Ribose-cysteine and levodopa abrogate Parkinsonism via the regulation of neurochemical and redox activities in alpha-synuclein transgenic Drosophila melanogaster models.

Parkinson's disease (PD), the most prevalent type of parkinsonism, is a progressive neurodegenerative condition marked by several non-motor and motor symptoms. PD is thought to have a complex aetiology that includes a combination of age, genetic predisposition, and environmental factors. Increased expression of α-synuclein (α-Syn) protein is central to the evolvement of neuropathology in this devastating disorder, but the potential of ribose-cysteine and levodopa in abating pathophysiologic changes in PD model is unknown. Crosses were set up between flies conditionally expressing a pathological variant of human α-Syn (UAS-α-Syn) and those expressing GAL4 in neurons (elav-GAL4) to generate offspring referred to as PD flies. Flies were randomly assigned to five groups (n = 40) from the total population of flies, with each group having five replicates. Groups of PD flies were treated with either 500 mg/kg ribose-cysteine diet, 250 mg/kg levodopa diet, or a combination of the two compounds for 21 days, whereas the control group (w1118) and the PD group were exposed to a diet without ribose-cysteine or levodopa. In addition to various biochemical and neurochemical assays, longevity, larval motility, and gravitaxis assays were carried out. Locomotive capability, lifespan, fecundity, antioxidant state, and neurotransmitter systems were all significantly (p < 0.05) compromised by overexpression of α-Syn. However, flies treated both ribose cysteine and levodopa showed an overall marked improvement in motor functions, lifespan, fecundity, antioxidant status, and neurotransmitter system functions. In conclusion, ribose-cysteine and levodopa, both singly and in combination, potentiated a therapeutic effect on alpha-synuclein transgenic Drosophila melanogaster models of Parkinsonism.

Design, Synthesis and In Vitro Evaluation of Levodopa Stearic Acid Hydrazide Conjugate for the Management of Parkinson's DiseaseNovel Conjugate for Parkinson's Disease.

Parkinson's disease is the highest prevalent neurodegenerative disease in elderly individuals after Alzheimer's disease. The pathological identification for Parkinson's disease is loss of dopaminergic neurons in substantia nigra region of the brain that in turn leads to dopamine deficiency that affects the body's normal physiological and neurological disorder. The important drawback in the modality of treatment is levodopa is only supplying depleted dopamine in the brain, it does not affect neurodegeneration. Even though levodopa manages the disease, an alternative treatment strategy is required to stop or prevent further degeneration of neuron. The compound with neuroprotector activity suits the requirement. Of them, stearic acid plays a vital role in protecting neurons against oxidative stress through a Phosphoinositide 3-kinase-dependent mechanism. Hence, our present study aimed to design, synthesize, and characterize the levodopa stearic acid hydrazide conjugate. Additionally, evaluate the cytotoxicity of synthesized compound in SHSY5Y: cell lines. In brief, levodopa was conjugated to the stearic acid successfully and was confirmed with Fourier-transform infrared spectroscopy, Nuclear magnetic resonance, and Mass Spectroscopy. In vitro cell viability study in SHSY5Y: cell lines showed elevated cell viability in 0.134 µm concentration of Conjugate, and 0.563 µm concentration of levodopa. Showing that the synthesized compound could offer an improved treatment strategy for Parkinson's disease.

NanoIEA: A Nanopatterned Interdigitated Electrode Array-Based Impedance Assay for Real-Time Measurement of Aligned Endothelial Cell Barrier Functions.

A nanopatterned interdigitated electrode array (nanoIEA)-based impedance assay is developed for quantitative real-time measurement of aligned endothelial cell (EC) barrier functions in vitro. A bioinspired poly(3,4-dihydroxy-L-phenylalanine) (poly (l-DOPA)) coating is applied to improve the human brain EC adhesion onto the Nafion nanopatterned surfaces. It is found that a poly (l-DOPA)-coated Nafion grooved nanopattern makes the human brain ECs orient along the nanopattern direction. Aligned human brain ECs on Nafion nanopatterns exhibit increased expression of genes encoding tight and adherens junction proteins. Aligned human brain ECs also have enhanced impedance and resistance versus unaligned ones. Treatment with a glycogen synthase kinase-3 inhibitor (GSK3i) further increases impedance and resistance, suggesting synergistic effects occur on the cell-cell tightness of in vitro human brain ECs via a combination of anisotropic matrix nanotopography and GSK3i treatment. It is found that this enhanced cell-cell tightness of the combined approach is accompanied by increased expression of claudin protein. These data demonstrate that the proposed nanoIEA assay integrated with poly (l-DOPA)-coated Nafion nanopatterns and interdigitated electrode arrays can make not only biomimetic aligned ECs, but also enable real-time measurement of the enhanced barrier functions of aligned ECs via tighter cell-cell junctions.

