Focal Adhesion's Role in Cardiomyocytes Function: From Cardiomyogenesis to Mechanotransduction

Mechanotransduction refers to the ability of cells to sense mechanical stimuli and convert them into biochemical signals. In this context, the key players are focal adhesions (FAs): multiprotein complexes that link intracellular actin bundles and the extracellular matrix (ECM). FAs are involved in cellular adhesion, growth, differentiation, gene expression, migration, communication, force transmission, and contractility. Focal adhesion signaling molecules, including Focal Adhesion Kinase (FAK), integrins, vinculin, and paxillin, also play pivotal roles in cardiomyogenesis, impacting cell proliferation and heart tube looping. In fact, cardiomyocytes sense ECM stiffness through integrins, modulating signaling pathways like PI3K/AKT and Wnt/β-catenin. Moreover, FAK/Src complex activation mediates cardiac hypertrophic growth and survival signaling in response to mechanical loads. This review provides an overview of the molecular and mechanical mechanisms underlying the crosstalk between FAs and cardiac differentiation, as well as the role of FA-mediated mechanotransduction in guiding cardiac muscle responses to mechanical stimuli.

Vitamin D Supplementation in Neonatal and Infant MIS-C Following COVID-19 Infection

To date, the SARS-CoV-2 pandemic still represents a great clinical challenge worldwide, and effective anti-COVID-19 drugs are limited. For this reason, nutritional supplements have been investigated as adjuvant therapeutic approaches in disease management. Among such supplements, vitamin D has gained great interest, due to its immunomodulatory and anti-inflammatory actions both in adult and pediatric populations. Even if there is conflicting evidence about its prevention and/or mitigation effectiveness in SARS-CoV-2 infection, several studies demonstrated a strict correlation between hypovitaminosis D and disease severity in acute COVID-19 and MIS-C (multisystem inflammatory syndrome in children). This narrative review offers a resume of the state of the art about vitamin D's role in immunity and its clinical use in the context of the current pandemic, specially focusing on pediatric manifestations and MIS-C. It seems biologically reasonable that interventions aimed at normalizing circulating vitamin D levels could be beneficial. To help clinicians in establishing the correct prophylaxis and/or supportive therapy with vitamin D, well-designed and adequately statistically powered clinical trials involving both adult and pediatric populations are needed. Moreover, this review will also discuss the few other nutraceuticals evaluated in this context.

Clinical variables associated with late-onset thrombotic and cardiovascular events, after SARS-CoV-2 infection, in a cohort of patients from the first epidemic wave: an 18-month analysis on the "Surviving-COVID" cohort from Bergamo, Italy

Importance

Population studies have recorded an increased, unexplained risk of post-acute cardiovascular and thrombotic events, up to 1 year after acute severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

Objectives

To search for clinical variables and biomarkers associated with late post-acute thrombotic and cardiovascular events after SARS-CoV-2 infection.

Design

Retrospective cohort study.

Setting

Third-level referral hospital in Bergamo (Italy).

Participants

Analysis of an existing database of adult patients, who received care for SARS-CoV-2 infection at our institution between 20 February and 30 September 2020, followed up on a single date ("entry date") at 3-6 months.

Exposure

Initial infection by SARS-CoV-2.

Main outcomes and measures

Primary outcome: occurrence, in the 18 months after entry date, of a composite endpoint, defined by the International Classification of Diseases-9th edition (ICD-9) codes for at least one of: cerebral/cardiac ischemia, venous/arterial thrombosis (any site), pulmonary embolism, cardiac arrhythmia, heart failure. Measures (as recorded on entry date): history of initial infection, symptoms, current medications, pulmonary function test, blood tests results, and semi-quantitative radiographic lung damage (BRIXIA score). Individual clinical data were matched to hospitalizations, voluntary vaccination against SARS-CoV-2 (according to regulations and product availability), and documented reinfections in the following 18 months, as recorded in the provincial Health Authority database. A multivariable Cox proportional hazard model (including vaccine doses as a time-dependent variable) was fitted, adjusting for potential confounders. We report associations as hazard ratios (HR) and 95% confidence intervals (CI).

Results

Among 1,515 patients (948 men, 62.6%, median age 59; interquartile range: 50-69), we identified 84 endpoint events, occurring to 75 patients (5%): 30 arterial thromboses, 11 venous thromboses, 28 arrhythmic and 24 heart failure events. From a multivariable Cox model, we found the following significant associations with the outcome: previous occurrence of any outcome event, in the 18 months before infection (HR: 2.38; 95% CI: 1.23-4.62); BRIXIA score ≥ 3 (HR: 2.43; 95% CI: 1.30-4.55); neutrophils-to-lymphocytes ratio ≥ 3.3 (HR: 2.60; 95% CI: 1.43-4.72), and estimated glomerular filtration rate < 45 ml/min/1.73 m2 (HR: 3.84; 95% CI: 1.49-9.91).

Conclusions and relevance

We identified four clinical variables, associated with the occurrence of post-acute thrombotic and cardiovascular events, after SARS-CoV-2 infection. Further research is needed, to confirm these results.

SARS-CoV-2 infection risk is higher in vaccinated patients with inflammatory autoimmune diseases or liver transplantation treated with mycophenolate due to an impaired antiviral immune response: results of the extended follow up of the RIVALSA prospective cohort

Background

A relevant proportion of immunocompromised patients did not reach a detectable seroconversion after a full primary vaccination cycle against SARS-CoV-2. The effect of different immunosuppressants and the potential risks for SARS-CoV-2 infection in these subjects is largely unknown.

Methods

Patients from the Rivalsa prospective, observational cohort study with planned anti SARS-CoV-2 third dose mRNA vaccination between October and December 2021 were asked to participate to this follow-up study. Patients were asked about eventual confirmed positivity to SARS-CoV-2 infection within 6 months from the third dose and to undergo a blood draw to evaluate seroconversion status after the additional vaccine shot.

Results

19 out of 114 patients taking part in the survey developed a confirmed SARS-CoV-2 infection; we identified mycophenolate treatment as an independent predictor of an increased risk of infection even after the third vaccine dose (OR: 5.20, 95% CI: 1.70-20.00, p=0.0053). This result is in agreement with the in vitro evidence that MMF impairs both B and T lymphocytes driven immune responses (reduction both in memory B cells producing anti-spike antibodies and in proliferating CD4+ and CD8+ T cells).

Conclusions

Immunocompromised patients need an additional vaccine administration to reach a detectable seroconversion, thus fostering a more personalized approach to their clinical management. Moreover, patients undergoing mycophenolate treatment show a specific increased infection risk, with respect to other immunosuppressants thus supporting a closer monitoring of their health status.

