Complexation of C-Functionalized Cyclams with Copper(II) and Zinc(II): Similarities and Changes When Compared to Parent Cyclam Analogues.

Herein, we report a comprehensive coordination study of the previously reported ligands cyclam, CB-cyclam, TMC, DMC, and CB-DMC and of their C-functional analogues, cyclam-E, CB-cyclam-E, TMC-E, DMC-E, and CB-DMC-E. This group of ligands includes cyclam, cross-bridged cyclams, their di- or tetramethylated derivatives, and the analogues bearing an additional hydroxyethyl group on one ß-N position of the ring. The Cu(II) and Zn(II) complexes of these macrocycles have been highlighted previously for the biological interest, but the details of their structures in the solid state and in solution remained largely unexplored. In particular, we analyzed the impact that adding noncoordinating N-methyl and C-hydroxyethyl functionalities has in the structures of the complexes. All the Cu(II) and Zn(II) complexes were synthesized and investigated using single crystal X-ray diffraction and NMR, electronic absorption, and EPR spectroscopies, along with DFT studies. Dissociation kinetics experiments in acidic conditions and electrochemical studies were also performed. Special attention was paid to analyze the different configurations present in solution and in the solid state, as well as the impact of the C-appended hydroxyethyl group on the coordination behavior. Various ratios of the trans-I, trans-III, and cis-V configurations have been observed depending on the degree of N-methylation and the presence of the ethylene cross-bridge.

Full control of the regiospecific N-functionalization of C-functionalized cyclam bisaminal derivatives and application to the synthesis of their TETA, TE2A, and CB-TE2A analogues.

We describe an easy synthesis of original C-functionalized cyclam derivatives based on the efficient bisaminal template method. In the perspective of developing bifunctional chelating agents (BCAs), this new synthetic strategy offers the possibility of introducing various coupling functions on one carbon atom in the ß-N position of the macrocycle, leaving the four nitrogen atoms available for the introduction of pendant coordinating arms. The methodology is based on a keystone C-functionalized oxo-cyclam bisaminal intermediate that is obtained by cyclization of a preorganized tetraamine using various methyl acrylate analogues. These compounds constitute valuable precursors for selective preparation of mono- and di-N-protected C-functionalized cyclams and C-functionalized cyclams, cross-bridged cyclams, and oxo-cyclam derivatives. This approach was successfully adapted to the synthesis of three BCAs with great interest especially for biomedical applications: TETA, TE2A, and CB-TE2A. The structures of different intermediates and Cu(II) complexes of C-functionalized cyclam derivatives were confirmed using single-crystal X-ray diffraction, while reactivity of the key intermediates was rationalized by the analysis of the electrostatic potentials calculated at the TPSSh/6-311G(d,p) level.

Long-read sequencing unravels the complexity of structural variants in PRKN in two individuals with early-onset Parkinson's disease.

Background: PRKN biallelic pathogenic variants are the most common cause of autosomal recessive early-onset Parkinson's disease (PD). However, the variants responsible for suspected PRKN- PD individuals are not always identified with standard genetic testing. Objectives: Identify the genetic cause in two siblings with a PRKN -PD phenotype using long-read sequencing (LRS). Methods: The genetic investigation involved standard testing using successively multiple ligation probe amplification (MLPA), Sanger sequencing, targeted sequencing, whole-exome sequencing and LRS. Results: MLPA and targeted sequencing identified one copy of exon four in PRKN but no other variants were identified. Subsequently, LRS unveiled a large deletion encompassing exon 3 to 4 on one allele and a duplication of exon 3 on the second allele; explaining the siblings' phenotype. MLPA could not identify the balanced rearrangement of exon 3. Conclusions: This study highlights the potential utility of long-read sequencing in the context of unsolved typical PRKN- PD individuals.

Electrocatalytic reduction of CO2 in water by a C-functionalized Ni-cyclam complex grafted onto carbon.

We present here a novel strategy based on the covalent grafting of a C-functionalized Ni-cyclam complex onto glassy carbon to achieve heterogeneous electrocatalytic CO2 reduction in neutral water at low overpotential (-500 mV vs. NHE), with moderate turnover number (TON = 454), high selectivity (85% CO produced) and good faradaic efficiency (56% CO). Direct comparison with the N-functionalized Ni-cyclam analogue highlights the benefits of this approach in terms of CO2 electroreduction.

