Clinical correlates of decreased plasma coenzyme Q10 levels in patients with multiple system atrophy

The Antioxidant Potential of Vitamins and Their Implication in Metabolic Abnormalities

Vitamins are micronutrients necessary for the normal function of the body. Although each vitamin has different physicochemical properties and a specific role in maintaining life, they may also possess a common characteristic, i.e., antioxidant activity. Oxidative stress can harm all the main biological structures leading to protein, DNA and lipid oxidation, with concomitant impairment of the cell. It has been established that oxidative stress is implicated in several pathological conditions such as atherosclerosis, diabetes, obesity, inflammation and metabolic syndrome. In this review we investigate the influence of oxidative stress on the above conditions, examine the interrelation between oxidative stress and inflammation and point out the importance of vitamins in these processes, especially in oxidative load manipulation and metabolic abnormalities.

New insights into healthy ageing, inflammageing and frailty using metabolomics

Human ageing is a normal process and does not necessarily result in the development of frailty. A mix of genetic, environmental, dietary, and lifestyle factors can have an impact on ageing, and whether an individual develops frailty. Frailty is defined as the loss of physiological reserve both at the physical and cellular levels, where systemic processes such as oxidative stress and inflammation contribute to physical decline. The newest "omics" technology and systems biology discipline, metabolomics, enables thorough characterisation of small-molecule metabolites in biological systems at a particular time and condition. In a biological system, metabolites-cellular intermediate products of metabolic reactions-reflect the system's final response to genomic, transcriptomic, proteomic, epigenetic, or environmental alterations. As a relatively newer technique to characterise metabolites and biomarkers in ageing and illness, metabolomics has gained popularity and has a wide range of applications. We will give a comprehensive summary of what is currently known about metabolomics in studies of ageing, with a focus on biomarkers for frailty. Metabolites related to amino acids, lipids, carbohydrates, and redox metabolism may function as biomarkers of ageing and/or frailty development, based on data obtained from human studies. However, there is a complexity that underpins biological ageing, due to both genetic and environmental factors that play a role in orchestrating the ageing process. Therefore, there is a critical need to identify pathways that contribute to functional decline in people with frailty.

Coenzyme Q10: A Biomarker in the Differential Diagnosis of Parkinsonian Syndromes

Multiple system atrophy (MSA) is generally a sporadic neurodegenerative disease which ranks among atypical Parkinson's syndromes. The main clinical manifestation is a combination of autonomic dysfunction and parkinsonism and/or cerebellar disability. The disease may resemble other Parkinsonian syndromes, such as Parkinson's disease (PD) or progressive supranuclear palsy (PSP), from which MSA could be hardly distinguishable during the first years of progression. Due to the lack of a reliable and easily accessible biomarker, the diagnosis is still based primarily on the clinical picture. Recently, reduced levels of coenzyme Q10 (CoQ10) were described in MSA in various tissues, including the central nervous system. The aim of our study was to verify whether the level of CoQ10 in plasma and lymphocytes could serve as an easily available diagnostic biomarker of MSA. The study reported significantly lower levels of CoQ10 in the lymphocytes of patients with MSA compared to patients with PD and controls. The reduction in CoQ10 levels in lymphocytes correlated with the increasing degree of clinical involvement of patients with MSA. CoQ10 levels in lymphocytes seem to be a potential biomarker of disease progression.

Involvement of Coenzyme Q10 in Various Neurodegenerative and Psychiatric Diseases

Coenzyme Q10 (CoQ10), commonly known as ubiquinone, is a vitamin-like component generated in mitochondrial inner membranes. This molecule is detected broadly in different parts of the human body in various quantities. This molecule can be absorbed by the digestive system from various nutritional sources as supplements. CoQ10 exists in three states: in a of reduced form (ubiquinol), in a semiquinone radical form, and in oxidized ubiquinone form in different organs of the body, playing a crucial role in electron transportation and contributing to energy metabolism and oxygen utilization, especially in the musculoskeletal and nervous systems. Since the early 1980s, research about CoQ10 has become the interest for two reasons. First, CoQ10 deficiency has been found to have a link with cardiovascular, neurologic, and cancer disorders. Second, this molecule has an antioxidant and free-radical scavenger nature. Since then, several investigations have indicated that the drug may benefit patients with cardiovascular, neuromuscular, and neurodegenerative illnesses. CoQ10 may protect the neurological system from degeneration and degradation due to its antioxidant and energy-regulating activity in mitochondria. This agent has shown its efficacy in preventing and treating neurological diseases such as migraine, Parkinson's disease, Alzheimer's disease, Huntington's disease, amyotrophic lateral sclerosis, and Friedreich's ataxia. This study reviews the literature to highlight this agent's potential therapeutic effects in the mentioned neurological disorders.