COVID-19 Biomarkers at the Crossroad between Patient Stratification and Targeted Therapy: The Role of Validated and Proposed Parameters

Clinical knowledge about SARS-CoV-2 infection mechanisms and COVID-19 pathophysiology have enormously increased during the pandemic. Nevertheless, because of the great heterogeneity of disease manifestations, a precise patient stratification at admission is still difficult, thus rendering a rational allocation of limited medical resources as well as a tailored therapeutic approach challenging. To date, many hematologic biomarkers have been validated to support the early triage of SARS-CoV-2-positive patients and to monitor their disease progression. Among them, some indices have proven to be not only predictive parameters, but also direct or indirect pharmacological targets, thus allowing for a more tailored approach to single-patient symptoms, especially in those with severe progressive disease. While many blood test-derived parameters quickly entered routine clinical practice, other circulating biomarkers have been proposed by several researchers who have investigated their reliability in specific patient cohorts. Despite their usefulness in specific contexts as well as their potential interest as therapeutic targets, such experimental markers have not been implemented in routine clinical practice, mainly due to their higher costs and low availability in general hospital settings. This narrative review will present an overview of the most commonly adopted biomarkers in clinical practice and of the most promising ones emerging from specific population studies. Considering that each of the validated markers reflects a specific aspect of COVID-19 evolution, embedding new highly informative markers into routine clinical testing could help not only in early patient stratification, but also in guiding a timely and tailored method of therapeutic intervention.

Effect of Lactoferrin on Clinical Outcomes of Hospitalized Patients with COVID-19: The LAC Randomized Clinical Trial

As lactoferrin is a nutritional supplement with proven antiviral and immunomodulatory abilities, it may be used to improve the clinical course of COVID-19. The clinical efficacy and safety of bovine lactoferrin were evaluated in the LAC randomized double-blind placebo-controlled trial. A total of 218 hospitalized adult patients with moderate-to-severe COVID-19 were randomized to receive 800 mg/die oral bovine lactoferrin (n = 113) or placebo (n = 105), both given in combination with standard COVID-19 therapy. No differences in lactoferrin vs. placebo were observed in the primary outcomes: the proportion of death or intensive care unit admission (risk ratio of 1.06 (95% CI 0.63-1.79)) or proportion of discharge or National Early Warning Score 2 (NEWS2) ≤ 2 within 14 days from enrollment (RR of 0.85 (95% CI 0.70-1.04)). Lactoferrin showed an excellent safety and tolerability profile. Even though bovine lactoferrin is safe and tolerable, our results do not support its use in hospitalized patients with moderate-to-severe COVID-19.

Gas6/TAM Axis Involvement in Modulating Inflammation and Fibrosis in COVID-19 Patients

Gas6 (growth arrest-specific gene 6) is a widely expressed vitamin K-dependent protein that is involved in many biological processes such as homeostatic regulation, inflammation and repair/fibrotic processes. It is known that it is the main ligand of TAMs, a tyrosine kinase receptor family of three members, namely MerTK, Tyro-3 and Axl, for which it displays the highest affinity. Gas6/TAM axis activation is known to be involved in modulating inflammatory responses as well as fibrotic evolution in many different pathological conditions. Due to the rapidly evolving COVID-19 pandemic, this review will focus on Gas6/TAM axis activation in SARS-CoV-2 infection, where de-regulated inflammatory responses and fibrosis represent a relevant feature of severe disease manifestation. Furthermore, this review will highlight the most recent scientific evidence supporting an unsuspected role of Axl as a SARS-CoV-2 infection driver, and the potential therapeutic advantages of the use of existing Axl inhibitors in COVID-19 management. From a physiological point of view, the Gas6/TAM axis plays a dual role, fostering the tissue repair processes or leading to organ damage and loss of function, depending on the prevalence of its anti-inflammatory or profibrotic properties. This review makes a strong case for further research focusing on the Gas6/TAM axis as a pharmacological target to manage different disease conditions, such as chronic fibrosis or COVID-19.

First-line levetiracetam versus enzyme-inducing antiseizure medication in glioma patients with epilepsy

OBJECTIVE

This study aimed to directly compare the effectiveness of first-line monotherapy levetiracetam (LEV) versus enzyme-inducing antiseizure medications (EIASMs) in glioma patients.

METHODS

In this nationwide retrospective observational cohort study, Grade 2-4 glioma patients were included, with a maximum duration of follow-up of 36 months. Primary outcome was antiseizure medication (ASM) treatment failure for any reason, and secondary outcomes were treatment failure due to uncontrolled seizures and due to adverse effects. For estimation of the association between ASM treatment and ASM treatment failure, multivariate cause-specific cox proportional hazard models were estimated, adjusting for potential confounders.

RESULTS

In the original cohort, a total of 808 brain tumor patients with epilepsy were included, of whom 109 glioma patients were prescribed first-line LEV and 183 glioma patients first-line EIASMs. The EIASM group had a significantly higher risk of treatment failure for any reason compared to LEV (adjusted hazard ratio [aHR] = 1.82, 95% confidence interval [CI] = 1.20-2.75, p = .005). Treatment failure due to uncontrolled seizures did not differ significantly between EIASMs and LEV (aHR = 1.32, 95% CI = .78-2.25, p = .300), but treatment failure due to adverse effects differed significantly (aHR = 4.87, 95% CI = 1.89-12.55, p = .001).

SIGNIFICANCE

In this study, it was demonstrated that LEV had a significantly better effectiveness (i.e., less ASM treatment failure for any reason or due to adverse effects) compared to EIASMs, supporting the current neuro-oncology guideline recommendations to avoid EIASMs in glioma patients.

Observation of Rayleigh-Lamb waves generated by the 2022 Hunga-Tonga volcanic eruption with the POLA detectors at Ny-Ålesund

The eruption of the Hunga-Tonga volcano in the South Pacific Ocean on January 15, 2022, at about 4:15 UTC, generated a violent explosion, which created atmospheric pressure disturbances in the form of Rayleigh-Lamb waves detected all over the globe. Here we discuss the observation of the Hunga-Tonga shock-wave performed at the Ny-Ålesund Research Station on the Spitsbergen island, by the detectors of the PolarquEEEst experiment and their ancillary sensors. Online pressure data as well as the results of dedicated offline analysis are presented and discussed in details. Results include wave arrival times, wave amplitude measurements and wave velocity calculation. We observed five passages of the shock wave with a significance larger than 3 [Formula: see text] and an amplitude up to 1 hPa. The average propagation velocity resulted to be (308 ± 0.6) m/s. Possible effects of the atmospheric pressure variation associated with the shock-wave multiple passages on the cosmic-ray rate at ground level are also investigated. We did not find any significant evidence of this effect.

