Junctional adhesion molecule-A deficient mice are protected from severe experimental autoimmune encephalomyelitis

In multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE), early pathological features include immune cell infiltration into the central nervous system (CNS) and blood-brain barrier (BBB) disruption. We investigated the role of junctional adhesion molecule-A (JAM-A), a tight junction protein, in active EAE (aEAE) pathogenesis. Our study confirms JAM-A expression at the blood-brain barrier and its luminal redistribution during aEAE. JAM-A deficient (JAM-A-/-) C57BL/6J mice exhibited milder aEAE, unrelated to myelin oligodendrocyte glycoprotein-specific CD4+ T-cell priming. While JAM-A absence influenced macrophage behavior on primary mouse brain microvascular endothelial cells (pMBMECs) under flow in vitro, it did not impact T-cell extravasation across primary mouse brain microvascular endothelial cells. At aEAE onset, we observed reduced lymphocyte and CCR2+ macrophage infiltration into the spinal cord of JAM-A-/- mice compared to control littermates. This correlated with increased CD3+ T-cell accumulation in spinal cord perivascular spaces and brain leptomeninges, suggesting JAM-A absence leads to T-cell trapping in central nervous system border compartments. In summary, JAM-A plays a role in immune cell infiltration and clinical disease progression in aEAE.

A phase I study of ATR inhibitor gartisertib (M4344) as a single agent and in combination with carboplatin in patients with advanced solid tumours

BACKGROUND

Gartisertib is an oral inhibitor of ataxia telangiectasia and Rad3-related protein (ATR), a key kinase of the DNA damage response. We aimed to determine the safety and tolerability of gartisertib ± carboplatin in patients with advanced solid tumours.

METHODS

This phase I open-label, multicenter, first-in-human study comprised four gartisertib cohorts: A (dose escalation [DE]; Q2W); A2 (DE; QD/BID); B1 (DE+carboplatin); and C (biomarker-selected patients).

RESULTS

Overall, 97 patients were enroled into cohorts A (n = 42), A2 (n = 26), B1 (n = 16) and C (n = 13). The maximum tolerated dose and recommended phase II dose (RP2D) were not declared for cohorts A or B1. In cohort A2, the RP2D for gartisertib was determined as 250 mg QD. Gartisertib was generally well-tolerated; however, unexpected increased blood bilirubin in all study cohorts precluded further DE. Investigations showed that gartisertib and its metabolite M26 inhibit UGT1A1-mediated bilirubin glucuronidation in human but not dog or rat liver microsomes. Prolonged partial response (n = 1 [cohort B1]) and stable disease >6 months (n = 3) did not appear to be associated with biomarker status. Exposure generally increased dose-dependently without accumulation.

CONCLUSION

Gartisertib was generally well-tolerated at lower doses; however, unexpected liver toxicity prevented further DE, potentially limiting antitumour activity. Gartisertib development was subsequently discontinued.

CLINICALTRIALS

GOV: NCT02278250.

Implementation of whole-exome sequencing for pharmacogenomics profiling and exploring its potential clinical utilities

Whole-exome sequencing (WES) is widely used in clinical settings; however, the exploration of its use in pharmacogenomic analysis remains limited. Our study compared the variant callings for 28 core absorption, distribution, metabolism and elimination genes by WES and array-based technology using clinical trials samples. The results revealed that WES had a positive predictive value of 0.71-0.92 and a sensitivity of single-nucleotide variants between 0.68 and 0.95, compared with array-based technology, for the variants in the commonly targeted regions of the WES and PhamacoScan™ assay. Besides the common variants detected by both assays, WES identified 200-300 exclusive variants per sample, totalling 55 annotated exclusive variants, including important modulators of metabolism such as rs2032582 (ABCB1) and rs72547527 (SULT1A1). This study highlights the potential clinical advantages of using WES to identify a wider range of genetic variations and enabling precision medicine.

A Phase 1 Study of the DNA-PK Inhibitor Peposertib in Combination With Radiation Therapy With or Without Cisplatin in Patients With Advanced Head and Neck Tumors

PURPOSE

DNA-dependent protein kinase (DNA-PK) plays a key role in the repair of DNA double strand breaks via nonhomologous end joining. Inhibition of DNA-PK can enhance the effect of DNA double strand break inducing anticancer therapies. Peposertib (formerly "M3814") is an orally administered, potent, and selective small molecule DNA-PK inhibitor that has demonstrated radiosensitizing and antitumor activity in xenograft models and was well-tolerated in monotherapy. This phase 1 trial (National Clinical Trial 02516813) investigated the maximum tolerated dose, recommended phase 2 dose (RP2D), safety, and tolerability of peposertib in combination with palliative radiation therapy (RT) in patients with thoracic or head and neck tumors (arm A) and of peposertib in combination with cisplatin and curative-intent RT in patients with squamous cell carcinoma of the head and neck (arm B).

METHODS AND MATERIALS

Patients received peposertib once daily in ascending dose cohorts as a tablet or capsule in combination with palliative RT (arm A) or in combination with intensity modulated curative-intent RT and cisplatin (arm B).

RESULTS

The most frequently observed treatment-emergent adverse events were radiation skin injury, fatigue, and nausea in arm A (n = 34) and stomatitis, nausea, radiation skin injury, and dysgeusia in arm B (n = 11). Based on evaluations of dose-limiting toxicities, tolerability, and pharmacokinetic data, RP2D for arm A was declared as 200 mg peposertib tablet once daily in combination with RT. In arm B (n = 11), 50 mg peposertib was declared tolerable in combination with curative-intent RT and cisplatin. However, enrollment was discontinued because of insufficient exposure at that dose, and the RP2D was not formally declared.

CONCLUSIONS

Peposertib in combination with palliative RT was well-tolerated up to doses of 200 mg once daily as tablet with each RT fraction. When combined with RT and cisplatin, a tolerable peposertib dose yielded insufficient exposure.

First-in-Human Study of the Ataxia Telangiectasia and Rad3-related (ATR) Inhibitor Tuvusertib (M1774) as Monotherapy in Patients with Solid Tumors

PURPOSE

Tuvusertib (M1774) is a potent, selective, orally administered ATR protein kinase inhibitor. This first-in-human study (NCT04170153) evaluated safety, tolerability, maximum tolerated dose (MTD), recommended dose for expansion (RDE), pharmacokinetics (PK), pharmacodynamics (PD), and preliminary efficacy of tuvusertib monotherapy.

PATIENTS AND METHODS

Ascending tuvusertib doses were evaluated in 55 patients with metastatic or locally advanced unresectable solid tumors. A safety monitoring committee determined dose escalation based on PK, PD, and safety data guided by a Bayesian 2‑parameter logistic regression model. Molecular responses (MRs) were assessed in circulating tumor DNA samples.

RESULTS

Most common Grade ≥3 treatment-emergent adverse events were anemia (36%), neutropenia and lymphopenia (both 7%). Eleven patients experienced dose-limiting toxicities, most commonly Grade 2 (n=2) or Grade 3 (n=8) anemia. No persistent effects on blood immune cell populations were observed. The RDE was 180mg tuvusertib QD, 2 weeks on/1 week off, which was better tolerated than the MTD (180mg QD continuously). Tuvusertib median time to peak plasma concentration ranged from 0.5-3.5h and mean elimination half-life from 1.2-5.6h. Exposure-related PD analysis suggested maximum target engagement at ≥130mg tuvusertib QD. Tuvusertib induced frequent MRs in the predicted efficacious dose range, MRs were enriched in patients with radiological disease stabilization and complete MRs were detected for mutations in ARID1A, ATRX and DAXX. One patient with platinum- and PARP inhibitor‑resistant BRCA wild-type ovarian cancer achieved an unconfirmed RECIST v1.1 partial response.

CONCLUSIONS

Tuvusertib demonstrated manageable safety and exposure-related target engagement. Further clinical evaluation of tuvusertib is ongoing.

Relationship among DDR gene mutations, TMB and PD-L1 in solid tumour genomes identified using clinically actionable biomarker assays

The DNA damage response (DDR) pathway regulates DNA repair and cell survival, and inactivating mutations in DDR genes can increase tumour mutational burden (TMB), a predictive biomarker of treatment benefit from anti-PD-1/PD-L1 immunotherapies. However, a better understanding of the relationship among specific DDR mutations, TMB and PD-L1 expression is needed to improve translational strategies. Here, we determined genomic alteration frequencies in selected DDR genes that are clinically actionable biomarkers and investigated their association with TMB and PD-L1 in bladder, colorectal, non-small cell lung, ovarian and prostate cancers using the FoundationInsights® web portal. Our results not only confirm known associations, such as mismatch repair and POLE gene mutations with high TMB, but also identify significant associations between mutations in the SWI/SNF chromatin remodelling genes ARID1A and SMARCA4 and high TMB in multiple tumour types. Mutations in the ATR gene were associated with high TMB in colorectal and prostate cancers; however, associations between individual DDR mutations and high PD-L1 expression were uncommon and tumour-type specific. Finally, we found that high TMB and high PD-L1 expression were poorly associated, emphasising their independence as predictive biomarkers for immune checkpoint inhibitor use.

