Circulating antibodies to cysteinyl catecholamines in amyotrophic lateral sclerosis and Parkinson's disease patients

SERS-based detection of 5-S-cysteinyl-dopamine as a novel biomarker of Parkinson's disease in artificial biofluids

The early detection of Parkinson's disease (PD) can significantly improve treatment and quality of life in patients. 5-S-Cysteinyl-dopamine (CDA) is a key metabolite of high relevance for the early detection of PD. Therefore, its sensitive detection with fast and robust methods can improve its use as a biomarker. In this work we show the potentialities of label-free SERS spectroscopy in detecting CDA in aqueous solutions and artificial biofluids, with a simple, fast and sensitive approach. We present a detailed experimental SERS band assignment of CDA employing silver nanoparticle (AgNP) substrates in aqueous media, which was supported by theoretical calculations and simulated Raman and SERS spectra. The tentative orientation of CDA over the AgNP was also studied, indicating that catechol and carboxylic acid play a key role in the metallic surface adsorption. Moreover, we showed that SERS can allow us to identify CDA in aqueous media at low concentration, leading to the identification of some of its characteristic bands in pure water and in synthetic cerebrospinal fluid (SCSF) below 1 × 10^-8 M, while its band identification in simulated urine (SUR) can be reached at 1 × 10^-7 M. In conclusion, we show that CDA can be suitably detected by means of label-free SERS spectroscopy, which can significantly improve its sensitive detection for further analytical studies as a novel biomarker and further clinical diagnosis in PD patients.

Mussel-inspired biomaterials: From chemistry to clinic

After several billions of years, nature still makes decisions on its own to identify, develop, and direct the most effective material for phenomena/challenges faced. Likewise, and inspired by the nature, we learned how to take steps in developing new technologies and materials innovations. Wet and strong adhesion by Mytilidae mussels (among which Mytilus edulis-blue mussel and Mytilus californianus-California mussel are the most well-known species) has been an inspiration in developing advanced adhesives for the moist condition. The wet adhesion phenomenon is significant in designing tissue adhesives and surgical sealants. However, a deep understanding of engaged chemical moieties, microenvironmental conditions of secreted proteins, and other contributing mechanisms for outstanding wet adhesion mussels are essential for the optimal design of wet glues. In this review, all aspects of wet adhesion of Mytilidae mussels, as well as different strategies needed for designing and fabricating wet adhesives are discussed from a chemistry point of view. Developed muscle-inspired chemistry is a versatile technique when designing not only wet adhesive, but also, in several more applications, especially in the bioengineering area. The applications of muscle-inspired biomaterials in various medical applications are summarized for future developments in the field.

5-S-cysteinyl-dopamine, a neurotoxic endogenous metabolite of dopamine: Implications for Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disease worldwide and is characterized for being an idiopathic and multifactorial disease. Extensive research has been conducted to explain the origin of the disease, but it still remains elusive. It is well known that dopamine oxidation, through the endogenous formation of toxic metabolites, is a key process in the activation of a cascade of molecular events that leads to cellular death in the hallmark of PD. Thio-catecholamines, such as 5-S-cysteinyl-dopamine, 5-S-glutathionyl-dopamine and derived benzothiazines, are endogenous metabolites formed in the dopamine oxidative degradation pathway. Those metabolites have been shown to be highly toxic to neurons in the substantia nigra pars compacta, activating molecular mechanisms that ultimately lead to neuronal death. In this review we describe the origin, formation and the toxic effects of 5-S-cysteinyl-dopamine and its oxidative derivatives that cause death to dopaminergic neurons. Furthermore, we correlate the formation of those metabolites with the neurodegeneration progress in PD. In addition, we present the reported neuroprotective strategies of products that protect against the cellular damage of those thio-catecholamines. Finally, we discuss the advantages in the use of 5-S-cysteinyl-dopamine as a potential biomarker for PD.

The mercapturomic profile of health and non-communicable diseases

The mercapturate pathway is a unique metabolic circuitry that detoxifies electrophiles upon adducts formation with glutathione. Since its discovery over a century ago, most of the knowledge on the mercapturate pathway has been provided from biomonitoring studies on environmental exposure to toxicants. However, the mercapturate pathway-related metabolites that is formed in humans—the mercapturomic profile—in health and disease is yet to be established. In this paper, we put forward the hypothesis that these metabolites are key pathophysiologic factors behind the onset and development of non-communicable chronic inflammatory diseases. This review goes from the evidence in the formation of endogenous metabolites undergoing the mercapturate pathway to the methodologies for their assessment and their association with cancer and respiratory, neurologic and cardiometabolic diseases.

In utero and early-life exposure of rats to a Wi-Fi signal: screening of immune markers in sera and gestational outcome

An experimental approach was used to assess immunological biomarkers in the sera of young rats exposed in utero and postnatal to non-ionizing radiofrequency fields. Pregnant rats were exposed free-running, 2 h/day and 5 days/week to a 2.45 GHz Wi-Fi signal in a reverberation chamber at whole-body specific absorption rates (SAR) of 0, 0.08, 0.4, and 4 W/kg (with 10, 10, 12, and 9 rats, respectively), while cage control rats were kept in the animal facility (11 rats). Dams were exposed from days 6 to 21 of gestation and then three newborns per litter were further exposed from birth to day 35 postnatal. On day 35 after birth, all pups were sacrificed and sera collected. The screening of sera for antibodies directed against 15 different antigens related to damage and/or pathological markers was conducted using enzyme-linked immunosorbent assay (ELISA). No change in humoral response of young pups was observed, regardless of the types of biomarker and SAR levels. This study also provided some data on gestational outcome following in utero exposure to Wi-Fi signals. Mass evaluation of dams and pups and the number of pups per litter was monitored, and the genital tracts of young rats were observed for abnormalities by measuring anogenital distance. Under these experimental conditions, our observations suggest a lack of adverse effects of Wi-Fi exposure on delivery and general condition of the animals.

Evaluation of GSH adducts of adrenaline in biological samples

The sustained high release of catecholamines to circulation is a deleterious condition that may induce toxicity, which seems to be partially related to the products formed by oxidation of catecholamines that can be further conjugated with glutathione (GSH). The aim of the present study was to develop a method for the determination of GSH adducts of adrenaline in biological samples. Two position isomers of the glutathion-S-yl-adrenaline were synthesized and characterized by HPLC using diode array, coulometric and mass detectors. A method for the extraction of these adducts from human plasma was also developed, based on adsorption to activated alumina, which showed adequate recoveries and proved to be crucial in removing interferences from plasma. The selectivity, precision and linearity of the method were all within the accepted values for these parameters. Furthermore, the sensitivity of this method allows the detection of adduct amounts that are within the range of the expected concentrations for these adducts under certain pathophysiological conditions and/or drug treatments. In conclusion, the development of this method allows the direct analysis of GSH adducts of adrenaline in human plasma, providing a valuable tool for the study of the catecholamine oxidation process and its related toxicity.