Structural Integrity of Nucleolin Is Required to Suppress TDP-43-Mediated Cytotoxicity in Yeast and Human Cell Models

The Transactivating response (TAR) element DNA-binding of 43 kDa (TDP-43) is mainly implicated in the regulation of gene expression, playing multiple roles in RNA metabolism. Pathologically, it is implicated in amyotrophic lateral sclerosis and in a class of neurodegenerative diseases broadly going under the name of frontotemporal lobar degeneration (FTLD). A common hallmark of most forms of such diseases is the presence of TDP-43 insoluble inclusions in the cell cytosol. The molecular mechanisms of TDP-43-related cell toxicity are still unclear, and the contribution to cell damage from either loss of normal TDP-43 function or acquired toxic properties of protein aggregates is yet to be established. Here, we investigate the effects on cell viability of FTLD-related TDP-43 mutations in both yeast and mammalian cell models. Moreover, we focus on nucleolin (NCL) gene, recently identified as a genetic suppressor of TDP-43 toxicity, through a thorough structure/function characterization aimed at understanding the role of NCL domains in rescuing TDP-43-induced cytotoxicity. Using functional and biochemical assays, our data demonstrate that the N-terminus of NCL is necessary, but not sufficient, to exert its antagonizing effects on TDP-43, and further support the relevance of the DNA/RNA binding central region of the protein. Concurrently, data suggest the importance of the NCL nuclear localization for TDP-43 trafficking, possibly related to both TDP-43 physiology and toxicity.

Secreted Metabolome of ALS-Related hSOD1(G93A) Primary Cultures of Myocytes and Implications for Myogenesis

Amyotrophic lateral sclerosis (ALS) is a motor neuron (MN) disease associated with progressive muscle atrophy, paralysis, and eventually death. Growing evidence demonstrates that the pathological process leading to ALS is the result of multiple altered mechanisms occurring not only in MNs but also in other cell types inside and outside the central nervous system. In this context, the involvement of skeletal muscle has been the subject of a few studies on patients and ALS animal models. In this work, by using primary myocytes derived from the ALS transgenic hSOD1(G93A) mouse model, we observed that the myogenic capability of such cells was defective compared to cells derived from control mice expressing the nonpathogenic hSOD1(WT) isoform. The correct in vitro myogenesis of hSOD1(G93A) primary skeletal muscle cells was rescued by the addition of a conditioned medium from healthy hSOD1(WT) myocytes, suggesting the existence of an in trans activity of secreted factors. To define a dataset of molecules participating in such safeguard action, we conducted comparative metabolomic profiling of a culture medium collected from hSOD1(G93A) and hSOD1(WT) primary myocytes and report here an altered secretion of amino acids and lipid-based signaling molecules. These findings support the urgency of better understanding the role of the skeletal muscle secretome in the regulation of the myogenic program and mechanisms of ALS pathogenesis and progression.

Temporal trend of drug-resistance and APOBEC editing in PBMC genotypic resistance tests from HIV-1 infected virologically suppressed individuals

BACKGROUND

We aimed at evaluating the temporal trend of drug-resistance and APOBEC editing from HIV-DNA genotypic resistance tests (GRT) in virologically suppressed individuals.

MATERIAL AND METHODS

Major resistance mutations (MRM), genotypic susceptibility score (GSS) for the current regimen and APOBEC-related mutations (APO-M) were evaluated. Potential changes in trends of MRM and APO-M over-time were assessed and predictors of MRM detection or sub-optimal GSS (GSS<2) at HIV-DNA-GRT were estimated through logistic regression analyses.

RESULTS

Among the 1126 individuals included, 396 (35.2%) harboured at least one MRM (23.4% to NRTI, 18.8% to NNRTI, 7.7% to PI and 1.4% to INSTI [N=724]); 132 (12.3%) individuals showed a GSS <2. APO-M and stop codons were found in 229 (20.3%) and 105 (9.3%) individuals, respectively. APO-DRMs were found in 16.8% of individuals and were more likely observed in those individuals with stop codons (40.0%) compared to those without (14.4%, P<0.001). From 2010 to 2021 no significant changes of resistance or APO-M were found. Positive predictors of MRM detection at HIV-DNA GRT were drug abuse, subtype B infection, and a prolonged and complex treatment history. Perinatal infection and having at least 2 stop codons were associated with a current suboptimal regimen.

CONCLUSIONS

In virologically suppressed individuals, resistance in HIV-DNA and the extent of APOBEC editing were generally stable in the last decade. A careful evaluation of APOBEC editing might be helpful to improve the reliability of HIV-DNA GRT. Further investigations are required to understand how to apply the estimation of APOBEC editing in refining genotypic evaluation.

AB1094 SAFETY AND EFFICACY OF VACCINES FOR SARS-CoV-2 IN PATIENTS WITH RHEUMATIC AND IMMUNE-MEDIATED INFLAMMATORY DISEASES: DATA FROM THE ARGENTINEAN REGISTRY SAR-CoVAC

Background

Currently there is little information on the efficacy and safety of SARS-CoV-2 vaccination in patients with immune-mediated diseases and/or under immunosuppressive treatment in our country, where different types of vaccines and mix regimens are used. For this reason, the Argentine Society of Rheumatology (SAR) with the Argentine Society of Psoriasis (SOARPSO) set out to develop a national register of patients with rheumatic and immune-mediated inflammatory diseases (IMIDs) who have received a SARS-CoV-2 vaccine in order to assess their efficacy and safety in this population.

Objectives

To assess SARS-CoV-2 vaccine efficacy and safety in patients with rheumatic and IMIDs.

Methods

SAR-CoVAC is a national, multicenter and observational registry. Adult patients with a diagnosis of rheumatic or IMIDs who have been vaccinated for SARS-CoV-2 were consecutively included between June 1st and September 17th, 2021. Sociodemographic data, comorbidities, underlying rheumatic or IMIDs, treatments received and their modification prior to vaccination and history of SARS-CoV-2 infection were recorded. In addition, the date and place of vaccination, type of vaccine applied, scheme and indication will be registered. Finally, adverse events (AE), as well as SARS-CoV-2 infection after the application of the vaccine were documented

Results

A total of 1234 patients were included, 79% were female, with a mean age of 57.8 (SD 14.1) years. The most frequent diseases were rheumatoid arthritis (41.2%), osteoarthritis (14.5%), psoriasis (12.7%) and spondyloarthritis (12.3%). Most of them were in remission (28.5%) and low disease activity (41.4%). At the time of vaccination, 21% were receiving glucocorticoid treatment, 35.7% methotrexate, 29.7% biological (b) Disease Modifying Anti-Rheumatic Drugs (DMARDs) and 5.4% JAK inhibitors. Before vaccine application 16.9% had had a SARS-CoV-2 infection.

Regarding the first dose of the vaccine, the most of the patients (51.1%) received Gam-COVID-Vac, followed by ChAdOx1 nCoV-19 (32.8%) and BBIBP-CorV (14.5%). In a lesser proportion, BNT162b2 (0.6%), Ad26.COV2.S (0.2%) and CoronaVac (0.2%) vaccines were used. Almost half of them (48.8%) completed the scheme, 12.5% were mix regimenes, the most frequent being Gam-COVID-Vac / mRNA-1273. The median time between doses was 51days (IQR 53).

More than a quarter (25.9%) of the patients reported at least one AE after the first dose and 15.9% after the second. The flu-like syndrome and local hypersensitivity were the most frequent manifestations. There was one case of mild anaphylaxis. No patient was hospitalized. Altogether, the incidence of AE was 246.5 events/1000 doses. BBIBP-CorV presented significantly lower incidence of AE in comparison with the other types of vaccines. (118.5 events/1000 doses, p<0.002 in all cases)

Regarding efficacy, 63 events of SARS-CoV-2 infection were reported after vaccination, 19% occurred before 14 days post-vaccination, 57.1% after the first dose (>14 days) and 23.8% after the second. In most cases (85.9%) the infection was asymptomatic or had an outpatient course and 2 died due to COVID-19.

Conclusion

In this national cohort of patients with rheumatic and IMIDs vaccinated for SARS-CoV-2, the most widely used vaccines were Gam-COVID-Vac and ChAdOx1 nCoV-19, approximately half completed the schedule and in most cases homologously. A quarter of the patients presented some AE, while 5.1% presented SARS-CoV-2 infection after vaccination, in most cases mild.

