Angela De Iuliis

Identification of circulating microRNAs for the differential diagnosis of Parkinson's disease and Multiple System Atrophy

Background: Parkinsons disease (PD) is a progressive neurodegenerative disorder which may be misdiagnosed with atypical conditions such as Multiple System Atrophy (MSA), due to overlapping clinical features. MicroRNAs (miRNAs) are small non-coding RNAs with a key role in post-transcriptional gene regulation. We hypothesized that identification of a distinct set of circulating miRNAs (cmiRNAs) could distinguish patients affected by PD from MSA and healthy individuals. Results. Using TaqMan Low Density Array technology, we analyzed 754 miRNAs and found 9 cmiRNAs differentially expressed in PD and MSA patients compared to healthy controls. We also validated a set of 4 differentially expressed cmiRNAs in PD and MSA patients vs. controls. More specifically, miR-339-5p was downregulated, whereas miR-223*, miR-324-3p, and mir-24 were upregulated in both diseases. We found cmiRNAs specifically deregulated in PD (downregulation of miR-30c and miR-148b) and in MSA (upregulation of miR-148b). Finally, comparing MSA and PD, we identified 3 upregulated cmiRNAs in MSA serum (miR-24, miR-34b, miR-148b). Conclusions. Our results suggest that cmiRNA signatures discriminate PD from MSA patients and healthy controls and may be considered specific, non-invasive biomarkers for differential diagnosis.

Enzymatic dopamine peroxidation in substantia nigra of human brain.

The main metabolic pathway affected in Parkinsons disease is that of dopamine oxidation and melanin formation in substantia nigra which involves both oxidative and reductive enzymes. The cyclic nature of the biosynthetic pathway from dopamine to melanin implies that a derangement at any of the steps may result in the disappearance of melanin. Possible pathogenetic events such as oxidative stress have therefore no clearcut interpretation since they may be both cause or consequence of the disease. This paper documents the existence of a peroxidase converting dopamine to dopaminochrome in the presence of hydrogen peroxide in the substantia nigra of autopsied human brain. The activatory effect of dopaminochrome on a purified peroxidase is shown, together with the inhibitory effect of dopaminochrome-derived melanin and the activatory effect of melanin/Fe. The toxic effect of dopaminochrome on murine neuroblastoma cells cultured in vitro is demonstrated together with the inhibition of dopaminochrome melanization induced by acetylcholine in vitro.

The biochemical basis of Parkinson's disease: The role of catecholamineo-quinones: A review-discussion

This paper reviews the possible role of catecholamineo-quinones (OQs) in the genesis of Parkinsons disease (PD). This disease is characterized by damage caused to the pigmented catecholaminergic cells in various areas of the brain. The pigment involved is neuromelanin that is the end product of catecholamine oxidation by theo-quinone route. Evidence is presented regarding the overproduction in PD of these catecholamine OQs that damage the electron chain in the mitochondria leading to cell death. The roles of glutathione S-transferase and reactive oxygen species in this are also surveyed. A review of all known biochemical properties of theseo-quinones is included. The hypothesis is put forward that an important factor in the genesis of PD may be the overload by environmental toxins of enzymes such as glutathioneS-transferase that also detoxify catecholamine OQs.

Differences of ropivacaine and bupivacaine relevant to antiinflammatory actvity, platelet aggregation and antioxidant activity in vitro

Ropivacaine and bupivacaine affect the in vitro growth of rat fibroblasts and monkey kidney Vero cells with bupivacaine generally showing the stronger effect. Up to 3 mM concentration the two anesthetics affect the expression of genes differently for CD2, CD3 gamma, CD40L, IL-2, IL-2R alpha, IL-2R beta, IL-2R gamma, IL-4, and IL-4R during activation of human lymphocytes, with bupivacaine showing the higher effect. Human platelet aggregation is inhibited by the two anesthetics which also show an antioxidant effect on lipid peroxidation of rat liver microsomes. In both cases bupivacaine seems more active than ropivacaine.

Novel copper amine oxidase activity from rat liver mitochondria matrix.

