MitoTimer reporter gene

Mitochondria are the power plants in mammalian cells for ATP production essential for cellular processes. Mitochondrial dysfunction is associated with most of the prevalent health disorders, including cardiovascular disease, diabetes, cancer, and neurodegeneration. Impaired mitochondrial function often triggers a vicious cycle of excess reactive oxygen specises production and additional mitochondrial damage, further exacerbating disease conditions. However, current understanding of mitochondrial oxidative stress and damage in the etiology of these diseases remains elusive mainly due to lack of a convenient and robust assessment of mitochondrial quantity and quality in vivo. To bridge this gap, the Yan Lab engineered a novel pMitoTimer reporter gene from a newly invented pTimer reporter gene that encodes a DsRed mutant with green fluorescence that irreversibly shifts to red fluorescence when oxidized. Taking advantage of multiple systems ranging from cultured cells, C. elegans, D. melanogaster to mice, the lab's research shows that MitoTimer protein targets exclusively to mitochondria, shifts from green to red and displays some pure red puncta of mitochondrial origin in response to known mitochondrial stressors, including high-fat diet feeding. The research team has confirmed by somatic gene transfer in vivo that pMitoTimer allows for simultaneous measurements of mitochondrial content, density, structure, stress and damage. Finally, the lab has generated a conditional MitoTimer transgenic mouse line that allows robust measurements of mitochondrial health in vivo. The team will use this model to test an important gap in knowledge under conditions of metabolic challenges, including poor diet and normal physiology, including exercise. The studies will have a high impact as it will allow for an easy, robust assessment of mitochondrial health in any given tissue, promoting rigorous research of mitochondria in various mouse models of disease.

Publications

Laker RC, Xu P, Ryall KA, Sujkowski A, Kenwood BM, Chain KH, Zhang M, Royal MA, Hoehn KL, Dirscoll M, Adler PN, Wessells RJ, Saucerman JJ, Yan Z. A novel MitoTimer reporter gene for mitochondrial content, structure, stress and damage in vivo. J Biol Chem. 2014 Mar 18. [Epub ahead of print] PubMed PMID: 24644293. 

Forrester SJ, Elliott KJ, Kawai T, Obama T, Boyer MJ, Preston KJ, Yan Z, Eguchi S, Rizzo V. Caveolin-1 Deletion Prevents Hypertensive Vascular Remodeling Induced by Angiotensin II. Hypertension. 2017 Jan;69(1):79-86. PubMed PMID: 27895190; PubMed Central PMCID: PMC5145768.

Call JA, Wilson RJ, Laker RC, Zhang M, Kundu M, Yan Z. Ulk1-mediated autophagy plays an essential role in mitochondrial remodeling and functional regeneration of skeletal muscle. Am J Physiol Cell Physiol. 2017 Jun 1;312(6):C724-C732. PubMed PMID: 28356270; PubMed Central PMCID: PMC5494591.

Laker RC, Drake JC, Wilson RJ, Lira VA, Lewellen BM, Ryall KA, Fisher CC, Zhang M, Saucerman JJ, Goodyear LJ, Kundu M, Yan Z. Ampk phosphorylation of Ulk1 is required for targeting of mitochondria to lysosomes in exercise-induced mitophagy. Nat Commun. 2017 Sep 15;8(1):548. PubMed PMID: 28916822; PubMed Central PMCID: PMC5601463.

Wilson RJ, Drake JC, Cui D, Zhang M, Perry HM, Kashatus JA, Kusminski CM, Scherer PE, Kashatus DF, Okusa MD, Yan Z. Conditional MitoTimer reporter mice for assessment of mitochondrial structure, oxidative stress, and mitophagy. Mitochondrion. 2017 Dec 20. pii: S1567-7249(17)30196-4. PubMed PMID: 29274400.

Perry HM, Huang L, Wilson RJ, Bajwa A, Sesaki H, Yan Z, Rosin DL, Kashatus DF, Okusa MD. Dynamin-Related Protein 1 Deficiency Promotes Recovery from AKI. J Am Soc Nephrol. 2018 Jan;29(1):194-206. PubMed PMID: 29084809; PubMed Central PMCID: PMC5748924.

Wilson RJ, Drake JC, Cui D, Lewellen BM, Fisher CC, Zhang M, Kashatus DF, Palmer LA, Murphy MP, Yan Z. Mitochondrial protein S-nitrosation protects against ischemia reperfusion-induced denervation at neuromuscular junction in skeletal muscle. Free Radic Biol Med. 2018 Feb 9;117:180-190.PubMed PMID: 29432799. 

Wilson RJ, Drake JC, Cui D, Ritger ML, Guan Y, Call JA, Zhang M, Leitner LM, Gödecke A, Yan Z. Voluntary running protects against neuromuscular dysfunction following hindlimb ischemia-reperfusion in mice. J Appl Physiol (1985). 2018 Nov 15. doi: 10.1152/japplphysiol.00358.2018. [Epub ahead of print] PubMed PMID: 30433863.

Xu P, Damschroder D, Zhang M, Ryall KA, Adler PN,Saucerman JJ, Wessells RJ, Yan Z. Atg2, Atg9 and Atg18 in mitochondrial integrity, cardiac function and healthspan in Drosophila. J Mol Cell Cardiol. 2018 Dec 17. pii: S0022-2828(18)31296-3. PMID: 30571977