Coupling High-Throughput and Targeted Screening for Identification of Nonobvious Metabolic Engineering Targets.

Identification of metabolic engineering targets is a fundamental challenge in strain development programs. While high-throughput (HTP) genetic engineering methodologies capable of generating vast diversity are being developed at a rapid rate, a majority of industrially interesting molecules cannot be screened at sufficient throughput to leverage these techniques. We propose a workflow that couples HTP screening of common precursors (e.g., amino acids) that can be screened either directly or by artificial biosensors, with low-throughput targeted validation of the molecule of interest to uncover nonintuitive beneficial metabolic engineering targets and combinations hereof. Using this workflow, we identified several nonobvious novel targets for improving p-coumaric acid (p-CA) and l-DOPA production from two large 4k gRNA libraries each deregulating 1000 metabolic genes in the yeast Saccharomyces cerevisiae. We initially screened yeast cells transformed with gRNA library plasmids for individual regulatory targets improving the production of l-tyrosine-derived betaxanthins, identifying 30 targets that increased intracellular betaxanthin content 3.5-5.7 fold. Hereafter, we screened the targets individually in a high-producing p-CA strain, narrowing down the targets to six that increased the secreted titer by up to 15%. To investigate whether any of the six targets could be additively combined to improve p-CA production further, we created a gRNA multiplexing library and subjected it to our proposed coupled workflow. The combination of regulating PYC1 and NTH2 simultaneously resulted in the highest (threefold) improvement of the betaxanthin content, and an additive trend was also observed in the p-CA strain. Lastly, we tested the initial 30 targets in a l-DOPA producing strain, identifying 10 targets that increased the secreted titer by up to 89%, further validating our screening by proxy workflow. This coupled approach is useful for strain development in the absence of direct HTP screening assays for products of interest.

A metabolomics study in aqueous humor discloses altered arginine metabolism in Parkinson's disease.

BACKGROUND: The lack of accessible and informative biomarkers results in a delayed diagnosis of Parkinson's disease (PD), whose symptoms appear when a significant number of dopaminergic neurons have already disappeared. The retina, a historically overlooked part of the central nervous system (CNS), has gained recent attention. It has been discovered that the composition of cerebrospinal fluid influences the aqueous humor composition through microfluidic circulation. In addition, alterations found in the brain of patients with PD have a correlate in the retina. This new paradigm highlights the potential of the aqueous humor as a sample for identifying differentially concentrated metabolites that could, eventually, become biomarkers if also found altered in blood or CSF of patients. In this research we aim at analyzing the composition of the aqueous humor from healthy controls and PD patients. METHODS: A targeted metabolomics approach with concentration determination by mass spectrometry was used. Statistical methods including principal component analysis and linear discriminants were used to select differentially concentrated metabolites that allow distinguishing patients from controls. RESULTS: In this first metabolomics study in the aqueous humor of PD patients, elevated levels of 16 compounds were found; molecules differentially concentrated grouped into biogenic amines, amino acids, and acylcarnitines. A biogenic amine, putrescine, alone could be a metabolite capable of differentiating between PD and control samples. The altered levels of the metabolites were correlated, suggesting that the elevations stem from a common mechanism involving arginine metabolism. CONCLUSIONS: A combination of three metabolites, putrescine, tyrosine, and carnitine was able to correctly classify healthy participants from PD patients. Altered metabolite levels suggest altered arginine metabolism. The pattern of metabolomic disturbances was not due to the levodopa-based dopamine replacement medication because one of the patients was not yet taking levodopa but a dopamine receptor agonist.

Limiting Monoamines Degradation Increases L-DOPA Pro-Locomotor Action in Newborn Rats.