Right Heart Catheterization: An Antecubital Vein Approach to Reduce Fluoroscopy Time, Radiation Dose, and Guidewires Need

Antecubital access for right heart catheterization (RHC) is a widespread technique, even though there is a need to clarify if there are differences and significant advantages compared to proximal vein access. To pursue this issue, we retrospectively identified patients who underwent RHC in our clinic over a 7 year period (between January 2015 and December 2022). We revised demographic, anthropometric, and procedural data, including the fluoroscopy time, the radiation exposure, and the use of guidewires. The presence of any complications was also assessed. In patients with antecubital access, the fluoroscopy time and the radiation exposure were lower compared to proximal vein access (6 vs. 3 min, mean difference of 2 min, CI 95% 1-4 min, p < 0.001 and 61 vs. 30 cGy/m2, mean difference 64 cGy/m2, CI 95% 50-77, p < 0.001). The number of patients requiring the use of at least one guidewire was lower in the group undergoing RHC through antecubital access compared to proximal vein access (55% vs. 43%, p = 0.01). The feasibility was optimal, as just 0.9% of procedures switched from antecubital to femoral access, with a negligible rate of complications. The choice of the antecubital site exhibits advantages, e.g., a shorter fluoroscopy time, a reduced radiation dose, and a lower average number of guidewires used compared to proximal vein access.

Targeting the TCA cycle can ameliorate widespread axonal energy deficiency in neuroinflammatory lesions

Inflammation in the central nervous system can impair the function of neuronal mitochondria and contributes to axon degeneration in the common neuroinflammatory disease multiple sclerosis (MS). Here we combine cell-type-specific mitochondrial proteomics with in vivo biosensor imaging to dissect how inflammation alters the molecular composition and functional capacity of neuronal mitochondria. We show that neuroinflammatory lesions in the mouse spinal cord cause widespread and persisting axonal ATP deficiency, which precedes mitochondrial oxidation and calcium overload. This axonal energy deficiency is associated with impaired electron transport chain function, but also an upstream imbalance of tricarboxylic acid (TCA) cycle enzymes, with several, including key rate-limiting, enzymes being depleted in neuronal mitochondria in experimental models and in MS lesions. Notably, viral overexpression of individual TCA enzymes can ameliorate the axonal energy deficits in neuroinflammatory lesions, suggesting that TCA cycle dysfunction in MS may be amendable to therapy.

Integrating transcriptomic datasets across neurological disease identifies unique myeloid subpopulations driving disease-specific signatures

Microglia and bone marrow-derived monocytes are key elements of central nervous system (CNS) inflammation, both capable of enhancing and dampening immune-mediated pathology. However, the study-specific focus on individual cell types, disease models or experimental approaches has limited our ability to infer common and disease-specific responses. This meta-analysis integrates bulk and single-cell transcriptomic datasets of microglia and monocytes from disease models of autoimmunity, neurodegeneration, sterile injury, and infection to build a comprehensive resource connecting myeloid responses across CNS disease. We demonstrate that the bulk microglial and monocyte program is highly contingent on the disease environment, challenging the notion of a universal microglial disease signature. Integration of six single-cell RNA-sequencing datasets revealed that these disease-specific signatures are likely driven by differing proportions of unique myeloid subpopulations that were individually expanded in different disease settings. These subsets were functionally-defined as neurodegeneration-associated, inflammatory, interferon-responsive, phagocytic, antigen-presenting, and lipopolysaccharide-responsive cellular states, revealing a core set of myeloid responses at the single-cell level that are conserved across CNS pathology. Showcasing the predictive and practical value of this resource, we performed differential expression analysis on microglia and monocytes across disease and identified Cd81 as a new neuroinflammatory-stable gene that accurately identified microglia and distinguished them from monocyte-derived cells across all experimental models at both the bulk and single-cell level. Together, this resource dissects the influence of disease environment on shared immune response programmes to build a unified perspective of myeloid behavior across CNS pathology.

Hypertension in a cohort of obese Caucasian children and adolescents and its association with glycometabolic indices: A proposed screening tool

BACKGROUND AND AIM

Hypertension (HTN) is common among obese children and adolescents and increases their cardiovascular risk later in adulthood. The aim of the study was to evaluate the prevalence of HTN identified by office blood pressure (BP) measurement and ambulatory BP monitoring (ABPM) in a cohort of obese children and adolescents and its association with anthropometric and glycometabolic indices.

METHODS AND RESULTS

Seventy consecutive obese Caucasian children and adolescents aged 7-16 years were enrolled. Patients underwent ABPM, echocardiogram and carotid ultrasonography. Sex- and age-adjusted logistic multivariable analysis models were used to assess the association between HOMA-IR, HOMA-β, QUICKI with HTN at ABPM. Receiver Operation Curve (ROC) analysis with Youden J statistics was used to identify the optimal HOMA-IR, HOMA-β and QUICKI cut-off to predict HTN at ABPM. Hypertensive office BP was found in 25.7% of obese patients. ABPM diagnosed HTN in 34.9% of patients: 20.6% of obese patients had masked HTN (MHTN), and 12.7% had white coat HTN (WCH). Hypertensive obese patients (according to ABPM) had higher HOMA-IR and HOMA-β, and a lower QUICKI than normotensive subjects. HOMA-IR, HOMA-β and QUICKI predicted HTN at ABPM in obese patients in age- and sex-adjusted logistic multivariable models. Optimal cut-offs to predict HTN at ABPM in obese patients were: HOMA-IR ≥ 3.30, HOMA-β ≥ 226.7 and QUICKI <0.33, with high sensitivity.

CONCLUSIONS

A sequential testing strategy applying office BP and glycometabolic indices can identify hypertensive obese pediatric patients with high diagnostic accuracy and potentially reducing costs. This strategy needs validation in an external and larger cohort.

Insulin-like growth factor-1 receptor controls the function of CNS-resident macrophages and their contribution to neuroinflammation

Signaling by insulin-like growth factor-1 (IGF-1) is essential for the development of the central nervous system (CNS) and regulates neuronal survival and myelination in the adult CNS. In neuroinflammatory conditions including multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE), IGF-1 can regulate cellular survival and activation in a context-dependent and cell-specific manner. Notwithstanding its importance, the functional outcome of IGF-1 signaling in microglia/macrophages, which maintain CNS homeostasis and regulate neuroinflammation, remains undefined. As a result, contradictory reports on the disease-ameliorating efficacy of IGF-1 are difficult to interpret, together precluding its potential use as a therapeutic agent. To fill this gap, we here investigated the role of IGF-1 signaling in CNS-resident microglia and border associated macrophages (BAMs) by conditional genetic deletion of the receptor Igf1r in these cell types. Using a series of techniques including histology, bulk RNA sequencing, flow cytometry and intravital imaging, we show that absence of IGF-1R significantly impacted the morphology of both BAMs and microglia. RNA analysis revealed minor changes in microglia. In BAMs however, we detected an upregulation of functional pathways associated with cellular activation and a decreased expression of adhesion molecules. Notably, genetic deletion of Igf1r from CNS-resident macrophages led to a significant weight gain in mice, suggesting that absence of IGF-1R from CNS-resident myeloid cells indirectly impacts the somatotropic axis. Lastly, we observed a more severe EAE disease course upon Igf1r genetic ablation, thus highlighting an important immunomodulatory role of this signaling pathway in BAMs/microglia. Taken together, our work shows that IGF-1R signaling in CNS-resident macrophages regulates the morphology and transcriptome of these cells while significantly decreasing the severity of autoimmune CNS inflammation.

