Inhibition of IL-34 Unveils Tissue-Selectivity and Is Sufficient to Reduce Microglial Proliferation in a Model of Chronic Neurodegeneration

The proliferation and activation of microglia, the resident macrophages in the brain, is a hallmark of many neurodegenerative diseases such as Alzheimer’s disease (AD) and prion disease. Colony stimulating factor 1 receptor (CSF1R) is critically involved in regulating microglial proliferation, and CSF1R blocking strategies have been recently used to modulate microglia in neurodegenerative diseases. However, CSF1R is broadly expressed by many cell types and the impact of its inhibition on the innate immune system is still unclear. CSF1R can be activated by two independent ligands, CSF-1 and interleukin 34 (IL-34). Recently, it has been reported that microglia development and maintenance depend on IL-34 signaling. In this study, we evaluate the inhibition of IL-34 as a novel strategy to reduce microglial proliferation in the ME7 model of prion disease. Selective inhibition of IL-34 showed no effects on peripheral macrophage populations in healthy mice, avoiding the side effects observed after CSF1R inhibition on the systemic compartment. However, we observed a reduction in microglial proliferation after IL-34 inhibition in prion-diseased mice, indicating that microglia could be more specifically targeted by reducing IL-34. Overall, our results highlight the challenges of targeting the CSF1R/IL34 axis in the systemic and central compartments, important for framing any therapeutic effort to tackle microglia/macrophage numbers during brain disease

P055 CXCL13 as biomarker for histological involvement in sjogren's syndrome

n/

CSF1R inhibitor JNJ-40346527 attenuates microglial proliferation and neurodegeneration in P301S mice

Neuroinflammation and microglial activation are significant processes in Alzheimer's disease pathology. Recent genome-wide association studies have highlighted multiple immune-related genes in association with Alzheimer's disease, and experimental data have demonstrated microglial proliferation as a significant component of the neuropathology. In this study, we tested the efficacy of the selective CSF1R inhibitor JNJ-40346527 (JNJ-527) in the P301S mouse tauopathy model. We first demonstrated the anti-proliferative effects of JNJ-527 on microglia in the ME7 prion model, and its impact on the inflammatory profile, and provided potential CNS biomarkers for clinical investigation with the compound, including pharmacokinetic/pharmacodynamics and efficacy assessment by TSPO autoradiography and CSF proteomics. Then, we showed for the first time that blockade of microglial proliferation and modification of microglial phenotype leads to an attenuation of tau-induced neurodegeneration and results in functional improvement in P301S mice. Overall, this work strongly supports the potential for inhibition of CSF1R as a target for the treatment of Alzheimer's disease and other tau-mediated neurodegenerative diseases

Stromal cells in tertiary lymphoid structures:Architects of autoimmunity

The molecular mediators present within the inflammatory microenvironment are able, in certain conditions, to favor the initiation of tertiary lymphoid structure (TLS) development. TLS is organized lymphocyte clusters able to support antigen-specific immune response in non-immune organs. Importantly, chronic inflammation does not always result in TLS formation; instead, TLS has been observed to develop specifically in permissive organs, suggesting the presence of tissue-specific cues that are able to imprint the immune responses and form TLS hubs. Fibroblasts are tissue-resident cells that define the anatomy and function of a specific tissue. Fibroblast plasticity and specialization in inflammatory conditions have recently been unraveled in both immune and non-immune organs revealing a critical role for these structural cells in human physiology. Here, we describe the role of fibroblasts in the context of TLS formation and its functional maintenance in the tissue, highlighting their potential role as therapeutic disease targets in TLS-associated diseases.</p

Use of orthodontic methods in the treatment of dental luxations: A scoping review

(1) Background: Treating dental luxation injuries is challenging for the clinician. Dental luxations account for 18–33% of injuries to permanent teeth and can be addressed using different therapeutic approaches. The present work was conducted with two aims: (i) to evaluate, through a scoping review, current knowledge of the orthodontic methods (repositioning and stabilization splinting) that can be used at the time of the trauma, and (ii) to investigate the frequency and type of pulp consequences arising after these traumatic injuries. (2) Methods: The literature search was conducted in the period June 2020–December 2020 using the PubMed/MEDLINE, SCOPUS and Web of Science databases. The research questions were formulated according to the PICO (Population, Intervention, Comparison, Outcomes) method and considered the following aspects: type of luxation injury and stage of root development; use of orthodontic repositioning and splinting techniques; frequency and type of pulp consequences; and compliance of treatments with international guidelines. (3) Results: The initial screening of the databases, using the selected search keywords, yielded a total of 587 articles, just 8 fully met the inclusion criteria. Closer analysis of these 8 publications revealed that they would not produce clear meta-analytical data. This made it necessary to limit the data collected to the following six items: number and type of injuries, initial therapeutic intervention, duration of follow-up, number, and type of different pulp consequences. (4) Conclusions: While orthodontic techniques are commonly used to treat dental intrusions, in the case of extrusive and lateral luxation injuries, they are less frequently used and the orthodontic approach is generally confined to the stabilization phase. Among the various possible pulp consequences, many authors consider only pulp canal obliteration (PCO) and pulp necrosis (PN), often tending to overlook physiological healing (pulp survival) and the possible development of PN after PCO. There is therefore a clear need for new, high-quality clinical studies of this topic based on systematic and standardized data collection

THU0220 AUTOPHAGY IN SJOGREN’S SYNDROME SALIVARY GLAND EPITHELIAL CELLS (SGECS) IS ASSOCIATED WITH THE SEVERITY OF INFLAMMATION AND EPITHELIAL CELLS ACTIVATION.

