Lewy body-associated proteins: victims, instigators, or innocent bystanders? The case of AIMP2 and alpha-synuclein

Lewy bodies (LBs), one of the neuropathological defining hallmarks of Parkinson's disease (PD), are composed of a complex mixture of alpha-synuclein (aSyn) filaments and hundreds of proteins, lipids, and membranous organelles. However, these proteins' role in aSyn aggregation and the biogenesis of LBs remains poorly understood. Previous studies have focused on investigating the role of these proteins as modifiers of aSyn aggregation, inclusion formation, and toxicity; very often, one protein at a time. In a recent study, Ham et al. suggest that one of these proteins, aminoacyl tRNA synthase complex-interacting multifunctional protein 2 (AIMP2), plays a primary role in the initiation of aSyn aggregation and is essential for aSyn inclusion formation and toxicity in cells and several models of synucleinopathies (Ham et al., 2020). Based on in vitro aggregation studies, they proposed a model in which AIMP2 self-associates to form amyloid-like aggregates that interact with monomeric aSyn and catalyze/seed the formation of aSyn fibrils and, eventually, LB-like inclusions. Herein, we present a critical analysis of their results and conclusions, review previous studies on AIMP2 aggregation, and reexamine the role of AIMP2 in regulating aSyn inclusion formation and clearance and aSyn-induced neurodegeneration in Parkinson's disease. We conclude by presenting lesson learned and recommendations on experimental factors and approaches that should be considered in future studies aimed at investigating the potential of targeting LBs-associated proteins, including AIMP2, for developing therapies to treat PD and other synucleinopathies.

RELAY, ramucirumab plus erlotinib versus placebo plus erlotinib in patients with untreated, EGFR-mutated, metastatic non-small cell lung cancer: Europe/United States subset analysis

BACKGROUND

In EGFR mutation-positive NSCLC, dual EGFR/VEGFR inhibition compared to EGFR alone increases anti-tumor efficacy. The Phase III RELAY trial demonstrated superior PFS for ramucirumab plus erlotinib (RAM + ERL) over placebo plus erlotinib (PBO + ERL) (HR 0.591 [95% CI 0.461-0.760], p<0.0001). EGFR mutated NSCLC is less prevalent in Western versus Asian patients. This prespecified analysis evaluates efficacy and safety of RAM + ERL in EU and US patients enrolled in RELAY.

PATIENTS AND METHODS

Patients were randomized 1:1 to ERL + RAM (10 mg/kg IV) or PBO Q2W. Treatment continued until unacceptable toxicity or progressive disease. Patients were stratified by geographic region (East Asia vs "other" [EU/US and Canada (EU/US)]). Objectives included PFS, ORR, DoR, OS, PFS2, safety and biomarker analysis.

RESULTS

EU/US subset included 113/449 (25.9%) patients (58 RAM + ERL, 55 PBO + ERL). RAM + ERL improved PFS (20.6 vs 10.9 months, HR 0.605 [95% CI: 0.362-1.010]). ORR and DCR were similar, but median DoR was longer with RAM + ERL (18.0 vs 10.1 months, HR 0.527 [95% CI: 0.296-0.939]). OS and PFS2 were immature at data cut-off (censoring rates 81.0-81.8% and 67.3-79.3%, respectively). Most commonly reported Grade ≥3 TEAE for RAM + ERL was hypertension (17 [29.8%]) and for PBO + ERL, dermatitis acneiform (5 [9.1%]).

CONCLUSION

EU/US subset analysis showed improved efficacy outcomes for RAM + ERL and a safety profile consistent with the overall population. Ramucirumab is a safe and effective addition to standard-of-care EGFR-TKI for EGFR mutation-positive metastatic NSCLC.

Clinical features associated with early drop-out among outpatients with unipolar and bipolar depression

