The Prion-Like Spreading of Alpha-Synuclein in Parkinson's Disease: Update on Models and Hypotheses.

The pathological aggregation of the presynaptic protein α-synuclein (α-syn) and propagation through synaptically coupled neuroanatomical tracts is increasingly thought to underlie the pathophysiological progression of Parkinson's disease (PD) and related synucleinopathies. Although the precise molecular mechanisms responsible for the spreading of pathological α-syn accumulation in the CNS are not fully understood, growing evidence suggests that de novo α-syn misfolding and/or neuronal internalization of aggregated α-syn facilitates conformational templating of endogenous α-syn monomers in a mechanism reminiscent of prions. A refined understanding of the biochemical and cellular factors mediating the pathological neuron-to-neuron propagation of misfolded α-syn will potentially elucidate the etiology of PD and unravel novel targets for therapeutic intervention. Here, we discuss recent developments on the hypothesis regarding trans-synaptic propagation of α-syn pathology in the context of neuronal vulnerability and highlight the potential utility of novel experimental models of synucleinopathies.

Schwann cell p75 neurotrophin receptor modulates small fiber degeneration in diabetic neuropathy.

Diabetic neuropathy has an incidence as high as 50% of diabetic patients and is characterized by damage to neurons, Schwann cells and blood vessels within the peripheral nervous system. The low-affinity neurotrophin receptor p75 (p75NTR ), particularly expressed by the Schwann cells in the peripheral nerve, has previously been reported to play a role in developmental myelination and cell survival/death. Increased levels of p75NTR , in the endoneurium and plasma from diabetic patients and rodent models of disease, have been observed, proposing that this receptor might be involved in the pathogenesis of diabetic neuropathy. Therefore, in this study, we addressed this hypothesis by utilizing a mouse model of selective nerve growth factor receptor (Ngfr) deletion in Schwann cells (SC-p75NTR -KO). Electron microscopy of sciatic nerves from mice with high fat diet induced obesity demonstrated how loss of Schwann cell-p75NTR aggravated axonal atrophy and loss of C-fibers. RNA sequencing disclosed several pre-clinical signaling alterations in the diabetic peripheral nerves, dependent on Schwann cell p75NTR signaling, specially related with lysosome, phagosome, and immune pathways. Morphological and biochemical analyses identified abundant lysosomes and autophagosomes in the C-fiber axoplasm of the diabetic SC-p75NTR -KO nerves, which together with increased Cathepsin B protein levels corroborates gene upregulation from the phagolysosomal pathways. Altogether, this study demonstrates that Schwann cell p75NTR deficiency amplifies diabetic neuropathy disease by triggering overactivation of immune-related pathways and increased lysosomal stress.

Fat Quality Matters: Distinct Proteomic Signatures Between Lean and Obese Cardiac Visceral Adipose Tissue Underlie its Differential Myocardial Impact.

BACKGROUND/AIMS: Heart failure with preserved ejection fraction (HFpEF) is recognised as an important cause of cardiovascular mortality and morbidity, accounting for approximately 50% of heart failure cases. Metabolic-related complications, such as obesity, have been associated with the pathophysiology of this complex syndrome. The anatomic proximity between cardiac visceral adipose tissue (CVAT) and the myocardium has been drawing attention due to its potential pathogenic role in cardiac diseases. Thus, we aimed to characterise the phenotypic and proteomic differences between CVAT from ZSF1 lean (control) and ZSF1 obese (HFpEF) rats as well as to evaluate the myocardial impact of conditioned media derived from CVAT of these 2 groups. METHODS: CVAT of 20-weeks-old lean and obese ZSF1 rats was collected for: 1) 24h DMEM incubation to obtain conditioned media, 2) separation of proteins to mass spectrometry identification, 3) adipokines' expression, 4) adipocytes cross-sectional area assessment. Organotypic cultures were prepared from 7 days-old Wistar Han cardiac explants and incubated for 24h with the conditioned media. After incubation, cross-section area of cardiomyocytes and fibrosis were evaluated. Cardiomyocytes were isolated from Wistar Han and incubated with conditioned media for viability studies. RESULTS: CVAT from lean rats presented a higher expression of uncoupling protein-1 (UCP-1) protein, associated with a multilocular appearance and an increased expression of brown adipose tissue markers. Contrarily, CVAT from obese rats revealed a white adipose tissue-like phenotype accompanied by hypertrophy of adipocytes. The analysis of the CVAT proteome reinforced the phenotypic differences between lean and obese CVAT, showing enrichment of proteins involved in triglyceride metabolic processes in obese CVAT. In contrast, mitochondrial proteins were prominent in lean CVAT, further suggesting a brown adipose tissue-like phenotype. The twenty-four hours-long incubation of myocardial organo-cultures with conditioned media obtained from CVAT obese (CM-obese) rats significantly reduced cell viability, induced cardiomyocytes hypertrophy and fibrosis, in stark contrast with the incubation with the conditioned media from lean rats CVAT (CM-lean). Furthermore, the deleterious effect imposed by CM-obese was associated with a pro-inflammatory profile, characterised by an increased expression of several pro-inflammatory adipokines. CONCLUSION: Obesity promotes alterations in CVAT proteome signature, structure, composition and secretome, translating into dramatic myocardial consequences.