Copper containing amine oxidases (Cu-AO) represent a heterogeneous class of enzymes classified as EC 1.4.3.6. The present study reports preliminary results on the presence of a novel amine oxidase activity in rat liver mitochondria lysates. Such enzymatic activity was found in the soluble mitochondrial fraction, obtained by simple osmotic shock. The mitochondrial amine oxidase was isolated by affinity chromatography on a newly synthesised spermine-Sepharose. SDS-PAGE showed a single band at about 60kDa. Upon chromatographic purification, the enzymatic activity was very labile. The crude enzyme activity was tested by spectrophotometric measurements, determining hydrogen peroxide production following oxidative deamination of different substrates, such as polyamines (spermine, spermidine, putrescine and cadaverine) and monoamines (dopamine and benzylamine). The activity, observed on polyamines and not on monoamines, was inhibited by semicarbazide and azide, but not by pargyline, clorgyline and l-deprenil. Enzyme specificity was tested on several diamines characterized by different carbon atom chain length in the range 2-6 carbon atoms. The highest activity was found with 1,2-diamino-ethane and the highest affinity with 1,5-diamino-pentane. The above reported results suggest the presence of a novel copper-dependent amine oxidase in liver mitochondria matrix.

Nigral anatomy and striatal denervation in genetic Parkinsonism: A family report.

The pathological hallmark in Parkinson’s disease (PD) is the neuronal loss in substantia nigra (SN) compacta, particularly in the ventrolateral tier neurons. A recent study with 7T-magnetic resonance imaging (MRI) demonstrated in PD patients the loss of the three-layered organization of the SN, specifically of its intermediate component (compacta ventralis); however, if such a nigral change appears early or in the late PD stage is unknown. We report a family carrying the same G2019S LRRK2 gene mutation; two were asymptomatic, the mother and her son, and one was affected, her daughter (disease duration, 3 y; ON—Unified Parkinson’s Disease Rating Scale motor score: 12, without any cognitive or psychiatric complications). The MRI scans targeted on SN were performed with a 7T GE 950 MRI scanner (GE Healthcare Medical Systems, Milwaukee, WI, USA), and both image acquisition and evaluation were performed according to previously published methodology at different midbrain levels along the rostro-caudal axis, at the level of the inferior third of the red nucleus (level I), and of the superior cerebellar peduncles decussation (level II). The SN was judged as “abnormal” if the tri-layered structure or nigrosome formation were not detectable at least at one side of the midbrain. All subjects underwent a single-photon emission computed tomography (SPECT) study using the dopamine transporter ligand 123I-FP-CIT. Single-photon emission computed tomography was defined as “pathological” when tracer uptake values were at least 2 standard deviations below the mean values of a dataset of healthy controls. In case 1, the MRI was evaluated as “abnormal,” because the normal anatomy was lost on both sides at level II and at the right side on level I (Fig. 1A); case 2 was evaluated as “healthy” (Fig. 1B). In case 3, presenting PD, the SN was evaluated as “abnormal” for its homogenous hypointense structure (Fig 1C). In all three family members carrying the same G2019S LRRK2 gene mutations, a clearcut reduction of [123 I]N-x-fluoropropyl-2b-carbomethoxy-3b-{4-iodophenyl}nortropane (123I-FP-CIT) striatal uptake was reported (Fig. 1A-C). The nigral changes detected by 7T MRI are presumably attributable to the loss of melanized neurons or an increase of iron deposition, which can occur in the substantia nigra compacta of sporadic as well as in monogenic PD patients. In case 2, the inconsistency between preserved nigral anatomy and impaired nigrostriatal pathway could be attributable to the fact that 123I-FP-CIT SPECT reflects an early alteration of dopaminergic synapses preceding cells depletion and iron accumulation, which could be delayed with respect to striatal denervation and dopamine nerve terminals loss. Conversely, possibly compensatory down-regulation of the dopamine transporter (DAT) could overestimate the extent of nigral degeneration in the premotor disease stage when it is presumably undetectable by MRI. In case 1 (83 y old), the nigral MR pattern was abnormal, probably indicating a forthcoming conversion to clinical parkinsonism, considering that the risk of PD for a person carrying the LRRK2 G2019S mutation markedly increases with aging. Follow-up of the two asymptomatic cases could provide additional information on the relationship between nigral MRI changes and clinical phenoconversion.

Erratum to: Preliminary kinetic characterization of a copper amine oxidase from rat liver mitochondria matrix

Unfortunately, Table 1 of the original article was published with errors. Some of the signs of electrical charges of terminal amino groups of polyamines had negative charges instead of positive charges. The correct version of Table 1 is produced here. The correct affiliation of Enzo Agostinelli is given below: Istituto Pasteur-Fondazione Cenci Bolognetti, Department of Biochemical Sciences, SAPIENZA University of Rome and CNR, Institute Biology and Molecular Pathology, Piazzale Aldo Moro 5, 00185 Rome, Italy. Table 1 Structure and chain length of amines used as MMAO substrates