Ex vivo drug testing of patient-derived lung organoids to predict treatment responses for personalized medicine

Lung cancer is the leading cause of global cancer-related mortality resulting in ∼ 1.8 million deaths annually. Systemic, molecular targeted, and immune therapies have provided significant improvements of survival outcomes for patients. However, drug resistance usually arises and there is an urgent need for novel therapy screening and personalized medicine. 3D patient-derived organoid (PDO) models have emerged as a more effective and efficient alternative for ex vivo drug screening than 2D cell culture and patient-derived xenograft (PDX) models. In this review, we performed an extensive search of lung cancer PDO-based ex vivo drug screening studies. Lung cancer PDOs were successfully established from fresh or bio-banked sections and/or biopsies, pleural effusions and PDX mouse models. PDOs were subject to ex vivo drug screening with chemotherapy, targeted therapy and/or immunotherapy. PDOs consistently recapitulated the genomic alterations and drug sensitivity of primary tumors. Although sample sizes of the previous studies were limited and some technical challenges remain, PDOs showed great promise in the screening of novel therapy drugs. With the technical advances of high throughput, tumor-on-chip, and combined microenvironment, the drug screening process using PDOs will enhance precision care of lung cancer patients.

Oxytocin Modifies the Excitability and the Action Potential Shape of the Hippocampal CA1 GABAergic Interneurons

Oxytocin (OT) is a neuropeptide that modulates social-related behavior and cognition in the central nervous system of mammals. In the CA1 area of the hippocampus, the indirect effects of the OT on the pyramidal neurons and their role in information processing have been elucidated. However, limited data are available concerning the direct modulation exerted by OT on the CA1 interneurons (INs) expressing the oxytocin receptor (OTR). Here, we demonstrated that TGOT (Thr4,Gly7-oxytocin), a selective OTR agonist, affects not only the membrane potential and the firing frequency but also the neuronal excitability and the shape of the action potentials (APs) of these INs in mice. Furthermore, we constructed linear mixed-effects models (LMMs) to unravel the dependencies between the AP parameters and the firing frequency, also considering how TGOT can interact with them to strengthen or weaken these influences. Our analyses indicate that OT regulates the functionality of the CA1 GABAergic INs through different and independent mechanisms. Specifically, the increase in neuronal firing rate can be attributed to the depolarizing effect on the membrane potential and the related enhancement in cellular excitability by the peptide. In contrast, the significant changes in the AP shape are directly linked to oxytocinergic modulation. Importantly, these alterations in AP shape are not associated with the TGOT-induced increase in neuronal firing rate, being themselves critical for signal processing.

Loss-of-function of GNAL dystonia gene impairs striatal dopamine receptors-mediated adenylyl cyclase/ cyclic AMP signaling pathway

Loss-of-function mutations in the GNAL gene are responsible for DYT-GNAL dystonia. However, how GNAL mutations contribute to synaptic dysfunction is still unclear. The GNAL gene encodes the Gαolf protein, an isoform of stimulatory Gαs enriched in the striatum, with a key role in the regulation of cAMP signaling. Here, we used a combined biochemical and electrophysiological approach to study GPCR-mediated AC-cAMP cascade in the striatum of the heterozygous GNAL (GNAL+/-) rat model. We first analyzed adenosine type 2 (A2AR), and dopamine type 1 (D1R) receptors, which are directly coupled to Gαolf, and observed that the total levels of A2AR were increased, whereas D1R level was unaltered in GNAL+/- rats. In addition, the striatal isoform of adenylyl cyclase (AC5) was reduced, despite unaltered basal cAMP levels. Notably, the protein expression level of dopamine type 2 receptor (D2R), that inhibits the AC5-cAMP signaling pathway, was also reduced, similar to what observed in different DYT-TOR1A dystonia models. Accordingly, in the GNAL+/- rat striatum we found altered levels of the D2R regulatory proteins, RGS9-2, spinophilin, Gβ5 and β-arrestin2, suggesting a downregulation of D2R signaling cascade. Additionally, by analyzing the responses of striatal cholinergic interneurons to D2R activation, we found that the receptor-mediated inhibitory effect is significantly attenuated in GNAL+/- interneurons. Altogether, our findings demonstrate a profound alteration in the A2AR/D2R-AC-cAMP cascade in the striatum of the rat DYT-GNAL dystonia model, and provide a plausible explanation for our previous findings on the loss of dopamine D2R-dependent corticostriatal long-term depression.