Disclosure of Interests

None declared

POS1200 DIFFERENCES BETWEEN THE FIRST AND THE SECOND WAVE OF SARS-COV-2 INFECTION IN PATIENTS WITH IMMUNE-MEDIATED INFLAMMATORY DISEASES IN ARGENTINA: DATA FROM THE SAR-COVID REGISTRY

Background

In Argentina we have witnessed two COVID 19 waves between 2020 and 2021. The first wave occurred during the spring of 2020 and it was related to the wild type of the virus, the second occurred during the fall/winter of 2021 when the gamma variant showed a clear predominance. During the first wave, patient with rheumatic diseases showed a higher frequency of hospitalization and mortality (4% vs 0.26%) when compared to the general population1; at that time, however, vaccination was not yet available.

Objectives

To compare sociodemographic and disease characteristics, course and outcomes of SARS-CoV-2 infection in patients with immune-mediated/autoinflammatory diseases (IMADs) during the first and second waves in Argentina.

Methods

SAR-COVID is a national, multicenter, longitudinal and observational registry, in which patients ≥18 years of age, with a diagnosis of a rheumatic disease who had confirmed SARS-CoV-2 infection (RT-PCR or positive serology) were consecutively included since August 2020. For the purpose of this report, only patients with IMADs who had SARS-CoV-2 infection during the first wave (defined as cases occurred between March 2020 and March 2021) and the second wave (cases occurred between April and August 2021) were examined. Sociodemographic characteristics, disease diagnosis and activity, comorbidities, immunosuppressive treatment and COVID 19 clinical characteristics, complications and outcomes: hospitalization, intensive care unit (ICU) admission, use of mechanical ventilation and death were compared among groups. Descriptive statistical analysis was performed. Variables were compared with Chi squared test and Student T test or Mann Whitney test. Multivariable logistic regression models with forward and backward selection method, using hospitalization, ICU admission and death as dependent variables were carried out.

Results

A total of 1777 patients were included, 1342 from the first wave and 435 of the second one. Patients had a mean (SD) age of 50.7 (14.2) years and 81% were female. Both groups of patients were similar in terms of socio-demographic features, disease diagnosis, disease activity, the use of glucocorticoids ≥ 10 mg/day and the immunosuppressive drugs (Table 1 below). Patients infected during the first wave have higher frequency of comorbidities (49% vs 41%; p= 0.004). Hospitalizations due to COVID 19 (31% vs 20%; p <0.001) and ICU admissions (9% vs 5%; p= 0.009) were higher during the first wave. No differences in the use of mechanical ventilation (16% vs 16%; p= 0.97) nor in the mortality rate (5% vs 4%; p= 0.41) were observed. In the multivariable analysis, after adjusting for demographics, clinical features and immunosuppressive treatment, patients infected during the second wave were 40% less likely to be hospitalized (OR= 0.6, IC95% 0.4-0.8) and to be admitted to the ICU (OR= 0.6, IC95% 0.3-0.9).

Table 1.Variable (% or Mean – SD)First wave(n=1342)Second wave(n=435)p ValueFemale gender81800.7Age (years)51.0 (14.5)50.0 (13.3)0.2Disease diagnosis Rheumatoid arthritis46461 Ankylosing spondylitis10110.8 Systemic lupus erythematosus171850.9 Systemic Scleroderma551 Sjögren´s syndrome650.7 Inflammatory myopathies330.5 Vasculitis430.4Disease activity High430.5Use of immune modulatorsDMARDcs53560.2DMARDts460.1DMARDb82821Use of glucocorticoids ≥10 mg12120.9Comorbidities49410.004

Conclusion

The impact of COVID 19 in Argentina, in terms of mortality in patients with IMADs was still higher compared to the general population during the second wave. However, the frequency of hospitalizations and ICU admissions was lower. These findings could be explained by the introduction of the SARS COV 2 vaccination and, probably, by the cumulative knowledge and management improvement of this infection among physicians.

References

[1]Isnardi CA et al. Epidemiology and outcomes of patients with rheumatic diseases and SARS-COV-2 infection: data from the argentinean SAR-COVID Registry. Ann Rheum Dis, 2021, suppl 1, 887.

Disclosure of Interests

None declared

AB1101 PREVALENCE OF LONG COVID IN RHEUMATIC DISEASE PATIENTS: ANALYSIS OF SAR COVID REGISTRY

Background

Persistent symptoms after acute COVID have been described previously. Main symptoms reported are fatigue, arthralgias, myalgias and mental sickness. Definition and methods vary widely.1

Objectives

To asses prevalence and related factors to long COVID in a retrospective cohort of patients with rheumatic diseases from Argentina.

Methods

A total of 1915 patients were registered from August 18th, 2020 to July 29th, 2021. Patients > 18 years old, with rheumatic disease and confirmed infection by SARS-CoV-2 (antigen or RT-PCR) were included. Those dead, with unknown outcome, wrong date or missing data were excluded. Demographic data, comorbidities, rheumatic disease, and characteristics of SARS-CoV-2 infection were recorded.

Long COVID was defined according to NICE guidelines (persistent symptoms for more than 4 weeks, without alternative diagnosis). Long COVID symptoms were defined by rheumatologist. Severity of infection was classified according to WHO ordinal scale.

We used descriptive statistics, univariate model (Student’s test, chi square test, ANOVA) and multivariate logistic regression analysis.

Results

230 (12%) had long COVID. Median age was 51 (IQR 40-61]) years, 82% were females, 51% were not caucasian. Median of education was 13.3 years (IQR 12 – 16), 79 % had private health insurance and 55 % were employed. Nearly half (n=762, 46%) had comorbidities, the most prevalent was hypertension (n=396, 24%).

The most frequent rheumatic diseases were rheumatoid arthritis (n=719, 42%) and systemic lupus erythematosus (n=280, 16 %). Most were in low activity/remission (79%), used Conventional DMARD (n=773 patients, 45%) and steroids (n=588, 34%) at low dose (n=415, 71%).

Main laboratory findings were abnormal D-dimer (n=94, 28%) and leukopenia (n=93, 26%). Most patients had a WHO ordinal scale < 5 (n=1472, 86%). Median of hospitalization at intensive care unit (ICU) was 8 days [IQR 5, 13]. Treatment for SARS-CoV-2 infection (steroids, anticoagulation, azithromycin, convalescent plasma) was used in 461 (27%) patients.

Most of long COVID (n= 152, 69%) reported 1 symptom, the most frequent was fatigue (n= 55, 22%). Figure 1.

Univariate analysis is presented in Table 1. In multivariate logistic regression analysis non-caucasian ethnicity OR 1.44 (1.07-1.95), years of education OR 1.05 (1-1.09), treatment with cyclophosphamide OR 11.35 (1.56-112.97), symptoms of COVID – 19 OR 13.26 (2.75-242.08), severity scale WHO ≥ 5 OR 2.46 (1.68-3.57), and ICU hospitalization days OR 1.09 (1.05-1.14) were factors associated to long COVID.

Table 1.

Univariate analysis of long COVID syndrome in SAR – COVID registry

VariableAcute COVID n=1486Long COVID n=221P valueAge, years, median [IQR]51 [40, 60]54 [42, 62]0.032Caucasian, n (%)744 (48)132 (53)0.227Female sex, n (%)1242 (80)215 (86)0.066Education, years, median [IQR]12 [10, 17]13 [12, 16]-Private health insurance, n (%)1161 (79)181 (82)0.325Smoking, n (%)381 (25)71 (29)0.224Comorbidities, n (%)650 (45)108 (52)0.066Dyslipidemia, n (%)173 (12)39 (19)0.008Hypertension, n (%)332 (23)60 (29)0.053Low activity/remission disease, n (%)1140 (80)179 (77)1Rheumatoid arthritis, n (%)623 (42)96 (42)1Systemic lupus erythematosus, n (%)243 (16)37 (16)0.996DMARD, n (%)664 (45)109 (47)0.486Cyclophosphamide, n (%)3 (0.2)3 (1)0.035Rituximab, n (%)19 (1)9 (34)0.008Lymphocyte66 (23)19 (30)0.011<1.500 / mm3, n (%)Ferritin > 2000 ng/ml, n (%)32 (11)16 (25)0.011ICU hospitalization, days,7 [4, 10]10 [8, 24]<0.001median [IQR]Treatment for COVID-19, n (%)394 (27)91 (41)<0.001

Conclusion

Prevalence of long COVID was 12%. Non-caucasian ethnicity, higher education, treatment with cyclophosphamide, symptoms of COVID – 19, severe disease and ICU hospitalization days were related to long COVID.