POS0400 MODULATION OF HUMAN EARLY B CELL DEVELOPMENT THROUGH TARGETED DEGRADATION OF IKAROS AND AIOLOS WITH IBERDOMIDE

Background

B differentiation in the bone marrow (BM) is impaired in patients carrying mutation in the IKFZ1 gene, coding for Ikaros a zinc-finger transcription factor. High Ikaros expression is on the contrary associated with systemic lupus erythematosus[1] and multiple myeloma[2]. Targeted treatment with iberdomide, a cereblon modulator which enhances degradation of Ikaros and Aiolos, is under clinical investigation in multiple myeloma patients and systemic lupus erythematosus. However, consequences of the treatment on human early B cell development remain elusive. Immature B cells develop in the BM from hematopoietic stem cells. An intricate network of transcription factors regulates the maturation process. Ikaros and Aiolos regulate gene expression during B cell development. As reported in mice, Ikaros is essential for the commitment to the lymphoid lineage and later, together with Aiolos, ensures the transition from pre-BII large to pre-BII small cells.

Objectives

Investigate the effect of iberdomide (CC-220) on human early B cell development simulated in vitro.

Methods

We tested the impact of iberdomide on short term culture of BM-derived lymphocytes and in a unique in vitro modeling of early B cell development starting from cord blood (CB)- CD34+ progenitors [3, 4]. We used multi-dimensional spectra flow cytometry (17-color pan-el) to dissect early B cell subpopulations.

Results

Iberdomide treatment led to enhanced degradation of Ikaros and Aiolos in both BM- and CB-derived cultures. Addition of iberdomide early (day 7) to the CB-derived culture impaired the specification to the lymphoid lineage and later also the commitment to the B cell lineage. These observations were confirmed by reduced E2A and PAX5 gene expression, respectively. Treatment with iberdomide on B cell precursors (pro- and pre-B cells, day 28 of culture) on one side it enhanced the proliferation of early progenitors resulting in increased amount of CD10+CD38+ lymphoid-committed cells. On the other side, it resulted in a accumulation of pre-B cells and inefficient development of immature B cells.

Conclusion

Iberdomide impairs the commitment to the lymphoid lineage by enhancing Ikaros’ degrada-tion. When targeting already committed B cells, iberdomide treatment undermines the transition of pre-BII large to pre-BII small cells due to increased Aiolos’ degradation, conse-quently impairing the development of immature B cells. Our data can instruct immunologi-cal monitoring of patients treated with iberdomide, and provide insights in the mechanisms of therapeutic efficacy.

References

[1]Rivellese, F., et al., Effects of targeting the transcription factors Ikaros and Aiolos on B cell activation and differentiation in systemic lupus erythematosus. Lupus Sci Med, 2021. 8(1).

[2]Thakurta, A., et al., Developing next generation immunomodulatory drugs and their combinations in multiple myeloma. Oncotarget, 2021. 12(15): p. 1555-1563.

[3]Kraus, H., et al., A Feeder-Free Differentiation System Identifies Autonomously Proliferating B Cell Precursors in Human Bone Marrow. The Journal of Immunology, 2014. 192(3): p. 1044-1054.

[4]Troilo, A., et al., Nonpermissive bone marrow environment impairs early B-cell development in common variable immunodeficiency. Blood, 2020. 135(17): p. 1452-1457.

Disclosure of Interests

Iga Janowska: None declared, Jakov Korzhenevich: None declared, Julian Staniek: None declared, Raquel Lorenzetti: None declared, Lukas Konstantinidis: None declared, Miriam Erlacher: None declared, Peter Schafer Employee of: BMS, Reinhard Voll: None declared, Jens Thiel Grant/research support from: BMS (former Cellgene), Nils Venhoff: None declared, Marta Rizzi Grant/research support from: BMS (former Cellgene)

Rilpivirine plus cobicistat-boosted darunavir as a two-drug switch regimen in HIV-infected, virologically suppressed subjects on steady standard three-drug therapy: a randomized, controlled, non-inferiority trial (PROBE 2)

BACKGROUND

We explored the combination of rilpivirine plus cobicistat-boosted darunavir [a two-drug regimen (2DR)] when switching from standard triple combined ART.

METHODS

In this randomized, open-label, non-inferiority trial, participants had an HIV-RNA <50 copies/mL on a stable (>6 months) three-drug regimen. The primary endpoint was proportion with HIV-RNA <50 copies/mL at Week 24 (snapshot algorithm), with a -12% non-inferiority margin. ClinicalTrials.gov: NCT04064632.

RESULTS

One hundred and sixty patients were allocated (1:1) to 2DR or to continue current ART (CAR). At Week 24, 72 (90.0%) of participants with 2DR and 75 (93.8%) with CAR maintained HIV-RNA <50 copies/mL [difference -3.75% (95% CI = -11.63 to 5.63)], confirming non-inferiority. Non-inferiority was confirmed considering an HIV-RNA >50 copies/mL (0% for 2DR; 3.7% for CAR; 95% CI = -0.4 to 7.9). Four patients reported adverse events not leading to treatment discontinuation (one patient in the 2DR group and three patients in the CAR group); eight subjects discontinued therapy in the 2DR group and three in the CAR group. With 2DR, lipid serum concentrations increased, but differences were statistically significant only for tenofovir disoproxil fumarate-containing CAR and in 2DR patients receiving a pre-switch regimen including tenofovir disoproxil fumarate. Median bone stiffness decreased in the CAR group from 86.1 g/cm2 (IQR = 74-98) to 83.2 g/cm2 (IQR = 74-97) and increased in the 2DR group from 84.9 g/cm2 (IQR = 74-103) to 85.5 g/cm2 (IQR = 74-101). The reduction within the CAR group was significant (P = 0.043).

CONCLUSIONS

Once-daily rilpivirine plus cobicistat-boosted darunavir is an effective 2DR that combines a high virological efficacy with a potential to avoid major NRTI toxicities.

AB0701 ANTIBODY RAPID TEST POSITIVE HEALTH CARE WORKERS AT A GERMAN UNIVERSITY HOSPITAL: FIRST WAVE CHARACTERISTICS

Background:

Freiburg was among the most heavily affected German cities during the first wave of Sars-Cov-2 infections in spring 2020. Consequently, the University Medical Center Freiburg was one of the first hospitals in Germany to treat Covid19 patients.

Objectives:

To assess the proportion and characteristics of health care workers (HCW) that have been infected during that first wave SARS-CoV-2 serum IgG and IgM antibodies were measured.

Methods:

HCW (n=902, mean age: 40.7 years) participated in this study, and filled out an epidemiological questionnaire. Serum samples were analysed for SARS-Cov-2 IgG/IgM antibodies via rapid diagnostic test (RT) and via ELISA. Statistical analyses were performed using STATA 14.2. An exposure prevention score was developed to quantify the adherence to preventive measures in everyday life.