Multiple beneficial effects of 1-year nutritional-behavioral intervention on anthropometric and metabolic parameters in overweight and obese boys

PURPOSE

Childhood obesity is on the rise worldwide increasing the risk for metabolic, cardiovascular and liver diseases in children. Eating habits and lifestyle changes are currently the standard of care for treating pediatric obesity. Our study aimed to determine the impact of a dietary intervention based on the Mediterranean Diet (MD) and the Health Eating Plate, on anthropometric and metabolic parameters in obese and overweight boys.

METHODS

We studied 126 overweight/obese boys with anthropometric measurements, blood biochemistry and nutrient intakes evaluation by means of Food Frequency Questionnaire (FFQ) at baseline, at 6 and 12 months after a nutritional-behavioral intervention.

RESULTS

We observed a significant reduction in energy, macronutrients and micronutrients intakes. BMI-SDS significantly decreased after 1 year with the proportion of obese boys decreasing by 33% and of overweight boys by 41%, while also all fat mass measures decreased both in obese and overweight individuals. In obese boys, ALT decreased significantly after 1-year nutritional intervention and these changes correlated with BMI-SDS reduction. Insulin-resistance and secretion indexes correlated with fat mass and BMI-SDS. In obese boys, significant changes were observed at 6 months for insulin concentrations, 1/HOMA-IR and QUICKI. With regard to the lipid profile, significant decreases were observed for total and LDL cholesterol in obese boys.

CONCLUSION

Metabolic and anthropometric risk factors in overweight and obese boys can be improved by a nutritional-behavioral intervention of 1-year duration.

C-STIM: Protocol for a randomized, single-blind, crossover study of cerebellar repetitive transcranial magnetic stimulation (rTMS) for postural instability in people with progressive supranuclear palsy (PSP)

Background

Methods for modulating the cerebellum with transcranial magnetic stimulation (TMS) are well established, and preliminary data from our group and others has shown evidence of transient improvements in balance after cerebellar repetitive transcranial magnetic stimulation (rTMS) in progressive suprancuclear palsy (PSP). This study examines extensive posturography measures before and after 10 sessions of cerebellar rTMS and sham TMS in PSP.

Methods

Thirty subjects with PSP and postural instability will undergo cerebellar active and sham rTMS in a single-blind, crossover design with a randomized order of a 10-day intervention. Primary outcomes will be changes in sway area and medio-lateral range of sway with eyes open while standing on a stationary force-plate, and safety, tolerability, and blindedness. Secondary outcomes will include posturography and gait analysis with body-worn, triaxial inertial sensors, clinical balance scales and questionnaires, and a bedside test of vestibular function. Exploratory outcomes are changes in functional near infrared spectroscopy (fNIRS) signal over the prefrontal, supplementary motor, and primary motor cortices while standing and walking, and speech samples for future analysis.

Discussion

The C-STIM crossover intervention study adds a longer duration of stimulation and extensive posturography measures to more finely measure the improvements in balance and exploratory functional near-infrared spectroscopy (fNIRS) over the prefronal, supplementary motor, and primary motor cortices during balance assessments before and after 10 sessions of cerebellar rTMS and 10 sessions of sham cerebellar TMS. This project will improve our understanding of the importance of the cerebellum for control of postural stability in PSP.

Synaptic mechanisms underlying onset and progression of memory deficits caused by hippocampal and midbrain synucleinopathy

Cognitive deficits, including working memory, and visuospatial deficits are common and debilitating in Parkinson's disease. α-synucleinopathy in the hippocampus and cortex is considered as the major risk factor. However, little is known about the progression and specific synaptic mechanisms underlying the memory deficits induced by α-synucleinopathy. Here, we tested the hypothesis that pathologic α-Synuclein (α-Syn), initiated in different brain regions, leads to distinct onset and progression of the pathology. We report that overexpression of human α-Syn in the murine mesencephalon leads to late onset memory impairment and sensorimotor deficits accompanied by reduced dopamine D1 expression in the hippocampus. In contrast, human α-Syn overexpression in the hippocampus leads to early memory impairment, altered synaptic transmission and plasticity, and decreased expression of GluA1 AMPA-type glutamate receptors. These findings identify the synaptic mechanisms leading to memory impairment induced by hippocampal α-synucleinopathy and provide functional evidence of the major neuronal networks involved in disease progression.

