Oxidative phosphorylation (OxPhos) is the basic function of mitochondria, although the landscape of mitochondrial functions is continuously growing to include more aspects of cellular homeostasis. ...Thanks to the application of -
technologies to the study of the OxPhos system, novel features emerge from the cataloging of novel proteins as mitochondrial thus adding details to the mitochondrial proteome and defining novel metabolic cellular interrelations, especially in the human brain. We focussed on the diversity of bioenergetics demand and different aspects of mitochondrial structure, functions, and dysfunction in the brain. Definition such as '
', '
' and '
' have entered the field of 'mitochondrial medicine'. In this context, we reviewed several genetic defects that hamper the last step of aerobic metabolism, mostly involving the nervous tissue as one of the most prominent energy-dependent tissues and, as consequence, as a primary target of mitochondrial dysfunction. The dual genetic origin of the OxPhos complexes is one of the reasons for the complexity of the genotype-phenotype correlation when facing human diseases associated with mitochondrial defects. Such complexity clinically manifests with extremely heterogeneous symptoms, ranging from organ-specific to multisystemic dysfunction with different clinical courses. Finally, we briefly discuss the future directions of the multi-omics study of human brain disorders.
Inflammation of the adipose tissue plays an important role in the development of several chronic diseases associated with obesity. Polyphenols of extra virgin olive oil (EVOO), such as the ...secoiridoids oleocanthal (OC) and oleacein (OA), have many nutraceutical proprieties. However, their roles in obesity-associated adipocyte inflammation, the NF-κB pathway and related sub-networks have not been fully elucidated. Here, we investigated impact of OC and OA on the activation of NF-κB and the expression of molecules associated with inflammatory and dysmetabolic responses. To this aim, fully differentiated Simpson-Golabi-Behmel syndrome (SGBS) adipocytes were pre-treated with OC or OA before stimulation with TNF-α. EVOO polyphenols significantly reduced the expression of genes implicated in adipocyte inflammation (IL-1β, COX-2), angiogenesis (VEGF/KDR, MMP-2), oxidative stress (NADPH oxidase), antioxidant enzymes (SOD and GPX), leukocytes chemotaxis and infiltration (MCP-1, CXCL-10, MCS-F), and improved the expression of the anti-inflammatory/metabolic effector PPARγ. Accordingly, miR-155-5p, miR-34a-5p and let-7c-5p, tightly connected with the NF-κB pathway, were deregulated by TNF-α in both cells and exosomes. The miRNA modulation and NF-κB activation by TNF-α was significantly counteracted by EVOO polyphenols. Computational studies suggested a potential direct interaction between OC and NF-κB at the basis of its activity. This study demonstrates that OC and OA counteract adipocyte inflammation attenuating NF-κB activation. Therefore, these compounds could be novel dietary tools for the prevention of inflammatory diseases associated with obesity.
Genetic defects in the nuclear encoded subunits and assembly factors of cytochrome c oxidase (mitochondrial complex IV) are very rare and are associated with a wide variety of phenotypes. Biallelic ...pathogenic variants in the COX11 protein were previously identified in two unrelated children with infantile-onset mitochondrial encephalopathies. Through comprehensive clinical, genetic and functional analyses, here we report on a new patient harboring novel heterozygous variants in
, presenting with Leigh-like features, and provide additional experimental evidence for a direct correlation between COX11 protein expression and sensitivity to oxidative stress. To sort out the contribution of the single mutations to the phenotype, we employed a multi-faceted approach using
as a genetically manipulable system, and in silico structure-based analysis of human COX11. Our results reveal differential effects of the two novel
mutations on yeast growth, respiration, and cellular redox status, as well as their potential impact on human protein stability and function. Strikingly, the functional deficits observed in patient fibroblasts are recapitulated in yeast models, validating the conservation of COX11's role in mitochondrial integrity across evolutionarily distant organisms. This study not only expands the mutational landscape of COX11-associated mitochondrial disorders but also underscores the continued translational relevance of yeast models in dissecting complex molecular pathways.
