Research Paper Volume 8, Issue 3 pp 484—505

MicroRNA-15b regulates mitochondrial ROS production and the senescence-associated secretory phenotype through sirtuin 4/SIRT4

Alexander Lang 1, 5, *, , Susanne Grether-Beck 2, *, , Madhurendra Singh 1, *, , Fabian Kuck 1, , Sascha Jakob 2, , Andreas Kefalas 1, , Simone Altinoluk-Hambüchen 1, , Nina Graffmann 3, , Maren Schneider 2, , Antje Lindecke 4, , Heidi Brenden 2, , Ingo Felsner 2, , Hakima Ezzahoini 1, , Alessandra Marini 2, , Sandra Weinhold 3, , Andrea Vierkötter 2, , Julia Tigges 2, , Stephan Schmidt 1, , Kai Stühler 5, , Karl Köhrer 4, , Markus Uhrberg 3, , Judith Haendeler 2, , Jean Krutmann 2, 6, #, , Roland P. Piekorz 1, #, ,

  • 1 Institut für Biochemie und Molekularbiologie II, Universitätsklinikum der Heinrich-Heine-Universität, Düsseldorf, Germany
  • 2 IUF – Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
  • 3 Institut für Transplantationsdiagnostik und Zelltherapeutika (ITZ), Düsseldorf, Germany
  • 4 Biologisch-Medizinisches Forschungszentrum (BMFZ), Düsseldorf, Germany
  • 5 Molecular Proteomics Laboratory, BMFZ, Universitätsklinikum der Heinrich-Heine-Universität, Düsseldorf, Germany
  • 6 University of Düsseldorf, Medical Faculty, Düsseldorf, Germany
* Shared first authorship
# Shared last authorship

received: August 5, 2015 ; accepted: January 30, 2016 ; published: February 26, 2016 ;

https://doi.org/10.18632/aging.100905
How to Cite

Abstract

Mammalian sirtuins are involved in the control of metabolism and life-span regulation. Here, we link the mitochondrial sirtuin SIRT4 with cellular senescence, skin aging, and mitochondrial dysfunction. SIRT4 expression significantly increased in human dermal fibroblasts undergoing replicative or stress-induced senescence triggered by UVB or gamma-irradiation. In-vivo, SIRT4 mRNA levels were upregulated in photoaged vs. non-photoaged human skin. Interestingly, in all models of cellular senescence and in photoaged skin, upregulation of SIRT4 expression was associated with decreased levels of miR-15b. The latter was causally linked to increased SIRT4 expression because miR-15b targets a functional binding site in the SIRT4 gene and transfection of oligonucleotides mimicking miR-15b function prevented SIRT4 upregulation in senescent cells. Importantly, increased SIRT4 negatively impacted on mitochondrial functions and contributed to the development of a senescent phenotype. Accordingly, we observed that inhibition of miR-15b, in a SIRT4-dependent manner, increased generation of mitochondrial reactive oxygen species, decreased mitochondrial membrane potential, and modulated mRNA levels of nuclear encoded mitochondrial genes and components of the senescence-associated secretory phenotype (SASP). Thus, miR-15b is a negative regulator of stress-induced SIRT4 expression thereby counteracting senescence associated mitochondrial dysfunction and regulating the SASP and possibly organ aging, such as photoaging of human skin.

Abbreviations

CytC: cytochrom C; γIR: gamma-irradiation; GDH: glutamate dehydrogenase; miRNA: microRNA; mitoQ: 10-(6′-ubiquinonyl) decyltriphenylphosphonium bromide; MMP1: matrix metalloproteinase-1; MTCO2: mitochondrially encoded cytochrome C oxidase II; mtSIRT: mitochondrially localized sirtuin; NRF1: nuclear respiratory factor 1; PDH: pyruvate dehydrogenase; qRT-PCR: quantitative real-time PCR; ROS: reactive oxygen species; SASP: senescence associated secretory phenotype; SIRT: sirtuin; TACC3: Transforming Acidic Coiled Coil 3; TFAM: transcription factor A; UTR: untranslated region; UV: ultraviolet; VEGF: vascular endothelial growth factor.