Correlation between bituberous diameter and mode of delivery in a cohort of low-risk nulliparous women

OBJECTIVE

The aim our study was to evaluate the association between the antepartum clinical measurement of the Bituberous Diameter (BTD) and the occurrence of unplanned obstetrical intervention (UOI) due to labor dystocia, including either operative vaginal delivery or caesarean section in a cohort of low-risk, nulliparous at term.

DESIGN

Retrospective analysis of prospectively collected data.

SETTING

Tertiary maternity care.

INTERVENTIONS

With the women lying in lithotomic the distance between two ischial tuberosities was assessed using a tape measure during the routine antenatal booking between 37 and 38 weeks of gestation.

MEASUREMENTS AND FINDINGS

Overall, 116 patient were included, and of these 23(19.8%) were submitted to an UOI due to labor dystocia. Compared to women that had a spontaneous vaginal delivery, women submitted to an UOI had a shorter BTD (8.25 + 0.843 vs 9.60 + 1.12, p < 0.001), a higher frequency of epidural analgesia (21/23 or 91.3% vs 50/93 or 53.8%; p = 0.002) and of augmentation of labor (14/23 or 60.9% vs 19/93 or 20.4%; p < 0.001) as well as a longer first [455 (IQR 142-455 min vs 293 (IQR 142-455) min] and second stages of labor [129 (IQR 85-155) min vs 51 (IQR 27-78) min]. Multivariable logistic regression showed that the BTD (aOR 0.16, 95% CI 0.04-0.60; p = 0.007) and the length of the second stage of labor (aOR 6.83, 95% CI 2.10-22.23; p = 0.001) were independently associated with UOI. When evaluating the diagnostic accuracy of the BTD for the prediction of UOI due to labor dystocia, the BTD showed an AUC of 0.82 (95 %CI 0.73-0.91; p < 0.001) with an optimal cut-off value of 8.6 cm (78.3% (95 %CI 56.3-92.5) sensitivity, 77.4% (95 %CI 67.6-85.4) specificity, 46.2% (95% CI 30.1-62.8) PPV, 93.5% (95% CI 85.5-97.9) NPV, 3.5 (95% CI 2.3-5.4) positive LR, and 0.28 (95% CI 0.13-0.61) negative LR. A significant inverse correlation between the length of the second stage of labour and the BTD in patients that had a vaginal delivery was also demonstrated (Spearman's rho = -0.24, p = 0.01).

KEY CONCLUSIONS

Our study suggests that antepartum clinical assessment of the BTD might be used as a reliable predictor of UOI due to labor dystocia in low-risk, nulliparous women at term gestation.

IMPLICATIONS FOR PRACTICE

Antenatal identification of women at higher risk for labor dystocia might trigger some interventions during the second stage of labor, such as maternal position shifting, to increase the pelvic capacity and potentially improve outcomes or might prompt a referral of the patient to a district hospital prior to the onset of labor.

Abstract 207: Ex vivo modeling of multiple myeloma: A novel drug sensitivity screening platform

Multiple Myeloma (MM) is a heterogeneous malignancy characterized by abnormal clonal plasma cell infiltration in the bone marrow. It is the second most common hematologic malignancy, after non-Hodgkin’s Lymphoma. This deadly disease globally affects 1 to 5 people in every 100,000 people each year. After initial diagnosis, the 5-year survival rate is 44% because there is no curative therapy, and most patients will eventually experience relapse, and some become refractory. Large inter-patient and intra-patient genetic heterogeneity limit the identification of universal drivers of MM. However, several oncogenic dependencies such as primary events related to driver gene mutations and primary translocations can be targeted for better treatment strategies for R/R multiple myeloma. To establish a robust drug sensitivity screening platform, both MM cell lines and cryopreserved primary MM patient samples were used. MM cell lines screen with H929, MM1R and RPMI-8226 was performed to narrow down optimal concentrations of investigative test agents. During assay development, a panel of FDA approved agents for relapsed MM including panobinostat, bortezomib, melphalan, omacetaxine, and selinexor were tested. The cells were seeded at 50,000 cells per well in triplicates in a 96-well plate on day 0. The test agents were added in 9 concentrations with the top concentration being 25 uM with 2-fold dilutions. After 6- days of incubation, a luminescent cell viability assay was performed to calculate relative viability with drug treatment and IC50 was computed by fitting data using a standard four-parameter logistic model. For primary multiple myeloma samples, bone marrow aspirates were collected from Multiple Myeloma patients procured from different providers. BM mononuclear (BMMNC) cells were separated by Ficoll-Hypaque density sedimentation. Unfractionated BMMNC cells were used in these assays to preserve intra-tumor heterogeneity. Primary cells were seeded in triplicates per dose point on day 0 in Champions’ proprietary media. The test agents were also added on day 0 and were incubated for 6 days. On Day 6, the relative cell viability was measured based on Cell Titer Glo readout. The cryopreserved primary MM patient samples were viable in culture for the entire assay duration validating assay feasibility. A panel of FDA approved, standard of care drugs were tested in numerous clinically well-annotated and diverse MM patient models. Primary model selection was based on disease burden including plasma cell count from Core Biopsy and BM aspirates. Multiparametric flow cytometric immunophenotyping was also performed in these primary samples using monoclonal antibodies against CD56, CD19, CD117, CD27, CD138, and CD38. For the first time, we demonstrate the feasibility of a novel, ex-vivo drug sensitivity screening platform with cryopreserved, primary multiple myeloma cells from diverse, clinically well-annotated patient samples.