Temperature-dependence of the single-cell variability in the kinetics of transcription activation in Escherichia coli.

From in vivo single-cell, single-RNA measurements of the activation times and subsequent steady-state active transcription kinetics of a single-copy Lac-ara-1 promoter in Escherichia coli, we characterize the intake kinetics of the inducer (IPTG) from the media, following temperature shifts. For this, for temperature shifts of various degrees, we obtain the distributions of transcription activation times as well as the distributions of intervals between consecutive RNA productions following activation in individual cells. We then propose a novel methodology that makes use of deconvolution techniques to extract the mean and the variability of the distribution of intake times. We find that cells, following shifts to low temperatures, have higher intake times, although, counter-intuitively, the cell-to-cell variability of these times is lower. We validate the results using a new methodology for direct estimation of mean intake times from measurements of activation times at various inducer concentrations. The results confirm that E. coli's inducer intake times from the environment are significantly higher following a shift to a sub-optimal temperature. Finally, we provide evidence that this is likely due to the emergence of additional rate-limiting steps in the intake process at low temperatures, explaining the reduced cell-to-cell variability in intake times.

Increased cytoplasm viscosity hampers aggregate polar segregation in Escherichia coli.

In Escherichia coli, under optimal conditions, protein aggregates associated with cellular aging are excluded from midcell by the nucleoid. We study the functionality of this process under sub-optimal temperatures from population and time lapse images of individual cells and aggregates and nucleoids within. We show that, as temperature decreases, aggregates become homogeneously distributed and uncorrelated with nucleoid size and location. We present evidence that this is due to increased cytoplasm viscosity, which weakens the anisotropy in aggregate displacements at the nucleoid borders that is responsible for their preference for polar localisation. Next, we show that in plasmolysed cells, which have increased cytoplasm viscosity, aggregates are also not preferentially located at the poles. Finally, we show that the inability of cells with increased viscosity to exclude aggregates from midcell results in enhanced aggregate concentration in between the nucleoids in cells close to dividing. This weakens the asymmetries in aggregate numbers between sister cells of subsequent generations required for rejuvenating cell lineages. We conclude that the process of exclusion of protein aggregates from midcell is not immune to stress conditions affecting the cytoplasm viscosity. The findings contribute to our understanding of E. coli's internal organisation and functioning, and its fragility to stressful conditions.

Differential expression of Cathepsin E in transthyretin amyloidosis: from neuropathology to the immune system.