References

[1]Cabrera Martimbianco AL, Pacheco RL, Bagattini ÂM, Riera R. Frequency, signs and symptoms, and criteria adopted for long COVID-19: A systematic review. Int J Clin Pract.

Disclosure of Interests

None declared

POS1201 SAFETY OF SARS-COV-2 VACCINES IN PATIENTS WITH RHEUMATIC DISEASES: DATA FROM THE NATIONAL REGISTRY SAR-CoVAC FROM ARGENTINA

Background

Patients with rheumatic diseases (RD) have been excluded from SARS-CoV-2 vaccine trials, though data appear to show safety and efficacy, mostly evidence remains in mRNA vaccines. In our country, adenovirus-vector, inactivated and heterologous scheme vaccines are frequently used.

Objectives

To describe the safety of SARS-CoV-2 vaccines in patients with RD from the national registry SAR-CoVAC and to assess sociodemographic and clinical factors associated to AE and disease flares after vaccination.

Methods

Adult patients with RD who have been vaccinated for SARS-CoV-2 from de Argentine Society of Rheumatology Vaccine Registry (SAR-CoVAC) were consecutively included between June 1st and December 21st, 2021, This is a national multicentric observational registry that includes patients that have received at least one dose of any SARS-CoV-2 available vaccines in Argentina. Data is voluntarily collected by the treating physician. Naranjo scale was use to assess the association between the AE and vaccination.

Homologous and heterologous schedules were defined according to whether both vaccines received were the same or different, respectively. Descriptive statics, Chi2 test, Fischer test, T test, ANOVA and multivariate regression logistic model were used.

Results

A total of 1679 patients, with 2795 SARS-CoV-2 vaccine doses were included. Vaccines more frequently used were: Gam-COVID-Vac (1227 doses, 44%), ChAdOx1 nCov-19 (872 doses, 31%), BBIBP-CorV (482 doses, 17%) and mRAN-1273 (172 doses, 6%). Altogether, 510 EA were experienced by 449 (27%) patients. Pseudo-flu syndrome was the most frequent (11%), followed by injection site reaction (7%). They were significantly more frequent after the first dose in comparison to the second one (13% vs 7% and 9% vs 5%, respectively, p<0.001 in both cases). All were mild or moderate and no patient was hospitalized due to an AE. One case of moderate anaphylaxis was reported by a patient who received Gam-COVID-Vac. No cases of vaccine-induced thrombotic thrombocytopenia were observed. There were 25 disease flares reported, 17 (68%) cases of arthritis. Among patients with two doses, those with heterologous schedule presented AE more frequent after the second dose (39% vs 17%).

Total incidence of EA was 182.5 events/10 00 doses, it was significantly lower for BBIBP-CorV (105.9 events/1000 dosis, p<0.002 for all cases). The higher incidence of AE was observed for mRAN-1273 (261.6 events/1000 doses) and ChAdOx1 nCov-19 (232.8 events/1000 doses).

Patients with AE were younger [mean 55 years (SD 14) vs 59 years (SD 14), p <0.010], not Caucasian ethnicity [48% vs 35%, p<0.001], had higher education level [mean 13.8 years (SD 4) vs 11.9 years (SD 5), p<0.001], were more frequently employed [54% vs 44%, p<0.001], lived mostly in urban area [99% vs 95% p <0.001, had more frequently dyslipidemia [38% vs 28% p 0.012], and less frequently arterial hypertension [49% vs 65%, p<0.001]. Systemic lupus erythematosus [11% vs 7%, p=0.039] and Sjögren syndrome [6% vs 1.8%, p<0.001] were more frequent among them, while non inflammatory diseases were less prevalent [19% vs 31%, p<0.001]. They were taking steroids [24 vs 18%, p=0.007], antimalarials [17% vs 10%, p<0.001] and methotrexate [41% vs 31%, p <0.001] more frequently.

In the multivariable analysis, mRAN-1273 and ChAdOx1 nCov-19 were associated with AE, while BBIBP-CorV with lower probability of having one. (Figure 1)

Figure 1.

Variables associated with the development of AE. Multivariate logistic regression model

Conclusion

The incidence of AE was 1825 events/1000 doses, were significantly higher for mRAN-1273 and ChAdOx1 nCov-19 and lower for BBIBP-CorV. Most common AE was pseudo-flu syndrome. Female sex, being younger, higher education level, ChAdOx1 nCov-19 and mRAN-1273 vaccines, the use of methotrexate and antimalarials were related of EA in patients with RD.

References

[1]Sattui SE et al. Early experience of COVID-19 vaccination in adults with systemic rheumatic diseases: results from the COVID-19 Global Rheumatology Alliance Vaccine Survey. RMD Open 2021;7.

Disclosure of Interests

None declared

POS0655 SURVIVAL AND SAFETY OF BIOLOGICAL AND TARGETED SYNTHETIC THERAPIES AS REGARDS TO AGE GROUPS. BIOBADASAR 3.0 REGISTRY

Background

Advances in rheumatology and new therapeutic options have certainly impacted patient survival, changing the age range, from youth to seniors. The differences between the age groups could influence the evolution of the disease and the adverse events (AEs) related to the treatments. There are few real-world data on the safety and efficacy of treatments in different age groups.

Objectives

To evaluate the frequency of AEs and the survival of treatments according to the age in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) or ankylosing spondylitis (AS).

Methods

Retrospective, observational, multicenter study of real-life data of patients included in the BIOBADASAR 3.0 registry; exposed and not exposed to original biological treatments (b-DMARDs), biosimilars, targeted synthetic drugs (ts-DMARDs). The unexposed group received treatment with conventional disease-modifying drugs (cDMARDs). A Kaplan-Meier and Log Rank Test analysis was performed to study AEs-free survival and treatment in different age groups (young people <25; young adults 25-34; mature adults 34-65; old adults >65). Factors related to treatment survival were evaluated using Cox regression models.

Results

5,297 patients were included, 80.3% female, mean age 43.7 years (SD 15.6) and median disease progression 14.3 [IQR 11.5]. RA 4658 (87.9%); APs 490 (9.25%) and EA 149 (2.8%). The main reason for treatment discontinuation was ineffectiveness, in 624 patients in the exposed group and in 53 (2.5%) patients in control group, followed by the presence of AEs in 352 (11.2%) and 83 (3.9%), respectively (p=0.001).

A mean Charlson Score of 0.268 (SD 0.6) in the exposed group and 0.306 (SD 0.7) in the control group (p=0.095). Median EAs-free survival in the exposed group was 12.5 years [IQR 16.6] while in controls was 28 years [IQR 11], p<0.0001. Median AEs-free survival was 12 years (IQR 11) in young people, 11.5 years [IQR: 4.9] in young adults, 10 years [IQR: 3.25] in mature adults and 7.6 years [IQR: 6] in old adults with a difference statistically significant (p>0.017). The exposed group presented a median treatment survival in years of 11.25 years [IQR: 10] in young people; 12.5 years [IQR: 4.7] in young adults, 7.5 years [IQR: 12.1] in mature adults and 4.5 years [IQR: 1.14] in old adults (p>0.0001). Considering only the first line of treatment, a median survival of 11.5 years [IQR: 10] was evidenced in the age group <25; 12 years [IQR: 2.6] between 25-34 years old, 10 years [IQR: 12] in the group between 34-65 years old and 5.5 years [IQR: 1.14] in the group > 65 years old (p>0.004). (Figure 1). Considering the second line of treatment, the differences between the groups were not statistically significant (p=0.57). In the multivariate regression model for patients with RA, the factors with the greatest impact on treatment survival were female sex (HR 1.3, 95% CI 1.2-1.4), old age (HR 1.01, 95% CI 1.008-1.01), treatment with steroids (HR 1.19, 95% CI1.1-1.2) and longer disease duration (HR 1.01, 95% CI1.01 – 1.02).

Conclusion

In the present study we were able to demonstrate a greater occurrence of AEs in old adults and mature adults compared to young people and young adults. Conversely, survival for b-DMARDs and ts-DMARDs were greater in youth and young adults. In patients with RA, female sex, corticosteroid therapy, old aged and longer disease duration were associated with treatment discontinuation.