Citation Format: Vaishnavi Sambandam, Sharvari Inamdar, Haoting Hsu, Brandon Walling, Paolo Schiviani, Abhay Andar, Marianna Zipeto, Michael Ritchie, Karin Abarca Heidemann, Maria Mancini. Ex vivo modeling of multiple myeloma: A novel drug sensitivity screening platform [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 207.

Dopamine Transmission Imbalance in Neuroinflammation: Perspectives on Long-Term COVID-19

Dopamine (DA) is a key neurotransmitter in the basal ganglia, implicated in the control of movement and motivation. Alteration of DA levels is central in Parkinson’s disease (PD), a common neurodegenerative disorder characterized by motor and non-motor manifestations and deposition of alpha-synuclein (α-syn) aggregates. Previous studies have hypothesized a link between PD and viral infections. Indeed, different cases of parkinsonism have been reported following COVID-19. However, whether SARS-CoV-2 may trigger a neurodegenerative process is still a matter of debate. Interestingly, evidence of brain inflammation has been described in postmortem samples of patients infected by SARS-CoV-2, which suggests immune-mediated mechanisms triggering the neurological sequelae. In this review, we discuss the role of proinflammatory molecules such as cytokines, chemokines, and oxygen reactive species in modulating DA homeostasis. Moreover, we review the existing literature on the possible mechanistic interplay between SARS-CoV-2-mediated neuroinflammation and nigrostriatal DAergic impairment, and the cross-talk with aberrant α-syn metabolism.

TURN-IT: a novel turning intervention program to improve quality of turning in daily life in people with Parkinson's disease

BACKGROUND

People with Parkinson's disease (PD) have a high fall rate and many falls are associated with turns. Despite this, there is minimal research on effects of rehabilitation on the quality of turns. Further, quantifying turns in the home may have broader implications since rehabilitation of turns would ideally improve turning in real world mobility.

METHODS

Sixty people with PD and a history of falls will be randomized to receive either a novel TURNing InTervention (TURN-IT) or no intervention (control group). The TURN-IT group will be seen for 6 weeks (18 visits) for an individualized, progressive program that is based on the specific constraints of turning in PD. Wearable sensors will be used to measure 7 days of mobility, including turns, before and after intervention or control period. In addition, blinded assessments of gait, mobility and turns will occur before and after intervention for both groups and falls will be monitored for twelve months post intervention with bimonthly email questionnaires.

DISCUSSION

This study has the potential to change how we rehabilitate and assess turning in people with PD and falls. There are several novel aspects to our study including a comprehensive turning-focused intervention that is tailored to the underlying constraints that impair turning in people with PD. Further, our outcome measure of turning quality during 7 days of daily life is novel and has implications for determining real-life changes after rehabilitation. The ultimate goal of this rehabilitation intervention is to improve how patients turn in daily life and to reduce falls.

TRIALS REGISTRATION

This protocol is registered at clinicaltrials.gov; #NCT04897256; https://clinicaltrials.gov/ct2/show/NCT04897256?term=Horak&cond=Parkinson+Disease&draw=2&rank=4 .

Contribution of integrase inhibitor use, body mass index, physical activity and caloric intake to weight gain in people living with HIV

Background: Integrase inhibitor (INSTI) use has been associated with greater weight gain (WG) among people living with HIV (PLWH), but it is unclear how this effect compares in magnitude to traditional risk factors for WG. We assessed the population attributable fractions (PAFs) of modifiable lifestyle factors and INSTI regimens in PLWH who experienced a ≥5% WG over follow-up.

