Sox-2 Positive Neural Progenitors in the Primate Striatum Undergo Dynamic Changes after Dopamine Denervation.

The existence of endogenous neural progenitors in the nigrostriatal system could represent a powerful tool for restorative therapies in Parkinson's disease. Sox-2 is a transcription factor expressed in pluripotent and adult stem cells, including neural progenitors. In the adult brain Sox-2 is expressed in the neurogenic niches. There is also widespread expression of Sox-2 in other brain regions, although the neurogenic potential outside the niches is uncertain. Here, we analyzed the presence of Sox-2+ cells in the adult primate (Macaca fascicularis) brain in naïve animals (N = 3) and in animals exposed to systemic administration of 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine to render them parkinsonian (N = 8). Animals received bromodeoxyuridine (100 mg/kg once a day during five consecutive days) to label proliferating cells and their progeny. Using confocal and electron microscopy we analyzed the Sox-2+ cell population in the nigrostriatal system and investigated changes in the number, proliferation and neurogenic potential of Sox-2+ cells, in control conditions and at two time points after MPTP administration. We found Sox-2+ cells with self-renewal capacity in both the striatum and the substantia nigra. Importantly, only in the striatum Sox-2+ was expressed in some calretinin+ neurons. MPTP administration led to an increase in the proliferation of striatal Sox-2+ cells and to an acute, concomitant decrease in the percentage of Sox-2+/calretinin+ neurons, which recovered by 18 months. Given their potential capacity to differentiate into neurons and their responsiveness to dopamine neurotoxic insults, striatal Sox-2+ cells represent good candidates to harness endogenous repair mechanisms for regenerative approaches in Parkinson's disease

Fast and efficient neural conversion of human hematopoietic cells

Neurons obtained directly from human somatic cells hold great promise for disease modeling and drug screening. Available protocols rely on overexpression of transcription factors using integrative vectors and are often slow, complex, and inefficient. We report a fast and efficient approach for generating induced neural cells (iNCs) directly from human hematopoietic cells using Sendai virus. Upon SOX2 and c-MYC expression, CD133-positive cord blood cells rapidly adopt a neuroepithelial morphology and exhibit high expansion capacity. Under defined neurogenic culture conditions, they express mature neuronal markers and fire spontaneous action potentials that can be modulated with neurotransmitters. SOX2 and c-MYC are also sufficient to convert peripheral blood mononuclear cells into iNCs. However, the conversion process is less efficient and resulting iNCs have limited expansion capacity and electrophysiological activity upon differentiation. Our study demonstrates rapid and efficient generation of iNCs from hematopoietic cells while underscoring the impact of target cells on conversion efficiency

Potential role of new molecular plasma signatures on cardiovascular risk stratification in asymptomatic individuals

The evaluation of cardiovascular (CV) risk is based on equations derived from epidemiological data in individuals beyond the limits of middle age such as the Framingham and SCORE risk assessments. Lifetime Risk calculator (QRisk®), estimates CV risk throughout a subjects' lifetime, allowing those. A more aggressive and earlier intervention to be identified and offered protection from the consequences of CV and renal disease. The search for molecular profiles in young people that allow a correct stratification of CV risk would be of great interest to adopt preventive therapeutic measures in individuals at high CV risk. To improve the selection of subjects susceptible to intervention with aged between 30-50 years, we have employed a multiple proteomic strategy to search for new markers of early CV disease or reported CV events and to evaluate their relationship with Lifetime Risk. Blood samples from 71 patients were classified into 3 groups according to their CV risk (healthy, with CV risk factors and with a previously reported CV event subjects) and they were analyzed using a high through quantitative proteomics approach. This strategy allowed three different proteomic signatures to be defined, two of which were related to CV stratification and the third one involved markers of organ damage.This work was supported by grants from the Instituto de Salud Carlos III (PI070537, IF08/3667-1, PI11-02239, PI 14/01917, PI11/01401, PI11/02432, PI13/01873, PI13/01746, PI13/01581, PI14/01650, PI14/01841), PT13/0001/0013, PIE13/00051, PIE13/00045, CP09/00229, CP15/00129, IDC Salud (3371/002), the MutuaMadrileña Foundation, the SENEFRO Foundation and FONDOS FEDER (RD06/0014/1015, RD12/0042/0071). Sociedad Española de cardiología para la Investigación Básica 2017. Grant PRB3 (IPT17/0019 - ISCIII-SGEFI / ERDF. These results are in line with the Spanish initiative on the Human Proteome Project.S