Background:Sjögren’s Syndrome (SS) is characterized by chronic inflammation supported by intrinsic activation of salivary gland epithelial cells (SGECs). Eventually, apoptosis of SGECs ensues, which leads to salivary gland dysfunction and exposition of autoantigens. Autophagy is a stress coping mechanisms of cells implicated in both survival and exposition of autoantigens, and is thereby plausibly implicated in the pathogenesis of SS. At present, the exact relationship between apoptosis and autophagy in SS SGECs is unclear, as is the link between these mechanisms and SGECs activation.Objectives:To explore autophagy in SGECs from patients with SS and to evaluate its relationship with apoptosis and SGECs activation.Methods:Consecutive patients with suspected SS referring to our “Sjogren Clinic” were enrolled, and minor salivary gland (MSG) biopsies were collected for: (1) SGECs culture, (2) PCR analysis, (3) IFI analysis. In SGECs cultures, the expression of autophagy (LC3II), apoptosis (annexin V/PI) and adhesion molecules (ICAM) was investigated by flow cytometry (results expressed as mean % ± SD). The expression of the autophagy gene MAP1LC3II was evaluated by PCR (expressed as 2^deltaCT normalized to GADPH) on both MSG sections and MSG acinar and ductal epithelium samples obtained by laser capture microdissection. Tissue expression of LC3II was evaluated by IFI on SS MSG.Results:Primary SGECs cultures were established from 14 MSG obtained for diagnostic purposes (SS n=8, Sicca n=6). These cells exhibited an inverse correlation between apoptosis and autophagy (p=0.007, r=-0.784), with lower levels of apoptosis (19.7±6.5 vs 24.5±8.5, p=ns) and higher levels of autophagy (59.7±13.1 vs 54.19±19.4, p=ns) in SS compared to Sicca. In SS, MAP1LC3 was positively correlated with Focus Score (p=0.021 r=0.478); however, PCR studies did not reveal significant differences in MAP1LC3 expression between SS (n=26) and Sicca (n=15) (0.024±0.010 vs 0.022±0.008, p=ns). Ductal SGECs (n=4) isolated by laser microdissection of MSG revealed a higher expression of MAP1LC3 (0.005±0.0005 vs 0.003±0.0008; p=0.057) compared to normal acinar epithelium (n=5); a major expression of LC3II in ducts was confirmed by IFI (Image).In SS, a higher expression of ICAM compared to sicca was observed (11.1±3.8 vs 6.9±6.9, p=0.006) and autophagy and apoptosis showed a trend of positive and negative correlation with this molecule, respectively (p=0.683 r=0.118 and p=0.106 r=-0.446).Figure.LC3-II staining in SS MSG [LC3-II+ (green) and Hoechst stain (blue); 60x magnification].Conclusion:In SS, autophagy is upregulated in SGECs and inversely correlated with apoptosis, thus supporting a role of this process in cells’ death prevention during inflammatory process. Indeed, the degree of msg inflammation is correlated more with the activation of autophagy than apoptosis. Interesting, in SS, SGECs autophagy is mainly observed at ductal level and is correlated with higher expression of adhesion molecules suggesting a link between this pathway and changes in SGECs immune phenotype.Disclosure of Interests: :Serena Colafrancesco: None declared, cristiana barbati: None declared, Valentina Iannizzotto: None declared, Linda Mastromanno: None declared, Saba Nayar: None declared, Elena Pipi: None declared, angelica gattamelata: None declared, francesco ciccia Grant/research support from: pfizer, novartis, roche, Consultant of: pfizer, novartis, lilly, abbvie, Speakers bureau: pfizer, novartis, lilly, abbvie, cristiano alessandri Grant/research support from: Pfizer, Francesca Barone: None declared, fabrizio conti Speakers bureau: BMS, Lilly, Abbvie, Pfizer, Sanofi, Roberta Priori: None declared</jats:sec

<i>Salmonella </i>infection induces the reorganisation of follicular dendritic cell networks concomitant with the failure to generate germinal centres