L-DOPA, the precursor of catecholamines, exerts a pro-locomotor action in several vertebrate species, including newborn rats. Here, we tested the hypothesis that decreasing the degradation of monoamines can promote the pro-locomotor action of a low, subthreshold dose of L-DOPA in five-day-old rats. The activity of the degrading pathways involving monoamine oxidases or catechol-O-methyltransferase was impaired by injecting nialamide or tolcapone, respectively. At this early post-natal stage, the capacity of the drugs to trigger locomotion was investigated by monitoring the air-stepping activity expressed by the animals suspended in a harness above the ground. We show that nialamide (100 mg/kg) or tolcapone (100 mg/kg), without effect on their own promotes maximal expression of air-stepping sequences in the presence of a sub-effective dose of L-DOPA (25 mg/kg). Tissue measurements of monoamines (dopamine, noradrenaline, serotonin and some of their metabolites) in the cervical and lumbar spinal cord confirmed the regional efficacy of each inhibitor toward their respective enzyme. Our experiments support the idea that the raise of monoamines boost L-DOPA's locomotor action. Considering that both inhibitors differently altered the spinal monoamines levels in response to L-DOPA, our data also suggest that maximal locomotor response can be reached with different monoamines environment.

Downregulation of PACAP and the PAC1 Receptor in the Basal Ganglia, Substantia Nigra and Centrally Projecting Edinger-Westphal Nucleus in the Rotenone model of Parkinson's Disease.

Numerous in vitro and in vivo models of Parkinson's disease (PD) demonstrate that pituitary adenylate cyclase-activating polypeptide (PACAP) conveys its strong neuroprotective actions mainly via its specific PAC1 receptor (PAC1R) in models of PD. We recently described the decrease in PAC1R protein content in the basal ganglia of macaques in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of PD that was partially reversed by levodopa therapy. In this work, we tested whether these observations occur also in the rotenone model of PD in the rat. The rotarod test revealed motor skill deterioration upon rotenone administration, which was reversed by benserazide/levodopa (B/L) treatment. The sucrose preference test suggested increased depression level while the open field test showed increased anxiety in rats rendered parkinsonian, regardless of the received B/L therapy. Reduced dopaminergic cell count in the substantia nigra pars compacta (SNpc) diminished the dopaminergic fiber density in the caudate-putamen (CPu) and decreased the peptidergic cell count in the centrally projecting Edinger-Westphal nucleus (EWcp), supporting the efficacy of rotenone treatment. RNAscope in situ hybridization revealed decreased PACAP mRNA (Adcyap1) and PAC1R mRNA (Adcyap1r1) expression in the CPu, globus pallidus, dopaminergic SNpc and peptidergic EWcp of rotenone-treated rats, but no remarkable downregulation occurred in the insular cortex. In the entopeduncular nucleus, only the Adcyap1r1 mRNA was downregulated in parkinsonian animals. B/L therapy attenuated the downregulation of Adcyap1 in the CPu only. Our current results further support the evolutionarily conserved role of the PACAP/PAC1R system in neuroprotection and its recruitment in the development/progression of neurodegenerative states such as PD.

Enzymatic Phosphorylation of Oxidized Tyrosine Residues.

Post-translational modifications (PTMs) alter the function and fate of proteins and cells in almost every conceivable way. Protein modifications can occur as a result of specific regulating actions of enzymes, such as tyrosine kinases phosphorylating tyrosine residues or by nonenzymatic reactions, such as oxidation related to oxidative stress and diseases. While many studies have addressed the multisite, dynamic, and network-like properties of PTMs, only little is known of the interplay of the same site modifications. In this work, we studied the enzymatic phosphorylation of oxidized tyrosine (l-DOPA) residues using synthetic insulin receptor peptides, in which tyrosine residues were replaced with l-DOPA. The phosphorylated peptides were identified by liquid chromatography-high-resolution mass spectrometry and the site of phosphorylation by tandem mass spectrometry. The results clearly show that the oxidized tyrosine residues are phosphorylated, displaying a specific immonium ion peak in the MS2 spectra. Furthermore, we detected this modification in our reanalysis (MassIVE ID: MSV000090106) of published bottom-up phosphoproteomics data. The modification, where both oxidation and phosphorylation take place at the same amino acid, has not yet been published in PTM databases. Our data indicate that there can be multiple PTMs that do not exclude each other at the same modification site.