IGF1R expression by adult oligodendrocytes is not required in the steady-state but supports neuroinflammation

In the central nervous system (CNS), insulin-like growth factor 1 (IGF-1) regulates myelination by oligodendrocyte (ODC) precursor cells and shows anti-apoptotic properties in neuronal cells in different in vitro and in vivo systems. Previous work also suggests that IGF-1 protects ODCs from cell death and enhances remyelination in models of toxin-induced and autoimmune demyelination. However, since evidence remains controversial, the therapeutic potential of IGF-1 in demyelinating CNS conditions is unclear. To finally shed light on the function of IGF1-signaling for ODCs, we deleted insulin-like growth factor 1 receptor (IGF1R) specifically in mature ODCs of the mouse. We found that ODC survival and myelin status were unaffected by the absence of IGF1R until 15 months of age, indicating that IGF-1 signaling does not play a major role in post-mitotic ODCs during homeostasis. Notably, the absence of IGF1R did neither affect ODC survival nor myelin status upon cuprizone intoxication or induction of experimental autoimmune encephalomyelitis (EAE), models for toxic and autoimmune demyelination, respectively. Surprisingly, however, the absence of IGF1R from ODCs protected against clinical neuroinflammation in the EAE model. Together, our data indicate that IGF-1 signaling is not required for the function and survival of mature ODCs in steady-state and disease.

P08.10.B Family-centred care in neuro-oncology: a longitudinal mixed-methods feasibility study

Background

A diagnosis of a malignant brain tumour represents a fearful event for patients, often followed by severe physical, cognitive, emotional, and psychosocial impairments. In turn, being a family member and an informal caregiver of a person with an oncological disease is also a burdensome experience. Family and network can influence patient outcomes, and family-centred intervention may help both patients and caregivers to face illness-related issues. However, studies aiming at implementing family-centered interventions in patients with high grade glioma (HGG) and their families are scarce. Therefore, this study aims to understand how patients with HGG and their families experienced the course of illness and investigate the impact of family and network consultations (FNCs) on both of them.

Material and Methods

We adopted a quasi-experimental feasibility study using a longitudinal mixed-methods design. The intervention consisted of three FNCs delivered over a 1-year period. Quantitative data on physical activity level, anxiety, depression, family functioning, perceived nursing support, symptom burden and interference on daily living, caregiver burden and quality of life were collected at four time points. Qualitative data on patients’ and families’ perspectives on the intervention were explored through telephone interviews.

Results

A total of 21 patients with HGG and 47 family members were included in the study. Patients mean age was 66 years and they were mainly male (86%), married and living with the patient (95%), and retired (54%). Caregivers mean age was 47 years, and they were mainly female (62%), children of the cared person (47%), and employed (55%). The integration of quantitative and qualitative data showed that many variables improved over time (e.g., symptom interference in patients, family functioning in caregivers, quality of life) or remained stable (e.g., anxiety and depression), apart from physical functioning and symptom burden that worsened. Families described FNCs as a valuable strategy to holistically address the needs and concerns of the entire family and to strengthen the family dialogue and union.

Conclusion

FNCs can be a valuable strategy to implement family-centred care practices. However, advanced nursing competencies are required to provide optimal family-centred care. Plus, the intervention should be personalized and based on the needs of each family.

An intervention to improve caregiver self-efficacy and contribution to self-care does not affect caregiver anxiety, depression, quality of life and sleep. Secondary outcome analysis of MOTIVATE-HF RCT

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Center of Excellence for Nursing Scholarship (CECRI), Rome, Italy.

Background

Caregiver contribution (CC) to self-care can improve patient outcomes in heart failure (HF). However, caring for a person with HF can be a burdensome experience for caregivers. Experimental studies aimed at improving caregiver self-efficacy and CC to HF self-care are scarce. Moreover, it is underexplored if interventions aiming to improve caregiver self-efficacy and CC to HF self-care consequently affect caregiver anxiety, depression, quality of life and sleep.

Purpose

To evaluate if the delivery of a Motivational Interviewing intervention aimed at improving caregiver self-efficacy and CC to HF self-care affects caregiver anxiety, depression, quality of life, and sleep.

Methods

Secondary outcome analysis of the MOTIVATE-HF randomized controlled trial. Participants were recruited from three centers in Italy, and they were randomized into three arms: Arm 1 (Motivational Interview for patients), Arm 2 (Motivational Interview for patients and caregivers), Arm 3 (standard care). The intervention consisted in one face-to-face MI session, plus three telephone contacts within two months from enrollment with patients (Arm 1) or with patients and caregivers (Arm 2). Data were collected at baseline and after 3, 6, 9, 12 months. Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale, quality of life was measured with the 12-Item Short-Form Health Survey, and sleep was evaluated with the Pittsburgh Sleep Quality Index.

Results

A total of 510 patient and caregiver dyads were enrolled. Caregiver median age ranged between 53 and 57, they were mainly female (76%), married (72%), spouses (37%), educated at high school or university level (55%), employed (73.5%), and living with the patient (60%). At baseline, anxiety, depression, quality of life and sleep scores were comparable among the three Arms. Over the year of follow-up, anxiety, depression, and sleep disturbances decreased, while quality of life slightly increased in all the three Arms. However, these changes were not significant in any of the study arms. When comparing these changes between Arm 2 and Arm 1 and 3, we did not observe any significant difference.

Conclusion

Delivering Motivational Interview to caregivers to improve their self-efficacy and contribution towards patient self-care did not increase caregivers’ own levels of anxiety and depression and did not decrease their quality of life and sleep. This may help tailoring future interventions for caregivers knowing that such an intervention does not worsen caregivers’ conditions and wellbeing.

Motivational Interviewing improves caregiver self-efficacy in heart failure: a secondary outcome analysis of the MOTIVATE-HF trial

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Center of Excellence for Nursing Scholarship, Rome, Italy.

Background

Caregiver self-efficacy, which is caregiver confidence in her own abilities to help the patient in performing self-care, directly influences caregiver contribution (CC) to self-care, while acting as a mediator between predictors of CC to self-care and CC to self-care itself. Although caregiver self-efficacy is associated with patient and caregiver outcomes, evidence on interventions aiming to improve this variable, as well as CC to self-care, is scarce.

Purpose

To evaluate the effect of Motivational Interviewing (MI) on caregiver self-efficacy and CC to self-care in heart failure.

Methods

Secondary outcome analysis of the MOTIVATE-HF RCT. A total of 235 caregivers and 238 patients completed the study. Participants were recruited from three centres in Italy and randomized into Arm 1 (MI for patients), Arm 2 (MI for patients and caregivers), Arm 3 (standard care). The intervention consisted in one face-to-face MI session followed by three telephone contacts delivered to patients (Arm 1) or to patients and caregivers (Arm 2). Caregiver self-efficacy and CC to self-care were assessed with the Caregiver Contribution to Self-Care of HF Index. Data were collected at baseline, before the intervention, and after 3, 6, 9, 12 months from enrolment.

Results

Among the three arms, caregivers median age was 55 years, they were mainly female (76%), married (72%), spouses (37%), employed (73.5%), with a high school level or higher education (55%), and living with the patients (60%). Patients median age was 74 years, they were mainly male (58%), retired (76%), in NYHA Class II (61.9%). Over the year of the study, caregiver self-efficacy significantly improved in all arms, and was significantly higher in Arm 2 compared to Arm 3 at 9-month follow-up (difference: 8.36, 95% CI (3.13; 13.59), p = 0.002). At 12-month follow-up, caregiver self-efficacy was still higher in Arm 2 compared to Arm 3, but this difference only approached statistical significance (difference: 6.59, 95% CI (-0.41; 13.60), p = 0.064). The longitudinal mixed linear model on self-efficacy, accounting for time, living with the patient, randomization arm and their interaction, confirmed a significantly higher improvement of caregiver self-efficacy in Arm 2 compared to Arm 3 (β ̂ = 1.39, 95% CI (0.02; 2.75), p = 0.046). CC to self-care significantly improved over time in all Arms, but without significant differences among the three Arms.

Conclusion

Our results show that MI was effective in improving caregiver self-efficacy, but not CC to self-care. This may indicate that MI was able to improve how well caregivers were supporting patients, as showed by improvements in self-efficacy, but not how much they were doing it, as showed by the lack of improvement in CC to self-care. Further studies need to better understand how caregiver self-efficacy affects CC to self-care, how caregiver self-efficacy can be further improved, and the necessary intensity of MI to improve CC to self-care.

CNS Antigen-Specific Neuroinflammation Attenuates Ischemic Stroke With Involvement of Polarized Myeloid Cells

Background and Objectives

Experimental studies indicate shared molecular pathomechanisms in cerebral hypoxia-ischemia and autoimmune neuroinflammation. This has led to clinical studies investigating the effects of immunomodulatory therapies approved in multiple sclerosis on inflammatory damage in stroke. So far, mutual and combined interactions of autoimmune, CNS antigen-specific inflammatory reactions and cerebral ischemia have not been investigated so far.

