Micro-RNA analysis of renal biopsies in human lupus nephritis demonstrates up-regulated miR-422a driving reduction of kallikrein-related peptidase 4.
Nephrol Dial Transplant
; 31(10): 1676-86, 2016 10.
Article
in En
| MEDLINE
| ID: mdl-26546590
ABSTRACT
BACKGROUND:
Aberrancies in gene expression in immune effector cells and in end-organs are implicated in lupus pathogenesis. To gain insights into the mechanisms of tissue injury, we profiled the expression of micro-RNAs in inflammatory kidney lesions of human lupus nephritis (LN).METHODS:
Kidney specimens were from patients with active proliferative, membranous or mixed LN and unaffected control tissue. Micro-RNAs were quantified by TaqMan Low Density Arrays. Bioinformatics was employed to predict gene targets, gene networks and perturbed signaling pathways. Results were validated by transfection studies (luciferase assay, real-time PCR) and in murine LN. Protein expression was determined by immunoblotting and immunohistochemistry.RESULTS:
Twenty-four micro-RNAs were dysregulated (9 up-regulated, 15 down-regulated) in human LN compared with control renal tissue. Their predicted gene targets participated in pathways associated with TGF-ß, kinases, NF-κB, HNF4A, Wnt/ß-catenin, STAT3 and IL-4. miR-422a showed the highest upregulation (17-fold) in active LN and correlated with fibrinoid necrosis lesions (ß = 0.63, P = 0.002). In transfection studies, miR-422a was found to directly target kallikrein-related peptidase 4 (KLK4) mRNA. Concordantly, KLK4 mRNA was significantly reduced in the kidneys of human and murine LN and correlated inversely with miR-422a levels. Immunohistochemistry confirmed reduced KLK4 protein expression in renal mesangial and tubular epithelial cells in human and murine LN.CONCLUSIONS:
KLK4, a serine esterase with putative renoprotective properties, is down-regulated by miR-422a in LN kidney suggesting that, in addition to immune activation, local factors may be implicated in the disease.Key words
Full text:
1
Database:
MEDLINE
Main subject:
Lupus Nephritis
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Kallikreins
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Gene Expression Regulation
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MicroRNAs
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Kidney
Type of study:
Observational_studies
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Prognostic_studies
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Risk_factors_studies
Limits:
Animals
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Humans
Language:
En
Year:
2016
Type:
Article