Yeast: A platform for the production of L -tyrosine derivatives.

L -Tyrosine derivatives are widely applied in the pharmaceutical, food, and chemical industries. Their production is mainly confined to chemical synthesis and plant extract. Microorganisms, as cell factories, exhibit promising advantages for valuable chemical production to fulfill the increase in the demand of global markets. Yeast has been used to produce natural products owing to its robustness and genetic maneuverability. Focusing on the progress of yeast cell factories for the production of L -tyrosine derivatives, we summarized the emerging metabolic engineering approaches in building L -tyrosoine-overproducing yeast and constructing cell factories of three typical chemicals and their derivatives: tyrosol, p-coumaric acid, and L -DOPA. Finally, the challenges and opportunities of L -tyrosine derivatives production in yeast cell factories were also discussed.

Parkinson's Disease Risk and Hyperhomocysteinemia: The Possible Link.

Parkinson's disease (PD) is one of the most common degenerative brain disorders caused by the loss of dopaminergic neurons in the substantia nigra (SN). Lewy bodies and -synuclein accumulation in the SN are hallmarks of the neuropathology of PD. Due to lifestyle changes and prolonged L-dopa administration, patients with PD frequently have vitamin deficiencies, especially folate, vitamin B6, and vitamin B12. These disorders augment circulating levels of Homocysteine with the development of hyperhomocysteinemia, which may contribute to the pathogenesis of PD. Therefore, this review aimed to ascertain if hyperhomocysteinemia may play a part in oxidative and inflammatory signaling pathways that contribute to PD development. Hyperhomocysteinemia is implicated in the pathogenesis of neurodegenerative disorders, including PD. Hyperhomocysteinemia triggers the development and progression of PD by different mechanisms, including oxidative stress, mitochondrial dysfunction, apoptosis, and endothelial dysfunction. Particularly, the progression of PD is linked with high inflammatory changes and systemic inflammatory disorders. Hyperhomocysteinemia induces immune activation and oxidative stress. In turn, activated immune response promotes the development and progression of hyperhomocysteinemia. Therefore, hyperhomocysteinemia-induced immunoinflammatory disorders and abnormal immune response may aggravate abnormal immunoinflammatory in PD, leading to more progression of PD severity. Also, inflammatory signaling pathways like nuclear factor kappa B (NF-κB) and nod-like receptor pyrin 3 (NLRP3) inflammasome and other signaling pathways are intricate in the pathogenesis of PD. In conclusion, hyperhomocysteinemia is involved in the development and progression of PD neuropathology either directly via induction degeneration of dopaminergic neurons or indirectly via activation of inflammatory signaling pathways.

Comparison of betalain compounds in two Beta vulgaris var. cicla and BvCYP76AD27 function identification in betalain biosynthesis.

Beta vulgaris var. cicla is an edible, ornamental and horticultural plant. However, the difference of components and contents of betalain in beets with different leaf color are not well understood. Here, the stress resistance and metabolites of two B. vulgaris var. cicla cultivars were determined. The differences in stress resistance between red leaf-colored chard (RC) and yellow leaf-colored chard (YC) were positively related to betacyanins (BC) and betaxathins (BX) content in the leaves. Furthermore, a total of 3615 distinct metabolites were identified by UPLC-QTOF-MS in two cultivars, including 70 alkaloids and their derivatives, 249 flavonoids, and 264 terpenoids. There were 17 metabolites attributed to betalain biosynthesis pathway, seven of nine BC were up-regulated, and eight BX showed no significant difference in RC compared with YC. The contents of celosianin II and betanin were the highest BC in RC, at approximately 84.38 and 19.97 times that of YC, respectively. The content of portulacaxanthin II was the highest BX in two beets. Additionally, the BvCYP450 genes were identified based on genome, and the members that might be involved in betalain biosynthesis were screened. BvCYP76AD27, a member of the BvCYP76AD subfamily, had a higher expression level in RC than YC under freezing, drought and shading stress. In yeast Saccharomyces cerevisiae, BvCYP76AD5 and BvCYP76AD27 only hydroxylated tyrosine to L-DOPA, which was transformed into portulacaxanthin II by 4,5-DOPA extradiol dioxygenase. The results contribute to illustrating the molecular mechanism of betalain biosynthesis and provide useful information for further investigation of beet chemistry and sufficient utilization of this species.

iPSC-based modeling of THD recapitulates disease phenotypes and reveals neuronal malformation.