Methods

Active MOG_35-55 experimental autoimmune encephalomyelitis (EAE) was induced in male C57Bl/6J mice. During different phases of EAE, transient middle cerebral artery occlusion (tMCAO, 60 minutes) was induced. Brain tissue was analyzed for infarct size and immune cell infiltration. Multiplex gene expression analysis was performed for 186 genes associated with neuroinflammation and hypoxic-ischemic damage.

Results

Mice with severe EAE disease showed a substantial reduction in infarct size after tMCAO. Histopathologic analysis showed less infiltration of CD45⁺ hematopoietic cells in the infarct core of severely diseased acute EAE mice; this was accompanied by an accumulation of Arginase1-positive/Iba1-positive cells. Gene expression analysis indicated an involvement of myeloid cell-driven anti-inflammatory mechanisms in the attenuation of ischemic injury in severely diseased mice exposed to tMCAO in the acute EAE phase.

Discussion

CNS autoantigen-specific autoimmunity has a protective influence on primary tissue damage after experimental stroke, indicating a very early involvement of CNS antigen-specific, myeloid cell-associated anti-inflammatory immune mechanisms that mitigate ischemic injury in the acute EAE phase.

Autoimmune neuroinflammation triggers mitochondrial oxidation in oligodendrocytes

Oligodendrocytes (ODCs) are myelinating cells of the central nervous system (CNS) supporting neuronal survival. Oxidants and mitochondrial dysfunction have been suggested as the main causes of ODC damage during neuroinflammation as observed in multiple sclerosis (MS). Nonetheless, the dynamics of this process remain unclear, thus hindering the design of neuroprotective therapeutic strategies. To decipher the spatio-temporal pattern of oxidative damage and dysfunction of ODC mitochondria in vivo, we created a novel mouse model in which ODCs selectively express the ratiometric H₂ O₂ biosensor mito-roGFP2-Orp1 allowing for quantification of redox changes in their mitochondria. Using 2-photon imaging of the exposed spinal cord, we observed significant mitochondrial oxidation in ODCs upon induction of the MS model experimental autoimmune encephalomyelitis (EAE). This redox change became already apparent during the preclinical phase of EAE prior to CNS infiltration of inflammatory cells. Upon clinical EAE development, mitochondria oxidation remained detectable and was associated with a significant impairment in organelle density and morphology. These alterations correlated with the proximity of ODCs to inflammatory lesions containing activated microglia/macrophages. During the chronic progression of EAE, ODC mitochondria maintained an altered morphology, but their oxidant levels decreased to levels observed in healthy mice. Taken together, our study implicates oxidative stress in ODC mitochondria as a novel pre-clinical sign of MS-like inflammation and demonstrates that evolving redox and morphological changes in mitochondria accompany ODC dysfunction during neuroinflammation.

Abstract 5744: Characterization of sideness-related differentiated genetic alterations in stage I-IV colorectal cancer patients by using whole exome sequencing

Background: Although constituting a single organ, the right colon and left colon arise from midgut and hindgut embryonic precursors respectively. In the context of these embryonic origins, tumor laterality has been associated with differential microsatellite instability (MSI), aneuploidic karyotype, and loss of heterozygosity between the left and right colon. Differential genetic mutation profiles are not fully characterized in the context of left vs right laterality colorectal cancer (CRC). Therefore, we investigated associations between CRC anatomical site and somatic gene mutation patterns using whole exome sequencing.

Methods: Whole exome sequencing data were collected from 55 FFPE samples from different stages (stage I: 11, II: 9; III: 19, IV: 16), treatment-naive CRC patients using the Personalis® tumor-only ImmunoID NeXT Platform®, which captures somatic mutations (SNVs), copy number variants (CNVs), percent MSI in the exome, oncovirus detection, etc. The R package maftools was used to identify differential rates of mutation between samples resected from the rectum, left, and right colon respectively. Maftools-derived mutated gene lists, filtered to p&lt;0.5 and odds-ratio&gt;1, were assessed for pathway enrichment with Enrichr.

Results: APC and TP53 were the most commonly mutated genes in the entire cohort, with mutations seen in &gt;90% (APC) and &gt;75% (TP53) of samples respectively. Individual gene mutation frequency was not significantly different among the primary tumor locations (left colon; right colon; rectum) after Bonferroni multiple test correction, with FBXW7, APC, trending towards differential mutation between right colon tumors and left/rectal tumors. Maftools-derived mutated gene lists, filtered to p&lt;0.5 and odds-ratio&gt;1, were processed with Enrichr, identifying an enrichment of estrogen-related mutation events in right-sided vs rectal tumors (n=81 genes; Bioplanet 2019; q=5x10-4; WikiPathway 2021 Human; q&lt;5x10-6). In rectal tumors compared to right side, PI3K/AKT signaling mutations were more enriched (n=106 genes; Kyoto Encyclopedia of Genes and Genomes 2021; q&lt;4x10-6; MSigDB Hallmark 2020; q=9x10-3).

Conclusion: A statistically significant increase in frequencies of estrogen pathway gene mutations on right-sided tumors, and on PI3K/AKT mutations on rectal tumors, were identified. These are consistent with prior expression-based findings indicating the association of estrogen signaling with right-sided tumors, and increased AKT expression with left-sided CRCs. The whole exome sequencing based laterality associated genetic mutation results provided clinically applicable evidence that patients suffered from left versus right CRC tumors may benefit differential treatment therapies, and further investigation is ongoing to explore the potential correlation between tumor laterality and stage.

Citation Format: Danyi Wang, Lee McDaniel, Sean Boyle, Giuseppe Locatelli, Juergen Scheuenpflug, Zheng Feng. Characterization of sideness-related differentiated genetic alterations in stage I-IV colorectal cancer patients by using whole exome sequencing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5744.

Microglia and monocytes in inflammatory CNS disease: integrating phenotype and function

In neurological diseases, the actions of microglia, the resident myeloid cells of the CNS parenchyma, may diverge from, or intersect with, those of recruited monocytes to drive immune-mediated pathology. However, defining the precise roles of each cell type has historically been impeded by the lack of discriminating markers and experimental systems capable of accurately identifying them. Our ability to distinguish microglia from monocytes in neuroinflammation has advanced with single-cell technologies, new markers and drugs that identify and deplete them, respectively. Nevertheless, the focus of individual studies on particular cell types, diseases or experimental approaches has limited our ability to connect phenotype and function more widely and across diverse CNS pathologies. Here, we critically review, tabulate and integrate the disease-specific functions and immune profiles of microglia and monocytes to provide a comprehensive atlas of myeloid responses in viral encephalitis, demyelination, neurodegeneration and ischemic injury. In emphasizing the differential roles of microglia and monocytes in the severe neuroinflammatory disease of viral encephalitis, we connect inflammatory pathways common to equally incapacitating diseases with less severe inflammation. We examine these findings in the context of human studies and highlight the benefits and inherent limitations of animal models that may impede or facilitate clinical translation. This enables us to highlight common and contrasting, non-redundant and often opposing roles of microglia and monocytes in disease that could be targeted therapeutically.

A phase 1b study evaluating the safety and preliminary efficacy of berzosertib in combination with gemcitabine in patients with advanced non-small cell lung cancer

OBJECTIVES

Berzosertib (formerly M6620, VX-970) is an intravenous, highly potent and selective, first-in-class ataxia telangiectasia and Rad3-related (ATR) protein kinase inhibitor. We assessed the safety, tolerability, preliminary efficacy, and pharmacokinetics (PK) of berzosertib plus gemcitabine in an expansion cohort of patients with advanced non-small cell lung cancer (NSCLC). The association of efficacy with TP53 status and other tumor markers was also explored.

MATERIALS AND METHODS

Adult patients with advanced histologically confirmed NSCLC received berzosertib 210 mg/m2 (days 2 and 9) and gemcitabine 1000 mg/m2 (days 1 and 8) at the recommended phase 2 dose established in the dose escalation part of the study.

RESULTS

Thirty-eight patients received at least one dose of study treatment. The most common treatment-emergent adverse events were fatigue (55.3%), anemia (52.6%), and nausea (39.5%). Gemcitabine had no apparent effect on the PK of berzosertib. The objective response rate (ORR) was 10.5% (4/38, 90% confidence interval [CI]: 3.7-22.5%). In the exploratory analysis, the ORR was 30.0% (3/10, 90% CI: 9.0-61.0%) in patients with high loss of heterozygosity (LOH) and 11.0% (1/9, 90% CI: 1.0-43.0%) in patients with low LOH. The ORR was 33.0% (2/6, 90% CI: 6.0-73.0%) in patients with high tumor mutational burden (TMB), 12.5% (2/16, 90% CI: 2.0-34.0%) in patients with intermediate TMB, and 0% (0/3, 90% CI: 0.0-53.6%) in patients with low TMB.