References

[1]Souto A, et al. Rate of discontinuation and drug survival of biologic therapies in rheumatoid arthritis: a systematic review and meta-analysis of drug registries and health care databases. Rheumatology (Oxford). 2016;55(3):523–34.

[2]Ray D, et al. Immune senescence, epigenetics and autoimmunity. Clin Immunol. 2018 Nov;196:59-63. doi: 10.1016/j.clim.2018.04.002. Epub 2018 Apr 11.

[3]Vela P, et al. Influence of age on the occurrence of adverse events in rheumatic patients at the onset of biological treatment: data from the BIOBADASER III register. Arthritis Res Ther. 2020 Jun 15;22(1):143. doi: 10.1186/s13075-020-02231-x.

Disclosure of Interests

None declared

Regulation of Endoplasmic Reticulum-Mitochondria Tethering and Ca2+ Fluxes by TDP-43 via GSK3β

Mitochondria-ER contacts (MERCs), tightly regulated by numerous tethering proteins that act as molecular and functional connections between the two organelles, are essential to maintain a variety of cellular functions. Such contacts are often compromised in the early stages of many neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS). TDP-43, a nuclear protein mainly involved in RNA metabolism, has been repeatedly associated with ALS pathogenesis and other neurodegenerative diseases. Although TDP-43 neuropathological mechanisms are still unclear, the accumulation of the protein in cytoplasmic inclusions may underlie a protein loss-of-function effect. Accordingly, we investigated the impact of siRNA-mediated TDP-43 silencing on MERCs and the related cellular parameters in HeLa cells using GFP-based probes for MERCs quantification and aequorin-based probes for local Ca2+ measurements, combined with targeted protein and mRNA profiling. Our results demonstrated that TDP-43 down-regulation decreases MERCs density, thereby remarkably reducing mitochondria Ca2+ uptake after ER Ca2+ release. Thorough mRNA and protein analyses did not highlight altered expression of proteins involved in MERCs assembly or Ca2+-mediated ER-mitochondria cross-talk, nor alterations of mitochondrial density and morphology were observed by confocal microscopy. Further mechanistic inspections, however, suggested that the observed cellular alterations are correlated to increased expression/activity of GSK3β, previously associated with MERCs disruption.

Perturbations of the Proteome and of Secreted Metabolites in Primary Astrocytes from the hSOD1(G93A) ALS Mouse Model

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease whose pathophysiology is largely unknown. Despite the fact that motor neuron (MN) death is recognized as the key event in ALS, astrocytes dysfunctionalities and neuroinflammation were demonstrated to accompany and probably even drive MN loss. Nevertheless, the mechanisms priming astrocyte failure and hyperactivation are still obscure. In this work, altered pathways and molecules in ALS astrocytes were unveiled by investigating the proteomic profile and the secreted metabolome of primary spinal cord astrocytes derived from transgenic ALS mouse model overexpressing the human (h)SOD1(G93A) protein in comparison with the transgenic counterpart expressing hSOD1(WT) protein. Here we show that ALS primary astrocytes are depleted of proteins-and of secreted metabolites-involved in glutathione metabolism and signaling. The observed increased activation of Nf-kB, Ebf1, and Plag1 transcription factors may account for the augmented expression of proteins involved in the proteolytic routes mediated by proteasome or endosome-lysosome systems. Moreover, hSOD1(G93A) primary astrocytes also display altered lipid metabolism. Our results provide novel insights into the altered molecular pathways that may underlie astrocyte dysfunctionalities and altered astrocyte-MN crosstalk in ALS, representing potential therapeutic targets to abrogate or slow down MN demise in disease pathogenesis.

HIV MDR is still a relevant issue despite its dramatic drop over the years

OBJECTIVES

To evaluate the prevalence and therapeutic relevance of drug resistance among isolates from ART-experienced HIV-1-infected patients over the past two decades in Italy.

METHODS

Dynamics of resistance to one, two and three or more antiretroviral classes were evaluated from 1999-2018. Virological success (VS) after the latest therapy switch was evaluated according to cumulative class resistance and cumulative genotypic susceptibility score (Stanford HIV_DB algorithm).

RESULTS

Among 13 663 isolates (from 6739 patients), resistance to at least one drug class decreased sharply from 1999 to 2010 (≤2001, 84.6%; 2010, 43.6%; P < 0.001), then remained relatively constant at ∼40% during 2010-18, with the proportion of resistance to three or more classes also stable (∼5%). After 2008, integrase inhibitor resistance slightly increased from 5.6% to 9.7% in 2018 and contributed to resistance, particularly in isolates with resistance to three or more classes (one class, 8.4%; two classes, 15.3%; three or more classes, 34.7%, P < 0.001). Among 1827 failing patients with an available follow-up, by 1 year after genotype-guided therapy start the probability of VS was 87.6%. Patients with cumulative resistance to three or more classes and receiving a poorly active regimen showed the lowest probability (62.6%) of VS (P < 0.001) compared with all other patients (≥81.8%). By Cox regression analysis, cumulative MDR and receiving poorly active antiretroviral regimens were associated with a lower hazard of VS compared with those without resistance.

CONCLUSIONS

A dramatic drop of HIV-1 drug resistance at failure has been achieved over the last two decades in Italy; resistance to three or more classes is low but present among currently failing patients. Its management still requires a rational and careful diagnostic and therapeutic approach.

POS1188 COVID-19 IN PATIENTS WITH RHEUMATIC DISEASES: COMPARISON OF DATA FROM THE ARGENTINE REGISTRY (SAR-COVID), WITH THE LATIN AMERICAN AND GLOBAL REGISTRY (GLOBAL RHEUMATOLOGY ALLIANCE)

Background:

SARS CoV-2 infection has recently burst onto the global scene, and the knowledge of the course of this infection in patients with rheumatic diseases receiving immunomodulatory treatment is still insufficient. The Argentine Society of Rheumatology (SAR) designed a national registry called SAR-COVID in order to get to assess our reality.

Objectives:

To identify the particular characteristics of patients with rheumatic diseases and COVID-19 in Argentina (SAR-COVID Registry), and to compare them with the data reported at the Latin American and Global level (Global International Alliance Rheum-COVID Registry).

Methods:

A national, multicenter, prospective and observational registry was carried out. Patients older than 18 years, with a diagnosis of rheumatic disease and SARS-CoV-2 infection by PCR or serology, were included between August 13, 2020 and January 17, 2021. Demographic data, underlying rheumatic disease (activity of the disease, current treatment), comorbidities, clinical-laboratory characteristics of the SARS-CoV-2 infection, as well as received treatments (pharmacological, oxygen therapy / ventilatory support) and outcomes (hospitalization, mortality) were recorded. The characteristics of the included patients were compared with the data reported at the Latin American and global level. Descriptive statistics were performed. Comparisons between groups were made using ANOVA, chi2 or Fisher’s test, according to the type of variable.

Results:

Four hundred sixty-five patients from Argentina, 74 patients from Latin America and 583 from the rest of the world were included, mostly women (79.6%, 73% and 71% respectively), with a mean age of 50.2 (SD 15.3), 53.5 (DE 15.6) and 55.8 (15.5), years respectively. The most frequent rheumatic diseases in the three groups were rheumatoid arthritis (43.9%, 35%, and 39%) and systemic lupus erythematosus (16.1%, 22%, and 14%) (Table 1).

In Argentina, fewer patients received specific pharmacological treatment for COVID-19 (40.9%, 68% and 43% respectively, p <0.0001), and there was a lower requirement of NIMV / IMV (Non-Invasive Mechanical Ventilation/Invasive Mechanical Ventilation) than in the rest of Latin America and the world (10.5% vs 31% vs 13%, p <0.0001).

Hospitalization was lower in Argentina than in the rest of Latin America (37.4% vs 61% p 0.0002) and of the world (37.4% vs 45% p 0.0123), and mortality was numerically lower in Argentina, but without statistically significant differences between the three groups (6.9%, 12% and 11%; p 0.6311). Most of the patients, (86.9%) did not present any complications in Argentina, with a statistically significant difference with the rest of the groups (62% and 77%, p <0.0001) (Graph 1).

Conclusion:

The patients with rheumatic diseases and SARS-CoV-2 infection reported in this argentinian registry received less specific pharmacological treatment for COVID-19, presented fewer complications and required less ventilatory support, than those reported in the Latinoamerican and Global registry. However, no statistically significant differences were observed in terms of mortality.