Tyrosine hydroxylase deficiency (THD) is a rare genetic disorder leading to dopaminergic depletion and early-onset Parkinsonism. Affected children present with either a severe form that does not respond to L-Dopa treatment (THD-B) or a milder L-Dopa responsive form (THD-A). We generated induced pluripotent stem cells (iPSCs) from THD patients that were differentiated into dopaminergic neurons (DAn) and compared with control-DAn from healthy individuals and gene-corrected isogenic controls. Consistent with patients, THD iPSC-DAn displayed lower levels of DA metabolites and reduced TH expression, when compared to controls. Moreover, THD iPSC-DAn showed abnormal morphology, including reduced total neurite length and neurite arborization defects, which were not evident in DAn differentiated from control-iPSC. Treatment of THD-iPSC-DAn with L-Dopa rescued the neuronal defects and disease phenotype only in THDA-DAn. Interestingly, L-Dopa treatment at the stage of neuronal precursors could prevent the alterations in THDB-iPSC-DAn, thus suggesting the existence of a critical developmental window in THD. Our iPSC-based model recapitulates THD disease phenotypes and response to treatment, representing a promising tool for investigating pathogenic mechanisms, drug screening, and personalized management.

Restorative cell and gene therapies for Parkinson's disease.

One of the core pathological features of Parkinson's disease (PD) is the loss of the dopaminergic nigrostriatal pathway which lies at the heart of many of the motor features of this condition as well as some of the cognitive problems. The importance of this pathological event is evident through the clinical benefits that are seen when patients with PD are treated with dopaminergic agents, at least in early-stage disease. However, these agents create problems of their own through stimulation of more intact dopaminergic networks within the central nervous system causing major neuropsychiatric problems including dopamine dysregulation. In addition, over time the nonphysiological stimulation of striatal dopamine receptors by l-dopa containing drugs leads to the genesis of l-dopa-induced dyskinesias that can become very disabling in many cases. As such, there has been much interest in trying to better reconstitute the dopaminergic nigrostriatal pathway using either factors to regrow it, cells to replace it, or gene therapies to restore dopamine transmission in the striatum. In this chapter, we lay out the rationale, history and current status of these different therapies as well as highlighting where the field is heading and what new interventions might come to clinic in the coming years.

AdpAlin regulates lincomycin and melanin biosynthesis by modulating precursors flux in Streptomyces lincolnensis.

Lincomycin is one of the most important antibiotics. However, transcriptional regulation network of secondary metabolism in Streptomyces lincolnensis, the lincomycin producer, remained obscure. AdpA from S. lincolnensis (namely AdpAlin ) has been proved to activate lincomycin biosynthesis. Here we found that both lincomycin and melanin took l-tyrosine as precursor, and AdpAlin activated melanin biosynthesis as well. Three tyrosinases, MelC2, MelD2, and MelE, and one tyrosine peroxygenase, LmbB2, participated in lincomycin and melanin biosynthesis in different ways. For melanin biosynthesis, MelC2 was the only key enzyme required. For lincomycin biosynthesis, MelD2 and LmbB2 were positive factors and were suggested to convert l-tyrosine to l-dihydroxyphenylalanine (l-DOPA). Otherwise, MelC2 and MelE were negative factors for lincomycin biosynthesis and they were supposed to oxidize l-DOPA to generate melanin and certain unknown metabolite, respectively. Based on in silico analysis combined with electrophoretic mobility shift assays (EMSAs), we proved that AdpAlin directly interacted with promoters of melC, melD, and melE by binding to putative AdpA-binding sites in vitro. Moreover, in vivo experiments revealed that AdpAlin positively regulated the transcription of melC and melE, but negatively regulated melD. In conclusion, AdpAlin was the switch of secondary metabolism in S. lincolnensis, and it modulated precursor flux of lincomycin and melanin biosynthesis by directly activating melC, melE, and lmbB1/lmbB2 or repressing melD.

Self-Sufficient In Vitro Multi-Enzyme Cascade for Efficient Synthesis of Danshensu from l-DOPA.