BACKGROUND: Increasing evidence supports a key role for inflammation in the neurodegenerative process of familial amyloidotic polyneuropathy (FAP). While there seems to be an overactivation of the neuronal interleukin-1 signaling pathway, the immune response is apparently compromised in FAP. Accordingly, little immune cell infiltration is observed around pre-fibrillar or fibrillar amyloid deposits, with the underlying mechanism for this phenomenon remaining poorly understood. Cathepsin E (CtsE) is an important intermediate for antigen presentation and chemotaxis, but its role in the pathogenesis of FAP disease remains unknown. METHODS: In this study, we used both mouse primary macrophages and in vivo studies based on transgenic models of FAP and human samples to characterize CtsE expression in different physiological systems. RESULTS: We show that CtsE is critically decreased in bone marrow-derived macrophages from a FAP mouse model, possibly contributing for cell function impairment. Compromised levels of CtsE were also found in injured nerves of transgenic mice and, most importantly, in naïve peripheral nerves, sensory ganglia, murine stomach, and sural nerve biopsies derived from FAP patients. Expression of CtsE in tissues was associated with transthyretin (TTR) deposition and differentially regulated accordingly with the physiological system under study. Preventing deposition with a TTR small interfering RNA rescued CtsE in the peripheral nervous system (PNS). In contrast, the expression of CtsE increased in splenic cells (mainly monocytes) or peritoneal macrophages, indicating a differential macrophage phenotype. CONCLUSION: Altogether, our data highlights the potential of CtsE as a novel FAP biomarker and a possible modulator for innate immune cell chemotaxis to the disease most affected tissues-the peripheral nerve and the gastrointestinal tract.

Overexpression of Protocadherin-10 in Transthyretin-Related Familial Amyloidotic Polyneuropathy.

Overwhelming data suggest that oncogenic and neurodegenerative pathways share several altered cellular responses to insults such as oxidative stress, extracellular matrix remodeling, inflammation, or cell dyscommunication. Protocadherin-10 (Pcdh10) is an adhesion molecule found to protect against tumorigenesis and essential for axonal elongation and actin dynamics during development. Here, by using genome microarrays we identified for the first time Pcdh10 up-regulation in tissues from transgenic mouse models, cultured Schwann cells, and human samples from a familial form of peripheral neuropathy (familial amyloidotic polyneuropathy). Familial amyloidotic polyneuropathy is characterized by poor functional recovery and impaired nerve regenerative response after misfolding and deposition in the peripheral nervous system of mutant transthyretin. Not only increased transcriptional and translational Pcdh10 levels occurred in axons and Schwann cells of nerves with deposited transthyretin aggregates but the pattern also extended to associated cues of axon guidance like neuropilin-1 and F-actin. These findings suggest that Pcdh10 may influence subcellular actin cytoskeletal organization and axon-axon interactions in the course of familial amyloidotic polyneuropathy. Moreover, when preventing nonfibrillar transthyretin deposition with anakinra or transthyretin siRNA, Pcdh10 protein levels were reduced, highlighting its potential as a novel disease biomarker. Whether Pcdh10 overexpression in familial amyloidotic polyneuropathy represents a protective or deleterious response, enhancing survival or promoting cell death will need further investigation.

Robustness of the Process of Nucleoid Exclusion of Protein Aggregates in Escherichia coli.

UNLABELLED: Escherichia coli segregates protein aggregates to the poles by nucleoid exclusion. Combined with cell divisions, this generates heterogeneous aggregate distributions in subsequent cell generations. We studied the robustness of this process with differing medium richness and antibiotics stress, which affect nucleoid size, using multimodal, time-lapse microscopy of live cells expressing both a fluorescently tagged chaperone (IbpA), which identifies in vivo the location of aggregates, and HupA-mCherry, a fluorescent variant of a nucleoid-associated protein. We find that the relative sizes of the nucleoid's major and minor axes change widely, in a positively correlated fashion, with medium richness and antibiotic stress. The aggregate's distribution along the major cell axis also changes between conditions and in agreement with the nucleoid exclusion phenomenon. Consequently, the fraction of aggregates at the midcell region prior to cell division differs between conditions, which will affect the degree of asymmetries in the partitioning of aggregates between cells of future generations. Finally, from the location of the peak of anisotropy in the aggregate displacement distribution, the nucleoid relative size, and the spatiotemporal aggregate distribution, we find that the exclusion of detectable aggregates from midcell is most pronounced in cells with mid-sized nucleoids, which are most common under optimal conditions. We conclude that the aggregate management mechanisms of E. coli are significantly robust but are not immune to stresses due to the tangible effect that these have on nucleoid size. IMPORTANCE: Escherichia coli segregates protein aggregates to the poles by nucleoid exclusion. From live single-cell microscopy studies of the robustness of this process to various stresses known to affect nucleoid size, we find that nucleoid size and aggregate preferential locations change concordantly between conditions. Also, the degree of influence of the nucleoid on aggregate positioning differs between conditions, causing aggregate numbers at midcell to differ in cell division events, which will affect the degree of asymmetries in the partitioning of aggregates between cells of future generations. Finally, we find that aggregate segregation to the cell poles is most pronounced in cells with mid-sized nucleoids. We conclude that the energy-free process of the midcell exclusion of aggregates partially loses effectiveness under stressful conditions.