Graph 1.

Main outcomes and evolution of patients with rheumatic disease and COVID-19.

References:

[1]Stokes, Erin K, Zambrano, Laura D, Anderson, Kayla N, et al. Coronavirus Disease 2019 Case Surveillance - United States, January 22-May 30, 2020. MMWR Morb Mortal Wkly Rep; 69(24): 759-765, 2020 Jun 19.

[2]Mehta P, McAuley DF, Brown M, et al. COVID-19: consider cytokine storm síndromes and immunosuppression. Lancet 2020;395:1033–4.

[3]Gianfrancesco M, et al. Characteristics associated with hospitalisation for COVID-19 in people with rheumatic disease: data from the COVID-19 Global Rheumatology Alliance physician-reported registry. Ann Rheum Dis 2020;79:859–866.

[4]Manuel F. Ugarte-Gil, et al. Characteristics associated with Covid-19 in patients with Rheumatic Disease in Latin America. Global Rheumatology. Septiembre 2020.

Disclosure of Interests:

Alvaro Andres Reyes Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Gelsomina Alle Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Romina Tanten Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Marina Scolnik Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Enrique Soriano Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Guillermo Berbotto Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Maria Haye Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, María Julieta Gamba Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Romina Nieto Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Mercedes García Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Veronica Savio Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Luciana Gonzalez Lucero Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Paula Alba Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Lorena Takashima Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, FABIAN RISUEÑO Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Luciana CASALLA Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Natalia Cucchiaro Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Ana Bertoli Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Sabrina POrta Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Carla Maldini Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Rosana Gallo Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Cecilia Goizueta Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Eugenia Picco Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Rosana Quintana Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Karen Roberts Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Carolina Ayelen Isnardi Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”, Guillermo Pons-Estel Grant/research support from: “Unrestricted grants: Pfizer, Abbvie, Elea Phoenix. None of them have access to patient data.”

Nucleolin Rescues TDP-43 Toxicity in Yeast and Human Cell Models

TDP-43 is a nuclear protein involved in pivotal processes, extensively studied for its implication in neurodegenerative disorders. TDP-43 cytosolic inclusions are a common neuropathologic hallmark in amyotrophic lateral sclerosis (ALS) and related diseases, and it is now established that TDP-43 misfolding and aggregation play a key role in their etiopathology. TDP-43 neurotoxic mechanisms are not yet clarified, but the identification of proteins able to modulate TDP-43-mediated damage may be promising therapeutic targets for TDP-43 proteinopathies. Here we show by the use of refined yeast models that the nucleolar protein nucleolin (NCL) acts as a potent suppressor of TDP-43 toxicity, restoring cell viability. We provide evidence that NCL co-expression is able to alleviate TDP-43-induced damage also in human cells, further supporting its beneficial effects in a more consistent pathophysiological context. Presented data suggest that NCL could promote TDP-43 nuclear retention, reducing the formation of toxic cytosolic TDP-43 inclusions.

ALS-Associated SOD1(G93A) Decreases SERCA Pump Levels and Increases Store-Operated Ca2+ Entry in Primary Spinal Cord Astrocytes from a Transgenic Mouse Model

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by the selective death of motor neurons (MNs), probably by a combination of cell- and non-cell-autonomous processes. The past decades have brought many important insights into the role of astrocytes in nervous system function and disease, including the implication in ALS pathogenesis possibly through the impairment of Ca²⁺-dependent astrocyte-MN cross-talk. In this respect, it has been recently proposed that altered astrocytic store-operated Ca²⁺ entry (SOCE) may underlie aberrant gliotransmitter release and astrocyte-mediated neurotoxicity in ALS. These observations prompted us to a thorough investigation of SOCE in primary astrocytes from the spinal cord of the SOD1(G93A) ALS mouse model in comparison with the SOD1(WT)-expressing controls. To this purpose, we employed, for the first time in the field, genetically-encoded Ca²⁺ indicators, allowing the direct assessment of Ca²⁺ fluctuations in different cell domains. We found increased SOCE, associated with decreased expression of the sarco-endoplasmic reticulum Ca²⁺-ATPase and lower ER resting Ca²⁺ concentration in SOD1(G93A) astrocytes compared to control cells. Such findings add novel insights into the involvement of astrocytes in ALS MN damage.

The Link of the Prion Protein with Ca2+ Metabolism and ROS Production, and the Possible Implication in Aβ Toxicity

The cellular prion protein (PrP^C) is an ubiquitous cell surface protein mostly expressed in neurons, where it localizes to both pre- and post-synaptic membranes. PrP^C aberrant conformers are the major components of mammalian prions, the infectious agents responsible for incurable neurodegenerative disorders. PrP^C was also proposed to bind aggregated misfolded proteins/peptides, and to mediate their neurotoxic signal. In spite of long-lasting research, a general consensus on the precise pathophysiologic mechanisms of PrP^C has not yet been reached. Here we review our recent data, obtained by comparing primary neurons from PrP-expressing and PrP-knockout mice, indicating a central role of PrP^C in synaptic transmission and Ca²⁺ homeostasis. Indeed, by controlling gene expression and signaling cascades, PrP^C is able to optimize glutamate secretion and regulate Ca²⁺ entry via store-operated channels and ionotropic glutamate receptors, thereby protecting neurons from threatening Ca²⁺ overloads and excitotoxicity. We will also illustrate and discuss past and unpublished results demonstrating that Aβ oligomers perturb Ca²⁺ homeostasis and cause abnormal mitochondrial accumulation of reactive oxygen species by possibly affecting the PrP-dependent downregulation of Fyn kinase activity.

Single cell analysis reveals the involvement of the long non-coding RNA Pvt1 in the modulation of muscle atrophy and mitochondrial network

Long non-coding RNAs (lncRNAs) are emerging as important players in the regulation of several aspects of cellular biology. For a better comprehension of their function, it is fundamental to determine their tissue or cell specificity and to identify their subcellular localization. In fact, the activity of lncRNAs may vary according to cell and tissue specificity and subcellular compartmentalization. Myofibers are the smallest complete contractile system of skeletal muscle influencing its contraction velocity and metabolism. How lncRNAs are expressed in different myofibers, participate in metabolism regulation and muscle atrophy or how they are compartmentalized within a single myofiber is still unknown. We compiled a comprehensive catalog of lncRNAs expressed in skeletal muscle, associating the fiber-type specificity and subcellular location to each of them, and demonstrating that many lncRNAs can be involved in the biological processes de-regulated during muscle atrophy. We demonstrated that the lncRNA Pvt1, activated early during muscle atrophy, impacts mitochondrial respiration and morphology and affects mito/autophagy, apoptosis and myofiber size in vivo. This work corroborates the importance of lncRNAs in the regulation of metabolism and neuromuscular pathologies and offers a valuable resource to study the metabolism in single cells characterized by pronounced plasticity.

Regulation of ER-mitochondria contacts by Parkin via Mfn2

Parkin, an E3 ubiquitin ligase and a Parkinson's disease (PD) related gene, translocates to impaired mitochondria and drives their elimination via autophagy, a process known as mitophagy. Mitochondrial pro-fusion protein Mitofusins (Mfn1 and Mfn2) were found to be a target for Parkin mediated ubiquitination. Mfns are transmembrane GTPase embedded in the outer membrane of mitochondria, which are required on adjacent mitochondria to mediate fusion. In mammals, Mfn2 also forms complexes that are capable of tethering mitochondria to endoplasmic reticulum (ER), a structural feature essential for mitochondrial energy metabolism, calcium (Ca²⁺) transfer between the organelles and Ca²⁺ dependent cell death. Despite its fundamental physiological role, the molecular mechanisms that control ER-mitochondria cross talk are obscure. Ubiquitination has recently emerged as a powerful tool to modulate protein function, via regulation of protein subcellular localization and protein ability to interact with other proteins. Ubiquitination is also a reversible mechanism, which can be actively controlled by opposing ubiquitination-deubiquitination events. In this work we found that in Parkin deficient cells and parkin mutant human fibroblasts, the tether between ER and mitochondria is decreased. We identified the site of Parkin dependent ubiquitination and showed that the non-ubiquitinatable Mfn2 mutant fails to restore ER-mitochondria physical and functional interaction. Finally, we took advantage of an established in vivo model of PD to demonstrate that manipulation of ER-mitochondria tethering by expressing an ER-mitochondria synthetic linker is sufficient to rescue the locomotor deficit associated to an in vivo Drosophila model of PD.

