahide
T
Furuno
School of Dentistry, Aichi Gakuin University, Nagoya, Japan.
Takahiro
T
Suzuki
School of Pharmacy, Aichi Gakuin University, Nagoya, Japan.
Yoshikazu
Y
Inoh
Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan.
Ryo
R
Suzuki
Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan. hirashim@phar.nagoya-cu.ac.jp.
Naohide
http://orcid.org/0000-0002-3652-5250
N
Hirashima
D000818:Animals; D015153:Blotting, Western; D000075982:Cell Adhesion Molecule-1; D015815:Cell Adhesion Molecules / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D005089:Exocytosis / Q000187:drug effects; D050416:Glucagon-Secreting Cells / Q000187:drug effects / Q000378:metabolism*; D007136:Immunoglobulins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018613:Microscopy, Confocal; D018715:Microscopy, Video; D015739:Nocodazole / Q000494:pharmacology; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism
C498598:Cadm1 protein, mouse; D000075982:Cell Adhesion Molecule-1; D015815:Cell Adhesion Molecules; D007136:Immunoglobulins; D034741:RNA, Small Interfering; D015739:Nocodazole
Cell adhesion molecule 1; Granule movement; Microtubule; Pancreatic α cell; Spinning disk microscopy