Results:

902 HCW were tested by RT, and 499 by ELISA. In total, 11.5% of recruited HCW were antibody-positive in the RT, 12.2% in the ELISA. 87.5% of RT positives, 98% of ELISA-positives reported symptoms, compared to 74.6% and 78% of negatives, respectively. Symptoms such as cough (57%/46%), loss of smell and taste (34%/5.2%), fatigue (68%/45%), fever (48%/24%), body aches (45%/22%), and headaches (58%/46%) were reported by significantly more RT positives compared to negatives. The respective differences were even more pronounced (p<0.001) among ELISA-positives compared to negatives with >50% of those positive reported impaired smell or taste compared to less than 7% among the group of ELISA-negatives (p<0.00001).

In logistic regression models, shift work and belonging to the lowest quartile of the exposure prevention score were significantly associated with seropositivity in both tests. Exposure towards children was inversely associated with seropositivity, however, in the finally adjusted model only significant for those that were RT-positive, but not ELISA-positive, reflecting the lower specificity of the former.

Conclusion:

The endemic infection rate in HCW was high. HCW adhering to preventive measures in everyday life had lower infection rates.

Disclosure of Interests:

Manuel Beck: None declared, Alexandra Nieters: None declared, Marta Rizzi: None declared, Ulrich Salzer: None declared, Jens Thiel Speakers bureau: BMS, Nils Venhoff Speakers bureau: Novartis, Nicole Peter: None declared, Hermann Eibel: None declared, Reinhard Voll Speakers bureau: Novartis, Grant/research support from: BMS, Pfizer, Novartis, Stephanie Finzel Speakers bureau: Novartis

An apparatus for the continuous measurement of thickness during the electropolishing of superconducting cavities

An apparatus allowing continuous acquisition of thickness measurements during electropolishing of superconducting cavities is described. The instrument is based on the ultrasound thickness measurement technique and allows the connection of up to six probes. The apparatus has been employed to monitor the surface treatment of PIP-II low beta single cell prototypes developed and manufactured by LASA-INFN and specifically to measure surface removal at different points of interest on the cavity surface. The apparatus facilitated the development and optimization of electropolishing parameters for incorporation into the cavity manufacturing process.

Factors controlling accumulation of organic carbon in a rift-lake, Oligocene Vietnam

Understanding of the processes of petroleum source rock (SR) accumulation in lacustrine rift basins and the behavior of lake systems as long-term carbon sinks is fragmentary. Investigation of an 800 m thick (500 m core and ~ 300 m outcrop), deep-lacustrine, Oligocene section in Vietnam, provides a rare insight into the controls and deposition of organic carbon (OC) and SR formation in continental rift basins. A multidisciplinary dataset, combining elemental data, inorganic and organic geochemistry with sedimentology, shows that the richest alginite-prone, sapropelic SR developed during periods of relative tectonic quiescence characterized by moderate primary productivity in a mainly dysoxic lacustrine basin. Increased rift activity and further development of graben morphology intensified water column stratification and anoxia, which hindered nutrient recycling. Sapropelic organic matter (OM) continued to accumulate, but with increasing amorphous OM content and decreasing total OC values. Periods of increased seasonality were characterized by thermocline weakening, enhanced mixing of water columns, increased primary productivity and diatom blooming. The results suggest that a change from dysoxia towards anoxia or extreme primary productivity does not necessarily enhance OC burial and SR quality. External nutrient input from a phosphate-rich hinterland is sufficient for sapropel formation, whereas the main limiting factor is methanogenesis.

“Transfer, Contestation and Conflict”: How Italian regional and national governments claim and challenge authority in mandatory vaccination policies

Background

This paper explores conflictual policy transfer in Italian vaccination policy 2007-2018. The region of Veneto formally suspended mandatory vaccination in 2007. Soon after, declining vaccination rates across the country sparked a public health crisis. Emilia Romagna adopted a new vaccine mandate for early education, which the national government adopted in 2017. Each policy decision invoked collaboration and contestation between governments. In showing the conflictual aspects of intra-state policy transfer, we offer lessons for multi-level health governance of contested issues.

Methods

We used qualitative documentary analysis of parliamentary transcripts, legislation and government reports, supplemented with semi-structured key informant interviews, using the coding software NVivo 12. We applied theoretical and conceptual scholarship to develop an analytical framework drawing out the key mechanisms through which contestation and conflict take place.

Results

Italian regional and national governments employed three key mechanisms to forcibly transfer or resist vaccination policy: ideas, evidence, and law. Ideas included “the nation”, “herd immunity” and “science.” Evidence included coverage rates and explanations of changes over time. Protagonists of Italy's coercive policy transfers used the law to claim and challenge authority. Contestations occurred in political and bureaucratic spheres. Discrepant historical and evidentiary narratives emerged between levels of government that had injected significant resources into acquiring or defending governance of vaccination policy.

Conclusions

Scholarship has predominantly considered coercive policy transfer at a supra-national or inter-state level. We demonstrate the political blood-spilling within a country when divergent regional policies become contested in a situation of national crisis. 'Evidence' and 'law' can be open to differing interpretations, with 'ideas' shaping the context in which policies prevail.

Communication breakdown in Italy’s vaccination governance

Background

In 2017, Italy rebooted its mandatory vaccination regime, following a series of unfavourable court decisions placing vaccination in disrepute. Vaccination rates had steadily declined for half a decade, culminating in a measles epidemic. Existing studies demonstrate the role of vaccine hesitancy, but none have explored the role of government in the years prior to the new mandate. This study analyses the drivers of failures to address sliding vaccine confidence in Italy.

Methods

We engaged in qualitative analysis of primary sources, Italian and international scholarship, and semi-structured interviews with key informants. These were analysed using the coding software NVivo 12. We developed an empirically and theoretically informed schema to make sense of governance failures in knowledge and action.

Results

The resort to mandates in 2017 was triggered by a series of unfortunate events, further thwarted by governance capacity gaps. During 2012-2017, Italy's vaccination governance included no online campaigns to address concerns. Public health officials lacked crucial knowledge regarding the population, including strategies to address hesitancy. They were preoccupied with other significant changes to Italy's vaccination governance, notably the vaccination schedule. Limited financial resources from the political class constrained officials' capacity in a context of austerity. A credibility gap ensued, which officials sought to plug by constructing Italians as in need of firm instruction by mandatory vaccination.

Conclusions

When voluntary vaccination failed in Italy, the new mandates improved coverage rates. However, the vaccine confidence work explored in this study should not be neglected. The future governance of vaccine confidence requires that effective communications to address vaccine confidence be implemented Italy and other jurisdictions facing vaccine hesitancy and refusal problems.