Controlled double-blind trial with Baryta carbonica 15 CH versus placebo in a group of hypertensive subjects confined to bed in two old people's homes

Taking into account the toxicology of soluble barium salts, the authors treated 32 hypertensive subjects who were confirned to bed in two old people's homes with Baryta carbonica 15 CH versus placebo in a randomized double-blind study. Seventeen patients were given Baryta carbonica and 15 placebo. Taking the groups as a whole, no statistically significant differences were found between the effects of placebo and active drug on the blood pressure. But the four subjects who had been prospectively considered sensitive and were treated with Baryta carbonica gave strongly positive results. Some interesting conclusions were arrived at both from the general medical and the homœopathic point of view.

Dynamics and phylogenetic relationships of HIV-1 transmitted drug resistance according to subtype in Italy over the years 2000-14

Background

Transmitted drug-resistance (TDR) remains a critical aspect for the management of HIV-1-infected individuals. Thus, studying the dynamics of TDR is crucial to optimize HIV care.

Methods

In total, 4323 HIV-1 protease/reverse-transcriptase sequences from drug-naive individuals diagnosed in north and central Italy between 2000 and 2014 were analysed. TDR was evaluated over time. Maximum-likelihood and Bayesian phylogenetic trees with bootstrap and Bayesian-probability supports defined transmission clusters.

Results

Most individuals were males (80.2%) and Italian (72.1%), with a median (IQR) age of 37 (30-45) years. MSM accounted for 42.2% of cases, followed by heterosexuals (36.4%). Non-B subtype infections accounted for 30.8% of the overall population and increased over time (<2005-14: 19.5%-38.5%, P < 0.0001), particularly among Italians (<2005-14: 6.5%-28.8%, P < 0.0001). TDR prevalence was 8.8% and increased over time in non-B subtypes (<2005-14: 2%-7.1%, P = 0.018). Overall, 467 transmission clusters (involving 1207 individuals; 27.9%) were identified. The prevalence of individuals grouping in transmission clusters increased over time in both B (<2005-14: 12.9%-33.5%, P = 0.001) and non-B subtypes (<2005-14: 18.4%-41.9%, P = 0.006). TDR transmission clusters were 13.3% within the overall cluster observed and dramatically increased in recent years (<2005-14: 14.3%-35.5%, P = 0.005). This recent increase was mainly due to non-B subtype-infected individuals, who were also more frequently involved in large transmission clusters than those infected with a B subtype [median number of individuals in transmission clusters: 7 (IQR 6-19) versus 4 (3-4), P = 0.047].

Conclusions

The epidemiology of HIV transmission changed greatly over time; the increasing number of transmission clusters (sometimes with drug resistance) shows that detection and proper treatment of the multi-transmitters is a major target for controlling HIV spread.

Neuronal pathophysiology featuring PrPC and its control over Ca2+ metabolism

Calcium (Ca²⁺) is an intracellular second messenger that ubiquitously masters remarkably diverse biological processes, including cell death. Growing evidence substantiates an involvement of the prion protein (PrP^C) in regulating neuronal Ca²⁺ homeostasis, which could rationalize most of the wide range of functions ascribed to the protein. We have recently demonstrated that PrP^C controls extracellular Ca²⁺ fluxes, and mitochondrial Ca²⁺ uptake, in neurons stimulated with glutamate (De Mario et al., J Cell Sci 2017; 130:2736-46), suggesting that PrP^C protects neurons from threatening Ca²⁺ overloads and excitotoxicity. In light of these results and of recent reports in the literature, here we review the connection of PrP^C with Ca²⁺ metabolism and also provide some speculative hints on the physiologic outcomes of this link. In addition, because PrP^C is implicated in neurodegenerative diseases, including prion disorders and Alzheimer's disease, we will also discuss possible ways by which disruption of PrP^C-Ca²⁺ association could be mechanistically connected with these pathologies.

Pre-existent NRTI and NNRTI resistance impacts on maintenance of virological suppression in HIV-1-infected patients who switch to a tenofovir/emtricitabine/rilpivirine single-tablet regimen

Objectives

To evaluate the maintenance of virological suppression (VS) in antiretroviral-treated HIV-1-suppressed patients switching to a tenofovir/emtricitabine/rilpivirine (TDF/FTC/RPV) single-tablet regimen, by considering pre-existent resistance (pRes).

Methods

pRes was evaluated according to resistance on all previous plasma genotypic resistance tests. Probability and predictors of virological rebound (VR) were evaluated.

Results

Three hundred and nine patients were analysed; 5.8% of them showed resistance to both NRTIs and NNRTIs, while 12.6% showed resistance to only one of these drug classes. By 72 weeks, the probability of VR was 11.3%. A higher probability of VR was found in the following groups: (i) patients with NRTI + NNRTI pRes compared with those harbouring NRTI or NNRTI pRes and with those without reverse transcriptase inhibitor pRes (39.2% versus 11.5% versus 9.4%, P  <   0.0001); (ii) patients with a virus with full/intermediate resistance to both tenofovir/emtricitabine and rilpivirine compared with those having a virus with full/intermediate resistance to tenofovir/emtricitabine or rilpivirine and those having a virus fully susceptible to TDF/FTC/RPV (36.4% versus 17.8% versus 9.7%, P  <   0.001); and (iii) patients with pre-therapy viraemia >500 000 copies/mL compared with those with lower viraemia levels (>500 000: 16.0%; 100 000-500 000: 9.3%; <100 000 copies/mL: 4.8%, P  =   0.009). pRes and pre-therapy viraemia >500 000 copies/mL were independent predictors of VR by multivariable Cox regression.

Conclusions

TDF/FTC/RPV as a treatment simplification strategy shows a very high rate of VS maintenance. The presence of pRes to both NRTIs and NNRTIs and a pre-therapy viraemia >500 000 copies/mL are associated with an increased risk of VR, highlighting the need for an accurate selection of patients before simplification.

Generation and validation of novel adeno-associated viral vectors for the analysis of Ca2+ homeostasis in motor neurons

A finely tuned Ca²⁺ homeostasis in restricted cell domains is of fundamental importance for neurons, where transient Ca²⁺ oscillations direct the proper coordination of electro-chemical signals and overall neuronal metabolism. Once such a precise regulation is unbalanced, however, neuronal functions and viability are severely compromised. Accordingly, disturbed Ca²⁺ metabolism has often been claimed as a major contributor to different neurodegenerative disorders, such as amyotrophic lateral sclerosis that is characterised by selective motor neuron (MN) damage. This notion highlights the need for probes for the specific and precise analysis of local Ca²⁺ dynamics in MNs. Here, we generated and functionally validated adeno-associated viral vectors for the expression of gene-encoded fluorescent Ca²⁺ indicators targeted to different cell domains, under the transcriptional control of a MN-specific promoter. We demonstrated that the probes are specifically expressed, and allow reliable local Ca²⁺ measurements, in MNs from murine primary spinal cord cultures, and can also be expressed in spinal cord MNs in vivo, upon systemic administration to newborn mice. Preliminary analyses using these novel vectors have shown larger cytosolic Ca²⁺ responses following stimulation of AMPA receptors in the cytosol of primary cultured MNs from a murine genetic model of ALS compared to the healthy counterpart.

The prion protein regulates glutamate-mediated Ca2+ entry and mitochondrial Ca2+ accumulation in neurons

The cellular prion protein (PrP^C) whose conformational misfolding leads to the production of deadly prions, has a still-unclarified cellular function despite decades of intensive research. Following our recent finding that PrP^C limits Ca²⁺ entry via store-operated Ca²⁺ channels in neurons, we investigated whether the protein could also control the activity of ionotropic glutamate receptors (iGluRs). To this end, we compared local Ca²⁺ movements in primary cerebellar granule neurons and cortical neurons transduced with genetically encoded Ca²⁺ probes and expressing, or not expressing, PrP^C Our investigation demonstrated that PrP^C downregulates Ca²⁺ entry through each specific agonist-stimulated iGluR and after stimulation by glutamate. We found that, although PrP-knockout (KO) mitochondria were displaced from the plasma membrane, glutamate addition resulted in a higher mitochondrial Ca²⁺ uptake in PrP-KO neurons than in their PrP^C-expressing counterpart. This was because the increased Ca²⁺ entry through iGluRs in PrP-KO neurons led to a parallel increase in Ca²⁺-induced Ca²⁺ release via ryanodine receptor channels. These data thus suggest that PrP^C takes part in the cell apparatus controlling Ca²⁺ homeostasis, and that PrP^C is involved in protecting neurons from toxic Ca²⁺ overloads.

