Abstract
Purpose
This study was to investigate the relation between the number of autophagosomes in podocytes and the syndromes of idiopathic membranous nephropathy (IMN) and secondary membranous nephropathy (sMN).
Methods
The pathological changes in the kidney tissues of patients were detected with the hematoxylin and eosin staining, the periodic acid–Schiff reagent treatment, the Masson’s trichrome staining and the immunofluorescence detection (IF). Meanwhile, the autophagosomes in podocyte were analyzed by transmission electron microscopy and the IF assay pointing to LC3-II, an autophagic marker. Clinical data, including age, sex, edema, serum creatinine, estimated glomerular filtration rate, hematuria, urine protein excretion and serum albumin, were collected from in-patient medical records. Finally, the association of podocyte autophagosome numbers with idiopathic membranous nephropathy and secondary membranous nephropathy was studied.
Results
Fewer autophagosomes were observed in podocytes of nephropathy group compared with the control group. Moreover, there was a significant difference in the autophagosome number between the two types of MN and each kind of nephropathy demonstrated distinct characteristics. Although the reduced autophagosome number in the IMN cases was not related to sex, this trend was exacerbated along with the progression from pathological stage I to II. In contrast, fewer autophagosomes were observed in class II and V LN patients compared with the controls, while greater numbers were detected in class III and IV LN patients.
Conclusions
The results indicated that the autophagy participated in the podocyte injury in IMN and sMN and the number of autophagosomes in podocytes was related to the pathological classification.
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Acknowledgments
This study was funded by the National Natural Science Foundation (Grant Number 81641026), the Provincial Foundation Project (Grant number WKJ2013-2-002), the Major Projects of Science and Technology Department of Zhejiang Province (Grant Number 2014C03047-2), the General Project of the Medical and Health of Zhejiang Province(Grant Number 2015KYA025), the Project of Scientific research Foundation of Chinese Medicine (Grant Number 2015ZA011), the Natural Science Foundation of Zhejiang Province (Grant Number LY16H050005) and Zhejiang Provincial Program for the Cultivation of High-level New Health Talent (Grant Number 2013).
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All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and national research committee and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.
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Informed consent was obtained from all individual participants included in the study.
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Jin, J., Zhan, H., Lin, B. et al. Association of podocyte autophagosome numbers with idiopathic membranous nephropathy and secondary membranous nephropathy. Int Urol Nephrol 49, 1025–1031 (2017). https://doi.org/10.1007/s11255-017-1555-5
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DOI: https://doi.org/10.1007/s11255-017-1555-5