Owing to their catalytic properties as reactive oxygen species scavengers, cerium oxide nanoparticles (nanoceria) have become an extremely promising candidate for medical applications, especially in ...the treatment of diseases where oxidative stress has been proposed as one of the main pathogenesis factors.
In this work, nanoceria antioxidant power has been tested in primary cultured skin fibroblasts, derived from healthy individuals, by evaluating the mitochondrial function both in basal condition and after an oxidative insult.
Combined with a clear lack of toxicity, antioxidant activity makes nanoceria promising in a wide range of clinical applications sharing the common signature of a global bioenergetic dysfunction.
Milk oligosaccharides are a complex class of carbohydrates that act as bioactive factors in numerous defensive and physiological functions, including brain development. Early nutrition can modulate ...nervous system development and can lead to epigenetic imprinting. We attempted to increase the sialylated oligosaccharide content of zebrafish yolk reserves, with the aim of evaluating any short-term effects of the treatment on mortality, locomotor behavior, and gene expression. Wild-type embryos were microinjected with saline solution or solutions containing sialylated milk oligosaccharides extracted from human and bovine milk. The results suggest that burst activity and larval survival rates were unaffected by the treatments. Locomotion parameters were found to be similar during the light phase between control and treated larvae; in the dark, however, milk oligosaccharide-treated larvae showed increased test plate exploration. Thigmotaxis results did not reveal significant differences in either the light or the dark conditions. The RNA-seq analysis indicated that both treatments exert an antioxidant effect in developing fish. Moreover, sialylated human milk oligosaccharides seemed to increase the expression of genes related to cell cycle control and chromosomal replication, while bovine-derived oligosaccharides caused an increase in the expression of genes involved in synaptogenesis and neuronal signaling. These data shed some light on this poorly explored research field, showing that both human and bovine oligosaccharides support brain proliferation and maturation.
Mutations in the receptor expression-enhancing protein 1 gene
are associated with hereditary spastic paraplegia type 31 (SPG31), a neurological disorder characterized by length-dependent degeneration ...of upper motor neuron axons. Mitochondrial dysfunctions have been observed in patients harboring pathogenic variants in
, suggesting a key role of bioenergetics in disease-related manifestations. Nevertheless, the regulation of mitochondrial function in SPG31 remains unclear. To elucidate the pathophysiology underlying REEP1 deficiency, we analyzed in vitro the impact of two different mutations on mitochondrial metabolism. Together with mitochondrial morphology abnormalities, loss-of-
expression highlighted a reduced ATP production with increased susceptibility to oxidative stress. Furthermore, to translate these findings from in vitro to preclinical models, we knocked down
in zebrafish. Zebrafish larvae showed a significant defect in motor axon outgrowth leading to motor impairment, mitochondrial dysfunction, and reactive oxygen species accumulation. Protective antioxidant agents such as resveratrol rescued free radical overproduction and ameliorated the SPG31 phenotype both in vitro and in vivo. Together, our findings offer new opportunities to counteract neurodegeneration in SPG31.
Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a multisystem hereditary ataxia associated with mutations in SACS, which encodes sacsin, a protein of still only partially ...understood function. Although mouse models of ARSACS mimic largely the disease progression seen in humans, their use in the validation of effective therapies has not yet been proposed. Recently, the teleost Danio rerio has attracted increasing attention as a vertebrate model that allows rapid and economical screening, of candidate molecules, and thus combines the advantages of whole-organism phenotypic assays and in vitro high-throughput screening assays. Through CRISPR/Cas9-based mutagenesis, we generated and characterized a zebrafish sacs-null mutant line that replicates the main features of ARSACS. The sacs-null fish showed motor impairment, hindbrain atrophy, mitochondrial dysfunction, and reactive oxygen species accumulation. As proof of principle for using these mutant fish in high-throughput screening studies, we showed that both acetyl-DL-leucine and tauroursodeoxycholic acid improved locomotor and biochemical phenotypes in sacs−/− larvae treated with these neuroprotective agents, by mediating significant rescue of the molecular functions altered by sacsin loss. Taken together, the evidence here reported shows the zebrafish to be a valuable model organism for the identification of novel molecular mechanisms and for efficient and rapid in vivo optimization and screening of potential therapeutic compounds. These findings may pave the way for new interventions targeting the earliest phases of Purkinje cell degeneration in ARSACS.