CONCLUSIONS

Berzosertib plus gemcitabine was well tolerated in patients with advanced, pre-treated NSCLC. Based on the observed clinical efficacy, future clinical trials should involve genomically selected patients.

208 Association between cardiovascular data and the development and progression of mild cognitive impairment: results from the retrospective cohort study

Aims

Mild cognitive impairment (MCI) is characterized by objective evidence of cognitive impairment in one or more cognitive domains in the absence of significant interference in daily-life activities. Anyway, people with MCI are considered to be at heightened risk of further cognitive decline and progression to dementia. To date, few evidence regarding the association between cardiovascular data and MCI are present in the literature. To investigate the association between various cardiovascular data (traditional risk factors and outcomes) and the development and progression of MCI.

Methods and results

The study included 127 patients referred to the Neurological Unit of the Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico of Milan for subjective memory complaints and/or clinical suspect of cognitive impairment. Neuropsychological tests evaluating executive functions and cardiovascular data were collected at baseline and 2-year follow-up. Visit reports and medical records were reviewed to extrapolate the data. The study was conducted between 2012 and 2020. The 51 (40.2%) patients on antiplatelet therapy (94% on aspirin) had a worse baseline degree of cognitive impairment on neuropsychological tests of executive functions and had greater worsening of MCI at 2 years (Table 1). Patients on antiplatelet therapy were significantly older (75.85 vs. 71.7; P = 0.009), more ischaemic (21.6% vs. 1.3%; P &lt; 0.001), hypertensive (90.2% vs. 60.5%; P &lt; 0.001), and dyslipidaemic (62.7% vs. 19.7%; P &lt; 0.001) than patients without antiplatelet therapy. No other single cardiovascular data analysed (presence of hypertension, dyslipidaemia, ischaemic heart disease, diabetes, atrial fibrillation, and anticoagulation therapy) showed a statistical significant association with MCI presence or progression.

Conclusions

The present study suggests that the prevalence and progression of MCI is significantly higher among patients on antiplatelet therapy, who carry a greater cardiovascular burden. Although patients on antiplatelet therapy were older, more ischaemic, hypertensive, and dyslipidaemic than patients without antiplatelet therapy, none of these parameters were associated with MCI presence and/or progression and can therefore be considered a confounding factor.

A motivational interviewing intervention improves the burden of physical symptoms in patients with heart failure: A secondary outcome analysis of a randomized clinical trial

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Center of Excellence for Nursing Scholarship, Rome, Italy

Background. Patients with heart failure (HF) experience a variety of physical symptoms. Symptoms are perceived by patients as burdensome and, as such, negatively affect  quality of life. Besides, physical symptoms are among the first reasons for seeking emergency care and hospitalization. Findings from the MOTIVATE-HF trial show that motivational interviewing (MI) leads to better self-care. However, whether MI also reduces the burden of physical symptoms is not yet known.

Purpose. To evaluate the effectiveness of MI on the burden of physical symptoms in patients with HF.

Methods. Secondary outcome analysis of the MOTIVATE-HF trial. The study was a three-arm, multicenter randomized controlled trial with a 12-month follow-up. Patients with HF and their informal caregivers were enrolled and randomly divided into three arms: MI performed only with patients (Arm 1); MI performed both with patients and caregivers (Arm 2); usual care (Arm 3). Patients with a diagnosis of HF in NYHA functional class II-IV were recruited in three Italian centers. Participants underwent one face-to-face MI session, followed by three phone calls within two months from enrollment. Physical symptoms were measured with the Heart Failure Somatic Perception Scale (HFSPS) with the dimensions of dyspnea, chest discomfort, early and subtle, and edema. Higher scores at the HFSPS and its dimensions indicate worse physical symptom. Data were collected at baseline, and 3 (T1), 6 (T2), 9 (T3) and 12 (T4) months after enrollment. T-test was used to compare differences in HFSPS scores in Arms 1 and 2 versus Arm 3 at each follow-up. Changes over time were analyzed with mixed linear longitudinal models.

Results. A sample of 510 patients (median 74 years, 58% male) and their caregivers (median 55 years, 75.5% female) were randomized to Arm 1 (n = 155), Arm 2 (n = 177) and Arm 3 (n = 178). Chest discomfort improved in Arms 1 and 2 versus Arm 3 at T4 (mean difference(Δ): -8.13, P = .014). Dyspnea also improved in Arms 1 and 2 than Arm 3 both at T3 and T4 (Δ: -7, P = .027 and Δ: -6.78, P = .038, respectively). HFSPS total score improved in Arms 1 and 2 versus Arm 3 at T3 (Δ: -4.55, P = .048). Over the year of observation, the mixed linear longitudinal models showed a significant improvement in Chest discomfort and total HFSPS score in Arm 2 versus Arm 3 (β = -2.61, P = .002 and, β = -1.35, P = .02).

Conclusions. The results of this secondary analysis indicate that MI may be effective in decreasing the burden of physical symptoms in HF patients, especially if also caregivers are involved in the intervention. Since symptom burden is among the first reasons for seeking emergency care and hospitalization in HF, MI might be a viable option to improve symptom burden via self-care.

Abstract 2062: Comprehensive molecular profiling of DNA damage response (DDR) deficiencies in advanced solid tumors using a real-world genomic database

Purpose: DNA damage response (DDR) deficiency is a hallmark of cancer and can be exploited with therapeutic interventions such as the use of PARP inhibitors and PD-1/PD-L1 immune checkpoint inhibitors. To understand the relationship between clinically actionable DDR genomic alterations (GA) and DDR deficiency biomarkers, we investigated the distribution of the GA in the most common DDR genes and explored the association with DDR deficiency biomarkers by utilizing the Foundation Medicine comprehensive genomic database across different cancer types. These data may provide essential information to refine and define the clinical translational strategies for innovative cancer therapies in clinical development. Methods: Molecular profiles from a total of 269,371 clinically advanced and diverse malignancies were analyzed using FoundationInsightsTM. Genomic alterations including short variants, copy number alterations and rearrangements in 35 DDR genes, more complex biomarkers (tumor mutation burden [TMB], genome-wide loss of heterozygosity [gLOH], microsatellite instability [MSI] status) and PD-L1 expression were studied. Only functional alterations (known or likely oncogenic) were analyzed. Results: DDR gene alterations are frequent and non-uniformly distributed by type and frequency across cancer types including breast, ovarian, colorectal, esophagus, biliary track, gastric, head and neck, pancreas, melanoma, lung, bladder, and prostate. TP53 is the most frequently altered DDR gene across all cancers as expected (59%), followed by ARID1A (9%), ATM (4%), SMARCA4 (3%), MDM2 (3%), BRCA2 (3%), BRCA1 (2%), CHK2 (2%), MUTYH (2%), whereas many other DDR genes are rarely altered (≤1%). Excluding TP53 from the analysis, bladder cancer has the highest cumulative rate of cases with mutations in DDR genes (46.59%), while other cancers have rates ranging between 20-40%. Further analyses including the relative distribution of TMB, MSI, gLOH and PD-L1 expression by tumor type and their association with DDR GA are ongoing. Conclusion: Identifying associations of DDR alterations and immuno-oncology associated predictive biomarkers (TMB, PD-L1) as well as assessment of signatures of genomic instability (MSI, gLOH) are critical for enabling biomarker-driven precision oncology. We systematically analyzed somatic alterations using the Foundation Medicine comprehensive genomic database and provide a comprehensive molecular profiling of DDR deficiencies in advanced solid tumors. It is anticipated that this data will collectively contribute to identify molecularly defined tumor subsets, where single and/or combination therapies such as DDR inhibitors, immunotherapies, targeted therapies etc. may result in increased clinical benefit for patients with cancer.

Citation Format: Danyi Wang, Brian Elenbaas, Karthikeyan Murugesan, Lee A. Albacker, Julien Doudement, Juergen Scheuenpflug, Giuseppe Locatelli, Zheng Feng. Comprehensive molecular profiling of DNA damage response (DDR) deficiencies in advanced solid tumors using a real-world genomic database [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2062.

