Calpain-Mediated Cleavage of Calcineurin in Puromycin Aminonucleoside-Induced Podocyte Injury.

The calcineurin inhibitors cyclosporine A (CsA) and tacrolimus are widely used in the treatment of proteinuria diseases. As the direct target of these drugs, calcineurin has previously been demonstrated to play a role in proteinuria diseases. However, aside from its immune-related effects, the local...

Full description

Bibliographic Details
Main Authors: Fangrui Ding, Xuejuan Li, Baihong Li, Jifan Guo, Yanqin Zhang, Jie Ding
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2016-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC4865207?pdf=render
_version_ 1811319917492830208
author Fangrui Ding
Xuejuan Li
Baihong Li
Jifan Guo
Yanqin Zhang
Jie Ding
author_facet Fangrui Ding
Xuejuan Li
Baihong Li
Jifan Guo
Yanqin Zhang
Jie Ding
author_sort Fangrui Ding
collection DOAJ
description The calcineurin inhibitors cyclosporine A (CsA) and tacrolimus are widely used in the treatment of proteinuria diseases. As the direct target of these drugs, calcineurin has previously been demonstrated to play a role in proteinuria diseases. However, aside from its immune-related effects, the local status of calcineurin in renal inherent cells has not been fully explored in the settings of proteinuria disease and podocyte injury. In this study, calcineurin activity and protein expression in the well-known puromycin aminonucleoside (PAN)-induced podocyte injury model were examined. Interestingly, we found that calcineurin activity was abnormally increased in PAN-treated podocytes, whereas the expression of the full-length 60-kDa calcineurin protein was decreased. This result suggests that there may be another activated form of calcineurin that is independent of the full-length phosphatase. To investigate whether calpain is involved in regulating calcineurin, we exposed PAN-treated podocytes to both pharmacological inhibitors of calpain and specific siRNAs against calpain. Calpain blockade reduced the enhanced calcineurin activity and restored the down-regulated expression of 60-kDa calcineurin. In addition, purified calpain protein was incubated with podocyte extracts, and a 45-kDa fragment of calcineurin was identified; this finding was confirmed in PAN-induced podocyte injury and calpain inhibition experiments. We conclude that calcineurin activity is abnormally increased during PAN-induced podocyte injury, whereas the expression of the full-length 60-kDa calcineurin protein is down-regulated due to over-activated calpain that cleaves calcineurin to form a 45-kDa fragment.
first_indexed 2024-04-13T12:50:42Z
format Article
id doaj.art-eb3a5ea58b3040149b0daca8adb71dbc
institution Directory Open Access Journal
issn 1932-6203
language English
last_indexed 2024-04-13T12:50:42Z
publishDate 2016-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj.art-eb3a5ea58b3040149b0daca8adb71dbc2022-12-22T02:46:14ZengPublic Library of Science (PLoS)PLoS ONE1932-62032016-01-01115e015550410.1371/journal.pone.0155504Calpain-Mediated Cleavage of Calcineurin in Puromycin Aminonucleoside-Induced Podocyte Injury.Fangrui DingXuejuan LiBaihong LiJifan GuoYanqin ZhangJie DingThe calcineurin inhibitors cyclosporine A (CsA) and tacrolimus are widely used in the treatment of proteinuria diseases. As the direct target of these drugs, calcineurin has previously been demonstrated to play a role in proteinuria diseases. However, aside from its immune-related effects, the local status of calcineurin in renal inherent cells has not been fully explored in the settings of proteinuria disease and podocyte injury. In this study, calcineurin activity and protein expression in the well-known puromycin aminonucleoside (PAN)-induced podocyte injury model were examined. Interestingly, we found that calcineurin activity was abnormally increased in PAN-treated podocytes, whereas the expression of the full-length 60-kDa calcineurin protein was decreased. This result suggests that there may be another activated form of calcineurin that is independent of the full-length phosphatase. To investigate whether calpain is involved in regulating calcineurin, we exposed PAN-treated podocytes to both pharmacological inhibitors of calpain and specific siRNAs against calpain. Calpain blockade reduced the enhanced calcineurin activity and restored the down-regulated expression of 60-kDa calcineurin. In addition, purified calpain protein was incubated with podocyte extracts, and a 45-kDa fragment of calcineurin was identified; this finding was confirmed in PAN-induced podocyte injury and calpain inhibition experiments. We conclude that calcineurin activity is abnormally increased during PAN-induced podocyte injury, whereas the expression of the full-length 60-kDa calcineurin protein is down-regulated due to over-activated calpain that cleaves calcineurin to form a 45-kDa fragment.http://europepmc.org/articles/PMC4865207?pdf=render
spellingShingle Fangrui Ding
Xuejuan Li
Baihong Li
Jifan Guo
Yanqin Zhang
Jie Ding
Calpain-Mediated Cleavage of Calcineurin in Puromycin Aminonucleoside-Induced Podocyte Injury.
PLoS ONE
title Calpain-Mediated Cleavage of Calcineurin in Puromycin Aminonucleoside-Induced Podocyte Injury.
title_full Calpain-Mediated Cleavage of Calcineurin in Puromycin Aminonucleoside-Induced Podocyte Injury.
title_fullStr Calpain-Mediated Cleavage of Calcineurin in Puromycin Aminonucleoside-Induced Podocyte Injury.
title_full_unstemmed Calpain-Mediated Cleavage of Calcineurin in Puromycin Aminonucleoside-Induced Podocyte Injury.
title_short Calpain-Mediated Cleavage of Calcineurin in Puromycin Aminonucleoside-Induced Podocyte Injury.
title_sort calpain mediated cleavage of calcineurin in puromycin aminonucleoside induced podocyte injury
url http://europepmc.org/articles/PMC4865207?pdf=render
work_keys_str_mv AT fangruiding calpainmediatedcleavageofcalcineurininpuromycinaminonucleosideinducedpodocyteinjury
AT xuejuanli calpainmediatedcleavageofcalcineurininpuromycinaminonucleosideinducedpodocyteinjury
AT baihongli calpainmediatedcleavageofcalcineurininpuromycinaminonucleosideinducedpodocyteinjury
AT jifanguo calpainmediatedcleavageofcalcineurininpuromycinaminonucleosideinducedpodocyteinjury
AT yanqinzhang calpainmediatedcleavageofcalcineurininpuromycinaminonucleosideinducedpodocyteinjury
AT jieding calpainmediatedcleavageofcalcineurininpuromycinaminonucleosideinducedpodocyteinjury