Mitochondrial complex I activity in microglia sustains neuroinflammation.

Sustained smouldering, or low-grade activation, of myeloid cells is a common hallmark of several chronic neurological diseases, including multiple sclerosis1. Distinct metabolic and mitochondrial features guide the activation and the diverse functional states of myeloid cells2. However, how these metabolic features act to perpetuate inflammation of the central nervous system is unclear. Here, using a multiomics approach, we identify a molecular signature that sustains the activation of microglia through mitochondrial complex I activity driving reverse electron transport and the production of reactive oxygen species. Mechanistically, blocking complex I in pro-inflammatory microglia protects the central nervous system against neurotoxic damage and improves functional outcomes in an animal disease model in vivo. Complex I activity in microglia is a potential therapeutic target to foster neuroprotection in chronic inflammatory disorders of the central nervous system3.

Extracellular vesicles and their synthetic analogues in aging and age-associated brain diseases.

Multicellular organisms rely upon diverse and complex intercellular communications networks for a myriad of physiological processes. Disruption of these processes is implicated in the onset and propagation of disease and disorder, including the mechanisms of senescence at both cellular and organismal levels. In recent years, secreted extracellular vesicles (EVs) have been identified as a particularly novel vector by which cell-to-cell communications are enacted. EVs actively and specifically traffic bioactive proteins, nucleic acids, and metabolites between cells at local and systemic levels, modulating cellular responses in a bidirectional manner under both homeostatic and pathological conditions. EVs are being implicated not only in the generic aging process, but also as vehicles of pathology in a number of age-related diseases, including cancer and neurodegenerative and disease. Thus, circulating EVs-or specific EV cargoes-are being utilised as putative biomarkers of disease. On the other hand, EVs, as targeted intercellular shuttles of multipotent bioactive payloads, have demonstrated promising therapeutic properties, which can potentially be modulated and enhanced through cellular engineering. Furthermore, there is considerable interest in employing nanomedicinal approaches to mimic the putative therapeutic properties of EVs by employing synthetic analogues for targeted drug delivery. Herein we describe what is known about the origin and nature of EVs and subsequently review their putative roles in biology and medicine (including the use of synthetic EV analogues), with a particular focus on their role in aging and age-related brain diseases.

Mitochondrial reverse electron transport in myeloid cells perpetuates neuroinflammation.

Sustained smouldering, or low grade, activation of myeloid cells is a common hallmark of several chronic neurological diseases, including multiple sclerosis (MS) 1 . Distinct metabolic and mitochondrial features guide the activation and the diverse functional states of myeloid cells 2 . However, how these metabolic features act to perpetuate neuroinflammation is currently unknown. Using a multiomics approach, we identified a new molecular signature that perpetuates the activation of myeloid cells through mitochondrial complex II (CII) and I (CI) activity driving reverse electron transport (RET) and the production of reactive oxygen species (ROS). Blocking RET in pro-inflammatory myeloid cells protected the central nervous system (CNS) against neurotoxic damage and improved functional outcomes in animal disease models in vivo . Our data show that RET in myeloid cells is a potential new therapeutic target to foster neuroprotection in smouldering inflammatory CNS disorders 3 .

Reactive astrocytes and Wnt/ß-catenin signaling link nigrostriatal injury to repair in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine model of Parkinson's disease.

Emerging evidence points to reactive glia as a pivotal factor in Parkinson's disease (PD) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mouse model of basal ganglia injury, but whether astrocytes and microglia activation may exacerbate dopaminergic (DAergic) neuron demise and/or contribute to DAergic repair is presently the subject of much debate. Here, we have correlated the loss and recovery of the nigrostriatal DAergic functionality upon acute MPTP exposure with extensive gene expression analysis at the level of the ventral midbrain (VM) and striata (Str) and found a major upregulation of pro-inflammatory chemokines and wingless-type MMTV integration site1 (Wnt1), a key transcript involved in midbrain DAergic neurodevelopment. Wnt signaling components (including Frizzled-1 [Fzd-1] and ß-catenin) were dynamically regulated during MPTP-induced DAergic degeneration and reactive glial activation. Activated astrocytes of the ventral midbrain were identified as candidate source of Wnt1 by in situ hybridization and real-time PCR in vitro. Blocking Wnt/Fzd signaling with Dickkopf-1 (Dkk1) counteracted astrocyte-induced neuroprotection against MPP(+) toxicity in primary mesencephalic astrocyte-neuron cultures, in vitro. Moreover, astroglial-derived factors, including Wnt1, promoted neurogenesis and DAergic neurogenesis from adult midbrain stem/neuroprogenitor cells, in vitro. Conversely, lack of Wnt1 transcription in response to MPTP in middle-aged mice and failure of DAergic neurons to recover were reversed by pharmacological activation of Wnt/ß-catenin signaling, in vivo, thus suggesting MPTP-reactive astrocytes in situ and Wnt1 as candidate components of neuroprotective/neurorescue pathways in MPTP-induced nigrostriatal DAergic plasticity.