Danshensu (DSS), a traditional Chinese medicine, is widely used for the treatment of cardiovascular and cancer diseases. Here, a one-pot multi-enzyme cascade pathway was designed for DSS synthesis from l-DOPA using tyrosine aminotransferase from Escherichia coli (EcTyrB) and d-isomer-specific 2-hydroxyacid dehydrogenase from Lactobacillus frumenti (LfD2-HDH). Glutamate dehydrogenase from Clostridium difficile (CdgluD) was also introduced for a self-sufficient system of α-ketoglutaric acid and NADH. Under optimal conditions (35 °C, pH 7.0, EcTyrB:LfD2-HDH:CdgluD = 3:2:1, glutamate:NAD+ = 1:1), 98.3% yield (at 20 mM l-DOPA) and space-time yield of 6.61 g L-1 h-1 (at 40 mM l-DOPA) were achieved. Decreased yields of DSS at elevated l-DOPA concentrations (100 mM) could be attributed to an inhibited CdgluD activity caused by NH4+ accumulation. This developed multi-enzyme cascade pathway (including EcTyrB, LfD2-HDH, and CdgluD) provides an efficient and sustainable approach for the production of DSS from l-DOPA.

Targeting G Protein-Coupled Receptors in the Treatment of Parkinson's Disease.

Parkinson's disease (PD) is a progressive neurodegenerative disease characterized in part by the deterioration of dopaminergic neurons which leads to motor impairment. Although there is no cure for PD, the motor symptoms can be treated using dopamine replacement therapies including the dopamine precursor L-DOPA, which has been in use since the 1960s. However, neurodegeneration in PD is not limited to dopaminergic neurons, and many patients experience non-motor symptoms including cognitive impairment or neuropsychiatric disturbances, for which there are limited treatment options. Moreover, there are currently no treatments able to alter the progression of neurodegeneration. There are many therapeutic strategies being investigated for PD, including alternatives to L-DOPA for the treatment of motor impairment, symptomatic treatments for non-motor symptoms, and neuroprotective or disease-modifying agents. G protein-coupled receptors (GPCRs), which include the dopamine receptors, are highly druggable cell surface proteins which can regulate numerous intracellular signaling pathways and thereby modulate the function of neuronal circuits affected by PD. This review will describe the treatment strategies being investigated for PD that target GPCRs and their downstream signaling mechanisms. First, we discuss new developments in dopaminergic agents for alleviating PD motor impairment, the role of dopamine receptors in L-DOPA induced dyskinesia, as well as agents targeting non-dopamine GPCRs which could augment or replace traditional dopaminergic treatments. We then discuss GPCRs as prospective treatments for neuropsychiatric and cognitive symptoms in PD. Finally, we discuss the evidence pertaining to ghrelin receptors, ß-adrenergic receptors, angiotensin receptors and glucagon-like peptide 1 receptors, which have been proposed as disease modifying targets with potential neuroprotective effects in PD.

Sleep benefit in patients with Parkinson's disease is associated with the dopamine transporter expression in putamen.

PURPOSE: Sleep benefit (SB) is a well-known phenomenon in patients with Parkinson's disease (PD); however, the mechanisms underlying this phenomenon remain unclear. This study aimed to evaluate whether the SB phenomenon in PD patients is associated with dopamine transporter (DAT) expression levels in the striatum. METHODS: The data of 125 PD patients were collected and divided into SB (n = 61) and non-SB (nSB) groups (n = 54) depending on whether they had SB or not. DAT expression on both sides of the striatum in PD patients was measured using 2b-carbomethoxy-3b-(4-trimethylstannylphenyl) tropane (11C-CFT) positron emission tomography imaging. The clinical variables, sleep scores, and striatum 11C-CFT uptake index of PD patients between the SB and nSB groups were compared. The associations of clinical variables, sleep scores, and striatum 11C-CFT uptake index with the SB variable were analyzed using logistic regression analysis. A receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of the striatum 11C-CFT uptake index in distinguishing SB patients from nSB patients. RESULTS: The tremor subtype ratio (P = 0.011), levodopa equivalent daily dose (LEDD) (P < 0.001), sleep efficiency score (P = 0.025), habitual sleep efficiency (P = 0.012), and night sleep duration (P = 0.005) in the SB group were significantly different from those in the nSB group. The 11C-CFT uptake index in both the contralateral and ipsilateral striata in the SB group was significantly higher than that in the nSB group (P < 0.05). The binary logistic regression showed that SB variables were significantly and independently associated with tremor subtype (P = 0.048), LEDD (P = 0.021), sleep duration at night (P = 0.035), 11C-CFT uptake index in the contralateral (P = 0.013) and ipsilateral (P = 0.019) putamen in PD patients after correction for important clinical confounders. ROC analysis showed that the 11C-CFT uptake index on the onset side of the putamen had a high capacity (AUC: 0.916) to distinguish SB patients from nSB patients with high sensitivity (83.33 %) and specificity (88.89 %). CONCLUSION: DAT expression in the putamen was associated with the SB phenomenon in PD patients, and the putamen DAT expression level could predict the SB phenomenon in PD patients.