Key messages

We analyse the Italian government’s response to the crisis of vaccine confidence prior to the introduction of mandates, in order to provide lessons for other governments. We identify and explain the gaps in governance capacity that prevented the addressing of sliding coverage rates.

Legitimising a ‘Zombie idea’: childhood vaccines and autism

Background

In June 2017 the Italian government made childhood vaccination mandatory following a drop in immunization rates. In the years preceding, two court judgments affirmed a causal link between vaccines and autism. Studies have linked these decisions to internet searches about vaccine-autism, the popularity of 'no-vax' theories, and drops in immunization rates. This paper provides an in-depth case study of both decisions and their impact.

Methods

We use a synthetic research design reliant on: (i) a systematic collection of primary sources (publicly available and obtained via official access to information requests); (ii) interviews with key actors prominently involved in the two cases or privy to the Italian vaccine-injury compensation regime (iii) a systematic analysis of media coverage.

Results

Circumstantial and systemic flaws enabled these decisions. Poor trial strategies, insufficient resources and laborious communication practices between arms of government were facilitators. Lack of awareness of the social sensitivity of vaccine issues, underestimation of the phenomenon of vaccine hesitancy, and a tendency to 'think in silos' informed the lack of attention dedicated to the cases. The decisions created false expectations of economic benefits and vindication for families with autistic children, resulting in increased litigation. Systemic flaws exist in the process of appointment of expert consultants acting for the court leading to judicial reliance on false data.

Conclusions

Lessons learned include greater levels of attention to vaccine cases by the administration and a matured attitude of adjudicating bodies. Two issues remain: (i) the inability of government lawyers to disseminate positive results to counteract unfounded narratives; (ii) flaws in the process of appointing expert consultants advising courts, which remains focused on the fiduciary nature of the relationship, rather than scientific authority.

Key messages

The Milan and Rimini decisions that directly affected vaccine governance stemmed from a combination of circumstantial decision-making and systemic flaws that still lurk in public health governance. Strategic decision-making that overlooks lower levels of the adjudicative system can lead to significant public health consequences as courts of law and courts of public opinion obey different logics.

THU0030 DISTINCT EFFECTS OF FIVE JAK INHIBITORS IN THE MODULATION OF HUMAN B CELL ACTIVATION

Background:

JAK inhibitors have been successfully introduced in the treatment of rheumatoid arthritis (RA) and psoriatic arthritis and are in clinical trials for numerous other autoimmune diseases. JAK inhibition effectively reduces cytokine-mediated activation and survival of pathology-driving immune cells by targeting signaling downstream of cytokine receptors. The outcome of such immunomodulation hence will largely depend on the intrinsic expression of the four different JAKs, the cytokine environment and the targeted cell type. Comparative studies investigating the effect on B cells are lacking. In light of the use of JAK inhibitor treatment in autoantibody mediated diseases, the study of the B cell compartment represents a milestone to assess their potential.

Objectives:

We thus aimed to study the B cell compartment as well as B cell function under JAK inhibition in RA patients and to compare the specific effect the JAK inhibitors tofacitinib (pan-JAK), baricitinib (JAK1/2), ruxolitinib (JAK1/2), upadacitinib and filgotinib (selective JAK1) on in vitro B cell activation, differentiation, proliferation, and class switch.

Methods:

B cell subpopulations in RA patients treated with baricitinib or tofacitinib was assessed by flow cytometric analysis of peripheral blood mononuclear cells. For in vitro studies, magnetically isolated total B cells from healthy donors were stimulated T-cell -independently with CpG and treated with scalar doses of the JAK inhibitors tofacitinib, baricitinib, ruxolitinib, upadacitinib and filgotinib. Flow cytometric analysis was performed on days 0, 3 and 6. Cytokine secretion was measured by Cytokine Multiplex Assay.

Results:

B cell phenotyping of RA patients treated with JAK inhibitors baricitinib or tofacitinib showed an increase in marginal zone (MZ) B cells. To investigate this further, we turned to an in vitro model of T-cell-independent B cell activation with CpG via TLR9, known to support MZ B cell expansion. Here, JAK1/2 and selective JAK1 inhibitor treatment led to a dose-dependent decrease of total B cell numbers. When assessing B cell-subpopulations, we observed an altered B cell differentiation with a significant increase in MZ-like B cells under JAK inhibition, which led to a subsequent increase in plasmablast differentiation in the first days. This effect was more pronounced upon pan-JAK inhibitor treatment than JAK1 or JAK1/2 inhibition, indicating that broader JAK inhibition is associated with a stronger effect (tofa > ruxo > bari > upa > filgo).

Notably, we further detected a significant dose-dependent reduction of switched memory formation, strongest with JAK1/2 inhibition (upa > ruxo > bari > tofa > filgo). Consistent with this finding, we observed decreased AID expression under JAK inhibition. Concomitantly, induction of STAT3 expression and STAT3 phosphorylation were reduced under JAK inhibition, suggesting that downstream signalling was abrogated.

To assess the role of autocrine signaling in this system, we measured cytokine secretion upon JAK inhibition and found that JAK2 inhibition led to reduced IL10 secretion. This in turn resulted in an increase of inflammatory cytokines such as IL6, TNF, highlighting the importance of B cell as cytokine-secreting cell type.

Conclusion:

In a T-independent in vitro B cell model JAK inhibition led to a reduced total B cell number as well as reduced switched memory development, whereas MZ-like B cells were increased. Especially JAK2 inhibition strongly impaired switched memory formation. JAK inhibition does not only impact cytokine signalling but also leads to changes in cytokine secretion dynamics and amounts, potentially impacting other cell types.

In conclusion, JAK inhibition has a major effect on B cell activation and maturation, with differential outcomes between JAK inhibitors hinting towards distinct and unique effects on B cell homeostasis.

Disclosure of Interests:

None declared

THU0053 CONTRIBUTION OF DEFECTIVE NON-APOPTOTIC FAS SIGNALING TO IMMUNE DYSREGULATION IN AUTOIMMUNE LYMPHOPROLIFERATIVE SYNDROME (ALPS)

Background:

ALPS patients show impaired generation of humoral memory for T independent antigens whereas they generate memory for self-antigens due to impaired FAS-dependent removal of autoreactive germinal center B cells. It is known that FAS signaling via caspase activation results in cell apoptosis. However, FAS ligation may also initiate or modulate non-apoptotic signaling as shown for example by its ability to activate NF-κB. Recent data implicate a regulatory role of FAS in the modulation of mTOR signaling in ALPS double-negative T cells. Moreover, a recently described C194V FAS mutation disturbs its post-translational modification leading to impaired apoptosis induction while non-apoptotic signalling is still intact. Consequently, C194V FAS protects from the autoimmune phenotype in the murine ALPS system. This supports the view that FAS may prevent autoimmunity with other mechanisms than inducing apoptosis.