Early cardiac changes induced by a hypercaloric Western-type diet in "subclinical" obesity.

"Obesity cardiomyopathy" effects have been widely described; however, the specific contribution of metabolic changes and altered adipokine secretion are still uncharacterized. Moreover, a diagnosis based on body mass index might not be the most accurate to identify increased adiposity and its outcomes. In this study, we aimed to determine the impact of a Western-type diet [hypercaloric diet (HCD)] ingestion on biventricular structure and function, as well as the metabolic and endocrine changes that occur before the establishment of overt obesity. Wistar rats were fed for 6 wk with a regular diet or HCD. At the end of the protocol, metabolic tests, cardiac structure, and functional evaluation were performed, and blood and tissue samples collected to perform histological, molecular biology, and functional studies. The animals that ingested the HCD presented increased adiposity and larger adipocyte cross-sectional area, but similar body weight compared with the regular diet group. At the cardiac level, HCD induced biventricular cardiomyocyte hypertrophy, fibrosis, increased stiffness, and impaired relaxation. Galectin-3 plasma expression was likewise elevated in the same animals. The nutritional modulation also altered the secretory pattern of the adipose tissue, originating a proinflammatory systemic environment. In this study, we observed that before "clinical" overweight or frank obesity is established, the ingestion of a HCD-induced cardiac remodeling manifests by increased biventricular stiffness and diastolic dysfunction. The mechanism triggering the cardiac alterations appears to be the proinflammatory environment promoted by the adipose tissue dysfunction. Furthermore, galectin-3, a profibrotic molecule, might be a potential biomarker for the myocardial alterations promoted by the HCD before overweight or obesity.

Cardioprotective effects of early and late aerobic exercise training in experimental pulmonary arterial hypertension.

Clinical studies suggest that aerobic exercise can exert beneficial effects in pulmonary arterial hypertension (PAH), but the underlying mechanisms are largely unknown. We compared the impact of early or late aerobic exercise training on right ventricular function, remodeling and survival in experimental PAH. Male Wistar rats were submitted to normal cage activity (SED), exercise training in early (EarlyEX) and in late stage (LateEX) of PAH induced by monocrotaline (MCT, 60 mg/kg). Both exercise interventions resulted in improved cardiac function despite persistent right pressure-overload, increased exercise tolerance and survival, with greater benefits in EarlyEX+MCT. This was accompanied by improvements in the markers of cardiac remodeling (SERCA2a), neurohumoral activation (lower endothelin-1, brain natriuretic peptide and preserved vascular endothelial growth factor mRNA), metabolism and mitochondrial oxidative stress in both exercise interventions. EarlyEX+MCT provided additional improvements in fibrosis, tumor necrosis factor-alpha/interleukin-10 and brain natriuretic peptide mRNA, and beta/alpha myosin heavy chain protein expression. The present study demonstrates important cardioprotective effects of aerobic exercise in experimental PAH, with greater benefits obtained when exercise training is initiated at an early stage of the disease.

Pathophysiology of infantile pulmonary arterial hypertension induced by monocrotaline.