MPTP induces neurodegeneration by modulating dopaminergic activity in catfish brain.

Tyrosine hydroxylase (Th) is an allosteric rate-limiting enzyme in catecholamine (CA) biosynthesis. The CAs, dopamine (DA), norepinephrine (NE), and epinephrine are important neurotransmitters wherein DA contributes a key role in the central nervous system of vertebrates. The present study evaluated DA and Th's significance in DA-ergic activity and neurodegeneration upon 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) exposure in catfish. Further, the expression of certain brain-and ovary-related genes measured through qPCR were downregulated upon MPTP treatment which is in accordance with the decreased levels of L-Dopa, DA, and NE levels estimated through HPLC-ECD. Additionally, TEM analysis depicted structural disarray of brain upon MPTP exposure and also decreased serum levels of testosterone, 11-ketotestosterone, and estradiol-17ß. MPTP treatment, in vitro, using primary brain cell culture resulted in diminished cell viability and increased ROS levels leading to elevated apoptotic cells significantly. Consequently, the study highlights the MPTP-induced neurodegeneration of the Th and DA-ergic activity in corroboration with female brain-related genes downregulation, also gonadal function as evidenced by depleted sex steroids level and low expression of ovary-related genes.

Avoiding One-Electron Oxidation of Biomolecules by 3,4-Dihydroxy-L-Phenylalanine (DOPA)†.

It has been proposed that 3,4-dihydroxy-L-phenylalanine (DOPA) has antioxidant properties, and thus, the objective of this work was to evaluate the effect of adding DOPA during the photosensitized oxidation of tyrosine (Tyr), tryptophan (Trp), histidine (His), 2'-deoxyguanosine 5'-monophosphate (dGMP) and 2'-deoxyadenosine 5'-monophosphate (dAMP). It was observed that, upon pterin-photosensitized degradation of a given biomolecule in acidic aqueous solutions, the rate of the biomolecule consumption decreases due to the presence of DOPA. Although DOPA deactivates the excited states of pterin (Ptr), biomolecules do as well, being the bimolecular quenching constants in the diffusional control limit, indicating that DOPA antioxidant mechanism is not a simple deactivation of Ptr excited states. Laser flash photolysis experiments provide evidence of the formation of DOPA radical (DOPA(-H)• , λMAX 310 nm), which is formed in a timescale longer than Ptr triplet excited state (3 Ptr*) lifetime, ruling out its formation in a reaction between DOPA and 3 Ptr*. The experimental results presented in this work indicate that the observed decrease on the rate of each biomolecule consumption due to the presence of DOPA is through a second one-electron transfer reaction from DOPA to the biomolecule radicals.

Anti-Inflammatory Activity of Velvet Bean (Mucuna pruriens) Substances in LPS-Stimulated RAW 264.7 Macrophages.

In this study, Mucuna pruriens extracts were used to verify their application as a natural-based raw material with anti-inflammatory function. A nitric oxide inhibition activity assay showed that M. pruriens extracted with hot water (MW), M. pruriens extracted with 70% ethanol (ME), and M. pruriens extracted with 70% acetone (MA) presented NO inhibition activity; among them, MW and ME demonstrated the best activity and were selected for Western blot analysis. After identifying the expression patterns of inflammation-related proteins, such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), c-jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB), through Western blots, both MW and ME showed inhibition patterns. As a result of analyzing L-DOPA contained in M. pruriens through ultra-performance liquid chromatography (UPLC), high L-DOPA content was detected in MW, ME, and MA. Therefore, it can be concluded that M. pruriens extracts have the potential for use as an anti-inflammatory material.