Retinal morphological and functional response to Idebenone therapy in Leber hereditary optic neuropathy

A New Approach for Orbital Wall Reconstruction in a Rabbit Animal Model Using a Hybrid Hydroxyapatite-Collagen-Based Implant

Reconstructing the orbit following complex craniofacial fractures presents significant challenges. Throughout the years, several materials have been used for orbital reconstruction, taking into account factors such as their durability, compatibility with living tissue, cost efficiency, safety, and capacity to be adjusted during surgery. Nevertheless, a consensus has not yet been reached on the optimal material for orbital restoration. This study investigates the potential of a hybrid hydroxyapatite-collagen (HAp-COL) material 3D-printed on Ti mesh to be used as an implant for orbital wall reconstruction. HAp-COL powder was synthesized using a high-pressure hydrothermal technique. The powder was further used to 3D-print HAp-COL structures on titanium mesh, with the latter having potential uses in orbital wall reconstruction. Biocompatibility was assessed by evaluating the effects of the HAp-COL material on the adhesion and proliferation of fibroblasts (3T3) and mesenchymal stem cells (MSCs) in culture. In vitro and in vivo results showed that HAp-COL is highly biocompatible and has a good integration of the implant in the bone. The findings reported in this study offer convincing evidence to support the use of our designed HAp-COL for the restoration of orbital wall fractures, with a high level of safety.

Acute liver damage generates age independent microglia morphology changes in mice

Non-alcoholic fatty liver disease (NAFLD) has emerged as a silent global epidemic, frequently contributing to systemic inflammation. As the primary immune cells of the central nervous system (CNS), microglia undergo morphological changes that serve as critical indicators of CNS health. In this study, we aimed to quantify alterations in microglial morphology within the cortex of young and aged mice with liver damage. Our results demonstrated that hepatic dysfunction leads to a significant increase in total branch length in both young (285.79±68.23 μm) and aged animals (268.67±69.06 μm), compared to their respective controls (164.07±33.05 μm and 140.96±27.18 μm) (p<0.0001). Additionally, aged animals with liver damage exhibited a mean branch length of 5.84±0.66 μm, higher than 2.63±0.19 μm observed in those without liver injury. The number of primary branches in aged mice with liver damage decreased from 6.6±1.2 branches to 3.1±1.5 (p<0.0001). In addition, we have shown a decrease in the number of secondary branches in aged animals with liver damage. This suggests that microglia not only respond to CNS-specific injuries but also to chronic systemic pathologies like NAFLD. These findings highlight the importance of better understanding the liver-brain axis in order to better understand the neuroimmune consequences of systemic diseases.

Neuroprotective effects of idebenone on hydrogen peroxide-induced oxidative damage in retinal ganglion cells-5

PURPOSE

To investigate the neuroprotective effect of idebenone against hydrogen peroxide (H2O2)-induced oxidative damage in retinal ganglion cells-5 (RGC-5 cells).

METHODS

RGC-5 cells were pre-treated with various idebenone concentrations (5, 10, and 20 µM) for 12 h and were then subjected to 300 µM H2O2 for a further 12 h. Apoptosis in RGC-5 was measured by flow cytometry. The changes of mitochondrial membrane potential (MMP) were detected by JC-1 staining. Autophagy in RGC-5 cells was observed by transmission electron microscopy. Western blots were used to measure the expression of autophagy-related protein light chain 3 (LC3), Beclin-1, and the release of Cytochrome c (Cyt-c).

RESULTS

Flow cytometry showed that the apoptosis rates in the normal control group, H2O2 group, and idebenone groups were 6.48 ± 0.55%, 27.3 ± 0.51%, 22.8 ± 0.52%, 15.45 ± 0.81%, and 12.59 ± 0.58%, respectively (F = 559.7, P < 0.0001). After incubation with H2O2, the number of autophagosomes increased significantly, whereas it was decreased in the idebenone groups. After incubation of RGC-5 cells with H2O2, MMP levels were significantly decreased, while idebenone could prevent the decrease in MMP levels. Compared with that in the normal control group, LC3 II/I, the expression levels of Beclin-1 and Cyt-c were increased significantly in the H2O2 group (P < 0.05). Compared with that in the H2O2 group, LC3 II/I, the expression of Beclin-1 and Cyt-c was significantly decreased in idebenone groups (P < 0.05).

CONCLUSIONS

Idebenone protects RGC-5 cells against H2O2-induced oxidative damage by reducing mitochondrial damage and autophagic activity.

Apparent Opportunities and Hidden Pitfalls: The Conflicting Results of Restoring NRF2-Regulated Redox Metabolism in Friedreich's Ataxia Pre-Clinical Models and Clinical Trials

Friedreich's ataxia (FRDA) is an autosomal, recessive, inherited neurodegenerative disease caused by the loss of activity of the mitochondrial protein frataxin (FXN), which primarily affects dorsal root ganglia, cerebellum, and spinal cord neurons. The genetic defect consists of the trinucleotide GAA expansion in the first intron of FXN gene, which impedes its transcription. The resulting FXN deficiency perturbs iron homeostasis and metabolism, determining mitochondrial dysfunctions and leading to reduced ATP production, increased reactive oxygen species (ROS) formation, and lipid peroxidation. These alterations are exacerbated by the defective functionality of the nuclear factor erythroid 2-related factor 2 (NRF2), a transcription factor acting as a key mediator of the cellular redox signalling and antioxidant response. Because oxidative stress represents a major pathophysiological contributor to FRDA onset and progression, a great effort has been dedicated to the attempt to restore the NRF2 signalling axis. Despite this, the beneficial effects of antioxidant therapies in clinical trials only partly reflect the promising results obtained in preclinical studies conducted in cell cultures and animal models. For these reasons, in this critical review, we overview the outcomes obtained with the administration of various antioxidant compounds and critically analyse the aspects that may have contributed to the conflicting results of preclinical and clinical studies.