Comprehensive Proteomic Profiling of Pressure Ulcers in Patients with Spinal Cord Injury Identifies a Specific Protein Pattern of Pathology

Objective: Severe pressure ulcers (PUs) do not respond to conservative wound therapy and need surgical repair. To better understand the pathogenesis and to advance on new therapeutic options, we focused on the proteomic analysis of PU, which offers substantial opportunities to identify significant changes in protein abundance during the course of PU formation in an unbiased manner. Approach: To better define the protein pattern of this pathology, we performed a proteomic approach in which we compare severe PU tissue from spinal cord injury (SCI) patients with control tissue from the same patients. Results: We found 76 proteins with difference in abundance. Of these, 10 proteins were verified as proteins that define the pathology: antithrombin-III, alpha-1-antitrypsin, kininogen-1, alpha-2-macroglobulin, fibronectin, apolipoprotein A-I, collagen alpha-1 (XII) chain, haptoglobin, apolipoprotein B-100, and complement factor B. Innovation: This is the first study to analyze differential abundance protein of PU tissue from SCI patients using high-throughput protein identification and quantification by tandem mass tags followed by liquid chromatography tandem mass spectrometry. Conclusion: Differential abundance proteins are mainly involved in tissue regeneration. These proteins might be considered as future therapeutic options to enhance the physiological response and permit cellular repair of damaged tissue.This work was supported by grants from the Instituto de Salud Carlos III (PI14/01917, PI18/00995, PT13/0001/0013) for Funding: ISCIII (‘‘PI14/01917, PI18/00995, PT13/0001/0013)’’, co-funded by ERDF/ESF, ‘‘Investing in your future’’. Redes Tema ticas de Investigacion Cooperativa (FONDOS FEDER, RD12/0042/0071). Sociedad Espanola de Cardiologıa para la Investigacion Basica 2017. Grant PRB3 (IPT17/0019—ISCIII-SGEFI/ERDF). These results are aligned with the Spanish initiative on the Human Proteome Project (SpHPP).S

Correction: Sox-2 Positive Neural Progenitors in the Primate Striatum Undergo Dynamic Changes after Dopamine Denervation.

[This corrects the article on p. e66377 in vol. 8.]

Adapting BODIPYs to singlet oxygen production on silica nanoparticles

International audienceA modified Stober method is used to synthesize spherical core-shell silica nanoparticles (NPs) with an external surface functionalized by amino groups and with an average size around 50 nm. Fluorescent dyes and photosensitizers of singlet oxygen were fixed, either separately or conjointly, respectively in the core or in the shell. Rhodamines were encapsulated in the core with relatively high fluorescence quantum yields (Φfl ≥ 0.3), allowing fluorescence tracking of the particles. Various photosensitizers of singlet oxygen (PS) were covalenty coupled to the shell, allowing singlet oxygen production. The stability of NP suspensions strongly deteriorated upon grafting the PS, affecting their apparent singlet oxygen quantum yields. Agglomeration of NPs depends both on the type and on the amount of grafted photosensitizer. New, lab-made, halogenated 4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes (BODIPY) grafted to the NPs achieved higher singlet oxygen quantum yields (ΦΔ ∼ 0.35-0.40) than Rose Bengal (RB) grafted NPs (ΦΔ ∼ 0.10-0.27). Finally, we combined both fluorescence and PS functions in the same NP, namely a rhodamine in the silica core and a BODIPY or RB grafted in the shell, achieving the performance Φfl ∼ 0.10-0.20, ΦΔ ∼ 0.16-0.25 with a single excitation wavelength. Thus, proper choice of the dyes, of their concentrations inside and on the NPs and the grafting method enables fine-tuning of singlet oxygen production and fluorescence emission.[on SciFinder (R)

LRRK2 Expression Is Deregulated in Fibroblasts and Neurons from Parkinson Patients with Mutations in PINK1