Multidimensional biomarkers for multiple system atrophy: an update and future directions

Multiple system atrophy (MSA) is a fatal progressive neurodegenerative disease. Biomarkers are urgently required for MSA to improve the diagnostic and prognostic accuracy in clinic and facilitate the development and monitoring of disease-modifying therapies. In recent years, significant research efforts have been made in exploring multidimensional biomarkers for MSA. However, currently few biomarkers are available in clinic. In this review, we systematically summarize the latest advances in multidimensional biomarkers for MSA, including biomarkers in fluids, tissues and gut microbiota as well as imaging biomarkers. Future directions for exploration of novel biomarkers and promotion of implementation in clinic are also discussed.

High-dose ubiquinol supplementation in multiple-system atrophy: a multicentre, randomised, double-blinded, placebo-controlled phase 2 trial

Background

Functionally impaired variants of COQ2, encoding an enzyme in biosynthesis of coenzyme Q10 (CoQ10), were found in familial multiple system atrophy (MSA) and V393A in COQ2 is associated with sporadic MSA. Furthermore, reduced levels of CoQ10 have been demonstrated in MSA patients.

Methods

This study was a multicentre, randomised, double-blinded, placebo-controlled phase 2 trial. Patients with MSA were randomly assigned (1:1) to either ubiquinol (1500 mg/day) or placebo. The primary efficacy outcome was the change in the unified multiple system atrophy rating scale (UMSARS) part 2 at 48 weeks. Efficacy was assessed in all patients who completed at least one efficacy assessment (full analysis set). Safety analyses included patients who completed at least one dose of investigational drug. This trial is registered with UMIN-CTR (UMIN000031771), where the drug name of MSA-01 was used to designate ubiquinol.

Findings

Between June 26, 2018, and May 27, 2019, 139 patients were enrolled and randomly assigned to the ubiquinol group (n = 69) or the placebo group (n = 70). A total of 131 patients were included in the full analysis set (63 in the ubiquinol group; 68 in the placebo group). This study met the primary efficacy outcome (least square mean difference in UMSARS part 2 score (-1.7 [95% CI, -3.2 to -0.2]; P = 0.023)). The ubiquinol group also showed better secondary efficacy outcomes (Barthel index, Scale for the Assessment and Rating of Ataxia, and time required to walk 10 m). Rates of adverse events potentially related to the investigational drug were comparable between ubiquinol (n = 15 [23.8%]) and placebo (n = 21 [30.9%]).

Interpretation

High-dose ubiquinol was well-tolerated and led to a significantly smaller decline of UMSARS part 2 score compared with placebo.

Funding

Japan Agency for Medical Research and Development.

Genetics of Multiple System Atrophy and Progressive Supranuclear Palsy: A Systemized Review of the Literature

Multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) are uncommon multifactorial atypical Parkinsonian syndromes, expressed by various clinical features. MSA and PSP are commonly considered sporadic neurodegenerative disorders; however, our understanding is improving of their genetic framework. The purpose of this study was to critically review the genetics of MSA and PSP and their involvement in the pathogenesis. A systemized literature search of PubMed and MEDLINE was performed up to 1 January 2023. Narrative synthesis of the results was undertaken. In total, 43 studies were analyzed. Although familial MSA cases have been reported, the hereditary nature could not be demonstrated. COQ2 mutations were involved in familial and sporadic MSA, without being reproduced in various clinical populations. In terms of the genetics of the cohort, synuclein alpha (SNCA) polymorphisms were correlated with an elevated likelihood of manifesting MSA in Caucasians, but a causal effect relationship could not be demonstrated. Fifteen MAPT mutations were linked with PSP. Leucine-rich repeat kinase 2 (LRRK2) is an infrequent monogenic mutation of PSP. Dynactin subunit 1 (DCTN1) mutations may imitate the PSP phenotype. GWAS have noted many risk loci of PSP (STX6 and EIF2AK3), suggesting pathogenetic mechanisms related to PSP. Despite the limited evidence, it seems that genetics influence the susceptibility to MSA and PSP. MAPT mutations result in the MSA and PSP pathologies. Further studies are crucial to elucidate the pathogeneses of MSA and PSP, which will support efforts to develop novel drug options.