Remarkable deregulation of several microRNAs (miRNAs) is demonstrated in cutaneous melanoma. hsa-miR-193a-3p is reported to be under-expressed in tissues and in plasma of melanoma patients, but the ...role of both miR-193a arms in melanoma is not known yet.
After observing the reduced levels of miR-193a arms in plasma exosomes of melanoma patients, the effects of hsa-miR-193a-3p and -5p transfection in cutaneous melanoma cell lines are investigated.
In melanoma cell lines A375, 501Mel, and MeWo, the ectopic over-expression of miR-193a arms significantly reduced cell viability as well as the expression of genes involved in proliferation (ERBB2, KRAS, PIK3R3, and MTOR) and apoptosis (MCL1 and NUSAP1). These functional features were accompanied by a significant downregulation of Akt and Erk pathways and a strong increase in the apoptotic process. Since in silico databases revealed TROY, an orphan member of the tumor necrosis receptor family, as a potential direct target of miR-193a-5p, this possibility was investigated using the luciferase assay and excluded by our results.
Our results underline a relevant role of miR-193a, both -3p and -5p, as tumor suppressors clarifying the intracellular mechanisms involved and suggesting that their ectopic over-expression could represent a novel treatment for cutaneous melanoma patients.
Display omitted
•Resveratrol-loaded NLCs have been proposed as therapeutic agents in ARSACS.•Results demonstrated their antioxidant and anti-inflammatory abilities.•Transcriptomics and proteomics ...confirm their therapeutic potentialities.
Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a neurological disease characterized by autosomal recessive mutations in the sacsin gene (SACS), that cause in patients progressive cerebellar atrophy, damage of the peripheral nerves, and cognitive impairment. No effective therapies have been proposed for ARSACS, even if some evidences suggest that powerful antioxidant agents can be considered as a therapeutic tool. Resveratrol (Res) is a natural polyphenol compound derived from vegetal sources, the application of which in biomedicine is increasing in the latest years owing to its significant therapeutic effects, in particular in neurodegenerative diseases. In this study, we provide evidences about its potential exploitation in the treatment of ARSACS. Because of the low solubility of Res in physiological media, a nanoplatform based on nanostructured lipid carriers is proposed for its encapsulation and delivery. Resveratrol-loaded nanostructured lipid carriers (Res-NLCs) have been synthetized, characterized, and tested on healthy and ARSACS patient fibroblasts. Nanovectors displayed optimal stability and biocompatibility, and excellent antioxidant and anti-inflammatory activities. A comprehensive investigation at gene (with real-time quantitative RT-PCR) and protein (with proteomics) level demonstrated the therapeutic potential of Res-NLCs, encouraging future investigations on pre-clinical models.
Introduction Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a rare incurable neurodegenerative disease caused by mutations in the SACS gene, which codes for sacsin, a large ...protein involved in protein homeostasis, mitochondrial function, cytoskeletal dynamics, autophagy, cell adhesion and vesicle trafficking. However, the pathogenic mechanisms underlying sacsin dysfunction are still largely uncharacterized, and so attempts to develop therapies are still in the early stages. Methods To achieve further understanding of how processes are altered by loss of sacsin, we used untargeted proteomics to compare protein profiles in ARSACS fibroblasts versus controls. Results Our analyses confirmed the involvement of known biological pathways and also implicated calcium and lipid homeostasis in ARSACS skin fibroblasts, a finding further verified in SH-SY5Y SACS –/– cells. Validation through mass spectrometry-based analysis and comparative quantification of lipids by LC-MS in fibroblasts revealed increased levels of ceramides coupled with a reduction of diacylglycerols. Discussion In addition to confirming aberrant Ca 2+ homeostasis in ARSACS, this study described abnormal lipid levels associated with loss of sacsin.
PDF