Pediatric pulmonary arterial hypertension (PAH) presents certain specific features. In this specific age group, experimental models to study the pathophysiology of PAH are lacking. To characterize hemodynamic, morphometric, and histological progression as well as the expression of neurohumoral factors and regulators of cardiac transcription in an infantile model of PAH induced by monocrotaline (MCT), eight-day-old Wistar rats were randomly injected with MCT (30 mg/kg, sc, n = 95) or equal volume of saline solution (n = 92). Animals were instrumented for biventricular hemodynamic recording 7, 14, and 21 days after MCT, whereas samples were collected at 1, 3, 7, 14, and 21 days after MCT. Different time point postinjections were defined for further analysis. Hearts and lungs were collected for morphometric characterization, assessment of right- and left-ventricle (RV and LV) cardiomyocyte diameter and collagen type-I and type-III ratio, RV collagen volume fraction, and pulmonary vessels wall thickness. mRNA quantification was undertaken for brain natriuretic peptide (BNP), endothelin-1 (ET-1), and for cardiac transcription regulators (HOP and Islet1). Animals treated with MCT at the 8th day of life presented RV hypertrophy since day 14 after MCT injection. There were no differences on the RV collagen volume fraction or collagen type-I and type-III ratio. Pulmonary vascular remodelling and PAH were present on day 21, which were accompanied by an increased expression of BNP, ET-1, HOP, and Islet1. The infantile model of MCT-induced PAH can be useful for the study of its pathophysiology and to test new therapeutic targets in pediatric age group.

Fibroblasts endocytose and degrade transthyretin aggregates in transthyretin-related amyloidosis.

Transthyretin (TTR)-related amyloidosis is a fatal disorder characterized by systemic extracellular deposition of TTR amyloid fibrils. Mutations in the TTR gene cause an autosomal dominant form of the disease-familial amyloidotic polyneuropathy (FAP). Wild-type (WT) TTR can also form amyloid fibrils in elderly patients with senile systemic amyloidosis. Regression of amyloid deposits in FAP patients who undergo liver transplantation to remove the main source of mutant TTR suggests the existence of mechanisms for the clearance of TTR deposits from the extracellular matrix (ECM), but the precise mechanisms are largely unknown. Because fibroblasts are abundant, playing a central role in the maintenance of the ECM and because the skin is one of the major sites of soluble TTR catabolism, in the present study, we analyzed their role in clearance of TTR aggregates. In vitro studies with a fibroblast cell line revealed that fibroblasts endocytosed and degraded aggregated TTR. Subcutaneous injection of soluble and aggregated TTR into WT mice showed internalization and clearance over time by both fibroblasts and macrophages. Immunohistochemical studies of skin biopsies from V30M patients, asymptomatic carriers, recipients of domino FAP livers as well as transgenic mice for human V30M showed intracellular TTR immunoreactivity in fibroblasts and macrophages that increased with clinical status and with age in transgenic mice. Overall, the present in vitro and in vivo data show that fibroblasts endocytose and degrade TTR aggregates. The function or dysfunction of TTR clearance by fibroblasts may have important implications for the development, progression, and regression of TTR deposition in the ECM.

Helicobacter pylori induces increased expression of Toll-like receptors and decreased Toll-interacting protein in gastric mucosa that persists throughout gastric carcinogenesis.

BACKGROUND: Toll-like receptors (TLR) are essential for Helicobacter pylori (HP) recognition. Their role in the progression of gastric lesions leading to cancer is not established. AIM: To evaluate for the first time in humans the expression of TLR2, TLR4, and TLR5, as well as the expression of other related molecules in the entire sequence of gastric lesions. METHODS: Biopsy samples (n = 80, 48% HP+) from normal mucosa, HP gastritis, metaplasia, dysplasia or adenocarcinoma were obtained from 44 patients. mRNA quantification of TLR2, TLR4, TLR5, Toll-interacting protein (TOLLIP), PPAR-γ, NF-κB, TNF-α, COX-1, COX-2, and CDX-2 was performed by real-time RT-PCR. TLR2, TLR4, and TLR5 protein expression was quantified by immunohistochemistry. RESULTS: When compared to normal mucosa (1.0 arbitrary unit (AU)), HP gastritis presented higher expression of TLR2 (2.23 ± 0.36 AU), TLR4 (1.92 ± 0.40 AU) and TNF-α (2.14 ± 0.50 AU) and lower TOLLIP and PPARγ expression (0.72 ± 0.12 AU, p < .05 all genes). Metaplasia and dysplasia/carcinoma presented higher expression of TLR2 (1.66 ± 0.46 and 1.48 ± 0.20 AU, respectively, p < .05), lower expression of TOLLIP (0.66 ± 0.09 and 0.52 ± 0.04 AU, p < .05) and PPARγ (0.73 ± 0.12 and 0.63 ± 0.10 AU, p < .05). The significant trend for decrease in TOLLIP and PPARγ was associated with increasing levels of CDX-2 from normal mucosa to carcinoma (p < .05), translating that in diffuse and higher TLRs protein expression (p < .05). CONCLUSION: Gastric carcinogenesis is associated with decreasing levels of TLRs inhibitors and elevated TLRs levels throughout all the spectrum of lesions. Future studies should investigate if modulation of these receptors activity may influence gastric carcinogenesis and tumor progression.