Objectives:

We hypothesize that FAS mutations impair this modulatory signaling, leading to hyper-activation of B cells. Therefore we aim to investigate non apoptotic FAS signaling in B cells derived from healthy individuals and ALPS patients.

Methods:

We studied resting and activated B cells in ALPS patients in presence or absence of FAS ligand by flow cytometry analysing relevant molecules to the CD40 signaling pathway. We used mass cytometry to perform functional phenotyping of B cells isolated from secondary lymphoid organs. Proteomic studies were performed to identify potential signaling circuits and RNA sequencing to study the consequences of FAS signaling on B cell fate.

Results:

In CD40L activated B cells, FAS signaling results in specific modulation of the mTOR signaling pathway. This modulation is absent in ALPS derived B cells. In line with these data germinal center B cells and plasmablast from secondary lymphoid organs of ALPS patients show hyperactive mTOR signaling pathway. Proteomic studies identify a circuit that links FAS to the phosphatase PTEN via DAXX and the deubiquitinase USP7.

Conclusion:

We describe a new role of FAS in the regulation of B cell activation. Defects in FAS signaling in ALPS contribute to dysregulation of the mTOR signaling pathway and disturbed B cell development.

Disclosure of Interests:

None declared

AB0033 CHARACTERIZATION OF THE PERIPHERAL B CELL COMPARTMENT IN PATIENTS WITH EOSINOPHILIC GRANULOMATOSIS WITH POLYANGIITIS

Background:

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare form of systemic vasculitis, which is characterized by bronchial asthma, hypereosinophilia, and systemic vasculitis. B-lymphocytes play a key role in EGPA as producers of IgE and anti-neutrophil cytoplasmic antibodies (ANCAs). Indeed, the neutrophils that are targeted by these antibodies are widely described as the mechanism of endothelial damage in this disease. On the other side, the therapeutic response to rituximab in EGPA patients provides evidence for a role of B-cells in the pathogenesis of EGPA. Therefore characterizing B cell subpopulations may help in understanding the disease and the treatment.

Objectives:

To characterize the peripheral B cell compartment in patients with EGPA and to analyze the in vivo potential of B lymphocytes to class-switch to IgE and to assess in vitro the differentiation potential of naïve B cells of EGPA patients into IgE-secreting plasmablasts.

Methods:

Clinical characteristics of the patients, including organ involvement and treatment regimen were evaluated. Laboratory work-up included ANCA-status, eosinophils, IgE, IgG, IgA, IgM, and peripheral CD19+B-cell count. For immunophenotyping isolated PBMCs were stained with monoclonal or polyclonal antibodies and B cells were classified into: naïve, marginal zone, class-switched memory B cells, unconventional memory B cells, transitional and plasmablasts. Furthermore, the expression of IgG+ and subclasses IgG1-4, IgA+, IgE+B cells, BAFFR and TACI was quantified. For in vitro differentiation assays magnetically isolated B lymphocytes from EGPA patients and age-matched healthy controls were stimulated with CD40L, IL-21 and IL-4. Starting the culture with equal number of B cells, the absolute number of plasmablasts, and IgE class switched cells after 9 days was determined by counting the events in the CD27highCD38high gate or the IgG/A/D-IgE+gate by flow cytometry. IgE secretion in the supernatant was measured by ELISA. JAK-STAT signalling pathway was analyzed in response to IL-4 and IL-21 stimulation and phosphorylation of STAT5 and 6 measured by flow cytometry.

Results:

34 patients with EGPA diagnosed according to ACR and CHC-criteria were included into the study. Ten of these patients were analysed separately because they received rituximab therapy. Peripheral B cell numbers in EGPA patients were markedly diminished. B cell subpopulation phenotyping showed in average 57.9% naïve B cells, 12.5 % marginal zone like B cells and 19.2% switched memory B cells. Plasmablasts constituted in average 1.15% of the peripheral B cell compartment, transitional B cells 2.0%. Interestingly, the expression of BAFF receptor and TACI in the memory B cell subset was significantly decreased in EGPA patients when compared with healthy donors. In vitro assays of isolated B cells from EGPA patients demonstrated an increased proportion of IgE-class-switched B cells after 9 days of culture under IL4 stimulation compared with controls. However, no differences were observed in the phosphorylation of STAT5 and STAT6 after stimulation with IL-4 or IL-21.

Conclusion:

In the EGPA-patients we observed markedly diminished B-cells despite of normal lymphocyte counts. B cells showed a reduced expression of BAFF-R and TACI. Class switch to IgE is enhanced in EGPA patients.

Disclosure of Interests:

None declared

The Ovarian Cancer Tumor Immune Microenvironment (TIME) as Target for Therapy: A Focus on Innate Immunity Cells as Therapeutic Effectors

Ovarian cancer (OvCA) accounts for one of the leading causes of death from gynecologic malignancy. Despite progress in therapy improvements in OvCA, most patients develop a recurrence after first-line treatments, dependent on the tumor and non-tumor complexity/heterogeneity of the neoplasm and its surrounding tumor microenvironment (TME). The TME has gained greater attention in the design of specific therapies within the new era of immunotherapy. It is now clear that the immune contexture in OvCA, here referred as tumor immune microenvironment (TIME), acts as a crucial orchestrator of OvCA progression, thus representing a necessary target for combined therapies. Currently, several advancements of antitumor immune responses in OvCA are based on the characterization of tumor-infiltrating lymphocytes, which have been shown to correlate with a significantly improved clinical outcome. Here, we reviewed the literature on selected TIME components of OvCA, such as macrophages, neutrophils, γδ T lymphocytes, and natural killer (NK) cells; these cells can have a role in either supporting or limiting OvCA, depending on the TIME stimuli. We also reviewed and discussed the major (immune)-therapeutic approaches currently employed to target and/or potentiate macrophages, neutrophils, γδ T lymphocytes, and NK cells in the OvCA context.

Charged molecular silica trigger in vitro NETosis in human granulocytes via both oxidative and autophagic pathways

OBJECTIVE

Neutrophils play a key role in immunity and are known to respond to exogenous threats by releasing neutrophil extracellular traps (NETs) through NETosis, a process involving the release of neutrophils nuclear DNA decorated with proteins into the extracellular space. In this study, attention has been focused on the ability of differently charged molecular systems polyhedral oligomeric silsesquioxanes (POSS) to induce NETosis.

MATERIALS AND METHODS

NETs formation was induced by phorbol myristate acetate (PMA) (positive control) and POSS treatment and visualized by confocal microscopy. Moreover, NETs production was quantified by Sytox green staining. Oxidative stress, autophagy as well as endocytosis involvement in the observed phenomena was evaluated by a specific inhibitory approach.

