Neuroinflammation and inhibitory synaptic control of cultured premotor circuits

My PhD project is focused on the impact of neuroinflammation processes in the mouse spinal cord, with particular attention to cytokines and their functional role. In particular, I have used as model the organotypic spinal cultures, which allowed me to investigate: i. spinal network activity changes induced by pro-inflammatory cytokines; ii. resident microglia and astrocytes response to inflammatory stress; iii. mechanisms by which pro-inflammatory cytokines modulate the inhibitory transmission. The principal aim of my work was to understand the crosstalk between neuroinflammation and the spinal pre-motor network. For this purpose, I combined electrophysiological and immunofluorescence methods to assess the interneurons synaptic activity especially localized in the ventral organotypic cultures from embryonic mouse spinal cord. I investigated a specific cytokines cocktail (TNF-\u3b1, IL-1\u3b2, and GM-CSF; CKs) and their effects on spontaneous and inhibitory postsynaptic currents (sPSCs and IPSCs). In cultured spinal networks, I have observed a progressive increase in the frequency of PSCs and IPSCs accompanied by a fastening of GABAergic currents, due to a reduction in the decay time constant (\u3c4). This difference in the GABAergic PSCs kinetic properties is maintained in miniature PSCs (mPSCs) recorded after CKs treatments, suggesting mechanisms strictly associated with post-synaptic modification. The specific CKs modulation of GABAergic currents is strengthened by the absence of such a regulation by another danger signal as LPS. In this work, I evaluated and compared resident neuroglial cells response to CKs and LPS. Microglia and astrocytes show a different activation in the spinal slices. In particular, CKs induce an increase of microglia proliferation and astrogliosis followed by decreasing of microglia ramification. On the other hand, LPS increases only microglia ramification maintaining unaffected the other properties. Regardless the cell morphology, the activation of an inflammatory status was confirmed by the presence of cytokines and chemokines release in the supernatants in both conditions. I investigated the mechanisms by which cytokines speeded up the GABAAR-mediated currents, and pharmacologically based electrophysiological experiments strongly indicated the presence of a modulation of GABAAR subunit, in particular of \u3b1-subunit

Cytokine inflammatory threat, but not LPS one, shortens GABAergic synaptic currents in the mouse spinal cord organotypic cultures

Background: Synaptic dysfunction, named synaptopathy, due to inflammatory status of the central nervous system (CNS) is a recognized factor potentially underlying both motor and cognitive dysfunctions in neurodegenerative diseases. To gain knowledge on the mechanistic interplay between local inflammation and synapse changes, we compared two diverse inflammatory paradigms, a cytokine cocktail (CKs; IL-1\u3b2, TNF-\u3b1, and GM-CSF) and LPS, and their ability to tune GABAergic current duration in spinal cord cultured circuits. Methods: We exploit spinal organotypic cultures, single-cell electrophysiology, immunocytochemistry, and confocal microscopy to explore synaptic currents and resident neuroglia reactivity upon CK or LPS incubation. Results: Local inflammation in slice cultures induced by CK or LPS stimulations boosts network activity; however, only CKs specifically reduced GABAergic current duration. We pharmacologically investigated the contribution of GABAAR \u3b1-subunits and suggested that a switch of GABAAR \u3b11-subunit might have induced faster GABAAR decay time, weakening the inhibitory transmission. Conclusions: Lower GABAergic current duration could contribute to providing an aberrant excitatory transmission critical for pre-motor circuit tasks and represent a specific feature of a CK cocktail able to mimic an inflammatory reaction that spreads in the CNS. Our results describe a selective mechanism that could be triggered during specific inflammatory stress

Bridging pro-inflammatory signals, synaptic transmission and protection in spinal explants in vitro

Multiple sclerosis is characterized by tissue atrophy involving the brain and the spinal cord, where reactive inflammation contributes to the neurodegenerative processes. Recently, the presence of synapse alterations induced by the inflammatory responses was suggested by experimental and clinical observations, in experimental autoimmune encephalomyelitis mouse model and in patients, respectively. Further knowledge on the interplay between pro-inflammatory agents, neuroglia and synaptic dysfunction is crucial to the design of unconventional protective molecules. Here we report the effects, on spinal cord circuits, of a cytokine cocktail that partly mimics the signature of T lymphocytes sub population Th1. In embryonic mouse spinal organ-cultures, containing neuronal cells and neuroglia, cytokines induced inflammatory responses accompanied by a significant increase in spontaneous synaptic activity. We suggest that cytokines specifically altered signal integration in spinal networks by speeding the decay of GABAA responses. This hypothesis is supported by the finding that synapse protection by a non-peptidic NGF mimetic molecule prevented both the changes in the time course of GABA events and in network activity that were left unchanged by the cytokine production from astrocytes and microglia present in the cultured tissue. In conclusion, we developed an important tool for the study of synaptic alterations induced by inflammation, that takes into account the role of neuronal and not neuronal resident cells

