scholarly journals mTORC1-induced retinal progenitor cell overproliferation leads to accelerated mitotic aging and degeneration of descendent Müller glia

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Soyeon Lim ◽  
You-Joung Kim ◽  
Sooyeon Park ◽  
Ji-heon Choi ◽  
Younghoon Sung ◽  
...  

Retinal progenitor cells (RPCs) divide in limited numbers to generate the cells comprising vertebrate retina. The molecular mechanism that leads RPC to the division limit, however, remains elusive. Here, we find that the hyperactivation of mechanistic target of rapamycin complex 1 (mTORC1) in an RPC subset by deletion of tuberous sclerosis complex 1 (Tsc1) makes the RPCs arrive at the division limit precociously and produce Müller glia (MG) that degenerate from senescence-associated cell death. We further show the hyperproliferation of Tsc1-deficient RPCs and the degeneration of MG in the mouse retina disappear by concomitant deletion of hypoxia-induced factor 1-a (Hif1a), which induces glycolytic gene expression to support mTORC1-induced RPC proliferation. Collectively, our results suggest that, by having mTORC1 constitutively active, an RPC divides and exhausts mitotic capacity faster than neighboring RPCs, and thus produces retinal cells that degenerate with aging-related changes.

2019 ◽  
Vol 33 (8) ◽  
pp. 8745-8758 ◽  
Author(s):  
Onkar B. Sawant ◽  
Vijay K. Jidigam ◽  
Rebecca D. Fuller ◽  
Olivia F. Zucaro ◽  
Cristel Kpegba ◽  
...  

Development ◽  
2013 ◽  
Vol 140 (7) ◽  
pp. 1445-1456 ◽  
Author(s):  
N. Surzenko ◽  
T. Crowl ◽  
A. Bachleda ◽  
L. Langer ◽  
L. Pevny

2019 ◽  
Author(s):  
Nikolas L. Jorstad ◽  
Matthew S. Wilken ◽  
Levi Todd ◽  
Paul Nakamura ◽  
Nick Radulovich ◽  
...  

AbstractMüller glia can serve as a source for retinal regeneration in some non-mammalian vertebrates. Recently we found that this process can be induced in mouse Müller glia after injury, by combining transgenic expression of the proneural transcription factor Ascl1 and the HDAC inhibitor TSA. However, new neurons are only generated from a subset of Müller glia in this model, and identifying factors that limit Ascl1-mediated MG reprogramming could potentially make this process more efficient, and potentially useful clinically. One factor that limits neurogenesis in some non-mammalian vertebrates is the STAT pathway activation that occurs in Müller glia in response to injury. In this report, we tested whether injury induced STAT activation hampers the ability of Ascl1 to reprogram Müller glia into retinal neurons. Using a STAT inhibitor, in combination with our previously described reprogramming paradigm, we found a large increase in the ability of Müller glia to generate neurons, similar to those we described previously. Single-cell RNA-seq showed that the progenitor-like cells derived from Ascl1-expressing Müller glia have a higher level of STAT signaling than those that become neurons. Using Ascl1 ChIP-seq and DNase-seq, we found that developmentally inappropriate Ascl1 binding sites (that were unique to the overexpression context) had enrichment for the STAT binding motif. This study provides evidence that STAT pathway activation reduces the efficiency of Ascl1-mediated reprogramming in Müller glia, potentially by directing Ascl1 to inappropriate targets.


Glia ◽  
2011 ◽  
Vol 59 (7) ◽  
pp. 1033-1046 ◽  
Author(s):  
Sandrine Joly ◽  
Vincent Pernet ◽  
Marijana Samardzija ◽  
Christian Grimm

Glia ◽  
2003 ◽  
Vol 43 (1) ◽  
pp. 70-76 ◽  
Author(s):  
Andy J. Fischer ◽  
Thomas A. Reh

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