Copper(II) and zinc(II) complexation with N-ethylene hydroxycyclams and consequences on the macrocyclic backbone configuration.

We report a series of four cyclams and cross-bridged cyclams, N-functionalized by one hydroxyethyl arm, which may incorporate additional methyl(s) group(s). The Cu(II) and Zn(II) complexes of these ligands were synthesized and fully characterized. The investigation of the metal complexes in solid-state and in solution was carried via X-ray diffraction, NMR, EPR, absorption spectroscopy and DFT calculations. The influence of N-functionalization on their structural/stereochemical properties, electrochemical behavior and kinetic inertness was carefully studied and identified. N-Functionalization by a hydroxyethyl group did not influence importantly the stereochemical properties of the complexes. However, it stabilized the complexes kinetically and electrochemically. As for N-methylation, it induces significant distortion of the coordination geometry, decreasing the kinetic inertness of the complexes and stabilizing Cu+. Overall, this work expanded the family of cyclam and cross-bridged cyclam metal complexes and provides a detailed analysis of their structural features. The rather large body of data accumulated for this family of complexes provides opportunities to design systems with pre-determined properties for specific applications.

Involvement of the thalamic parafascicular nucleus in mesial temporal lobe epilepsy.

Mesial temporal lobe epilepsy (MTLE) is characterized by focal seizures, associated with hippocampal sclerosis, and often resistance to antiepileptic drugs. The parafascicular nucleus (PF) of the thalamus is involved in the generation of physiological oscillatory rhythms. It receives excitatory inputs from the cortex and inhibitory inputs from the basal ganglia, a system implicated in the control of epileptic seizures. The aim of this study was to examine the involvement of the PF in the occurrence of hippocampal paroxysmal discharges (HPDs) in a chronic animal model of MTLE in male mice. We recorded the local field potential (LFP) and the extracellular and intracellular activity of hippocampal and PF neurons during spontaneous HPDs in vivo. The end of the HPDs was concomitant with a slow repolarization in hippocampal neurons leading to an electrical silence. In contrast, it was associated in the PF with a transient increase in the power of the 10-20 Hz band in LFPs and a depolarization of PF neurons resulting in a sustained firing. We tested the role of the PF in the control of HPDs by single 130 Hz electrical stimulation of this nucleus and bilateral intra-PF injection of NMDA and GABA(A) antagonist and agonist. High-frequency PF stimulation interrupted ongoing HPDs at an intensity devoid of behavioral effects. NMDA antagonist and GABA(A) agonist suppressed hippocampal discharges in a dose-dependent way, whereas NMDA agonist and GABA(A) antagonist increased HPDs. Altogether, these data suggest that the PF nucleus plays a role in the modulation of MTLE seizures.

Phosphate and polyphosphate anion recognition by a dinuclear copper(ii) complex of an unsymmetrical squaramide.

In the search for receptors suitable for the recognition of phosphate or polyphosphate anions, a new unsymmetrical squaramide-based ligand bearing dipicolylamine (dpa) and ethylpiperazine units (L) was designed and prepared. The acid-base reactions of L, its copper(ii) complexation behaviour and the binding of phosphate and polyphosphate anions by the copper(ii) complexes used as receptors were evaluated. 1H and 13C NMR titrations of L performed in D2O allowed the determination of its protonation sequence. The ligand L is able to coordinate two copper(ii) cations forming thermodynamically stable dinuclear complexes likely having two water molecules bound to each metal centre, as supported by DFT calculations. Coordinated water molecules can be replaced by the O-donors of the phosphate/polyphosphate anions. The potentiometric studies showed that at 2 : 1 Cu2+ : L ratio the dinuclear [Cu2LH-1]3+ species predominates from pH ∼ 5 to ∼7, and hydroxodinuclear species prevail at pH > 7. 1H NMR experiments in both H2O/D2O 9 : 1 v/v and in DMSO proved that copper(ii) coordination provokes deprotonation of the squaramide NH bound to the ethylpiperazine moiety, resulting in [Cu2LH-1]3+ species. The dicopper(ii) complexes of L, [Cu2LH-i]4-i, were used as the receptor for the uptake of some phosphate and polyphosphate anions. The receptor presents very high association constants with HPPi3- and ATP4- and the determined Keff showed that at physiological pH ATP4- is selectively taken from an aqueous solution containing phenylphosphate (PhPO42-), aminoethylphosphate (Haep-), AMP2- and ADP3-, but HPPi3- strongly interferes. DFT calculations suggest that the strong interaction with HPPi3- and ATP4- is related to the simultaneous coordination of the polyphosphate unit to the two copper(ii) centres.