Allergic diseases in the elderly: Biological characteristics and main immunological and non-immunological mechanisms

Life expectancy and the number of elderly people are progressively increasing around the world. Together with other pathologies, allergic diseases also show an increasing incidence in geriatric age. This is partly due to the growing emphasis on a more accurate and careful diagnosis of the molecular mechanisms that do not allow to ignore the real pathogenesis of many symptoms until now unknown, and partly to the fact that the allergic people from 20 years ago represent the elderly population now. Moreover, environmental pollution predisposes to the onset of allergic asthma and dermatitis which are the result of internal pathologies more than the expression of allergic manifestations. At the same time the food contamination permits the onset of allergic diseases related to food allergy. In this review we provide the state of the art on the physiological changes in the elderly responsible for allergic diseases, their biological characteristics and the major immunological and extra immunological mechanisms. Much emphasis is given to the management of several diseases in the elderly, including anaphylactic reactions. Moreover, some new features are discussed, such as management of asthma with the support of physical activity and the use of the AIT as prevention of respiratory diseases and for the purpose of a real and long lasting benefit. The mechanisms of adverse reactions to drugs are also discussed, due to their frequency in this age, especially in polytherapy regimens. Study of the modifications of the immune system is also of great importance, as regards to the distribution of the lymphocytes and also the presence of a chronic inflammatory disease related to the production of cytokines, especially in prevision of all the possible therapies to be adopted to allow an active and healthy aging

Allergic diseases in the elderly: Biological characteristics and main immunological and non-immunological mechanisms

Life expectancy and the number of elderly people are progressively increasing around the world. Together with other pathologies, allergic diseases also show an increasing incidence in geriatric age. This is partly due to the growing emphasis on a more accurate and careful diagnosis of the molecular mechanisms that do not allow to ignore the real pathogenesis of many symptoms until now unknown, and partly to the fact that the allergic people from 20 years ago represent the elderly population now. Moreover, environmental pollution predisposes to the onset of allergic asthma and dermatitis which are the result of internal pathologies more than the expression of allergic manifestations. At the same time the food contamination permits the onset of allergic diseases related to food allergy. In this review we provide the state of the art on the physiological changes in the elderly responsible for allergic diseases, their biological characteristics and the major immunological and extra immunological mechanisms. Much emphasis is given to the management of several diseases in the elderly, including anaphylactic reactions. Moreover, some new features are discussed, such as management of asthma with the support of physical activity and the use of the AIT as prevention of respiratory diseases and for the purpose of a real and long lasting benefit. The mechanisms of adverse reactions to drugs are also discussed, due to their frequency in this age, especially in polytherapy regimens. Study of the modifications of the immune system is also of great importance, as regards to the distribution of the lymphocytes and also the presence of a chronic inflammatory disease related to the production of cytokines, especially in prevision of all the possible therapies to be adopted to allow an active and healthy aging

Allergic sensitization to common pets (cats/dogs) according to different possible modalities of exposure: an Italian Multicenter Study

Background: The query "are there animals at home?" is usually administered for collecting information on anamnesis. This modality to consider exposure to pet allergens constitutes a potential bias in epidemiological studies and in clinical practice. The aim of our study was to evaluate/quantify different modalities of exposure to cat/dog in inducing allergic sensitization. Methods: Thirty Italian Allergy units participated in this study. Each centre was required to collect the data of at least 20 consecutive outpatients sensitized to cat/dog allergens. A standardized form reported all demographic data and a particular attention was paid in relieving possible modalities of exposure to cat/dog. Results: A total 723 patients sensitized to cat/dog were recorded, 359 (49.65%) reported direct pet contact, 213 patients (29.46%) were pet owners, and 146 subjects (20.19%) were exposed to pets in other settings. Other patients were sensitized by previous pet ownership (150-20.75%) or indirect contact (103-14.25%), in 111 subjects (15.35%) any contact was reported. Conclusions: Only 213 patients (29.46%) would be classified as "exposed to animals" and 510 (70.54%) as "not exposed" according to usual query. Our classification has shown that many "not-exposed" subjects (399-55.19%) were "really exposed". The magnitude of exposure to pet allergens at home is not related exclusively to pet ownership. These considerations should be taken into account during the planning of epidemiological studies and in clinical practice for the management of pet allergic individuals