Remodelling the injured CNS through the establishment of atypical ectopic perivascular neural stem cell niches.

Compelling evidence exists that somatic neural stem/precursor cell (NPC)-based therapies protect the central nervous system (CNS) from chronic inflammation-driven degeneration, such as that occurring in experimental autoimmune encephalomyelitis (EAE), multiple sclerosis (MS), cerebral ischemic/hemorrhagic stroke and spinal cord injury (SCI). However, while it was first assumed that NPC transplants may act through direct replacement of lost/damaged cells, it has now become clear that they are able to protect the damaged nervous system through a number of 'bystander' mechanisms other than the expected cell replacement. In immune-mediated experimental demyelination--both in rodents and non-human primates--others and we have shown that transplanted NPC possess a constitutive and inducible ability to mediate efficient 'bystander' myelin repair and axonal rescue. This novel mechanism(s), which may improve the success of transplantation procedures, is likely to be exerted by undifferentiated NPCs whose functional characteristics are regulated by both CNS-resident and blood-borne inflammatory cells releasing in situ major stem cell regulators. Here, we discuss some of these alternative 'bystander' mechanisms, while pointing at the formation of the atypical ectopic perivascular niches, as the most challenging example of reciprocal biologically sound cross talk between the inflamed microenvironment(s) and transplanted therapeutic NPCs.

Polyornithine-based polyplexes to boost effective gene silencing in CNS disorders.

Gene silencing therapies have successfully suppressed the translation of target proteins, a strategy that holds great promise for the treatment of central nervous system (CNS) disorders. Advances in the current knowledge on multimolecular delivery vehicles are concentrated on overcoming the difficulties in delivery of small interfering (si)RNA to target tissues, which include anatomical accessibility, slow diffusion, safety concerns, and the requirement for specific cell uptake within the unique environment of the CNS. The present work addressed these challenges through the implementation of polyornithine derivatives in the construction of polyplexes used as non-viral siRNA delivery vectors. Physicochemical and biological characterization revealed biodegradability and biocompatibility of our polyornithine-based system and the ability to silence gene expression in primary oligodendrocyte progenitor cells (OPCs) effectively. In summary, the well-defined properties and neurological compatibility of this polypeptide-based platform highlight its potential utility in the treatment of CNS disorders.

IL4 gene delivery to the CNS recruits regulatory T cells and induces clinical recovery in mouse models of multiple sclerosis.

Central nervous system (CNS) delivery of anti-inflammatory cytokines, such as interleukin 4 (IL4), holds promise as treatment for multiple sclerosis (MS). We have previously shown that short-term herpes simplex virus type 1-mediated IL4 gene therapy is able to inhibit experimental autoimmune encephalomyelitis (EAE), an animal model of MS, in mice and non-human primates. Here, we show that a single administration of an IL4-expressing helper-dependent adenoviral vector (HD-Ad) into the cerebrospinal fluid (CSF) circulation of immunocompetent mice allows persistent transduction of neuroepithelial cells and long-term (up to 5 months) CNS transgene expression without toxicity. Mice affected by chronic and relapsing EAE display clinical and neurophysiological recovery from the disease once injected with the IL4-expressing HD-Ad vector. The therapeutic effect is due to the ability of IL4 to increase, in inflamed CNS areas, chemokines (CCL1, CCL17 and CCL22) capable of recruiting regulatory T cells (CD4+CD69-CD25+Foxp3+) with suppressant functions. CSF delivery of HD-Ad vectors expressing anti-inflammatory molecules might represent a valuable therapeutic option for CNS inflammatory disorders.

Children's asthma and the third world: an approach.

BACKGROUND: More than a million visits/year characterize acute asthma morbidity at Venezuela's (24 million inhabitants) Ministry of Health ambulatory services, caring for 80% or more of the population; acute morbidity from asthma is second to "viral syndrome" but ahead of diarrhea and other diseases. These acute episodes are the only contact of a poor asthmatic child with this health care system and portray the prevailing approach focused around acute care: to be reversed, a simple cost/effective program ought to be implemented during these acute asthma visits. Since convenience of administration is a key factor in compliance, a pilot study to explore the efficacy of budesonide CFC 400 microg administered on a once-a-day basis for adherence was carried out within a naturalistic real-world design. METHODS: Thirty persistent asthmatic patients attending the Allergology Unit of the Hospital Pediátrico San Juan de Dios in Caracas were enrolled, and their asthma signs/symptoms quantified and registered on diary cards (0-3 scale) as well as peak flow measurements in am/pm for a period of 2 weeks prior to budesonide administration (control data) and until completion of study. Only 12 (mean age: 9 years) of the initial patients were able to properly keep a diary and scheduled visits for a period of 15 weeks. RESULTS: Data allowed comparison between pre- and post-treatment symptoms/signs scores and PF values. After 3 weeks treatment with budesonide, statistically significant improvements were shown for all parameters, except for PF, whose minor improvements did not reach statistical significance. CONCLUSIONS: Budesonide CFC 400 microg administered once a day seems effective in control of asthma signs/symptoms within study design. Confirmation of the above findings in larger groups of patients, treated similarly and for longer periods of time, seems justified. A simple cost-effective intervention, analogous conceptually to the proven successful oral rehydration therapies for diarrhea in public health, should be considered in third world countries with high urban asthma prevalence.

