Testicular hyperthermia induces Unfolded Protein Response signaling activation in spermatocyte

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• 作者：Jung-Hak Kim^a ; ¹ ; Sun-Ji Park^a ; ¹ ; Tae-Shin Kim^b ; Hyo-Jin Park^a ; Junghyung Park^a ; Bo Kyung Kim^a ; Gyeong-Ryul Kim^a ; Jin-Man Kim^c ; Song Mei Huang^c ; Jung-Il Chae^d ; Choon-Keun Park^e ; Dong-Seok Lee^a ; ^{lee1@knu.ac.kr}
• 关键词：Testicular hyperthermia ; Unfolded Protein Response signaling pathway ; ER stress ; Spermatocyte ; Apoptosis
• 刊名：Biochemical and Biophysical Research Communications
• 出版年：2013
• 出版时间：17 May, 2013
• 年：2013
• 卷：434
• 期：4
• 页码：861-866
• 全文大小：1440 K

文摘

The testes of most mammals are sensitive to temperature. To survive and adapt under conditions that promote endoplasmic reticulum (ER) stress such as heat shock, cells have a self-protective mechanism against ER stress that has been termed the ¡°Unfolded Protein Response¡± (UPR). However, the cellular and molecular events underlying spermatogenesis with testicular hyperthermia involved in the UPR signaling pathway under ER stress remain poorly understood. In the present study, we verified that UPR signaling via phospho-eIF2¦Á/ATF4/GADD34, p90ATF6, and phospho-IRE1¦Á/XBP-1 is activated with testicular hyperthermia (43 ¡ãC, 15 min/day) and induced ER stress-mediated apoptosis associated with CHOP, phospho-JNK, and caspase-3 after repetitive periods of hyperthermia. Levels of phospho-eIF2¦Á protein of mouse spermatocytes in the testis were rapidly increased by one cycle of testicular hyperthermia. ATF4/GADD34 and p90ATF6 expression gradually increased and decreased, respectively, with repetitive cycles of hyperthermia. Spliced XBP1 mRNA as a marker of IRE1 activity was increased after one, three cycles of hyperthermia and decreased by five cycles of hyperthermia. Although the levels of anti-apoptotic phospho-JNK (p54) were gradually decreased after three cycles of hyperthermia, CHOP expression was rapidly increased. After five cycles of testicular hyperthermia, the levels of cleaved caspase-3 and TUNEL-positive apoptotic spermatocytes cells were significantly increased. Our data demonstrated that testicular hyperthermia induces UPR signaling and repetitive cycles of hyperthermia lead to apoptosis of spermatocytes in mouse testis. These results suggest a link between the UPR signaling pathway and testicular hyperthermia.