SummaryGerminal centres (GCs) are sites where plasma and memory B cells form to generate high-affinity, Ig class switched antibodies. Specialised stromal cells called follicular dendritic cells (FDCs) are essential for GC formation. During systemicSalmonellaTyphimurium (STm) infection GCs are absent, whereas extensive extrafollicular switched antibody responses are maintained. The mechanisms that underpin the absence of GC formation are incompletely understood. Here, we show that STm-induces a reversible disruption of niches within the splenic microenvironment, including the T and B cell compartments and the marginal zone. Alongside to these effects post-infection, mature FDC networks are strikingly absent, whereas immature FDC precursors, including marginal sinus pre-FDCs (MadCAM-1+) and perivascular Pre-FDCs (PDGFRβ+) are enriched. As normal FDC networks re-establish, extensive GCs become detectable throughout the spleen. Therefore, the reorganisation of FDC networks and the loss of GC responses are key, parallel features of systemic STm infections.Graphical abstract</jats:sec

I polifenoli del foraggio di sulla per il miglioramento del benessere degli animali da latte e della qualità dei formaggi (DISOLASULLA)

Il progetto coinvolge per il triennio 2021-2023 due gruppi di ricerca afferenti a UNIPA e UNIPI nell’intento di valorizzare le potenzialità del foraggio di sulla (Sulla coronaria (L.) Medik.) nell’alimentazione dei ruminanti, proponendone la disidratazione per la costituzione di scorte. L’ipotesi è che la disidratazione consenta, in alternativa alla fienagione, di preservare le proprietà della sulla legate alla sua componente polifenolica, costituita principalmente da tannini condensati (TC). Ingeriti con la dieta, i TC esercitano attività antiossidante, migliorando la termo-tolleranza e lo stato immunitario degli animali, riducono la metanogenesi e le emissioni di metano nell’ambiente, limitano la degradabilità delle proteine alimentari e ne migliorano l’utilizzazione digestiva, da cui l’aumento di caseina nel latte e minori escrezioni di azoto nell’ambiente, e proteggono gli acidi grassi polinsaturi dalla bioidrogenazione ruminale, aumentandone il trasferimento nei prodotti. Su tali basi, il progetto mira a verificare se l’utilizzazione della sulla disidratata nella dieta delle pecore da latte comporti, al pari della sulla verde, effetti positivi su benessere e produttività degli animali, qualità tecnologica del latte, proprietà microbiologiche e nutrizionali dei prodotti caseari e sostenibilità ambientale. Le attività sperimentali sono volte alla produzione di latte e formaggi da pecore di razza Valle del Belìce in Sicilia e Massese in Toscana, alimentate con diete a base di sulla fresca, affienata o disidratata. Sugli animali si valutano i consumi alimentari, la digeribilità della dieta, la produzione di latte, lo stato immunitario e ossidativo in base a indicatori ematici, e l’ambiente biochimico e microbiologico del rumine mediante analisi del liquido ruminale. Sul latte sono determinati i parametri fisico-chimici che ne definiscono la qualità tecnologica e nutrizionale, mentre sui formaggi vengono rilevati i componenti che possono avere impatto positivo sulla salute dei consumatori, come acidi grassi polinsaturi, vitamine, polifenoli e capacità antiossidante. Gli effetti dei TC sono valutati anche sulle dinamiche microbiche rilevabili durante la fermentazione del latte e la maturazione del formaggio. Inoltre, le indagini sui formaggi prendono in esame la stabilità ossidativa, il profilo aromatico e le proprietà sensoriali valutate mediante test di tipo descrittivo e discriminante. L’impatto del sistema di produzione in termini di emissioni di azoto e metano nell’ambiente viene stimato in base ai parametri ruminali e di efficienza alimentare. I risultati ottenuti possono contribuire allo sviluppo della tecnica di disidratazione e pellettatura del foraggio di sulla e alla valorizzazione sul mercato di prodotti caseari “disolasulla”, in linea con le esigenze dei consumatori attenti ai sistemi di allevamento degli animali per quanto riguarda il tipo e la qualità degli alimenti somministrati, il loro benessere e la sostenibilità ambientale

Multiple modes of action mediate the therapeutic effect of IVIg in experimental epidermolysis bullosa acquisita

Substitution of IgG in antibody deficiency or application of high-dose intravenous IgG (IVIg) in patients with autoimmunity are well-established treatments. Data on the mode of action of IVIg are, however, controversial and may differ for distinct diseases. In this study, we investigated the impact and molecular mechanism of high-dose IgG treatment in murine autoantibody-induced skin inflammation, namely, epidermolysis bullosa acquisita (EBA). EBA is caused by antibodies directed against type VII collagen (COL7) and is mediated by complement activation, release of reactive oxygen species, and proteases by myeloid cells. In murine experimental EBA the disease can be induced by injection of anti-COL7 IgG. Here, we substantiate that treatment with high-dose IgG improves clinical disease manifestation. Mechanistically, high-dose IgG reduced the amount of anti-COL7 in skin and sera, which is indicative for an FcRn-dependent mode-of-action. Furthermore, in a non-receptor-mediated fashion, high-dose IgG showed antioxidative properties by scavenging extracellular reactive oxygen species. High-dose IgG also impaired complement activation and served as substrate for proteases, both key events during EBA pathogenesis. Collectively, the non-receptor-mediated anti-inflammatory properties of high-dose IgG may explain the therapeutic benefit of IVIg treatment in skin autoimmunity