Coenzyme Q10: Role in Less Common Age-Related Disorders

In this article we have reviewed the potential role of coenzyme Q10 (CoQ10) in the pathogenesis and treatment of a number of less common age-related disorders, for many of which effective therapies are not currently available. For most of these disorders, mitochondrial dysfunction, oxidative stress and inflammation have been implicated in the disease process, providing a rationale for the potential therapeutic use of CoQ10, because of its key roles in mitochondrial function, as an antioxidant, and as an anti-inflammatory agent. Disorders reviewed in the article include multi system atrophy, progressive supranuclear palsy, sporadic adult onset ataxia, and pulmonary fibrosis, together with late onset versions of Huntington’s disease, Alexander disease, lupus, anti-phospholipid syndrome, lysosomal storage disorders, fibromyalgia, Machado-Joseph disease, acyl-CoA dehydrogenase deficiency, and Leber’s optic neuropathy.

Multiple system atrophy

Multiple system atrophy (MSA) is a rare neurodegenerative disease that is characterized by neuronal loss and gliosis in multiple areas of the central nervous system including striatonigral, olivopontocerebellar and central autonomic structures. Oligodendroglial cytoplasmic inclusions containing misfolded and aggregated α-synuclein are the histopathological hallmark of MSA. A firm clinical diagnosis requires the presence of autonomic dysfunction in combination with parkinsonism that responds poorly to levodopa and/or cerebellar ataxia. Clinical diagnostic accuracy is suboptimal in early disease because of phenotypic overlaps with Parkinson disease or other types of degenerative parkinsonism as well as with other cerebellar disorders. The symptomatic management of MSA requires a complex multimodal approach to compensate for autonomic failure, alleviate parkinsonism and cerebellar ataxia and associated disabilities. None of the available treatments significantly slows the aggressive course of MSA. Despite several failed trials in the past, a robust pipeline of putative disease-modifying agents, along with progress towards early diagnosis and the development of sensitive diagnostic and progression biomarkers for MSA, offer new hope for patients.

Coenzyme Q10 and Parkinsonian Syndromes: A Systematic Review

Coenzyme Q₁₀ (CoQ₁₀) has an important role as an antioxidant. Being that oxidative stress is one of the mechanisms involved in the pathogenesis of Parkinson’s disease (PD) and other neurodegenerative diseases, several studies addressed the concentrations of CoQ₁₀ in the different tissues of patients with PD and other parkinsonian syndromes (PS), trying to elucidate their value as a marker of these diseases. Other studies addressed the potential therapeutic role of CoQ₁₀ in PD and PS. We underwent a systematic review and a meta-analysis of studies measuring tissue CoQ₁₀ concentrations which shows that, compared with controls, PD patients have decreased CoQ₁₀ levels in the cerebellar cortex, platelets, and lymphocytes, increased total and oxidized CoQ₁₀ levels in the cerebrospinal fluid and a non-significant trend toward decreased serum/plasma CoQ₁₀ levels. Patients with multiple system atrophy (MSA) showed decreased CoQ₁₀ levels in the cerebellar cortex, serum/plasma, cerebrospinal fluid, and skin fibroblasts. Patients with Lewy body dementia (LBD) showed decreased cerebellar cortex CoQ₁₀, and those with progressive supranuclear palsy (PSP) had decreased CoQ₁₀ levels in the cerebrospinal fluid. A previous meta-analysis of studies addressing the therapeutic effects of CoQ₁₀ in PD showed a lack of improvement in patients with early PD. Results of the treatment with CoQ₁₀ in PSP should be considered preliminary. The potential role of CoQ₁₀ therapy in the MSA and selected groups of PD patients deserves future studies.

Cytokines, miRNAs, and Antioxidants as Combined Non-invasive Biomarkers for Parkinson's Disease

Parkinson's disease (PD) is one of the most common long-term degenerative disorders of the CNS that primarily affects the human locomotor system. Owing to the heterogeneity of PD etiology and the lack of appropriate diagnostic tests, blood-based biomarkers became the most promising method for diagnosing PD. Even though various biomarkers for PD have been found, their specificity and sensitivity are not optimum when used alone. Therefore, the aim of this study was directed to evaluate changes in a group of sensitive blood-based biomarkers in the same PD patients compared to healthy individuals. Serum samples were collected from 20 PD patients and 15 age-matched healthy controls. We analyzed serum levels of cytokines (IL10, IL12, and TNF-α), α-synuclein proteins, miRNAs (miR-214, miR-221, and miR-141), and antioxidants (UA, PON1, ARE). Our results showed an increase in sera levels of cytokines in PD patients as well as a positive correlation among them. Also, we found a significant increase in sera levels of α-synuclein protein associated with a decrease in miR-214 which regulates its gene expression. Lastly, we observed a decrease in sera levels of miR-221, miR-141, UA, PON1, and ARE, which have a prominent role against oxidative stress. Because of the many etiologies of PD, a single measure is unlikely to become a useful biomarker. Therefore, to correctly predict disease state and progression, a mix of noninvasive biomarkers is required. Although considerable work has to be done, this study sheds light on the role of certain biomarkers in the diagnosis of PD.

