Hyperlipidemia is involved in apoptosis in rat submandibular glands

Koichiro Irie; Takaaki Tomofuji; Daisuke Ekuni; Tetsuji Azuma; Toshiki Yoneda; Yoshihiro Shimazaki; Manabu Morita

doi:10.1016/j.archoralbio.2017.05.004

Hyperlipidemia is involved in apoptosis in rat submandibular glands

Arch Oral Biol. 2017 Sep:81:136-140. doi: 10.1016/j.archoralbio.2017.05.004. Epub 2017 May 17.

Authors

Koichiro Irie¹, Takaaki Tomofuji², Daisuke Ekuni¹, Tetsuji Azuma¹, Toshiki Yoneda¹, Yoshihiro Shimazaki³, Manabu Morita¹

Affiliations

¹ Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan.
² Department of Community Oral Health, Asahi University School of Dentistry, 1851-1 Hozumi, Mizuho, Gifu 501-0296, Japan. Electronic address: tomofu@dent.asahi-u.ac.jp.
³ Department of Preventive Dentistry and Dental Public Health, Aichi Gakuin University, School of Dentistry, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan.

PMID: 28528308
DOI: 10.1016/j.archoralbio.2017.05.004

Abstract

Objective: The aim of the present study was to investigate the effects of hyperlipidemia on histological changes and apoptosis in submandibular glands using apolipoprotein E (apoE)-deficient rats.

Design: Histopathological findings related to induced apoptosis in the submandibular glands were compared between apoE-deficient rats (n=6; male; age, 16 weeks) and the corresponding wild-type rats (n=6).

Results: ApoE-deficient rats showed significantly higher plasma levels of oxidized low-density lipoprotein (LDL), total cholesterol, very LDL and LDL, and lower plasma levels of high-density lipoprotein when compared to control rats (P<0.05). Lipid deposition in the submandibular gland was observed in apoE-deficient rat group and in none of the control group. Significant increases in vacuolization and apoptosis in acinar cells were observed in apoE-deficient rats, as compared to control rats (P<0.05). The number of active caspase-3-positive cells was also higher in the apoE-deficient rat group when compared with the control group (P<0.01).

Conclusions: According to our results, hyperlipidemia induced apoptosis in apoE-deficient rat submandibular glands. Oxidized LDL generation in case of hyperlipidemia may trigger off a reaction of apoptotic acinar cells with vacuolization in the submandibular glands.

Keywords: Apoptosis; Hyperlipidemia; Rats; Submandibular gland.

MeSH terms

Animals
Apolipoproteins E / deficiency
Apoptosis*
Enzyme-Linked Immunosorbent Assay
Hyperlipidemias / pathology*
In Situ Nick-End Labeling
Lipoproteins, LDL / blood
Male
Rats
Rats, Sprague-Dawley
Submandibular Gland / pathology*

Substances

Apolipoproteins E
Lipoproteins, LDL
oxidized low density lipoprotein