Irradiation of intracerebral 9L gliosarcoma by a single array of microplanar x-ray beams from a synchrotron: balance between curing and sparing.

The purpose of this work was the understanding of microbeam radiation therapy at the ESRF in order to find the best compromise between curing of tumors and sparing of normal tissues, to obtain a better understanding of survival curves and to report its efficiency. This method uses synchrotron-generated x-ray microbeams. Rats were implanted with 9L gliosarcomas and the tumors were diagnosed by MRI. They were irradiated 14 days after implantation by arrays of 25 microm wide microbeams in unidirectional mode, with a skin entrance dose of 625 Gy. The effect of using 200 or 100 microm center-to-center spacing between the microbeams was compared. The median survival time (post-implantation) was 40 and 67 days at 200 and 100 microm spacing, respectively. However, 72% of rats irradiated at 100 microm spacing showed abnormal clinical signs and weight patterns, whereas only 12% of rats were affected at 200 microm spacing. In parallel, histological lesions of the normal brain were found in the 100 microm series only. Although the increase in lifespan was equal to 273% and 102% for the 100 and 200 microm series, respectively, the 200 microm spacing protocol provides a better sparing of healthy tissue and may prove useful in combination with other radiation modalities or additional drugs.

Glial responses during epileptogenesis in Mus musculus point to potential therapeutic targets.

The Mesio-Temporal Lobe Epilepsy syndrome is the most common form of intractable epilepsy. It is characterized by recurrence of focal seizures and is often associated with hippocampal sclerosis and drug resistance. We aimed to characterize the molecular changes occurring during the initial stages of epileptogenesis in search of new therapeutic targets for Mesio-Temporal Lobe Epilepsy. We used a mouse model obtained by intra-hippocampal microinjection of kainate and performed hippocampal whole genome expression analysis at 6h, 12h and 24h post-injection, followed by multilevel bioinformatics analysis. We report significant changes in immune and inflammatory responses, neuronal network reorganization processes and glial functions, predominantly initiated during status epilepticus at 12h and persistent after the end of status epilepticus at 24h post-kainate. Upstream regulator analysis highlighted Cyba, Cybb and Vim as central regulators of multiple overexpressed genes implicated in glial responses at 24h. In silico microRNA analysis indicated that miR-9, miR-19b, miR-129, and miR-223 may regulate the expression of glial-associated genes at 24h. Our data support the hypothesis that glial-mediated inflammatory response holds a key role during epileptogenesis, and that microglial cells may participate in the initial process of epileptogenesis through increased ROS production via the NOX complex.

Gender as a Modifying Factor Influencing Myotonic Dystrophy Type 1 Phenotype Severity and Mortality: A Nationwide Multiple Databases Cross-Sectional Observational Study.

BACKGROUND: Myotonic Dystrophy type 1 (DM1) is one of the most heterogeneous hereditary disease in terms of age of onset, clinical manifestations, and severity, challenging both medical management and clinical trials. The CTG expansion size is the main factor determining the age of onset although no factor can finely predict phenotype and prognosis. Differences between males and females have not been specifically reported. Our aim is to study gender impact on DM1 phenotype and severity. METHODS: We first performed cross-sectional analysis of main multiorgan clinical parameters in 1409 adult DM1 patients (>18 y) from the DM-Scope nationwide registry and observed different patterns in males and females. Then, we assessed gender impact on social and economic domains using the AFM-Téléthon DM1 survey (n = 970), and morbidity and mortality using the French National Health Service Database (n = 3301). RESULTS: Men more frequently had (1) severe muscular disability with marked myotonia, muscle weakness, cardiac, and respiratory involvement; (2) developmental abnormalities with facial dysmorphism and cognitive impairment inferred from low educational levels and work in specialized environments; and (3) lonely life. Alternatively, women more frequently had cataracts, dysphagia, digestive tract dysfunction, incontinence, thyroid disorder and obesity. Most differences were out of proportion to those observed in the general population. Compared to women, males were more affected in their social and economic life. In addition, they were more frequently hospitalized for cardiac problems, and had a higher mortality rate. CONCLUSION: Gender is a previously unrecognized factor influencing DM1 clinical profile and severity of the disease, with worse socio-economic consequences of the disease and higher morbidity and mortality in males. Gender should be considered in the design of both stratified medical management and clinical trials.

