Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant cerebellar ataxia characterized by a progressive cerebellar syndrome associated to saccadic slowing, peripheral neuropathy, cognitive disorders, and other multisystem features. SCA2 is caused by the abnormal expansion of cytosine-adenine-guanine triplet repeats in the encoding region of the ATXN2 gene and therefore the expression of toxic polyglutamine expansions in the ataxin 2 protein, which cause progressive neuronal death of Purkinje cells in the cerebellum and several pontine, mesencephalic, and thalamic neurons among other cells. Worldwide, SCA2 is the second most frequent type of spinocerebellar ataxia, only surpassed by SCA3. Nevertheless, in Holguin, Cuba, the disease reaches the highest prevalence, resulting from a putative foundational effect. This review discusses the most important advances in the genotypical and phenotypical studies of SCA2, highlighting the comprehensive characterization reached in Cuba through clinical, neuroepidemiological, neurochemical, and neurophysiological evaluation of SCA2 patients and presymptomatic subjects, which has allowed the identification of new disease biomarkers and therapeutical opportunities. These findings provide guidelines, from a Cuban viewpoint, for the clinical management of the disease, its diagnosis, genetic counseling, and therapeutical options through rehabilitative therapy and/or pharmacological options.

Intranasal delivery provides a practical, noninvasive method of bypassing the blood-brain barrier (BBB) in order to deliver therapeutic agents to the brain. This method allows drugs that do not cross the BBB to be delivered to the central nervous system in a few minutes. With this technology, it will be possible to eliminate systemic administration and its potential side effects. Using the intranasal delivery system, researchers have demonstrated neuroprotective effects in different animal models of stroke using erythropoietin (EPO) as a neuroprotector or other different types of EPO without erythropoiesis-stimulating activity. These new molecules retain their ability to protect neural tissue against injury and they include Asialoerythropoietin (asialoEPO) carbamylated EPO (CEPO), and rHu-EPO with low sialic acid content (Neuro-EPO). Contrary to the other EPO variants, Neuro-EPO is not chemically modified, making it biologically similar to endogenous EPO, with the advantage of less adverse reactions when this molecule is applied chronically. This constitutes a potential benefit of Neuro-EPO over other variants of EPO for the chronic treatment of neurodegenerative illnesses. Nasal administration of EPO is a potential, novel, neurotherapeutic approach. However, it will be necessary to initiate clinical trials in stroke patients using intranasal delivery in order to obtain the clinical evidence of its neuroprotectant capacity in the treatment of patients with acute stroke and other neurodegenerative disorders. This new therapeutic approach could revolutionize the treatment of neurodegenerative disorders in the 21 century.

BackgroundDelivery of therapeutic agents as erythropoietin (EPO) into Central Nervous System through intranasal route could benefit patients with neurological disorders. A new nasal formulation containing a non-hematopoietic recombinant EPO (NeuroEPO) has shown neuroprotective actions in preclinical models. In the current study, the safety of NeuroEPO was evaluated for the first time in humans.MethodsA phase I, randomized, parallel, open-label study was carried out in healthy volunteers. They received, intranasally, 1 mg of NeuroEPO every 8 h during 4 days (Group A) or 0.5 mg of NeuroEPO (Group B) with the same schedule. The working hypothesis was that intranasal NeuroEPO produce <10% of severe adverse reactions in the evaluated groups. Therefore, a rigorous assessment of possible adverse events was carried out, which included tolerance of the nasal mucosa and the effect on hematopoietic activity. Clinical safety evaluation was daily during treatment and laboratory tests were done before and on days 5 and 14 after starting treatment.ResultsTwenty-five volunteers, 56% women, with a mean age of 27 yrs. were included. Twelve of them received the highest NeuroEPO dose. Twenty types of adverse events occurred, with headache (20%) and increase of hepatic enzymes (20%) as the most reported ones. Nasopharyngeal itching was the most common local event but only observed in four patients (16%), all of them from the lowest dose group. About half of the events were very probably or probably caused by the studied product. Most of the events were mild (95.5%), did not require treatment (88.6%) and were completely resolved (81.8%). No severe adverse events were reported. During the study the hematopoietic variables were kept within reference values.ConclusionsNeuroEPO was a safe product, well tolerated at the nasal mucosa level and did not stimulate erythropoiesis in healthy volunteers.Trial registrationCuban Public Registry of Clinical Trials RPCEC00000157, June 10, 2013.