A first-in-human phase I study of ATR inhibitor M1774 in patients with solid tumors

TPS3153

Background: Ataxia telangiectasia and Rad3-related (ATR) protein kinase plays a critical role in the DNA damage response by sensing and responding to DNA replication stress, and by inducing cell cycle arrest to prevent aberrant replication and mitotic catastrophe. Based on extensive preclinical and limited clinical evidence, ATR inhibition is a promising treatment strategy as monotherapy for patients with advanced tumors harboring synthetically lethal conditions, such as alternative lengthening of telomeres (ALT) and inactivating mutations in ARID1A and ATM. M1774 is a potent, selective, orally administered ATR inhibitor that has been shown to exert antitumor activity in patient-derived xenograft tumors and acute myeloid leukemia xenograft tumors that express the ATR inhibition sensitizing mixed lineage leukemia fusion protein. This study (NCT04170153) aims to evaluate the safety and tolerability, maximum tolerated dose, recommended dose for expansion (RDE) and pharmacokinetics (PK) of M1774 (part A1), the effect of food on M1774 PK (part A2), and the efficacy of M1774 in patients with tumors harboring selected mutations (part A3). An additional objective is to assess the pharmacodynamics of M1774 by measuring relative changes in baseline p-CHK1 and γ-H2AX expression in paired tumor biopsies and serial blood samples. Methods: Patients aged ≥18 years, with an Eastern Cooperative Oncology Group performance status ≤1, adequate baseline hematological, renal and hepatic function, and with locally advanced or metastatic disease refractory to standard therapy are eligible. Patients with tumors bearing loss-of-function (LoF) mutations (determined by site testing or a central trial assay) in ARID1A, ATM, or ATRX and/or DAXX as ALT status surrogate markers; and measurable disease according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, will be enrolled in part A3. In the dose escalation phase (part A1 [open]), 18–24 patients are due to receive M1774 at a starting dose of 5 mg once daily. Dose escalation is determined by the safety monitoring committee and guided by a Bayesian 2-parameter logistic regression model. The preliminary food assessment (part A2) will follow a randomized two-sequence two-period crossover design in which ≤12 patients will be randomized (1:1) to receive a single dose of M1774 on Day –7 at the RDE (determined in part A1) in either a fed or fasted condition. After the food assessment, patients will subsequently receive M1774 according to the part A1 dosing schedule. In the preliminary efficacy study (part A3), patients (n = 20–24 for each of the three planned cohorts) with tumors harboring LoF mutations in the genes for ARID1A, ATM, ATRX and/or DAXX, will receive M1774 at the RDE. The primary efficacy endpoint is overall response (RECIST). The study is open and currently recruiting. Patients have been enrolled to seven cohorts in part A1 with no DLTs observed; dose escalation is ongoing. Clinical trial information: NCT04170153.

Central Nervous System Barriers Impact Distribution and Expression of iNOS and Arginase-1 in Infiltrating Macrophages During Neuroinflammation

In multiple sclerosis (MS) and other neuroinflammatory diseases, monocyte-derived cells (MoCs) traffic through distinct central nervous system (CNS) barriers and gain access to the organ parenchyma exerting detrimental or beneficial functions. How and where these MoCs acquire their different functional commitments during CNS invasion remains however unclear, thus hindering the design of MS treatments specifically blocking detrimental MoC actions. To clarify this issue, we investigated the distribution of iNOS⁺ pro-inflammatory and arginase-1⁺ anti-inflammatory MoCs at the distinct border regions of the CNS in a mouse model of MS. Interestingly, MoCs within perivascular parenchymal spaces displayed a predominant pro-inflammatory phenotype compared to MoCs accumulating at the leptomeninges and at the intraventricular choroid plexus (ChP). Furthermore, in an in vitro model, we could observe the general ability of functionally-polarized MoCs to migrate through the ChP epithelial barrier, together indicating the ChP as a potential CNS entry and polarization site for MoCs. Thus, pro- and anti-inflammatory MoCs differentially accumulate at distinct CNS barriers before reaching the parenchyma, but the mechanism for their phenotype acquisition remains undefined. Shedding light on this process, we observed that endothelial (BBB) and epithelial (ChP) CNS barrier cells can directly regulate transcription of Nos2 (coding for iNOS) and Arg1 (coding for arginase-1) in interacting MoCs. More specifically, while TNF-α+IFN-γ stimulated BBB cells induced Nos2 expression in MoCs, IL-1β driven activation of endothelial BBB cells led to a significant upregulation of Arg1 in MoCs. Supporting this latter finding, less pro-inflammatory MoCs could be found nearby IL1R1⁺ vessels in the mouse spinal cord upon neuroinflammation. Taken together, our data indicate differential distribution of pro- and anti-inflammatory MoCs at CNS borders and highlight how the interaction of MoCs with CNS barriers can significantly affect the functional activation of these CNS-invading MoCs during autoimmune inflammation.

Microglia Get a Little Help from "Th"-eir Friends

The presence of CD4+ T cells in the healthy brain parenchyma remains controversial due to the barrier function of the glia limitans. Pasciuto, Burton, Roca et al. in Cell describe the dynamic recruitment of CD4⁺ T cells within the brain parenchyma, their unexpected contribution to microglial maturation, and, ultimately, their influence on behavior.

Dwellers and Trespassers: Mononuclear Phagocytes at the Borders of the Central Nervous System

The central nervous system (CNS) parenchyma is enclosed and protected by a multilayered system of cellular and acellular barriers, functionally separating glia and neurons from peripheral circulation and blood-borne immune cells. Populating these borders as dynamic observers, CNS-resident macrophages contribute to organ homeostasis. Upon autoimmune, traumatic or neurodegenerative inflammation, these phagocytes start playing additional roles as immune regulators contributing to disease evolution. At the same time, pathological CNS conditions drive the migration and recruitment of blood-borne monocyte-derived cells across distinct local gateways. This invasion process drastically increases border complexity and can lead to parenchymal infiltration of blood-borne phagocytes playing a direct role both in damage and in tissue repair. While recent studies and technical advancements have highlighted the extreme heterogeneity of these resident and CNS-invading cells, both the compartment-specific mechanism of invasion and the functional specification of intruding and resident cells remain unclear. This review illustrates the complexity of mononuclear phagocytes at CNS interfaces, indicating how further studies of CNS border dynamics are crucially needed to shed light on local and systemic regulation of CNS functions and dysfunctions.

The epilepsy specialist nurse: A mixed-methods case study on the role and activities

PURPOSE

To describe the role and activities of epilepsy specialist nurses (ESNs) operating as a team in the setting of a hospital specialising in the diagnosis and management of seizure disorders.

METHODS

We conducted a descriptive mixed-methods embedded single case study. We recruited 9 ESNs, 14 of their professional colleagues and 9 'key informants' to analyse their perceptions of the role and activities of ESNs. We collected data through interviews, questionnaires, observations, and documentation. The study was conducted at the Filadelfia Epilepsy Hospital, Denmark.

RESULTS

The team of ESNs offers holistic care to patients and their caregivers regarding the clinical, social, and emotional aspects of epilepsy. The ESNs are integrated in a multidisciplinary team and promote collaboration among the team members. ESNs also contribute to organisational aspects and perform research activities.

CONCLUSION

A structured group of ESNs can operate effectively and extensively in a specialised hospital setting. Our findings contribute to clarifying the description of the ESN's role, and provide an example of how ESNs can be incorporated into a hospital's organisational structure.

Semaphorin 7A restricts serotonergic innervation and ensures recovery after spinal cord injury

Descending serotonergic (5-HT) projections originating from the raphe nuclei form an important input to the spinal cord that control basic locomotion. The molecular signals that control this projection pattern are currently unknown. Here, we identify Semaphorin7A (Sema7A) as a critical cue that restricts serotonergic innervation in the spinal cord. Sema7A deficient mice show a marked increase in serotonergic fiber density in all layers of the spinal cord while the density of neurons expressing the corresponding 5-HTR2α receptor remains unchanged. These alterations appear to be successfully compensated as no obvious changes in rhythmic locomotion and skilled stepping are observed in adult mice. When the system is challenged with a spinal lesion, serotonergic innervation patterns in both Sema7A-deficient and -competent mice evolve over time with excessive innervation becoming most pronounced in the dorsal horn of Sema7A-deficient mice. These altered serotonergic innervation patterns correlate with diminished functional recovery that predominantly affects rhythmic locomotion. Our findings identify Sema7A as a critical regulator of serotonergic circuit formation in the injured spinal cord.

P1106DETERMINANTS OF SERUM POTASSIUM IN HEMODIALYSIS PATIENTS. DOES JUST ONE COUNT?

Background and Aims

Potassium (K) is mostly an intracellular ion, with a complex homeostasis that is deeply modified in ESRD patients undergoing hemodialysis (HD). Several factors (diet, insulin, acid-base balance, aldosterone, etc) may contribute to determine the level of serum extracellular K, but it is not clear which factor contributes the most. We aimed to evaluate the importance of several factors in inducing hyperkalemia in HD patients.