Tolerance to Dose Escalation in Minibeam Radiation Therapy Applied to Normal Rat Brain: Long-Term Clinical, Radiological and Histopathological Analysis.

The major limitation to reaching a curative radiation dose in radioresistant tumors such as malignant gliomas is the high sensitivity to radiation and subsequent damage of the surrounding normal tissues. Novel dose delivery methods such as minibeam radiation therapy (MBRT) may help to overcome this limitation. MBRT utilizes a combination of spatial fractionation of the dose and submillimetric (600 µm) field sizes with an array ("comb") of parallel thin beams ("teeth"). The dose profiles in MBRT consist of peaks and valleys. In contrast, the seamless irradiations of the several squared centimeter field sizes employed in standard radiotherapy result in homogeneous dose distributions (and consequently, flat dose profiles). The innovative dose delivery methods employed in MBRT, unlike standard radiation therapy, have demonstrated remarkable normal tissue sparing. In this pilot work, we investigated the tolerance of the rat brain after whole-brain MBRT irradiation. A dose escalation was used to study the tissue response as a function of dose, so that a threshold could be established: doses as high as 100 Gy in one fraction were still well tolerated by the rat brain. This finding suggests that MBRT may be used to deliver higher and potentially curative radiation doses in clinical practice.

Heterogeneity and frequency of movement disorders in juvenile and adult-onset Niemann-Pick C disease.

Niemann-Pick type C disease (NPC) is a recessive neurolipidosis. We report five adolescent and adult NPC cases to underscore the frequency and heterogeneity of movement disorders in NPC. Clinical, morphologic, biochemical and genetic study was performed in the five patients. Disease onset was between 8 and 50 years. Movement disorders were present in all cases, were heterogeneous and often combined [cerebellar ataxia (5/5), myoclonus (3/5), dystonia (2/5), chorea (1/5) and tremor (1/5)] and were the first sign in 4/5. Two patients were reported to have no vertical supranuclear gaze palsy (VSGP) at the first examination. Two patients experienced acute neuropsychiatric signs leading to death in one case due to myoclonic storm. Filipin staining was always positive. Two NPC1 mutations were identified in three patients, only one in two siblings. NPC should be considered in case of unexplained movement disorders, even when VSGP or cataplexy are not reported. Filipin staining remains a strong support for the diagnosis. Treatment with miglustat should be considered which is currently the only approved disease-specific treatment of NPC in children and adults.

A functional magnetic resonance imaging study of pathophysiological changes responsible for mirror movements in Parkinson's disease.

Mirror movements correspond to involuntary movements observed in the limb contralateral to the one performing voluntary movement. They can be observed in Parkinson's disease (PD) but their pathophysiology remains unclear. The present study aims at identifying their neural correlates in PD using functional magnetic resonance imaging. Ten control subjects and 14-off drug patients with asymmetrical right-sided PD were included (8 with left-sided mirror movements during right-hand movements, and 6 without mirror movements). Between-group comparisons of BOLD signal were performed during right-hand movements and at rest (p<0.005 uncorrected). The comparison between PD patients with and without mirror movements showed that mirror movements were associated with an overactivation of the insula, precuneus/posterior cingulate cortex bilaterally and of the left inferior frontal cortex and with a deactivation of the right dorsolateral prefrontal cortex, medial prefrontal cortex, and pre-supplementary motor area and occipital cortex. These data suggest that mirror movements in Parkinson's disease are promoted by: 1- a deactivation of the non-mirroring inhibitory network (dorsolateral prefrontal cortex, pre-supplementary motor area); 2- an overactivation of prokinetic areas (notably the insula). The concomitant overactivation of a proactive inhibitory network (including the posterior cingulate cortex and precuneus) could reflect a compensatory inhibition of mirror movements.

Episodic weakness due to mitochondrial DNA MT-ATP6/8 mutations.

