title: Pathological adaptive responses of Schwann cells to endoplasmic reticulum stress in bortezomib-induced peripheral neuropathy.
abstract: Bortezomib, a proteasome inhibitor, has been considered as a promising anticancer drug in the treatment of recurrent multiple myeloma and some solid tumors. The bortezomib-induced peripheral neuropathy (BIPN) is a prominent cause of dose-limiting toxicities after bortezomib treatment. In this study, we found that BIPN in a mouse model is characterized by acute but transient endoplasmic reticulum (ER) damages to Schwann cells. These damaged Schwann cells exhibit abnormal outcomes from healing processes such as the myelination of Remak bundles. A morphometric analysis of polymyelinated Remak bundles revealed that the pathological myelination was not related to the axonal parameters that regulate the normal myelination process during development. In addition, demyelinating macrophages were focally infiltrated within endoneurium of the sciatic nerve. To identify the mechanism underlying these pathologies, we applied a gene microarray analysis to bortezomib-treated primary Schwann cells and verified the changes of several gene expression in bortezomib-treated sciatic nerves. The analysis showed that bortezomib-induced ER stress was accompanied by the activation of several protective molecular chaperones and the down-regulation of myelin gene expression. ER stress inducers such as thapsigargin and bredelfin A also suppressed the mRNA expression of myelin gene P0 at transcriptional levels. In addition, the expression of chemokines such as the macrophage chemoattractants Ccl3 and Cxcl2 was significantly increased in Schwann cells in response to bortezomib and ER stress inducers. Taken together, these observations suggest that the pathological adaptive responses of Schwann cells to bortezomib-induced ER stress may, in part, participate in the development of BIPN.
authors.affiliation: Department of Physiology, Medical Science Research Institute, College of Medicine, Dong-A University, Busan, South Korea.
authors.forename: Yoon Kyung
authors.initials: YK
authors.lastname: Shin
authors.forename: So Young
authors.initials: SY
authors.lastname: Jang
authors.forename: Hyun Kyoung
authors.initials: HK
authors.lastname: Lee
authors.forename: Junyang
authors.initials: J
authors.lastname: Jung
authors.forename: Duk Joon
authors.initials: DJ
authors.lastname: Suh
authors.forename: Su-Yeong
authors.initials: SY
authors.lastname: Seo
authors.forename: Hwan Tae
authors.initials: HT
authors.lastname: Park
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D001369:Axons / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D001897:Boronic Acids / Q000633:toxicity*; D000069286:Bortezomib; D004195:Disease Models, Animal; D004721:Endoplasmic Reticulum / Q000502:physiology*; D005260:Female; D008264:Macrophages / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D009185:Myelin Proteins / Q000235:genetics; D009186:Myelin Sheath / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D020411:Oligonucleotide Array Sequence Analysis; D010525:Peripheral Nerves / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D010523:Peripheral Nervous System Diseases / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology*; D011480:Protease Inhibitors / Q000633:toxicity; D058767:Protein Unfolding / Q000187:drug effects; D011719:Pyrazines / Q000633:toxicity*; D012583:Schwann Cells / Q000187:drug effects / Q000473:pathology / Q000502:physiology*; D013312:Stress, Physiological / Q000187:drug effects / Q000502:physiology*
chemical_list: D001897:Boronic Acids; D009185:Myelin Proteins; D011480:Protease Inhibitors; D011719:Pyrazines; D000069286:Bortezomib