Methods

Chronic tri-weekly HD patients were evaluated. Patients on diuretics or on potassium binders were excluded. For every patient we recorded age, sex, Kt/V and we measured the post-HD kalemia on the day before the long interHD interval. On the day after the long interHD interval we evaluated: pre-HD K, glucose, creatinine, aldosterone, LDH, CPK, arterial blood gases, ECG, overhydration by bioelectrical impedance analysis, body weight increase after the long interHD interval and daily urinary output. K amount introduced by diet was calculated by a dietitian from each patient’s daily food diary. Treatment with ARB, ACE-inhibitors, beta-blockers, insulin or heparin was recorded. Data are presented as mean±SD for each variable analyzed. Correlations between the serum K values and change in serum K (delta K) and the other patient medical data were determined through the two-tailed Pearson’s test or Spearman test according to data distribution.

Results

We enrolled 56 patients (male 53.6%), aged 72±13, with a mean Kt/V 1.44±0.25. Mean post-HD kalemia was 3.65±0.4 mmol/L, mean pre-HD kalemia was 5.23±0.72 mmol/L, with a mean delta 1.58±0.64 mmol/L. Medium pH was 7.37±0.01, with serum bicarbonate 20.15±4.0 mmol/L. Overhydration estimated by bioelectrical impedance analysis was 2.3±0.6 L, while mean daily intake of K was 1697.13±711.13 mg. We found a strong positive correlation between delta K and pre-HD kalemia (r=0.79, p&lt;0.0001). Surprisingly, a positive correlation was found between delta K and serum bicarbonate (r=0.27, p=0.04), while no correlations were present between delta K, mean pre-HD kalemia and dietary intake of K (p=ns). No difference in delta K was found between anuric and not anuric patients. No other statistically significant differences were found.

Conclusion

Potassium homeostasis is markedly altered in ESRD and several factors contribute to determine the serum K values. In this study we found that delta potassium correlates to pre-HD kalemia. We did not study the temporal kinetic of K increase, but it is reasonable to infer that a significant post-HD rebound may contribute to increase kalemia, as dietary intake of K was not found to correlate to delta K or to serum K after the long interdialytic interval. The positive correlation between delta K and serum bicarbonate is unexpected and difficult to explain. However, since we did not measure serum bicarbonate post-HD, we may speculate that patients with high delta K and serum bicarbonate might have even higher levels of bicarbonate after HD. In conclusion, our study shows that none of the examined factors prevales in determining high serum potassium in HD patients.

Single-cell profiling identifies myeloid cell subsets with distinct fates during neuroinflammation

The innate immune cell compartment is highly diverse in the healthy central nervous system (CNS), including parenchymal and non-parenchymal macrophages. However, this complexity is increased in inflammatory settings by the recruitment of circulating myeloid cells. It is unclear which disease-specific myeloid subsets exist and what their transcriptional profiles and dynamics during CNS pathology are. Combining deep single-cell transcriptome analysis, fate mapping, in vivo imaging, clonal analysis, and transgenic mouse lines, we comprehensively characterized unappreciated myeloid subsets in several CNS compartments during neuroinflammation. During inflammation, CNS macrophage subsets undergo self-renewal, and random proliferation shifts toward clonal expansion. Last, functional studies demonstrated that endogenous CNS tissue macrophages are redundant for antigen presentation. Our results highlight myeloid cell diversity and provide insights into the brain’s innate immune system.

Recent developments of c-Met as a therapeutic target in hepatocellular carcinoma

Aberrant c-Met activity has been implicated in the development of hepatocellular carcinoma (HCC), suggesting that c-Met inhibition may have therapeutic potential. However, clinical trials of nonselective kinase inhibitors with c-Met activity (tivantinib, cabozantinib, foretinib, and golvatinib) in patients with HCC have failed so far to demonstrate significant efficacy. This lack of observed efficacy is likely due to several factors, including trial design, lack of patient selection according to tumor c-Met status, and the prevalent off-target activity of these agents, which may indicate that c-Met inhibition is incomplete. In contrast, selective c-Met inhibitors (tepotinib, capmatinib) can be dosed at a level predicted to achieve complete inhibition of tumor c-Met activity. Moreover, results from early trials can be used to optimize the design of clinical trials of these agents. Preliminary results suggest that selective c-Met inhibitors have antitumor activity in HCC, with acceptable safety and tolerability in patients with Child-Pugh A liver function. Ongoing trials have been designed to assess the efficacy and safety of selective c-Met inhibition compared with standard therapy in patients with HCC that were selected based on tumor c-Met status. Thus, c-Met inhibition continues to be an active area of research in HCC, with well-designed trials in progress to investigate the benefit of selective c-Met inhibitors. (Hepatology 2018;67:1132-1149).

Extracorporeal Membrane Oxygenation with Veno-Venous Bypass and Apneic Oxygenation for Treatment of Severe Neonatal Respiratory Failure

Seven newborn infants with life-threatening respiratory failure were treated with veno-venous (V-V) extracorporeal lung support and apneic oxygenation after maximal ventilatory and pharmacological treatment failed. Diagnosis were meconium aspiration syndrome in 3 cases, respiratory distress syndrome in 2, sepsis in 1, congenital diaphragmatic hernia in 1. Before ECMO 6 infants received tolazoline, 4 surfactant, 3 high frequency ventilation, 1 prostaglandin E, 1 epoprostenol, 2 nitric oxide. Newborns were highly hypoxemic at admission and all but one underwent rescue cannulation. V-V bypass was performed with a single lumen single cannula and tidal flow was generated by an alternating clamp using a non-occlusive roller pump. The mean duration of bypass was 162, 4±162.3 hours and infants were extubated 94.5±74.8 hours after decannulation. Five newborns survived and two died. Growth and neurologic development of the older children is normal. The extracorporeal lung support with V-V bypass associated with apneic oxygenation was effective in reversing severe neonatal respiratory failure unresponsive to maximal ventilatory and pharmacological support. An early referral, prior to meeting ECMO criteria, is important in order to avoid hypoxic complications preceding ECMO.

Does c-Met remain a rational target for therapy in patients with EGFR TKI-resistant non-small cell lung cancer?

Non-small cell lung cancer (NSCLC) inevitably develops resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) treatment. In 5-20% of cases, this can be attributed to aberrant c-Met activity, providing a clear rationale for the use of c-Met inhibitors in these patients. EGFR TKI-resistant tumors often remain sensitive to EGFR signaling, such that c-Met inhibitors are likely to be most effective when combined with continued EGFR TKI therapy. The phase III trials of the c-Met inhibitors onartuzumab and tivantinib, which failed to demonstrate significant benefit in patients with NSCLC but excluded patients with EGFR TKI-resistant disease, do not allow c-Met to be dismissed as a rational target in EGFR TKI-resistant NSCLC. Selective c-Met TKIs exhibit more favorable properties, targeting both hepatocyte growth factor (HGF)-dependent and -independent c-Met activity, with a reduced risk of toxicity compared to non-selective c-Met TKIs. Phase Ib/II trials of the selective c-Met TKIs capmatinib and tepotinib have shown encouraging signs of efficacy. Factors affecting the success of ongoing and future trials of c-Met inhibitors in patients with EGFR TKI-resistant, c-Met-positive NSCLC are considered.

The selective c-Met inhibitor tepotinib can overcome epidermal growth factor receptor inhibitor resistance mediated by aberrant c-Met activation in NSCLC models

Non-small cell lung cancer (NSCLC) sensitive to first-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) often acquires resistance through secondary EGFR mutations, including the T790M mutation, aberrant c-Met receptor activity, or both. We assessed the ability of the highly selective c-Met inhibitor tepotinib to overcome EGFR TKI resistance in various xenograft models of NSCLC. In models with EGFR-activating mutations and low c-Met expression (patient explant-derived LU342, cell line PC-9), EGFR TKIs caused tumors to shrink, but growth resumed upon cessation of treatment. Tepotinib combined with EGFR TKIs delayed tumor regrowth, while tepotinib alone was ineffective. In patient explant-derived LU858, which has an EGFR-activating mutation and expresses high levels of c-Met/HGF, EGFR TKIs had no effect on tumor growth. Tepotinib combined with EGFR TKIs caused complete tumor regression and tepotinib alone caused tumor stasis. In cell line DFCI081 (activating EGFR mutation, c-Met amplification), EGFR TKIs were ineffective, whereas tepotinib alone induced complete tumor regression. Finally, in a 'double resistant' EGFR T790M-positive, high c-Met model (cell line HCC827-GR-T790M), the EGFR TKIs erlotinib, afatinib, and rociletinib, as well as tepotinib as a single agent or in combination with erlotinib or afatinib, slowed tumor growth, but only tepotinib in combination with rociletinib induced complete tumor regression. We conclude that tepotinib can overcome acquired resistance to EGFR TKIs. Based on these data, clinical trials of tepotinib in combination with EGFR TKIs in patients with NSCLC with acquired resistance to first-generation EGFR TKIs are warranted.