Recombinant adeno-associated virus mediated gene delivery in the extracranial nervous system of adult mice by direct nerve immersion.

This protocol outlines a minimally invasive and quickly performed approach for transgene delivery in the extracranial nervous system of adult mice using recombinant adeno-associated virus (AAV). The technique, named Sciatic Nerve Direct Immersion (SciNDi), relies on the direct bilateral immersion of the exposed sciatic nerve with AAV. We show that in comparison with intramuscular AAV delivery, SciNDi results in widespread transduction in connected neuroanatomical tracts both in the sciatic nerve trunk and the lumbar spinal cord. For complete details on the use and execution of this protocol, please refer to Jan et al. (2019) and Richner et al. (2011, 2017).

Sortilin Modulates Schwann Cell Signaling and Remak Bundle Regeneration Following Nerve Injury.

Peripheral nerve regeneration relies on the ability of Schwann cells to support the regrowth of damaged axons. Schwann cells re-differentiate when reestablishing contact with the sprouting axons, with large fibers becoming remyelinated and small nociceptive fibers ensheathed and collected into Remak bundles. We have previously described how the receptor sortilin facilitates neurotrophin signaling in peripheral neurons via regulated trafficking of Trk receptors. This study aims to characterize the effects of sortilin deletion on nerve regeneration following sciatic crush injury. We found that Sort1 - / - mice displayed functional motor recovery like that of WT mice, with no detectable differences in relation to nerve conduction velocities and morphological aspects of myelinated fibers. In contrast, we found abnormal ensheathment of regenerated C-fibers in injured Sort1 - / - mice, demonstrating a role of sortilin for Remak bundle formation following injury. Further studies on Schwann cell signaling pathways showed a significant reduction of MAPK/ERK, RSK, and CREB phosphorylation in Sort1 - / - Schwann cells after stimulation with neurotrophin-3 (NT-3), while Schwann cell migration and myelination remained unaffected. In conclusion, our results demonstrate that loss of sortilin blunts NT-3 signaling in Schwann cells which might contribute to the impaired Remak bundle regeneration after sciatic nerve injury.

Distinct mechanisms for diastolic dysfunction in diabetes mellitus and chronic pressure-overload.

