• This is a very good paper but a difficult one and unfortunately does not have clear contact with PBT434 and value of ATHE, however IMO it has. If you will not read but the abstract go in any case to the picture 10 in the free paper:
• In my opinion, this picture will help to understand the role of mitochondria providing energy to the nerve and how degenerated mitochondria are eliminated. The paper talks also about fusion and fission of mitochondria, which do relate to iron overload.
  

Nat Commun. 2019 Aug 13;10(1):3645. doi: 10.1038/s41467-019-11636-5.

Mul1 restrains Parkin-mediated mitophagy in mature neurons by maintaining ER-mitochondrial contacts.

Puri R¹, Cheng XT¹, Lin MY¹, Huang N¹, Sheng ZH².

Author information

1

Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Room 2B-215, 35 Convent Drive, Bethesda, MD, 20892-3706, USA.

2

Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Room 2B-215, 35 Convent Drive, Bethesda, MD, 20892-3706, USA. [email protected].

Abstract

Chronic mitochondrial stress associates with major neurodegenerative diseases. Recovering stressed mitochondria constitutes a critical step of mitochondrial quality control and thus energy maintenance in early stages of neurodegeneration. Here, we reveal Mul1-Mfn2 pathway that maintains neuronal mitochondrial integrity under stress conditions. Mul1 deficiency increases Mfn2 activity that triggers the first phasic mitochondrial hyperfusion and also acts as an ER-Mito tethering antagonist. Reduced ER-Mito coupling leads to increased cytoplasmic Ca²⁺ load that activates calcineurin and induces the second phasic Drp1-dependent mitochondrial fragmentation and mitophagy. Overexpressing Mfn2, but not Mfn1, mimics Mul1-deficient phenotypes, while expressing PTPIP51, an ER-Mito anchoring protein, suppresses Parkin-mediated mitophagy. Thus, by regulating mitochondrial morphology and ER-Mito contacts, Mul1-Mfn2 pathway plays an early checkpoint role in maintaining mitochondrial integrity. Our study provides new mechanistic insights into neuronal mitochondrial maintenance under stress conditions, which is relevant to several major neurodegenerative diseases associated with mitochondrial dysfunction and altered ER-Mito interplay.