RESULTS

Results obtained in this study demonstrate a POSS time and dose-dependent ability in inducing NETs release irrespectively to their charge. POSS induced NETosis is a consequence of their internalization, as demonstrated by the strong reduction in NETs formation after endocytosis inhibition. Moreover, POSS induced NETosis involves both an increase in superoxide anion generation and autophagy pathway activation as demonstrated by the protective effect displayed by sodium azide and wortmannin.

CONCLUSIONS

Data presented in this study indicate that nanomaterials and molecular systems could have a role in the onset of inflammatory phenomena.

Cutaneous mucormycosis by Rhizopus arrhizus treated with isavuconazole as first line therapy: A case report

Mucormycosis are a group of infections that affect principally immunocompromised host and have a high mortality. Liposomal amphotericin B is the first-line treatment with combined surgical removal of the infectious focus. We report the case of 67-year-old man with idiopathic granulocytic aplasia and a cutaneous lesion caused by Rhizopus arrhizus treated with isavuconazole. Its safety profile and spectrum of activity make it an important therapeutic option.

Tensor Network Annealing Algorithm for Two-Dimensional Thermal States

Tensor network methods have become a powerful class of tools to capture strongly correlated matter, but methods to capture the experimentally ubiquitous family of models at finite temperature beyond one spatial dimension are largely lacking. We introduce a tensor network algorithm able to simulate thermal states of two-dimensional quantum lattice systems in the thermodynamic limit. The method develops instances of projected entangled pair states and projected entangled pair operators for this purpose. It is the key feature of this algorithm to resemble the cooling down of the system from an infinite temperature state until it reaches the desired finite-temperature regime. As a benchmark, we study the finite-temperature phase transition of the Ising model on an infinite square lattice, for which we obtain remarkable agreement with the exact solution. We then turn to study the finite-temperature Bose-Hubbard model in the limits of two (hard-core) and three bosonic modes per site. Our technique can be used to support the experimental study of actual effectively two-dimensional materials in the laboratory, as well as to benchmark optical lattice quantum simulators with ultracold atoms.

[Pathogenesis of systemic lupus erythematosus]

The causes of diseases and disorders of the immune system, which lead to the development of systemic lupus erythematosus (SLE), are not yet completely understood; however, it is known that there are various mechanisms, which can lead to SLE. The development of the disease is based on an underlying genetic disposition but is first triggered by exposure to environmental factors, such as sunburn, viral infections or vitamin D deficiency. Disease flares can also be triggered by environmental factors. Many disease manifestations are caused by pathogenic autoantibodies; hence, B‑cells and plasma cells play a critical role in the pathogenesis of SLE. This review provides an overview of the most frequent factors leading to the development of SLE and describes the key mechanisms of its pathogenesis.

Near infrared laser irradiation induces NETosis via oxidative stress and autophagy

NETosis is a novel immune defense strategy in which neutrophil activation results in the formation of extracellular DNA/protein network which is able to kill microbial populations. NETosis can be induced in vitro by lipopolysaccharide (LPS) or phorbol myristate acetate (PMA). Due to the importance of NETosis in different physiological and pathological processes, photobiostimulation effect on this neutrophil activation mechanism has been investigated. Human granulocytes, isolated from venous blood of healthy donors, were stimulated with a diode laser emitting at 980 nm with an energy intensity ranging from 0 to 75 joules. After 3 h of laser stimulation, granulocytes were fixed and colored with crystal violet in order to assess the NETosis morphology while extracellular DNA produced has been quantified using Sytox Green fluorescent dye. To evaluate ROS production and autophagy role in photobiostimulation-induced NETosis, granulocytes were pre-treated with ROS scavengers (vitamin C, sodium pyruvate, L-NAME, sodium azide), and an autophagy inhibitor (wortmannin). Laser stimulation induced an energy-dependent neutrophil extracellular trap (NET) production in human granulocytes starting from 50-J laser intensity. ROS scavengers and the autophagy inhibitor were able to abrogate both morphological features of NETosis and extracellular DNA production without modifying the basal level of NETosis. Photobiostimulation induced an increase in NET production due to an increase in ROS levels and autophagy activation.

Isolated Pelvic Perfusion for the Treatment of Unresectable Primary or Recurrent Rectal Cancer

Between May 1990 and December 1995, 16 patients with primary or recurrent unresectable rectal cancer were treated by isolated pelvic perfusion. All patients had been previously treated and were considered unsuitable for surgery or further systemic chemotherapy or radiotherapy. The treatment was based on a perfusion lasting 90 min at 40.5 C° with 5-fluorouracil, mitomycin-C and mitoxantrone. Whenever technically feasible (10 cases), continuous intraarterial chemotherapy (through a Medtronic device with a catheter in the inferior mesenteric artery) was administered postoperatively. Two complete responses and 2 partial responses were observed; 8 other patients showed stable disease. One patient did not show any response. Finally, 3 patients for various reasons were not assessable. All patients experienced immediate relief of pain. No major side effects directly related to isolated pelvic perfusion were recorded; a transitory bone marrow depletion was observed in all cases. In conclusion, isolated pelvic perfusion is useful in inoperable disease of the pelvis by reliably relieving pain and thereby improving the patients quality of life.

A MOdular System for Acquisition, Interface and Control (MOSAIC) of detectors and their related electronics for high energy physics experiment

In this work the MOSAIC (“MOdular System for Acquisition, Interface and Control”) board, designed for the readout and testing of the pixel modules for the silicon tracker upgrade of the ALICE (A Large Ion Collider Experiment) experiment at teh CERN LHC, is described. It is based on an Artix7 Field Programmable Gate Array device by Xilinx and is compliant with the six unit “Versa Modular Eurocard” standard (6U-VME) for easy housing in a standard VMEbus crate from which it takes only power supplies and cooling.

Low concentrations of neutrophil extracellular traps induce proliferation in human keratinocytes via NF-kB activation

INTRODUCTION

Granulocytes play a pivotal role in innate immune response, as pathogen invasion activates neutrophils, a subclass of granulocytes, inducing the production of neutrophil extracellular traps (NETs). In this study, it has been evaluated how NETs could affect human keratinocytes (HaCaT cells) behaviour.

MATERIALS AND METHODS

HaCaT cells were treated with increasing NETs concentrations (0.01-200ng/ml) and the effect on cell proliferation was evaluated by MTT assay. Inhibition studies were performed by pre-treating cells with dexamethasone, chloropromazine or amiloride. NF-kB pathway activation was evaluated by western blot.