Mutations in PINK1 (PARK6), a serine/threonine kinase involved in mitochondrial homeostasis, are associated with early onset Parkinson’s disease. Fibroblasts from Parkinson’s disease patients with compound heterozygous mutations in exon 7 (c.1488 + 1G > A; c.1252_1488del) showed no apparent signs of mitochondrial impairment. To elucidate changes primarily caused by lack of functional PINK1, we over-expressed wild-type PINK1, which induced a significant downregulation of LRRK2 (PARK8). Indeed, we found that LRRK2 protein basal levels were significantly higher in the mutant PINK1 fibroblasts. To examine the interaction between the two PARK genes in a disease-relevant cell context, we generated induced pluripotent stem cell (iPSC) lines from mutant, carrier and control fibroblasts by lentiviral-mediated re-programming. Efficiency of neural induction and dopamine differentiation using a floor-plate induction protocol was similar in all genotypes. As observed in fibroblasts, PINK1 mutant neurons showed increased LRRK2 expression both at the RNA and protein level and transient over-expression of wild-type PINK1 efficiently downregulated LRRK2 levels. Additionally, we confirmed a dysregulation of LRRK2 expression in fibroblasts from patients with a different homozygous mutation in PINK1 exon 4, c.926G > A (G309D). Thus, our results identify a novel role of PINK1 modulating the levels of LRRK2 in Parkinson’s disease fibroblasts and neurons, suggest a convergent pathway for these PARK genes, and broaden the role of LRRK2 in the pathogenesis of Parkinson’s disease.This study is funded by grants from the European Commission, CORDIS FP7, HEALTH-2, 278871 (DDPDGENES), and the Joint Program in Neurodegenerative Diseases (DAMNDPATHS) to RSP. JPB is the recipient of grants from MINECO (SAF2013-41177-R) and the NIH/NIDA (1R21DA037678-01). GAu is the recipient of grants from DFG (AU96/10-1) and the German National Genome Research Network NGFNplus (Neuron-Parkinson-subproject 7).Peer reviewe

LRRK2 Expression Is Deregulated in Fibroblasts and Neurons from Parkinson Patients with Mutations in PINK1.

Mutations in PINK1 (PARK6), a serine/threonine kinase involved in mitochondrial homeostasis, are associated with early onset Parkinson's disease. Fibroblasts from Parkinson's disease patients with compound heterozygous mutations in exon 7 (c.1488 + 1G > A; c.1252_1488del) showed no apparent signs of mitochondrial impairment. To elucidate changes primarily caused by lack of functional PINK1, we over-expressed wild-type PINK1, which induced a significant downregulation of LRRK2 (PARK8). Indeed, we found that LRRK2 protein basal levels were significantly higher in the mutant PINK1 fibroblasts. To examine the interaction between the two PARK genes in a disease-relevant cell context, we generated induced pluripotent stem cell (iPSC) lines from mutant, carrier and control fibroblasts by lentiviral-mediated re-programming. Efficiency of neural induction and dopamine differentiation using a floor-plate induction protocol was similar in all genotypes. As observed in fibroblasts, PINK1 mutant neurons showed increased LRRK2 expression both at the RNA and protein level and transient over-expression of wild-type PINK1 efficiently downregulated LRRK2 levels. Additionally, we confirmed a dysregulation of LRRK2 expression in fibroblasts from patients with a different homozygous mutation in PINK1 exon 4, c.926G > A (G309D). Thus, our results identify a novel role of PINK1 modulating the levels of LRRK2 in Parkinson's disease fibroblasts and neurons, suggest a convergent pathway for these PARK genes, and broaden the role of LRRK2 in the pathogenesis of Parkinson's disease

MPTP effect on the nigrostriatal system.

<p>Midbrain sections at the level of the 3rd nerve from a control (<b>A</b>), a MPTP short-term (<b>B</b>) and a MPTP long-term treated monkey (<b>C</b>) immunostained for TH. Note the severe reduction of TH immunoreactivity in the SNpc of the lesioned monkeys. Scale bar = 1 cm. <b>D.</b> Stereological quantification of TH⁺ neurons in the SNpc. Data represent median and quartiles, N = 3, *p≤0.05. Images of precommisural striatum sections from a control monkey (<b>E</b>), a MPTP short-term monkey (<b>F</b>) and a MPTP long-term monkey (<b>G</b>) immunostained for TH. Note the loss of TH⁺ fibers in the lesioned monkeys. Scale bar = 1 cm. Representative striatal sections of a control <b>(e’)</b> a MPTP short-term monkey (<b>f’</b>) and a MPTP long-term monkey (<b>g’</b>), at higher magnification showing the intrinsic TH⁺ neurons (arrows). Scale bar = 300 µm. <b>H.</b> Quantification of striatal TH⁺ neurons. There was a significant increase in the density of TH⁺ neurons after MPTP administration in both groups. Data represent median and quartiles, N = 3, *p≤0.05. <b>I.</b> Western blot to assess striatal TH levels showing a reduction in the MPTP-short term group and a partial recovery in the MPTP-long term group with respect to controls. Data represent median and quartiles, N = 3, *p≤0.05. Abbreviations: 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine: MPTP; tyrosine hydroxylase: TH; substantia nigra pars compacta: SNpc.</p