Levels of Plasma Coenzyme Q10 Are Associated with Physical Capacity and Cardiovascular Risk in the Elderly

Coenzyme Q10 (CoQ10) is an essential factor for mitochondrial activity and antioxidant protection of cells, tissues and plasma lipoproteins. Its deficiency has been associated with aging progression in animals and humans. To determine if CoQ10 levels in plasma can be associated with frailty in elderly people (aged > 65), we studied the relationship of CoQ10 levels in blood with other parameters in plasma and with the physical activity and capacity in aged people. Our results indicate that high CoQ10 levels are directly associated with lower cardiovascular risk measured by the quotient total cholesterol/HDL cholesterol. Furthermore, high CoQ10 levels were found in people showing higher physical activity, stronger muscle capacity. CoQ10 also showed a strong inverse relationship with sedentarism and the up and go test, which is considered to be a frailty index. Interestingly, we found gender differences, indicating stronger correlations in women than in men. The importance of the maintenance of CoQ10 levels in elderly people to avoid sarcopenia and frailty in elderly people is discussed.

Opposite Roles of Co-enzyme Q10 and Formaldehyde in Neurodegenerative Diseases

Most of neurodegenerative diseases (NDD) have no cure. The common etiology of neurodegenerations is unclear. Air pollutant-gaseous formaldehyde is notoriously known to induce demyelination and cognitive impairments. Unexpectedly, an amount of formaldehyde has been detected in the brains. Multiple factors can induce the generation and accumulation of endogenous formaldehyde. Excessive formaldehyde can induce oxidative stress to generate H2O2; in turn, H2O2 promote formaldehyde production. Clinical investigations have shown that an abnormal high level of formaldehyde but low level of coenzyme Q10 (coQ10) was observed in patients with NDD. Further studies have proven that excessive formaldehyde directly inactivates coQ10, reduces the ATP generation, enhances oxidative stress, initiates inflammation storm, induces demyelination; subsequently, it results in neurodegeneration. Although the low water solubility of coQ10 limits its clinical application, nanomicellar water-soluble coQ10 exhibits positive therapeutical effects. Hence, nanopackage of coQ10 may be a promising strategy for treating NDD.

Secondary coenzyme Q deficiency in neurological disorders

Coenzyme Q (CoQ) is a ubiquitous lipid serving essential cellular functions. It is the only component of the mitochondrial respiratory chain that can be exogenously absorbed. Here, we provide an overview of current knowledge, controversies, and open questions about CoQ intracellular and tissue distribution, in particular in brain and skeletal muscle. We discuss human neurological diseases and mouse models associated with secondary CoQ deficiency in these tissues and highlight pharmacokinetic and anatomical challenges in exogenous CoQ biodistribution, recent improvements in CoQ formulations and imaging, as well as alternative therapeutical strategies to CoQ supplementation. The last section proposes possible mechanisms underlying secondary CoQ deficiency in human diseases with emphasis on neurological and neuromuscular disorders.

Diagnostic utility of fluid biomarkers in multiple system atrophy: a systematic review and meta-analysis

BACKGROUND

Multiple system atrophy (MSA) is an adult onset, fatal neurodegenerative disease. However, no reliable biomarker is currently available to guide clinical diagnosis and help to determine the prognosis. Thus, a comprehensive meta-analysis is warranted to determine effective biomarkers for MSA and provide useful guidance for clinical diagnosis.

METHODS

A comprehensive literature search was made of the PubMed, Embase, Cochrane and Web of Science databases for relevant clinical trial articles for 1984-2019. Two review authors examined the full-text records, respectively, and determined which studies met the inclusion criteria. We estimated the mean difference, standard deviation and 95% confidence intervals.

RESULTS

A total of 28 studies and 11 biomarkers were included in our analysis. Several biomarkers were found to be useful to distinguish MSA patients from healthy controls, including the reduction of phosphorylated tau, α-synuclein (α-syn), 42-amino-acid form of Aβ and total tau (t-tau), the elevation of neurofilament light-chain protein (NFL) in cerebrospinal fluid, the elevation of uric acid and reduction of homocysteine and coenzyme Q10 in plasma. Importantly, α-syn, NFL and t-tau could be used to distinguish MSA from Parkinson's disease (PD), indicating that these three biomarkers could be useful biomarkers in MSA diagnosis.

CONCLUSION

The findings of our meta-analysis demonstrated diagnostic biomarkers for MSA. Moreover, three biomarkers could be used in differential diagnosis of MSA and PD. The results could be helpful for the early diagnosis of MSA and the accuracy of MSA diagnosis.