Consistent trajectories of rhinitis control and treatment in 16,177 weeks : The MASK-air (R) longitudinal study

Introduction: Data from mHealth apps can provide valuable information on rhinitis control and treatment patterns. However, in MASK-air (R), these data have only been analyzed cross-sectionally, without considering the changes of symptoms over time. We analyzed data from MASK-air (R) longitudinally, clustering weeks according to reported rhinitis symptoms.Methods: We analyzed MASK-air (R) data, assessing the weeks for which patients had answered a rhinitis daily questionnaire on all 7days. We firstly used k-means clustering algorithms for longitudinal data to define clusters of weeks according to the trajectories of reported daily rhinitis symptoms. Clustering was applied separately for weeks when medication was reported or not. We compared obtained clusters on symptoms and rhinitis medication patterns. We then used the latent class mixture model to assess the robustness of results.Results: We analyzed 113,239 days (16,177 complete weeks) from 2590 patients (mean age +/- SD = 39.1 +/- 13.7 years). The first clustering algorithm identified ten clusters among weeks with medication use: seven with low variability in rhinitis control during the week and three with highly-variable control. Clusters with poorly-controlled rhinitis displayed a higher frequency of rhinitis co-medication, a more frequent change of medication schemes and more pronounced seasonal patterns. Six clusters were identified in weeks when no rhinitis medication was used, displaying similar control patterns. The second clustering method provided similar results. Moreover, patients displayed consistent levels of rhinitis control, reporting several weeks with similar levels of control.Conclusions: We identified 16 patterns of weekly rhinitis control. Co-medication and medication change schemes were common in uncontrolled weeks, reinforcing the hypothesis that patients treat themselves according to their symptoms.[GRAPHICS].Peer reviewe

Differentiation of COVID-19 signs and symptoms from allergic rhinitis and common cold : An ARIA-EAACI-GA(2)LEN consensus

Background Although there are many asymptomatic patients, one of the problems of COVID-19 is early recognition of the disease. COVID-19 symptoms are polymorphic and may include upper respiratory symptoms. However, COVID-19 symptoms may be mistaken with the common cold or allergic rhinitis. An ARIA-EAACI study group attempted to differentiate upper respiratory symptoms between the three diseases. Methods A modified Delphi process was used. The ARIA members who were seeing COVID-19 patients were asked to fill in a questionnaire on the upper airway symptoms of COVID-19, common cold and allergic rhinitis. Results Among the 192 ARIA members who were invited to respond to the questionnaire, 89 responded and 87 questionnaires were analysed. The consensus was then reported. A two-way ANOVA revealed significant differences in the symptom intensity between the three diseases (p < .001). Conclusions This modified Delphi approach enabled the differentiation of upper respiratory symptoms between COVID-19, the common cold and allergic rhinitis. An electronic algorithm will be devised using the questionnaire.Peer reviewe

Patient‐centered digital biomarkers for allergic respiratory diseases and asthma: The ARIA‐EAACI approach – ARIA‐EAACI Task Force Report

Biomarkers for the diagnosis, treatment and follow-up of patients with rhinitis and/ or asthma are urgently needed. Although some biologic biomarkers exist in specialist care for asthma, they cannot be largely used in primary care. There are no validated biomarkers in rhinitis or allergen immunotherapy (AIT) that can be used in clinical practice. The digital transformation of health and health care (including mHealth) places the patient at the center of the health system and is likely to optimize the practice of allergy. Allergic Rhinitis and its Impact on Asthma (ARIA) and EAACI (European Academy of Allergy and Clinical Immunology) developed a Task Force aimed at proposing patient-reported outcome measures (PROMs) as digital biomarkers that can be easily used for different purposes in rhinitis and asthma. It first defined control digital biomarkers that should make a bridge between clinical practice, randomized controlled trials, observational real-life studies and allergen challenges. Using the MASK-air app as a model, a daily electronic combined symptom-medication score for allergic diseases (CSMS) or for asthma (e-DASTHMA), combined with a monthly control questionnaire, was embedded in a strategy similar to the diabetes approach for disease control. To mimic real-life, it secondly proposed quality-of- life digital biomarkers including daily EQ-5D visual analogue scales and the bi-weekly RhinAsthma Patient Perspective (RAAP). The potential implications for the management of allergic respiratory diseases were proposed.info:eu-repo/semantics/publishedVersio