著者

Kosei SAKAI Tomohiro YONEZAWA Hideyuki YAMAWAKI Toshifumi OYAMADA

出版者

公益社団法人 日本獣医学会

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.15-0002, (Released:2015-05-18)

被引用文献数

1 4

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Somatostatin receptor 2 (SSTR2) is a negative regulator of cell proliferation in human breast cancer. Since there is little information about SSTR2 in canine mammary gland tumor (MGT), we clarified its distribution and expression level in normal mammary gland, benign MGT and malignant MGT. SSTR2 expression determined by immunohistochemical staining was observed in the cytoplasm of luminal epithelial cells. The intensity was negatively correlated with malignancy: normal tissues and some of the benign tumors had the highest levels, while the malignant tumors had little or no SSTR2 expression. As for the Western blotting, SSTR2 protein level in benign tumors was significantly lower than the normal mammary gland. On the other hand, SSTR2 protein levels in two of three malignant tumors were higher than the other groups. These results suggest that SSTR2 expression alters according to the malignancy of canine MGT.

著者

Yusei FUJIOKA Kosuke OTANI Tomoko KODAMA Muneyoshi OKADA Hideyuki YAMAWAKI

出版者

JAPANESE SOCIETY OF VETERINARY SCIENCE

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

vol.85, no.11, pp.1157-1164, 2023 (Released:2023-11-02)

参考文献数

34

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Cellular senescence is a highly stable state associated with cell cycle arrest, that is elicited in response to various stresses. The accumulation of senescent cells in tissues drives age-related diseases. Recent studies have shown that the cellular senescence enhances an extracellular vesicles (EV) secretion. EV are lipid-bilayer-capsuled particles released by various cells mediating cell-to-cell communication. It was recently reported that EV secreted by the senescent cells had several functions such as cancer cell proliferation and immune cell activation. In the present study, we investigated whether senescent cardiac fibroblasts-derived EV play an autocrine/paracrine role in the heart cells. Neonatal rat cardiac fibroblasts (NRCFs) were treated with doxorubicin (DOX) to induce cellular senescence. EV were isolated from NRCFs culture media. The vehicle-treated NRCFs-derived EV (D0-EV, 72 hr) increased a living cell number in NRCFs, which was attenuated by DOX (1,000 nM)-treated NRCFs-derived EV (D103-EV, 72 hr). While D0-EV did not affect protein concentration in NRCFs, D103-EV decreased it. Furthermore, D103-EV significantly increased a ratio of microtubule-associated protein 1 light chain 3 (LC3)-II to LC3-I in NRCFs, indicating an induction of autophagy. In addition, D103-EV increased phosphorylation of adenosine monophosphate-activated kinase (AMPK) α in NRCFs. In neonatal rat cardiomyocytes, however, NRCFs-derived EV (72 hr) had no effect on the living cell number, protein concentration, and ratio of LC3-II to LC3-I. In conclusion, we for the first time revealed that DOX-induced senescent NRCFs-derived EV induce autophagy in NRCFs perhaps partly through the activation of AMPKα.

著者

Masashi MUKOHDA Tomoka MORITA Muneyoshi OKADA Yukio HARA Hideyuki YAMAWAKI

出版者

公益社団法人 日本獣医学会

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.12-0345, (Released:2012-09-26)

被引用文献数

3 18

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Methylglyoxal (MGO) is a metabolite of glucose and likely related to pathogenesis of diabetes-related vascular complications including hypertension. In this study, long-term effects of MGO on endothelial function were examined. Rat isolated mesenteric artery was treated for 3 days with MGO using an organ culture method. The contractility, morphology, and protein expression of organ-cultured artery were examined. MGO (42 μM, 3 days) impaired acetylcholine (ACh: 1 nM–300 μM)-induced endothelium-dependent relaxation, while it had no effect on sodium nitroprusside (0.1 nM–10 μM)-induced endothelium-independent relaxation. MGO decreased ACh (3 μM)-induced nitric oxide (NO) production as measured by a fluorescence NO indicator, diaminofluorescein-2. Consistently, MGO inhibited ACh (3 μM)-induced phosphorylation of vasodilator stimulated phosphoprotein (an indicator of cyclic GMP production). MGO induced apoptosis in endothelium as detected by TdT-mediated dUTP-biotin nick-end labeling staining. MGO induced accumulation of superoxide in endothelium as detected by dihydroethidium staining. MGO decreased protein expression of endothelial NO synthase (eNOS). Gp91ds-tat (0.1 μM), an inhibitor of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX), prevented the impairment of endothelium-dependent relaxation and the decrease in eNOS protein caused by MGO. The present results demonstrated that long-term MGO treatment impairs endothelium-dependent relaxation through NOX-derived increased superoxide-mediated endothelial apoptosis.