Absolute quantification of myosin heavy chain isoforms by selected reaction monitoring can underscore skeletal muscle changes in a mouse model of amyotrophic lateral sclerosis

Skeletal muscle fibers contain different isoforms of myosin heavy chain (MyHC) that define distinctive contractile properties. In light of the muscle capacity to adapt MyHC expression to pathophysiological conditions, a rapid and quantitative assessment of MyHC isoforms in small muscle tissue quantities would represent a valuable diagnostic tool for (neuro)muscular diseases. As past protocols did not meet these requirements, in the present study we applied a targeted proteomic approach based on selected reaction monitoring that allowed the absolute quantification of slow and fast MyHC isoforms in different mouse skeletal muscles with high reproducibility. This mass-spectrometry-based method was validated also in a pathological specimen, by comparison of the MyHC expression profiles in different muscles from healthy mice and a genetic mouse model of amyotrophic lateral sclerosis (ALS) expressing the SOD1(G93A) mutant. This analysis showed that terminally ill ALS mice have a fast-to-slow shift in the fiber type composition of the tibialis anterior and gastrocnemius muscles, as previously reported. These results will likely open the way to accurate and rapid diagnoses of human (neuro)muscular diseases by the proposed method. Graphical Abstract Methods for myosin heavy chain (MyHC) quantification: a comparison of classical methods and selected reaction monitoring (SRM)-based mass spectrometry approaches.

Almost a century of prion protein(s): From pathology to physiology, and back to pathology

Prions are one of the few pathogens whose name is renowned at all population levels, after the dramatic years pervaded by the fear of eating prion-infected food. If now this, somehow irrational, scare of bovine meat inexorably transmitting devastating brain disorders is largely subdued, several prion-related issues are still unsolved, precluding the design of therapeutic approaches that could slow, if not halt, prion diseases. One unsolved issue is, for example, the role of the prion protein (PrP^C), whole conformational misfolding originates the prion but whose physiologic reason d'etre in neurons, and in cells at large, remains enigmatic. Preceded by a historical outline, the present review will discuss the functional pleiotropicity ascribed to PrP^C, and whether this aspect could fall, at least in part, into a more concise framework. It will also be devoted to radically different perspectives for PrP^C, which have been recently brought to the attention of the scientific world with unexpected force. Finally, it will discuss the possible reasons allowing an evolutionary conserved and benign protein, as PrP^C is, to turn into a high affinity receptor for pathologic misfolded oligomers, and to transmit their toxic message into neurons.

Virological response and resistance profile in HIV-1-infected patients starting darunavir-containing regimens

OBJECTIVES

We evaluated the virological response in patients starting a regimen based on darunavir/ritonavir (DRV/r), which is currently the most widely used ritonavir-boosted protease inhibitor.

METHODS

Data from 206 drug-naïve and 327 PI-experienced patients starting DRV/r 600/100 mg twice daily (DRV600) or 800/100 mg once daily (DRV800) were examined. The probabilities of virological success (VS) and virological rebound (VR) were evaluated in survival analyses. Baseline DRV/r resistance and its evolution at failure were also examined.

RESULTS

DRV600 was preferentially administered in patients with complex requirements (older age, higher viraemia, lower CD4 cell count and DRV/PI resistance) compared with DRV800. By 12 months, the probability of achieving VS was 93.2% and 84.3% in drug-naïve and PI-experienced patients, respectively. The higher the baseline viraemia, the longer was the time required to achieve VS, both in drug-naïve patients [>500 000 HIV-1 RNA copies/mL: median [interquartile range (IQR)] 6.1 (5.1-10.3) months; 100 000-500 000 copies/mL: median (IQR) 4.9 (3.8-6.1) months; <100 000 copies/mL: median (IQR) 3.9 (3.5-4.8) months; P < 0.001] and in PI-experienced patients [≥100 000 copies/mL: median (IQR) 7.2 (5.7-11.6) months; <100 000 copies/mL: median (IQR) 2.8 (2.4-3.3) months; P < 0.001]. In PI-experienced patients, the probability of VR was higher for higher viraemia levels (22.3% for ≥100 000 copies/ml vs. 9.7% for <100 000 copies/mL; P = 0.007). Baseline resistance did not affect the virological response. At failure, a high percentage of patients maintained virus susceptible to all PIs (drug-naïve: 95%; PI-experienced: 80%). Despite being used more often in patients with more complex requirements, DRV600 performed as well as DRV800.

CONCLUSIONS

In clinical practice, use of DRV/r (with its flexible dosage) results in high rates of virological response. These data support the use of PI/r in patients whose characteristics require potent drugs with a high genetic barrier.

The prion protein constitutively controls neuronal store-operated Ca(2+) entry through Fyn kinase

The prion protein (PrP^C) is a cell surface glycoprotein mainly expressed in neurons, whose misfolded isoforms generate the prion responsible for incurable neurodegenerative disorders. Whereas PrP^C involvement in prion propagation is well established, PrP^C physiological function is still enigmatic despite suggestions that it could act in cell signal transduction by modulating phosphorylation cascades and Ca²⁺ homeostasis. Because PrP^C binds neurotoxic protein aggregates with high-affinity, it has also been proposed that PrP^C acts as receptor for amyloid-β (Aβ) oligomers associated with Alzheimer’s disease (AD), and that PrP^C-Aβ binding mediates AD-related synaptic dysfunctions following activation of the tyrosine kinase Fyn. Here, use of gene-encoded Ca²⁺ probes targeting different cell domains in primary cerebellar granule neurons (CGN) expressing, or not, PrP^C, allowed us to investigate whether PrP^C regulates store-operated Ca²⁺ entry (SOCE) and the implication of Fyn in this control. Our findings show that PrP^C attenuates SOCE, and Ca²⁺ accumulation in the cytosol and mitochondria, by constitutively restraining Fyn activation and tyrosine phosphorylation of STIM1, a key molecular component of SOCE. This data establishes the existence of a PrP^C-Fyn-SOCE triad in neurons. We also demonstrate that treating cerebellar granule and cortical neurons with soluble Aβ_(1–42) oligomers abrogates the control of PrP^C over Fyn and SOCE, suggesting a PrP^C-dependent mechanizm for Aβ-induced neuronal Ca²⁺ dyshomeostasis.

HIV-1 integrase genotyping is reliable and reproducible for routine clinical detection of integrase resistance mutations even in patients with low-level viraemia

OBJECTIVES

Integrase drug resistance monitoring deserves attention because of the increasing number of patients being treated with integrase strand-transfer inhibitors. Therefore, we evaluated the integrase genotyping success rate at low-level viraemia (LLV, 51-1000 copies/mL) and resistance in raltegravir-failing patients.

METHODS

An integrase genotypic resistance test (GRT) was performed on 1734 HIV-1 samples collected during 2006-13. Genotyping success rate was determined according to the following viraemia levels: 51-500, 501-1000, 1001-10 000, 10 001-100 000 and >100 000 copies/mL. The reproducibility of integrase GRT was evaluated in 41 plasma samples processed in duplicate in two reference centres. The relationship between LLV and resistance prevalence was evaluated in a subset of 120 raltegravir-failing patients.

RESULTS

Overall, the integrase genotyping success rate was 95.7%. For viraemia levels 51-500 and 501-1000 copies/mL, the rate of success was 82.1% and 94.0%, respectively. GRT was reproducible, producing sequences with a high similarity and an equal resistance profile regardless of the sequencing centre or viraemia level. Resistance was detected both at LLV and at viraemia >1000 copies/mL (51-500 copies/mL = 18.2%; 501-1000 = 37.5%; 1001-10 000 = 53.7%; 10 001-100 000 = 30.0%; and >100 000 = 30.8%). At viraemia ≤500 copies/mL, Q148H/K/R and N155H had the same prevalence (9.1%), while the Y143C/H/R was completely absent. At early genotyping (within 3 months of raltegravir treatment), Q148H/K/R and N155H mutations were detected regardless of the viraemia level, while Y143C/H/R was observed only in samples with viraemia >1000 copies/mL.

CONCLUSIONS

Our findings prove the reliability of HIV-1 integrase genotyping and reinforce the concept that this assay may be useful in the management of failures even at LLV.