OBJECTIVE: To report that homoplasmic deleterious mutations in the mitochondrial DNA MT-ATP6/8 genes may be responsible for acute episodes of limb weakness mimicking periodic paralysis due to channelopathies and dramatically responding to acetazolamide. METHODS: Mitochondrial DNA sequencing and restriction PCR, oxidative phosphorylation functional assays, reactive oxygen species metabolism, and patch-clamp technique in cultured skin fibroblasts. RESULTS: Occurrence of a typical MELAS (mitochondrial encephalopathy with lactic acidosis and stroke-like episodes) syndrome in a single member of a large pedigree with episodic weakness associated with a later-onset distal motor neuropathy led to the disclosure of 2 deleterious mitochondrial DNA mutations. The MT-ATP6 m.9185T>C p.Leu220Pro mutation, previously associated with Leigh syndrome, was present in all family members, while the MT-TL1 m.3271T>C mutation, a known cause of MELAS syndrome, was observed in the sole patient with MELAS presentation. Significant defect of complexes V and I as well as oxidative stress were observed in both primary fibroblasts and cybrid cells with 100% m.9185T>C mutation. Permanent plasma membrane depolarization and altered permeability to K(+) in fibroblasts provided a link with the paralysis episodes. Screening of 9 patients, based on their clinical phenotype, identified 4 patients with similar deleterious MT-ATP6 mutations (twice m.9185T>C and once m.9176T>C or m.8893T>C). A fifth patient presented with an original potentially deleterious MT-ATP8 mutation (m.8403T>C). All mutations were associated with almost-normal complex V activity but significant oxidative stress and permanent plasma membrane depolarization. CONCLUSION: Homoplasmic mutations in the MT-ATP6/8 genes may cause episodic weakness responding to acetazolamide treatment.

Exploring new molecular architectures for anion recognition: synthesis and ATP binding properties of new cyclam-based ditopic polyammonium receptors.

Synthesis and characterization of three new polyamine receptors, composed of a cyclam unit (cyclam=1,4,8,11-tetraazacyclotetradecane) linked by a 2,6-dimethylpyridinyl spacer to the linear polyamines 1,4,8,11-tetraazaundecane (L1py), 1,4,7-triazaheptane (L2py), and to a quaternary ammonium group (L3py(+)), are reported. All receptors form highly charged polyammonium cations at neutral pH, suitable for anion recognition studies. ATP recognition was analyzed by using potentiometric, calorimetric, (1)H and (31)P NMR measurements in aqueous solution. All receptors form 1:1 adducts with ATP in aqueous solution, stabilized by charge-charge and hydrogen-bonding interactions between their ammonium groups and the anionic triphosphate chain of ATP. The binding ability of the three receptors for ATP increases in the order of L3py(+)

Bilateral subthalamic nucleus stimulation in advanced Parkinson's disease: five year follow-up.

OBJECTIVE: To assess the long-term efficacy and safety of bilateral subthalamic nucleus (STN) stimulation in patients with advanced Parkinson's disease (PD). METHODS: 42 consecutive patients with idiopathic PD treated with bilateral STN stimulation were enrolled. Parkinsonian status, medication intake and neuropsychological evaluation were assessed preoperatively and at 1 and 5 years postoperatively in on and off medication/on and off stimulation conditions. RESULTS: 23 patients could be followed-up 5 years after surgery. In the remaining cases, 5 died, 1 could not be assessed because of device removal for infection, 1 decided not to be stimulated, and 11 were lost of follow-up (one because of a liver carcinoma and the others because they refused the formal four conditions of assessment). STN stimulation reduced the UPDRS motor score by 55 % compared to baseline in the off-medication conditions. Tremor, rigidity, bradykinesia, postural stability, and gait improved by 74 %, 66 %, 59 %, 17 % and 37 %, respectively. UPDRS part II scores were reduced by 38 %. The dopaminergic treatment daily dose was reduced by 54.4 % after surgery. Axial dopa-unresponsive signs worsened in some patients. Among the 42 initial patients we observed the following: 2 brain hemorrhages, 3 infections of the device, 2 phlebitis and 1 pulmonary embolism. In addition, 2 patients needed a repositioning of the electrode. Among the 23 patients followed at 5 years, long lasting side effects consisted in dysarthria (56 %), depression (39 %), eyelid opening apraxia (30.4 %) and apathy (4.3 %). CONCLUSIONS: Our data confirm that bilateral STN stimulation is beneficial in the long-term for PD patients but does not prevent disease progression and the occurence of axial levodopa unresponsive signs in some patients.