Chronic pressure-overload and diabetes mellitus are two frequent disorders affecting the heart. We aimed to characterize myocardial structural and functional changes induced by both conditions. Pressure-overload was established in Wistar-han male rats by supra-renal aortic banding. Six-weeks later, diabetes was induced by streptozotocin (65 mg/kg,ip), resulting in four groups: SHAM, banding (BA), diabetic (DM) and diabetic-banding (DB). Six-weeks later, pressure-volume loops were obtained and left ventricular samples were collected to evaluate alterations in insulin signalling pathways, extracellular matrix as well as myofilament function and phosphorylation. Pressure-overload increased cardiomyocyte diameter (BA 22.0 ± 0.4 µm, SHAM 18.2 ± 0.3 µm) and myofilament maximal force (BA 25.7 ± 3.6 kN/m(2), SHAM 18.6 ± 1.4 kN/m(2)), Ca(2+) sensitivity (BA 5.56 ± 0.02, SHAM 5.50 ± 0.02) as well as MyBP-C, Akt and Erk phosphorylation, while decreasing rate of force redevelopment (K (tr); BA 14.9 ± 1.1 s(-1), SHAM 25.2 ± 1.5 s(-1)). At the extracellular matrix level, fibrosis (BA 10.8 ± 0.9%, SHAM 5.3 ± 0.6%), pro-MMP-2 and MMP-9 activities increased and, in vivo, relaxation was impaired (τ; BA 14.0 ± 0.9 ms, SHAM 12.9 ± 0.4 ms). Diabetes increased cardiomyocyte diameter, fibrosis (DM 21.4 ± 0.4 µm, 13.9 ± 1.8%, DB 20.6 ± 0.4 µm, 13.8 ± 0.8%, respectively), myofilament Ca(2+)sensitivity (DM 5.57 ± 0.02, DB 5.57 ± 0.01), advanced glycation end-product deposition (DM 4.9 ± 0.6 score/mm(2), DB 5.1 ± 0.4 score/mm(2), SHAM 2.1 ± 0.3 score/mm(2)), and apoptosis, while decreasing K (tr) (DM 13.5 ± 1.9 s(-1), DB 15.2 ± 1.4 s(-1)), Akt phosphorylation and MMP-9/TIMP-1 and MMP-1/TIMP-1 ratios. Diabetic hearts were stiffer (higher end-diastolic-pressure: DM 7.0 ± 1.2 mmHg, DB 6.7 ± 0.7 mmHg, SHAM 5.3 ± 0.4 mmHg, steeper end-diastolic-pressure-volume relation: DM 0.59 ± 0.18, DB 0.83 ± 0.17, SHAM 0.41 ± 0.10), and hypo-contractile (decreased end-systolic-pressure-volume-relation). DB animals presented further pulmonary congestion (Lungs/body-weight: DB 5.23 ± 0.21 g/kg, SHAM 3.80 ± 0.14 g/kg) as this group combined overload-induced relaxation abnormalities and diabetes-induced stiffness. Diabetes mellitus and pressure overload led to distinct diastolic dysfunction phenotypes: while diabetes promoted myocardial stiffening, pressure overload impaired relaxation. The association of these damages accelerates the progression of diastolic heart failure progression in diabetic-banded animals.

Trans-synaptic spreading of alpha-synuclein pathology through sensory afferents leads to sensory nerve degeneration and neuropathic pain.

Pain is a common non-motor symptom of Parkinson's disease (PD), with current limited knowledge of its pathophysiology. Here, we show that peripheral inoculation of mouse alpha-synuclein (α-Syn) pre-formed fibrils, in a transgenic mouse model of PD, elicited retrograde trans-synaptic spreading of α-Syn pathology (pSer129) across sensory neurons and dorsal nerve roots, reaching central pain processing regions, including the spinal dorsal horn and the projections of the anterolateral system in the central nervous system (CNS). Pathological peripheral to CNS propagation of α-Syn aggregates along interconnected neuronal populations within sensory afferents, was concomitant with impaired nociceptive response, reflected by mechanical allodynia, reduced nerve conduction velocities (sensory and motor) and degeneration of small- and medium-sized myelinated fibers. Our findings show a link between the transneuronal propagation of α-Syn pathology with sensory neuron dysfunction and neuropathic impairment, suggesting promising avenues of investigation into the mechanisms underlying pain in PD.

Attenuation of toll-like receptor 2-mediated innate immune response in patients with alcoholic chronic liver disease.

BACKGROUND: Alcoholic chronic liver disease (ACLD) is a common form of acquired immunodeficiency. AIM: To evaluate ex vivo toll-like receptor (TLR) 2 and TLR4 innate immune response in stable ACLD. METHODS: Blood was collected from 26 males with stable ACLD and from 17 controls. Serum was used for lipopolysaccharide (LPS), sCD14, LPS-binding protein (LBP), tumour necrosis factor-alpha (TNF-alpha) and interleukin 10 (IL-10) quantification. Peripheral blood monocytes (PBM) protein expression of TLR2 and TLR4 was determined by flow cytometry. Primary cultures of anti-CD11b positive selected PBM were stimulated with the TLR2/TLR6 ligand zymosan (Zym), with TLR2/TLR1 ligand lipopeptide (Lp) and with TLR4 ligand LPS. PBM TLR1, TLR2, TLR4, TLR6, MD2, CD14, TNF-alpha and IL-10 gene expression was evaluated by reverse transcription-polymerase chain reaction. RESULTS: Stable ACLD patients showed increased circulating LPS (+22.5+/-4.1%), LBP (+60.6+/-12.2%) and sCD14 (+23.5+/-4.6%), with no differences in TNF-alpha and IL-10. Zym and Lp, but not LPS, induced TNF-alpha production by monocytes was blunted in ACLD (-66+/-20.4% Zym; -40.1+/-13.5% Lp; P<0.05). Basal TNF-alpha mRNA expression was decreased in PBM from ACLD patients (-50.1+/-21.0%; P<0.05), with no significant differences in the other studied genes. Results were similar in Child-Pugh A and B/C patients. CONCLUSIONS: Patients with stable ACLD show an attenuation of TLR2-mediated innate immune response in PBM, which may represent an important mechanism for acquired immunodeficiency. This was neither related with decreased TLR2 or its co-receptors expression nor with impaired TLR4 activation, being already present in the early stages of disease.

