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The mitochondrial F1Fo-ATPase Inhibitory Factor 1 (IF1) blocks the reversal of the F1Fo-ATPsynthase to prevent detrimental consumption of cellular ATP and associated demise. Herein, we infer further its molecular physiology by assessing its protective function in neurons during conditions of challenged homeostatic respiration. By adopting in vitro and in vivo protocols of hypoxia/ischemia and re-oxygenation, we show that a shift in the IF1:F1Fo-ATPsynthase expression ratio occurs in neurons. This increased IF1 level is essential to induce accumulation of the PTEN-induced putative kinase 1 (PINK-1) and recruitment of the mitophagic ubiquitin ligase PARK-2 to promote autophagic "control" of the mitochondrial population. In IF1 overexpressing neurons ATP depletion is reduced during hypoxia/ischemia and the mitochondrial membrane potential (ΔYm) resilient to re-oxygenation as well as resistant to electrogenic, Ca(2+) dependent depolarization. These data suggest that in mammalian neurons mitochondria adapt to respiratory stress by upregulating IF1, which exerts a protective role by coordinating pro-survival cell mitophagy and bioenergetics resilience.

Alzheimer’s disease (AD) is regarded as a multifactorial disease characterized by a complex pathogenesis including a cholinergic deficit - due to degeneration of cholinergic projections from the basal forebrain - and the extracellular accumulation of amyloid beta (Aβ) peptide. Aβ containing 39 to 42 amino acids is the predominant component of the senile plaques that, together with neurofibrillary tangles, are regarded as the neuropathological hallmarks of AD (Sorrentino et al. 2014). Aβ may assume different conformations changing from random coil or α-helical monomers to β-sheet structures forming toxic oligomers and/or β-sheet mature fibrils. In this framework, we studied the effect of acetylcholine (ACh) on the conformation of Aβ by circular dichroism analysis. Moreover we investigated the ability of ACh to protect neuronal cells from the toxic action of amyloid peptide and to modulate the neuroinflammatory response occurring via the phospholipase A2 (PLA2). Results show that the amount of Aβ(25-35) β-strand raised linearly in absence of ACh, whereas it remained almost constant in presence of ACh. In addition, in a micelle solution mimicking the membrane environment ACh was found effective in increasing and stabilizing the soluble and not toxic helical content of Aβ(25-35) suggesting that ACh is capable to preserve the soluble form of Aβ(25-35), reducing the incipit of Aβ aggregation. In order to assess the neuro-protective ability of ACh against toxic Aβ(25-35) accumulation, we used neural cell (NCC) cultures containing both astrocytes and glial cells prepared from brains embryos from timed pregnant Wistar rats and infused ACh for 48h. By immunostaining, we observed that ACh reduced Aβ(25-35)-induced cell death. Then, we tested the protective effect of ACh on inflammation induced by Aβ administration. NCC were challenged with Aβ(25-35) in the presence and absence of ACh and immunostained for astroglial and neuronal markers: results showed a reduction of the morphological features of astrogliosys in ACh treated cells. PLA2 expression analysis corroborated these data also underlying that ACh can negatively regulate inflammation pathways in glial cells., Italian Journal of Anatomy and Embryology, Vol. 120, No. 1 (Supplement) 2015

Mitophagy is a novel identified autophagic process through which defective and malfunctioning mitochondria are degraded or recycled. The balance between this process and mitochondrial biogenesis is crucial for post-mitotic neurons’ survival, as mitochondria are the primary energetic source required for the formation and function of axon terminals and dendritic spines (Amadoro et al 2014). As other cell types, neuronal populations also continually modulate size and number of these organelles, according to the variable energy demands and metabolic states throughout the entire lifetime and/or different sub-cellular compartments. In polarized neurons removal of damaged mitochondria can be a bioenergetically demanding task because these organelles need to be actively transported from the axons and dendrites in order to fuse to cell body resident lysosomes (Wang et al 2006). Physiologically aging as well as numerous human neurodegenerative disease, including Parkison’s disease, Huntington’s disease, amyotrophic lateral sclerosis and Alzheimer’s disease (AD) has been associated with alterations in quality control of neuronal mitochondria (Santos et al 2010), but still now, mitophagy pathway and its dysfunction in neudegenerative disease remain undisclosed. Data from several neurotoxic models show that mitochondria undergo to selective morphological changes in distribution, shape and interconnectivity which are hallmarks of mitophagy. These changes are typically studied at the confocal and TEM microscopes and quantified through a morphometric approach. Due to their polarized nature, neurons present a loss in the neuritic domain more pronounced in respect to the cell body compartment. In addition, morphometric analysis show that the mitochondria interconnectivity, area/perimeter ratio and elongation, major/minor axis ratio, are reduced in neurotoxic models and that these changes parallel in vivo findings from tissue derived from several neurodegenerative diseases. Thus, neurotoxic models, which are acute insults, are able to trigger mitophagy in similar way to human neurodegenerative diseases which, instead, develop the pathology in the course of several years., Italian Journal of Anatomy and Embryology, Vol 119, No 1 (Supplement) 2014

Macroautophagy is a highly regulated cellular process that serves to remove damaged proteins and organelles from the cell. Research during the last decade has made it increasingly clear that autophagy plays important roles in most of the major human diseases as well as in infection and immunity, with increasing evidence for selective autophagy of protein aggregates, organelles and pathogens (Levine et al., 2008). The purpose of autophagy is not the simple elimination of materials, but instead, autophagy serves as a dynamic recycling system that produces new building blocks and energy for cellular renovation and homeostasis. Here we provide a multidisciplinary sight of our current understanding of autophagy’s role in metabolic adaptation, intracellular quality control, and renovation during development and differentiation., Italian Journal of Anatomy and Embryology, Vol 117, No 2 (Supplement) 2012

Diabetic polyneuropathy (DPN), characterized by early hyperalgesia and increased nerve growth factor (NGF) availability, evolves in late irreversible neuropathic symptoms with reduced NGF support to sensory neurons. Electroacupuncture (EA) modulates NGF presence and activity in the peripheral nervous system, being effective for the treatment of DPN symptoms Our working hypotheses are that NGF plays an important pathogenic role in DPN development while EA could be useful in the therapy of DPN by modulating NGF expression and activity. Diabetes was induced in rats by streptozotocin (STZ) injection. One week after STZ, EA treatments were started and continued for three weeks. NGF system and hyperalgesia-related mediators were analyzed in the dorsal root ganglia (DRG), and in their spinal and skin innervation territories. Four weeks diabetes inceased NGF and NGF receptors and deregulated intracellular signaling mediators of DRG neurons hyper-sensitizations. EA in diabetic rats decreased both NGF and NGF receptors, normalized c-Jun N-terminal and p38 kinases activation, decreased transient receptor potential vanilloid-1 ion channel and possibly activated Nf-κB. Increase of NGF signaling might play an important role in the development of DPN. EA represent a supportive tools aimed at controlling DPN by modulating NGF signaling in diabetestargeted neurons., Italian Journal of Anatomy and Embryology, Vol 117, No 2 (Supplement) 2012

Italian Journal of Anatomy and Embryology, Vol 115, No 1/2 (Supplement) 2010