Drop-out from follow-up visits carries significant burden for people diagnosed with depression. The present study assesses multiple clinical moderators of drop-out among depressed outpatients. We retrospectively followed-up 131 outpatients over 6 months: 78 major depressive disorder (MDD), and 53 bipolar disorder (BD-I = 24; BD-II = 29) patients diagnosed according to the Diagnostic and Statistical Manual for Mental Disorders, Fifth Edition. Participants were assessed with standard rating scales administered by experienced psychiatrists. Upon descriptive and Cox regression analyses, 17/53 BDs (32%) dropped-out; the overall survival time until drop-out was 57.94 ± 17.79 days. BD drop-outs were younger, had an earlier age at onset, shorter illness duration, lower rates of lifetime obsessive-compulsive disorder/suicidal behavior, higher rates of substance use disorder (SUD), anxious and mixed features of depression compared to BDs attending up to six months. Among MDD patients, 10/78 cases (13%) dropped-out by month-6 with an average survival of 42.40 ± 16.45 days. Earlier age of onset, younger age, positive family history for mood disorders, lower rates of lifetime generalized anxiety disorder were significantly more frequent among drop-outs than completers, as opposite to SUD, and lifetime recurrent depression. Older age predicted lower drop-out among BDs and MDDs, although with almost null hazard ratio (HR) = 0.928, p < 0.01 vs. HR = 0.941, p < 0.01, respectively. Higher rates of lifetime SUD predicted higher drop-out rates by month-6 among MDDs (HR = 5.477, p = 0.02). Limitations of the study: retrospective design, small sample size, lack of objective measures of treatment-adherence/mood rating during follow-up. Drop-out is common in the real-world setting, warranting specific interventions since the beginning of the treatment.

Mitochondrial P2X7 Receptor Localization Modulates Energy Metabolism Enhancing Physical Performance

Basal expression of the P2X7 receptor (P2X7R) improves mitochondrial metabolism, Adenosine 5'-triphosphate (ATP) synthesis, and overall fitness of immune and non-immune cells. We investigated P2X7R contribution to energy metabolism and subcellular localization in fibroblasts (mouse embryo fibroblasts and HEK293 human fibroblasts), mouse microglia (primary brain microglia, and the N13 microglia cell line), and heart tissue. The P2X7R localizes to mitochondria, and its lack (1) decreases basal respiratory rate, ATP-coupled respiration, maximal uncoupled respiration, resting mitochondrial potential, mitochondrial matrix Ca²⁺ level, (2) modifies expression pattern of oxidative phosphorylation enzymes, and (3) severely affects cardiac performance. Hearts from P2rx7-deleted versus wild-type mice are larger, heart mitochondria smaller, and stroke volume, ejection fraction, fractional shortening, and cardiac output, are significantly decreased. Accordingly, the physical fitness of P2X7R-null mice is severely reduced. Thus, the P2X7R is a key modulator of mitochondrial energy metabolism and a determinant of physical fitness.

Pharmacological antagonism of kainate receptor rescues dysfunction and loss of dopamine neurons in a mouse model of human parkin-induced toxicity

Mutations in the PARK2 gene encoding the protein parkin cause autosomal recessive juvenile Parkinsonism (ARJP), a neurodegenerative disease characterized by dysfunction and death of dopamine (DA) neurons in the substantia nigra pars compacta (SNc). Since a neuroprotective therapy for ARJP does not exist, research efforts aimed at discovering targets for neuroprotection are critically needed. A previous study demonstrated that loss of parkin function or expression of parkin mutants associated with ARJP causes an accumulation of glutamate kainate receptors (KARs) in human brain tissues and an increase of KAR-mediated currents in neurons in vitro. Based on the hypothesis that such KAR hyperactivation may contribute to the death of nigral DA neurons, we investigated the effect of KAR antagonism on the DA neuron dysfunction and death that occur in the parkinQ311X mouse, a model of human parkin-induced toxicity. We found that early accumulation of KARs occurs in the DA neurons of the parkinQ311X mouse, and that chronic administration of the KAR antagonist UBP310 prevents DA neuron loss. This neuroprotective effect is associated with the rescue of the abnormal firing rate of nigral DA neurons and downregulation of GluK2, the key KAR subunit. This study provides novel evidence of a causal role of glutamate KARs in the DA neuron dysfunction and loss occurring in a mouse model of human parkin-induced toxicity. Our results support KAR as a potential target in the development of neuroprotective therapy for ARJP.

Immune checkpoint inhibitors for patients with advanced lung cancer and oncogenic driver alterations: results from the IMMUNOTARGET registry

Background

Anti-PD1/PD-L1 directed immune checkpoint inhibitors (ICI) are widely used to treat patients with advanced non-small-cell lung cancer (NSCLC). The activity of ICI across NSCLC harboring oncogenic alterations is poorly characterized. The aim of our study was to address the efficacy of ICI in the context of oncogenic addiction.

Patients and methods

We conducted a retrospective study for patients receiving ICI monotherapy for advanced NSCLC with at least one oncogenic driver alteration. Anonymized data were evaluated for clinicopathologic characteristics and outcomes for ICI therapy: best response (RECIST 1.1), progression-free survival (PFS), and overall survival (OS) from ICI initiation. The primary end point was PFS under ICI. Secondary end points were best response (RECIST 1.1) and OS from ICI initiation.