High levels of cerebrospinal fluid IgM binding to myelin basic protein are associated with early benign course in multiple sclerosis.

We assessed human myelin basic protein (MBP) binding IgM levels in CSF. MBP is the most studied putative antigen in multiple sclerosis (MS) and immune responses against it may be involved in the demyelination process. We also correlated these levels with EDSS score and other parameters of disease progression and prognosis, both at the time of CSF analysis and during follow-up. CSF IgM anti-MBP levels were assayed by measuring total IgM levels with solid-phase ELISA in CSF samples from 66 patients with relapsing-remitting MS, 11 subjects without neurological diseases, 20 patients with non-inflammatory neurological diseases and 7 patients with lymphocytic meningitis, before and after immunoabsorption with human MBP. Confirmation of IgM binding specificity was performed by immunoblotting of positive CSF samples onto MBP coated-nitrocellulose sheets. Clinical evaluation (disability score, number and time of attacks) was performed during a mean follow-up of 2.7 +/- 1.1 years. 23 of the 66 relapsing-remitting MS patients (33.8%) had elevated IgM anti-MBP levels. In this patient subgroup, IgM anti-MBP levels correlated with the IgM index (r = 0.71; P = 0.0001), but not with CSF/serum albumin (r = 0.08; P = 0.72). In the first year of follow-up, patients with low IgM anti-MBP suffered from more numerous attacks than those with elevated levels (0.86 +/- 0.63 versus 0.43 +/- 0.58; P = 0.017). Patients with high IgM binding to MBP had a first attack during follow-up in a significantly higher time than those with low binding (28.87 +/- 4.7 versus 17 +/- 2.6 months, respectively; P = 0.005) and reached a decrease of 0.5 EDSS point significantly faster than those with low IgM (16.17 +/- 1.2 versus 29.7 +/- 2.6 months, respectively; P = 0.0002). A similar significant finding was observed when the time to reach low disability score (EDSS < or = 2.0) was analyzed (10.7 +/- 2.57 +/- 3.3 months, respectively; P = 0.014). These findings demonstrate that in a subgroup of MS patients, elevated CSF levels of IgM anti-MBP are associated with early favorable course and therefore suggest that IgM binding to MBP could be a possible prognostic marker in relapsing-remitting MS to select early MS patients for future trials.

The influence of the estrous cycle on the accumulation of 3H-noradrenaline in rat uterus and on efflux of radioactivity from the uterus.

Groups of female rats were used throughout the 4-days estrous cycle and the accumulation of noradrenaline and its efflux were studied after incubation with the labelled amine. Comparisons were made between uterine horns corresponding to each one of the 4 stages of the cycle, i.e., diestrus, proestrus, metestrus and estrus. Accumulation in diestrus reached the highest value, which was 1.64-fold higher than in estrus. An estimate of the original distribution of the amine into the extraneuronal and neuronal compartments of the tissue was obtained by compartmental analysis of the efflux curves. Size and half times of neuronal and extraneuronal compartments showed some relationship with the stage of the cycle.

Antibodies and myelination: facts and misacts.

Polyreactive (auto)antibodies are frequently found in healthy subjects and are bona fide considered to be nonpathogenic. However, autoreactive B cells and circulating (auto)antibodies have been associated with several neurological syndromes, including demyelinating disorders. Whether these antibodies can have a real impact on disease development is still a matter of debate. Here, we briefly summarize some of the most recently published data on both the deleterious and the protective effects of antibodies in autoimmune demyelinating disorders of the central nervous system.

[Effect of the administration of furosemide on the fluid filtration rate and in pulmonary artery pressure in isolated lungs of rabbits]. / Efecto de la administración de furosemida en la tasa de filtracion de liquido y en la presión de la arteria pulmonar en el pulmón aislado de conejo.

To study the possible effects of Furosemide at the lung level, two groups of isolated rabbit lung preparation were studied. An experimental group underwent a pulmonary hydrostatic oedema when the pressure of the left auricle (PAI) was increased from 0.45 +/- 0.74 t0 11.8 +/- 2.9 cm of H2O, with that increase in PAI we obtained an increase of 0.457 +/- 0.51 g/min in FFR (Fluid Filtration Rate), during this stable and sustained oedema, a 2 mg/Kg dosis of Furosemide was injected every 10 minutes and the possible changes in PAP, PAI, PVA, TFL, PaO2, PaCO2 and pH was observed, but no changes were observed in these parameters during the Furosemide infusion, and the same effect was observed in the control group were the preparations were maintained in basal conditions and without oedema. These results suggests that the Furosemide hat not a direct cardio-pulmonary effects, and the only possible effects could be by increasing diuresis at renal level.