Impact of USP8 Gene Mutations on Protein Deregulation in Cushing Disease

Weigand I, Knobloch L, Flitsch J, Saeger W, Monoranu CM, Höfner K, Herterich S, Rotermund R, Ronchi CL, Buchfelder M, Glatzel M, Hagel C, Fassnacht M, Deutschbein T, Sbiera S (2019)

Publication Type: Journal article

Publication year: 2019

Journal

Journal of Clinical Endocrinology and Metabolism Oxford University Press

Book Volume: 104

Pages Range: 2535-2546

Journal Issue: 7

DOI: 10.1210/jc.2018-02564

Abstract

CONTEXT: Cushing disease (CD) is a rare disorder with severe sequels and incompletely understood pathogenesis. The underlying corticotroph adenomas harbor frequently somatic mutations in the ubiquitin-specific peptidase 8 (USP8) gene. These mutations render USP8 hyperactive and prevent client proteins from degradation. OBJECTIVE: To investigate the impact of USP8 mutations on proteins deregulated in CD. DESIGN: One hundred eight pituitary adenomas (75 corticotroph [58 USP8 wild type (WT) and 17 USP8 mutated], 14 somatotroph, and 19 nonfunctioning) were investigated by immunohistochemistry. All evaluated proteins [USP8, arginine vasopressin receptor 1b and 2, corticotropin-releasing hormone receptor, cAMP response element-binding protein (CREB), p27/kip1, cyclin E, heat shock protein 90 (HSP90), orphan nuclear receptor 4, epidermal growth factor receptor, histone deacetylase 2, glucocorticoid receptor, cyclin-dependent kinase 5 and Abelson murine leukemia viral oncogene homolog 1 enzyme substrate 1] were known to be deregulated in CD. Furthermore, AtT20 cells were transfected with USP8 to investigate the expression of possible downstream proteins by immunoblot. RESULTS: Whereas most of the investigated proteins were not differentially expressed, the cell-cycle inhibitor p27 was significantly reduced in USP8 mutated corticotroph adenoma (H-score 2.0 ± 1.0 vs 1.1 ± 1.1 in WT adenomas; P = 0.004). In contrast, the chaperone HSP90 was expressed higher (0.5 ± 0.4 vs 0.2 ± 0.4; P = 0.29), and the phosphorylation of the transcription factor CREB was increased in USP8 mutated adenomas (1.30.5 ± 0.40.9 vs 0.70.5 ± 0.40.7; P = 0.014). Accordingly, AtT20 cells transfected with the USP8 P720R mutant had higher phosphorylated CREB (pCREB) levels than WT transfected cells (1.3 ± 0.14 vs 1 ± 0.23; P = 0.13). CONCLUSIONS: We could demonstrate that USP8 mutations are associated with deregulation of p27/kip1, HSP90, and pCREB. These findings suggest that these proteins are direct or indirect clients of USP8 and could therefore be potential targets for therapeutic approaches in patients with CD.

Authors with CRIS profile

Michael Buchfelder Lehrstuhl für Neurochirurgie

Involved external institutions

Universitätsklinikum Hamburg-Eppendorf (UKE) DE Germany (DE) Universitätsklinikum Würzburg DE Germany (DE) Julius-Maximilians-Universität Würzburg DE Germany (DE)

How to cite

APA:

Weigand, I., Knobloch, L., Flitsch, J., Saeger, W., Monoranu, C.M., Höfner, K.,... Sbiera, S. (2019). Impact of USP8 Gene Mutations on Protein Deregulation in Cushing Disease. Journal of Clinical Endocrinology and Metabolism, 104(7), 2535-2546. https://dx.doi.org/10.1210/jc.2018-02564

MLA:

Weigand, Isabel, et al. "Impact of USP8 Gene Mutations on Protein Deregulation in Cushing Disease." Journal of Clinical Endocrinology and Metabolism 104.7 (2019): 2535-2546.

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