Basilar Artery Changes in Fabry Disease

BACKGROUND AND PURPOSE

Dolichoectasia of the basilar artery is a characteristic finding of Fabry disease. However, its prevalence, severity, and course have been poorly studied. This study quantitatively evaluated, by MRA, a panel of basilar artery parameters in a large cohort of patients with Fabry disease.

MATERIALS AND METHODS

Basilar artery mean diameter, curved length, "origin-to-end" linear distance (linear length), and tortuosity index ([curved length ÷ linear length] - 1) were retrospectively measured on 1.5T MRA studies of 110 patients with Fabry disease (mean age, 39.4 ± 18.6 years; 40 males) and 108 control patients (mean age, 42.0 ± 18.2 years; 40 males).

RESULTS

Patients with Fabry disease had increased basilar artery mean diameter (P < .001) and basilar artery linear length (P = .02) compared with control patients. Basilar artery curved length and tortuosity index correlated with age in both groups (P < .001), whereas basilar artery linear length correlated with age only in patients with Fabry disease (P = .002). Patients with Fabry disease showed a basilar artery curved length mean increase of 4.2% (9.7% in male patients with Fabry disease versus male control patients), whereas the basilar artery mean diameter had a mean increase of 12.4% (14.3% in male patients with Fabry disease versus male control patients). Male patients with Fabry disease had increased basilar artery mean diameter, curved length, and tortuosity index compared with female patients with Fabry disease (P = .04, P = .02, and P < .001, respectively) and male control patients (P < .001, P = .01, and P = .006, respectively). Female patients with Fabry disease demonstrated an age-dependent increase of basilar artery mean diameter that became significant (P < .001) compared with female control patients above the age of 45 years.

CONCLUSIONS

The basilar artery of patients with FD is subjected to major remodeling that differs according to age and sex, thus providing interesting clues about the pathophysiology of cerebral vessels in Fabry disease.

Development of a novel Italian speech-in-noise test using a roving-level adaptive method: adult population-based normative data

In recent years the increasing development of hearing devices has led to a critical analysis of the standard methods employed to evaluate hearing function. Being too far from reality, conventional investigation of hearing loss based on pure-tone threshold audiometry and on mono/disyllabic word lists, presented in quiet conditions, has been shown to be inadequate. A speech-in-noise test using a roving-level adaptive method employs target and competing signals varying in level in order to reproduce everyday life speaking conditions and explore a more complete sound range. Up to now, only few roving-level adaptive tests have been published in the literature. We conducted a rovinglevel adaptive test in healthy Italian adults to produce new normative data on a language of Latin origin.

Abstract 4663: Combination of c-Met inhibitor tepotinib (MSC2156119J) and a third-generation EGFR inhibitor can overcome double resistance mediated by EGFR T790M mutation and c-Met amplification in non-small cell lung cancer models

In clinical practice, acquired resistance to EGFR tyrosine kinase inhibitors (TKIs) in EGFR-mutant non-small cell lung cancer (NSCLC) causes EGFR TKI treatment failure. Several resistance mechanisms have been identified; EGFR T790M mutation and aberrant activation of c-Met through c-Met gene amplification and/or HGF upregulation are the two most common mechanisms. We have previously shown that combining the highly selective c-Met inhibitor tepotinib with 1st or 2nd-generation EGFR TKIs overcomes gefitinib resistance caused only by c-MET amplification. Third-generation EGFR TKIs such as rociletinib have been developed specifically to overcome T790M-mediated resistance to EGFR TKIs. We hypothesized that combining a 3rd-generation EGFR TKI with tepotinib could overcome resistance to a 1st or 2nd-generation EGFR TKI (e.g. gefitinib) regardless of the mechanism of resistance.

We assessed the efficacy of tepotinib and a Merck-synthesized version of rociletinib (MSR) as monotherapy or in combination in a NSCLC cell line xenograft model (HCC827-GR-T790M) with an EGFR del 19 mutation, c-Met amplification, and exogenous T790M expression, and in a patient-derived xenograft model (DFCI081) with an EGFR del 19 mutation and c-Met amplification, but not a T790M mutation.

Single-agent tepotinib, erlotinib, and afatinib did not show antitumor activity in HCC827-GR-T790M xenografts and tumors progressed on treatment (median tumor volume [TV] changes &gt;73%). The combinations of tepotinib + erlotinib and tepotinib + afatinib delayed tumor regrowth more than single-agent therapy, but were no more effective than single-agent MSR. In contrast, the combination of tepotinib + MSR had strong antitumor activity in this model with double resistance due to c-Met amplification and exogenous T790M expression, resulting in complete tumor regression (median TV change -97%).

In the patient-derived xenograft model DFCI081, tumors progressed under single-agent therapy with the EGFR TKIs erlotinib, afatinib, and MSR, as expected given that this cell line expresses c-Met. In contrast, tepotinib induced complete tumor regression as monotherapy and when combined with each of the EGFR TKIs (median TV change -100%). Complete regression was maintained until the end of the 60-day observation period after treatment termination.

These findings are compatible with the hypothesis that combining tepotinib with a 3rd-generation EGFR TKI to overcome double resistance to 1st and 2nd-generation TKIs mediated by T790M and c-Met in NSCLC is more effective than using either agent alone. Furthermore, whereas EGFR TKIs were not effective in tumor models showing c-Met amplification and EGFR del 19 mutation but not T790M mutation, ie resistance is c-Met mediated, tepotinib monotherapy induced complete tumor regression.

Citation Format: Manja Friese-Hamim, Giuseppe Locatelli, Friedhelm Bladt. Combination of c-Met inhibitor tepotinib (MSC2156119J) and a third-generation EGFR inhibitor can overcome double resistance mediated by EGFR T790M mutation and c-Met amplification in non-small cell lung cancer models. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4663.

Mature oligodendrocytes actively increase in vivo cytoskeletal plasticity following CNS damage

BACKGROUND

Oligodendrocytes are myelinating cells of the central nervous system which support functionally, structurally, and metabolically neurons. Mature oligodendrocytes are generally believed to be mere targets of destruction in the context of neuroinflammation and tissue damage, but their real degree of in vivo plasticity has become a matter of debate. We thus investigated the in vivo dynamic, actin-related response of these cells under different kinds of demyelinating stress.

METHODS

We used a novel mouse model (oLucR) expressing luciferase in myelin oligodendrocyte glycoprotein-positive oligodendrocytes under the control of a β-actin promoter. Activity of this promoter served as surrogate for dynamics of the cytoskeleton gene transcription through recording of in vivo bioluminescence following diphtheria toxin-induced oligodendrocyte death and autoimmune demyelination. Cytoskeletal gene expression was quantified from mature oligodendrocytes directly isolated from transgenic animals through cell sorting.

RESULTS

Experimental demyelinating setups augmented oligodendrocyte-specific in vivo bioluminescence. These changes in luciferase signal were confirmed by further ex vivo analysis of the central nervous system tissue from oLucR mice. Increase in bioluminescence upon autoimmune inflammation was parallel to an oligodendrocyte-specific increased transcription of β-tubulin.

CONCLUSIONS

Mature oligodendrocytes acutely increase their cytoskeletal plasticity in vivo during demyelination. They are therefore not passive players under demyelinating conditions but can rather react dynamically to external insults.

Deletion of Jun proteins in adult oligodendrocytes does not perturb cell survival, or myelin maintenance in vivo

Oligodendrocytes, the myelin-forming glial cells of the central nervous system (CNS), are fundamental players in rapid impulse conduction and normal axonal functions. JunB and c-Jun are DNA-binding components of the AP-1 transcription factor, which is known to regulate different processes such as proliferation, differentiation, stress responses and death in several cell types, including cultured oligodendrocyte/lineage cells. By selectively inactivating Jun B and c-Jun in myelinating oligodendrocytes in vivo, we generated mutant mice that developed normally, and within more than 12 months showed normal ageing and survival rates. In the adult CNS, absence of JunB and c-Jun from mature oligodendrocytes caused low-grade glial activation without overt signs of demyelination or secondary leukocyte infiltration into the brain. Even after exposure to toxic or autoimmune oligodendrocyte insults, signs of altered oligodendrocyte viability were mild and detectable only upon cuprizone treatment. We conclude that JunB and c-Jun expression in post-mitotic oligodendrocytes is mostly dispensable for the maintainance of white matter tracts throughout adult life, even under demyelinating conditions.