RESULTS

HaCaT cells stimulation with increasing concentrations of NETs (0.01-50ng/ml) for 48h resulted in a modulation of cell proliferation with a maximum increase corresponding to 0.5-1ng/ml stimulation. NETs low concentrations not only increased cell proliferation, but were also able to induce a faster wound closure in an in vitro scratch assay. NETs scaffold, composed by histone proteins and DNA, is recognized by Toll Like Receptor 9 (TLR 9) that, in turn, activates the NF-kB pathway. In fact, NETs induced proliferation was inhibited by chloropromazine (1nM), that blocks chlatrin vesicles formation, and by amiloride (50nM) that inhibits macropinocytosis. Moreover, dexamethasone, an inhibitor of NF-kB, was able to abolish the NETs effect.

DISCUSSION

This study thus demonstrates that low NETs concentrations undergo internalization finally resulting in a quick NF-kB pathway activation and HaCaT cells proliferation increase, suggesting a close relationship between first immune response and wound healing onset.

Verteporfin based silica nanoparticle for in vitro selective inhibition of human highly invasive melanoma cell proliferation

Photodinamic therapy (PDT) has gained an increasing interest as a new tool to treat skin cancers such as melanoma. This clinical approach take advantage from the combination of a photosensitizer and a specific light wavelength able to induce singlet oxygen production. Mesoporous silica nanoparticles (MSNs) have been widely investigated as drug nanocarriers as their structure and morphology could be customized to produce suitable nanoplatforms enabling high cargo capacity. In the present study MSNs were successfully conjugated with the second generation photosensitizer verteporfin and the resulting nanoplatform (Ver-MSNs) was tested in an in vitro PDT model as a potential tool for melanoma treatment. Ver-MSNs based PDT did not affect cell proliferation of neither a normal human keratinocyte cell line (HaCaT) or a low mestastatic melanoma cell line (A375P). On the other hand Ver-MSNs based PDT deeply affect the highly invasive SK-MEL-28 melanoma cell line behavior, as testified by the strong reduction in cell proliferation along with the dramatic change in cellular morphology, through a nanoparticle internalization dependent mechanism. In fact, experiments performed in the presence of endocytosis inhibitors (chlorpromazine and amiloride) resulted in an attenuation of Ver-MSNs based PDT induced cell death, along with a recover in cellular morphology. MSN doped with verteporfin could thus represent a promising and useful tool for PDT treatment of highly invasive melanoma.

Genitourinary infections in diabetic patients in the new era of diabetes therapy with sodium-glucose cotransporter-2 inhibitors

AIMS

To review prevalence and significance of urinary tract (UTI) and genital infections (GI) in diabetes and the effects of sodium glucose cotransporter 2 (SGLT-2) inhibitors on these complications.

DATA SYNTHESIS

The prevalence of asymptomatic bacteriuria (ASB) is 2-3 times higher in diabetic than in non-diabetic women. The treatment of ASB has no impact on the development of UTIs and/or a decline in renal function. Therefore, there is no indication for screening for and/or treatment of ASB. The incidence of UTI is higher and frequently complicated in diabetic patients, particularly in those with longer duration of disease and of older age. There is no consistent evidence of an association between A1c levels, glycosuria and the risk of ASB and/or UTIs. Diabetes is a known risk factor for Candida colonization and GI, and a poor glycemic control is associated with a higher risk. While patients treated with SGLT-2 inhibitors may have a non-significant increased risk of UTI, they have a clearly increased risk of GI; most of these infections are mild, easy to treat, and the rate of recurrence is low.

CONCLUSION

Diabetic patients are at high risk of UTIs and of GI. Only GI are associated with poor glycemic control. Although patients treated with SGLT-2 inhibitors have an increased 3-5 fold risk of GI, proper medical education can reduce this risk.

Near-infrared laser increases MDPC-23 odontoblast-like cells proliferation by activating redox sensitive pathways

Near infrared laser is known to induce biostimulatory effects, resulting in cell proliferation enhancement. Although such positive effect is widely exploited in various clinical applications, molecular mechanisms involved are still poorly understood. The aim of the study was to investigate the ability of laser stimulation to increase cell proliferation through an early activation of three redox sensitive pathways, namely Nrf-2, NF-κB and ERK in a rat odontoblast-like cell line (MDPC-23 cells). MDPC-23 cells were irradiated with different energy settings (0-50J, corresponding to 0-32.47J/cm²) and cell proliferation was evaluated by cell counting. Nrf-2, NF-κB and ERK signaling pathways activation was investigated through Western blot analysis. Our results show that a single 25J laser stimulation is able to increase cell proliferation and that this effect could be increased by repeating the stimulation twice with a time lapse of 24h. Western blot experiments demonstrated that laser stimulation is able to induce an early activation response in intracellular signaling, with an overlapping time pattern between the three considered pathways. Results discussed in this paper reveal a complex mechanism underlying near-infrared induced increase in pre-odontoblasts proliferation, involving three survival pathways that can act both separately or through reciprocal crosstalk. In particular, data presented suggest an important role for ERK pathway that could act directly by stimulating cell proliferation but can also induce both Nrf-2 and NF-κB activation, acting as a critical cellular checkpoint in response to imbalanced redox state generated by a laser induced increase in ROS production.

Epiregulin-loaded PLGA nanoparticles increase human keratinocytes proliferation: preliminary data

OBJECTIVE

Epiregulin is a member of the epidermal growth factor (EGF) family produced by keratinocytes: the aim of this study was to investigate the ability of biocompatible nanoparticles loaded with such growth factor to increase human keratinocytes proliferation.

MATERIALS AND METHODS

Different PLGA (Poly-d,l-lactide-co-glycolide)-nanoparticles (NPs) formulations have been characterized in size and zeta potential by dynamic light scattering (DLS) analysis. The ability of the different PLGA-NPs formulations to adhere onto dental surfaces has been tested, and epiregulin-enriched PLGA-NPs has been produced. Epiregulin release from NPs has been tested by enzyme-linked immunosorbent (ELISA) assay and the proliferative effects of epiregulin-NPs on human keratinocytes have been evaluated.

RESULTS

DLS analysis revealed a different size distribution depending on the PLA/PGA (poly lactic acid/poly glycolic acid) ratio used. 50:50 PLGA-NPs exhibited the smaller size and the best dental adhesive ability. Moreover, such epiregulin-loaded NPs was able to increase cell proliferation.

CONCLUSIONS

Direct dental pocket drug delivery implies the NPs solution loading onto the dental surface at the cement-enamel junction level: 50:50 PLGA-NPs, with their small size and excellent adhesive ability, represent an interesting tool to deliver epiregulin directly where there is the need for epithelial proliferation. These results describe a possible strategy for periodontal pocket delivery of Epiregulin-loaded PLGA-NPs and might provide a new approach for the treatment of gingival recession, where gingival epithelium proliferation is needed.