The cellular prion protein counteracts cardiac oxidative stress

AIMS

The cellular prion protein, PrP(C), whose aberrant isoforms are related to prion diseases of humans and animals, has a still obscure physiological function. Having observed an increased expression of PrP(C) in two in vivo paradigms of heart remodelling, we focused on isolated mouse hearts to ascertain the capacity of PrP(C) to antagonize oxidative damage induced by ischaemic and non-ischaemic protocols.

METHODS AND RESULTS

Hearts isolated from mice expressing PrP(C) in variable amounts were subjected to different and complementary oxidative perfusion protocols. Accumulation of reactive oxygen species, oxidation of myofibrillar proteins, and cell death were evaluated. We found that overexpressed PrP(C) reduced oxidative stress and cell death caused by post-ischaemic reperfusion. Conversely, deletion of PrP(C) increased oxidative stress during both ischaemic preconditioning and perfusion (15 min) with H2O2. Supporting its relation with intracellular systems involved in oxidative stress, PrP(C) was found to influence the activity of catalase and, for the first time, the expression of p66(Shc), a protein implicated in oxidative stress-mediated cell death.

CONCLUSIONS

Our data demonstrate that PrP(C) contributes to the cardiac mechanisms antagonizing oxidative insults.

Prions and prion-like pathogens in neurodegenerative disorders

Prions are unique elements in biology, being able to transmit biological information from one organism to another in the absence of nucleic acids. They have been identified as self-replicating proteinaceous agents responsible for the onset of rare and fatal neurodegenerative disorders—known as transmissible spongiform encephalopathies, or prion diseases—which affect humans and other animal species. More recently, it has been proposed that other proteins associated with common neurodegenerative disorders, such as Alzheimer’s and Parkinson’s disease, can self-replicate like prions, thus sustaining the spread of neurotoxic entities throughout the nervous system. Here, we review findings that have contributed to expand the prion concept, and discuss if the involved toxic species can be considered bona fide prions, including the capacity to infect other organisms, or whether these pathogenic aggregates share with prions only the capability to self-replicate.

Genotypic testing on HIV-1 DNA as a tool to assess HIV-1 co-receptor usage in clinical practice: results from the DIVA study group

PURPOSE

We have developed a sequencing assay for determining the usage of the genotypic HIV-1 co-receptor using peripheral blood mononuclear cell (PBMC) DNA in virologically suppressed HIV-1 infected patients. Our specific aims were to (1) evaluate the efficiency of V3 sequences in B versus non-B subtypes, (2) compare the efficiency of V3 sequences and tropism prediction using whole blood and PBMCs for DNA extraction, (3) compare the efficiency of V3 sequences and tropism prediction using a single versus a triplicate round of amplification.

RESULTS

The overall rate of successful V3 sequences ranged from 100 % in samples with >3,000 copies HIV-1 DNA/10(6) PBMCs to 60 % in samples with <100 copies total HIV-1 DNA /10(6) PBMCs. Analysis of 143 paired PBMCs and whole-blood samples showed successful V3 sequences rates of 77.6 % for PBMCs and 83.9 % for whole blood. These rates are in agreement with the tropism prediction obtained using the geno2pheno co-receptor algorithm, namely, 92.1 % with a false-positive rate (FPR) of 10 or 20 % and of 96.5 % with an FPR of 5.75 %. The agreement between tropism prediction values using single versus triplicate amplification was 98.2 % (56/57) of patients using an FPR of 20 % and 92.9 % (53/57) using an FPR of 10 or 5.75 %. For 63.0 % (36/57) of patients, the FPR obtained via the single amplification procedure was superimposable to all three FPRs obtained by triplicate amplification.

CONCLUSIONS

Our results show the feasibility and consistency of genotypic testing on HIV-1 DNA tropism, supporting its possible use for selecting patients with suppressed plasma HIV-1 RNA as candidates for CCR5-antagonist treatment. The high agreement between tropism prediction by single and triple amplification does not support the use of triplicate amplification in clinical practice.

Spanish LupusPRO: cross-cultural validation study for lupus

Purpose

LupusPRO is a disease-targeted, patient-reported, outcome measure that was developed and validated among US patients with systemic lupus erythematosus (SLE). To expand the availability and use of the tool, we undertook a cross-cultural adaptation and validation study of the Spanish-translated version of the LupusPRO.

Method

Forward and back translations of the 43-item English LupusPRO were undertaken and pretested in five individuals. The finalized Spanish version was administered to 211 SLE patients of Hispanic ancestry from the US and Latin America. Short Form-36 (Spanish) and Spanish LupusPRO were also administered. Disease activity was ascertained using the systemic lupus erythematosus disease activity index. A Spanish LupusPRO questionnaire that could be completed within 2–3 days was mailed to SLE patients of Hispanic ancestry and they mailed it back. Internal consistency reliability, test-retest reliability, criterion validity (against disease activity or health status) and convergent validity were tested. All reported p values are two-tailed.

Results

A total of 211 Spanish-speaking SLE patients (90% women) participated. Test-retest reliability of LupusPRO domains ranged from 0.80–0.95, while internal consistency reliability of the domains ranged from 0.71–0.96. Convergent validity with corresponding domains of the SF-36 was present. All health-related quality of life domains of the LupusPRO (except procreation) performed well against disease activity measures, establishing its criterion validity. Confirmatory factor analysis showed a good fit.

Conclusion

The Spanish LupusPRO has fair psychometric properties and is now available to be included in clinical trials and in longitudinal studies for testing of responsiveness to change.

Aroma characterisation and UV elicitation of purple basil from different plant tissue cultures

Exposure to stressful environmental conditions can induce severe metabolic variations in basil (Ocimum basilicum) aroma. The aromatic profiles of Dark Opal and Red Rubim varieties (in vivo plants, in vitro shoots, callus, and suspension cultures) were investigated for the first time. The established calli represented the most interesting miniaturised aromatic plant systems, as they were able to emit many typical basil volatiles with very low amounts of phenylpropanoids (1-2%). The hydrocarbon monoterpenes and oxygenated volatiles emitted from calli of both varieties were greatly and conversely affected by UV-C and UV-B, in comparison with the non-irradiated samples. As calli of both varieties still maintained very low levels of phenylpropanoids even after UV elicitation, they might be regarded not only as efficient in vitro plant models to study volatile compounds under UV stress conditions, but also as safe aromatic biomass in comparison with in vivo basil plants.

The lowest X4 Geno2Pheno false-positive rate is associated with greater CD4 depletion in HIV-1 infected patients

Through this study we evaluated whether the HIV-1 tropism determined by genotypic analysis correlates with HIV-1 markers, such as CD4 cell count and plasma HIV-RNA. The analysis was performed on 1221 HIV-1 B-subtype infected patients with an available V3 sequence (all maraviroc naive). Of them, 532 were antiretroviral therapy (ART) naive and 689 ART experienced. Tropism determination was performed by using the geno2pheno (co-receptor) algorithm set at a false-positive rate (FPR) of 10% and 2%. Potential associations of FPR with CD4 cell count and viraemia were evaluated. Association of V3 mutations with genotypic-determined tropism was also evaluated according to different FPR ranges. About 26% of patients (either ART naive or ART experienced) were infected by X4-tropic viruses (using the classical 10% FPR cut-off). However, a significantly lower proportion of ART-naive patients had FPR ≤ 2% in comparison with ART-experienced patients (4.9% vs. 12.6%, respectively, p <0.001). The risk of advanced HIV-1 infection (with CD4 cell count ≤ 200 cells/mm(3)) was significantly greater in X4-infected patients, either ART-naive (OR (95% CI)), 4.2 (1.8-9.2); p 0.0006) or ART-experienced (2.3 (1.4-3.6); p 0.0003), with FPR set at 2% (but not at 10%). This finding was confirmed by multivariable logistic analysis. No relationship was found between viraemia and FPR ≤2%. Some X4-related mutations were significantly associated with FPR ≤2% (ART-naive patients, S11R, Y21V, G24K and G24R, p ≤0.001; ART-experienced patients, Y7K, S11R, H13Y, p ≤0.002). In conclusion, these findings show that within the context of genotypically-assessed CXCR4 tropism, FPR ≤2% defines (far better than 10%-FPR) a viral population associated with low CD4 rank, with potentially greater cytopathic effect, and with more advanced disease.