Results

We studied 551 patients treated in 24 centers from 10 countries. The molecular alterations involved KRAS (n = 271), EGFR (n = 125), BRAF (n = 43), MET (n = 36), HER2 (n = 29), ALK (n = 23), RET (n = 16), ROS1 (n = 7), and multiple drivers (n = 1). Median age was 60 years, gender ratio was 1 : 1, never/former/current smokers were 28%/51%/21%, respectively, and the majority of tumors were adenocarcinoma. The objective response rate by driver alteration was: KRAS = 26%, BRAF = 24%, ROS1 = 17%, MET = 16%, EGFR = 12%, HER2 = 7%, RET = 6%, and ALK = 0%. In the entire cohort, median PFS was 2.8 months, OS 13.3 months, and the best response rate 19%. In a subgroup analysis, median PFS (in months) was 2.1 for EGFR, 3.2 for KRAS, 2.5 for ALK, 3.1 for BRAF, 2.5 for HER2, 2.1 for RET, and 3.4 for MET. In certain subgroups, PFS was positively associated with PD-L1 expression (KRAS, EGFR) and with smoking status (BRAF, HER2).

Conclusions

: ICI induced regression in some tumors with actionable driver alterations, but clinical activity was lower compared with the KRAS group and the lack of response in the ALK group was notable. Patients with actionable tumor alterations should receive targeted therapies and chemotherapy before considering immunotherapy as a single agent.

Identification of distinct pathological signatures induced by patient-derived α-synuclein structures in nonhuman primates

Dopaminergic neuronal cell death, associated with intracellular α-synuclein (α-syn)-rich protein aggregates [termed "Lewy bodies" (LBs)], is a well-established characteristic of Parkinson's disease (PD). Much evidence, accumulated from multiple experimental models, has suggested that α-syn plays a role in PD pathogenesis, not only as a trigger of pathology but also as a mediator of disease progression through pathological spreading. Here, we have used a machine learning-based approach to identify unique signatures of neurodegeneration in monkeys induced by distinct α-syn pathogenic structures derived from patients with PD. Unexpectedly, our results show that, in nonhuman primates, a small amount of singular α-syn aggregates is as toxic as larger amyloid fibrils present in the LBs, thus reinforcing the need for preclinical research in this species. Furthermore, our results provide evidence supporting the true multifactorial nature of PD, as multiple causes can induce a similar outcome regarding dopaminergic neurodegeneration.

Diagnosis and treatment of early and locally advanced non-small-cell lung cancer: The 2019 AIOM (Italian Association of Medical Oncology) clinical practice guidelines

The Italian Association of Medical Oncology (AIOM) has developed clinical practice guidelines for the diagnosis and treatment of patients with early and locally advanced non-small cell lung cancer. In the current paper a panel of AIOM experts in the field of thoracic malignancies discussed these topics, analyzing available scientific evidences, with the final aim of providing a summary of clinical recommendations, which may guide physicians in their current practice.

Choice of second-line systemic therapy in stage IV small cell lung cancer (SCLC) - A decision-making analysis amongst European lung cancer experts

OBJECTIVES

Stage IV small cell lung cancer (SCLC) is associated with short survival and progression after first-line systemic therapy frequently occurs within months. Although topotecan is approved for second-line treatment, its efficacy is limited, and treatment heterogeneity exists.

MATERIAL AND METHODS

The decision-making patterns for second line treatment of 13 European medical oncologists with expertise in SCLC were analyzed.

RESULTS

The two criteria most relevant to decision-making were the performance status and the interval of recurrence since first-line treatment. With an interval of less than 3 months since the end of first-line chemotherapy, 62 % of the experts recommended cyclophosphamide, doxorubicin and vincristine (CAV) for fit patients and 54 % recommended topotecan for unfit patients. For an interval of more than 6 months, a clear consensus for a re-challenge with a platinum doublet was achieved (92 %). However, there was no consensus on the second-line therapy with an interval of 3-6 months since the end of first-line therapy.

CONCLUSION

Real world practice may differ from recommendations in general guidelines and cannot always be directly derived from trial results as other factor such as habits, patient's preference, convenience or costs have to be factored in.

Treatment of advanced non-small-cell lung cancer: The 2019 AIOM (Italian Association of Medical Oncology) clinical practice guidelines

The Italian Association of Medical Oncology (AIOM) has developed clinical practice guidelines for the treatment of patients with advanced non-small cell lung cancer (NSCLC). In the current paper a panel of AIOM experts in the field of thoracic malignancies discussed the available scientific evidences, with the final aim of providing a summary of clinical recommendations, which may guide physicians in their current practice.