A high-calorie diet attenuates cachexia and adipose tissue inflammation in monocrotaline-induced pulmonary hypertensive rats.

INTRODUCTION: Cardiac cachexia is a catabolic state in which adipose tissue atrophy is accompanied by a proinflammatory state. The molecular mechanisms underlying proinflammatory activation remain, however, largely unknown. In this experimental study, the effect of a high-calorie diet was analyzed in the advanced stages of monocrotaline-induced pulmonary hypertension (PH). METHODS: Male Wistar rats (180-200 g; n=28) were randomly injected with either monocrotaline (MCT; 60 mg/kg; sc) or vehicle. Each group was then assigned to either a regular diet (2.9 kcal/g) or a high-calorie diet with a high fat and simple carbohydrate content (5.4 kcal/g). Twenty-four to 32 days after injection, adipose tissue was collected for morphometric, histological and molecular analysis. The proportional weight of the gonadal fat pad was used as an adiposity index. Detection of macrophages in adipose tissue was performed with an anti-CD6 monoclonal antibody. Interleukin-6 (IL-6) mRNA quantification was performed using real-time RT-PCR. RESULTS: MCT injection was accompanied by a reduction in adiposity (-51 +/- 3.4%) and by adipocyte atrophy (-18 +/- 1.4%). This was accompanied by IL-6 overexpression (+879 +/- 444%), but there were no changes in adipose tissue macrophage content. Exposure to a high-calorie diet in the MCT group attenuated adipose tissue atrophy as well as IL-6 gene overexpression. CONCLUSION: A high-calorie diet attenuates cachexia and proinflammatory activation in the advanced stages of monocrotaline-induced PH. These results suggest nutritional state potential therapeutic target in advanced PH

Modulation of Small RNA Signatures in Schwann-Cell-Derived Extracellular Vesicles by the p75 Neurotrophin Receptor and Sortilin.

Schwann cells (SCs) are the main glial cells of the peripheral nervous system (PNS) and are known to be involved in various pathophysiological processes, such as diabetic neuropathy and nerve regeneration, through neurotrophin signaling. Such glial trophic support to axons, as well as neuronal survival/death signaling, has previously been linked to the p75 neurotrophin receptor (p75NTR) and its co-receptor Sortilin. Recently, SC-derived extracellular vesicles (EVs) were shown to be important for axon growth and nerve regeneration, but cargo of these glial cell-derived EVs has not yet been well-characterized. In this study, we aimed to characterize signatures of small RNAs in EVs derived from wild-type (WT) SCs and define differentially expressed small RNAs in EVs derived from SCs with genetic deletions of p75NTR (Ngfr-/-) or Sortilin (Sort1-/-). Using RNA sequencing, we identified a total of 366 miRNAs in EVs derived from WT SCs of which the most highly expressed are linked to the regulation of axonogenesis, axon guidance and axon extension, suggesting an involvement of SC EVs in axonal homeostasis. Signaling of SC EVs to non-neuronal cells was also suggested by the presence of several miRNAs important for regulation of the endothelial cell apoptotic process. Ablated p75NTR or sortilin expression in SCs translated into a set of differentially regulated tRNAs and miRNAs, with impact in autophagy and several cellular signaling pathways such as the phosphatidylinositol signaling system. With this work, we identified the global expression profile of small RNAs present in SC-derived EVs and provided evidence for a regulatory function of these vesicles on the homeostasis of other cell types of the PNS. Differentially identified miRNAs can pave the way to a better understanding of p75NTR and sortilin roles regarding PNS homeostasis and disease.