Cuban patients with Spinocerebellar Ataxia type 2 (SCA2) have reduced concentrations of zinc in serum and cerebrospinal fluid (CSF). To assess the effect and safety of zinc supplementation, 36 Cuban SCA2 patients were randomly assigned to receive daily either 50 mg ZnSO(4) or placebo, together with neurorehabilitation therapy in a randomized, double-blind, placebo-controlled clinical trial during 6 months. Outcome measures included the changes of zinc levels in CSF and serum, ataxia score, oxidative stress and saccadic eye movements. At the end of the study, the Zinc-treated group showed: (i) a significant increase of the Zn levels in the CSF, (ii) mild decrease in the ataxia scale subscores for gait, posture, stance and dysdiadochocinesia (iii) reduction of lipid's oxidative damage, and (iv) reduction of saccadic latency when compared with the placebo group. The treatment was safe and well tolerated by all subjects. This study demonstrated the efficacy and safety of Zn supplementation, combined with neurorehabilitation for SCA2 patients and therefore it may encourage further studies on the clinical effect of zinc supplementation in SCA2 based in the conduction of future clinical trials with higher number of subjects.

Understanding the role of oxidative injury will allow for therapy with agents that scavenge ROS (reactive oxygen species) and antioxidants in the management of several diseases related to free radical damage. The majority of free radicals are generated by mitochondria as a consequence of the mitochondrial cycle, whereas free radical accumulation is limited by the action of a variety of antioxidant processes that reside in every cell. In the present review, we provide an overview of the mitochondrial generation of ROS and discuss the role of ROS in the regulation of endothelial and adipocyte function. Moreover, we also discuss recent findings on the role of ROS in sepsis, cerebral ataxia and stroke. These results provide avenues for the therapeutic potential of antioxidants in a variety of diseases.

Spinocerebellar ataxia type 2 (SCA2) is a redox-sensitive neurodegenerative disease affecting the cerebellum, fibre connections in the cerebellum, the peripheral nervous system, and extracerebellar central pathways. Currently, Cuba has the highest reported global rate for this disease. The aim of this review article is to summarize and discuss the current knowledge about evidence of oxidative stress during SCA2. Recent reports have suggested that ataxin 2 and other related factors contribute to the redox imbalance in this disease. It is important to recognize and clarify the molecular mechanisms associated with the redox imbalance to consider ataxias innovative approaches to counteract oxidative stress-induced tissue damage, through alternative therapeutic or nutritional intervention in SCA2 and related diseases.

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Background Several pieces of evidence have shown the neurotrophic effect of erythropoietin (EPO) and its introduction in the therapeutic practice of neurological diseases. However, its usefulness in the treatment of spinocerebellar ataxia type 2 (SCA2) has not been proven despite the fact that it is endogenously reduced in these patients. Objective The study aims to investigate the safety, tolerability, and clinical effects of a nasally administered recombinant EPO in SCA2 patients. Methods Thirty‐four patients were enrolled in this double‐blind, randomized, placebo‐controlled, phase I–II clinical trial of the nasally administered human‐recombinant EPO (NeuroEPO) for 6 months. The primary outcome was the change in the spinocerebellar ataxia functional index (SCAFI), while other motor, neuropsychological, and oculomotor measures were assessed. Results The 6‐month changes in SCAFI score were slightly higher in the patients allocated to NeuroEPO treatment than placebo in spite of the important placebo effect observed for this parameter. However, saccade latency was significantly decreased in the NeuroEPO group but not in placebo. The frequency and severity of adverse events were similar between both groups, without evidences of hematopoietic activity of the drug. Conclusions This study demonstrated the safety and tolerability of NeuroEPO in SCA2 patients after 6 months of treatments and suggested a small clinical effect of this drug on motor and cognitive abnormalities, but confirmatory studies are warranted. © 2022 International Parkinson and Movement Disorder Society.