Methods: In an observational cohort study from 2007 to 2019 at Modena HIV Metabolic Clinic, Italy, ART-experienced but INSTI-naive PLWH were grouped as INSTI-switchers vs non-INSTI. Groups were matched for sex, age, baseline BMI and follow-up duration. Significant WG was defined as an increase of ≥5% from 1st visit weight over follow-up. PAFs and 95% CIs were estimated to quantify the proportion of the outcome that could be avoided if the risk factors were not present.

Results: 118 PLWH switched to INSTI and 163 remained on current ART. Of 281 PLWH (74.3% males), mean follow-up was 4.2 years, age 50.3 years, median time since HIV diagnosis 17.8 years, CD4 cell count 630 cells/µL at baseline. PAF for weight gain was the greatest for high BMI (45%, 95% CI: 27-59, p < 0.001), followed by high CD4/CD8 ratio (41%, 21-57, p < 0.001) and lower physical activity (32%, 95% CI 5-52, p = 0.03). PAF was not significant for daily caloric intake (-1%, -9-13, p = 0.45), smoking cessation during follow-up (5%, 0-12, p = 0.10), INSTI switch (11%, -19-36; p = 0.34).

Conclusions: WG in PLWH on ART is mostly influenced by pre-existing weight and low physical activity, rather than switch to INSTI.

Leptin Promotes Striatal Dopamine Release via Cholinergic Interneurons and Regionally Distinct Signaling Pathways

Dopamine (DA) is a critical regulator of striatal network activity and is essential for motor activation and reward-associated behaviors. Previous work has shown that DA is influenced by the reward value of food, as well as by hormonal factors that reguate food intake and energy expenditure. Changes in striatal DA signaling also have been linked to aberrant eating patterns. Here we test the effect of leptin, an adipocyte-derived hormone involved in feeding and energy homeostasis regulation, on striatal DA release and uptake. Immunohistochemical evaluation identified leptin receptor (LepR) expression throughout mouse striatum, including on striatal cholinergic interneurons (ChIs) and their extensive processes. Using fast-scan cyclic voltammetry (FSCV), we found that leptin causes a concentration-dependent increase in evoked extra-cellular DA concentration ([DA]o) in dorsal striatum (dStr) and nucleus accumbens (NAc) core and shell in male mouse striatal slices, and also an increase in the rate of DA uptake. Further, we found that leptin increases ChI excitability, and that the enhancing effect of leptin on evoked [DA]o is lost when nicotinic acetylcholine (ACh) receptors are antagonized or when examined in striatal slices from mice lacking ACh synthesis. Evaluation of signaling pathways underlying leptin's action revealed a requirement for intracellular Ca2+, and the involvement of different downstream pathways in dStr and NAc core versus NAc shell. These results provide the first evidence for dynamic regulation of DA release and uptake by leptin within brain motor and reward pathways, and highlight the involvement of ChIs in this process.SIGNIFICANCE STATEMENT Given the importance of striatal dopamine (DA) in reward, motivation, motor behavior and food intake, identifying the actions of metabolic hormones on DA release in striatal subregions should provide new insight into factors that influence DA-dependent motivated behaviors. We find that one of these hormones, leptin, boosts striatal DA release through a process involving striatal cholinergic interneurons (ChIs) and nicotinic acetylcholine (ACh) receptors. Moreover, we find that the intracellular cascades downstream from leptin receptor (LepR) activation that lead to enhanced DA release differ among striatal subregions. Thus, we not only show that leptin regulates DA release, but also identify characteristics of this process that could be harnessed to alter pathologic eating behaviors.

Hand grip support for rehabilitation and assistance: from patent to TRL5

In the last decades, the continuous increase in the number of the vast cohort of chronic patients that constantly need medical assistance and supervision, and the widespread lack of therapist has brought to an increased interest in the role of medical technologies in rehabilitative programs and assistive scenarios. Current clinical evidence in rehabilitation demonstrates that there is an important and increasing demand for innovative therapeutic solutions to recover the hand functions to prevent patients to need assistance in performing daily life activities. This works describes the pathway from patent to TRL5 of a device to support hand grip actions and interaction with daily life objects. E-KIRO is based on the use of electromagnets, which are able to attach/detach interactive objects equipped with a ferromagnetic plate. Five end-users used the device and scored it with excellent usability based on the System Usability Scale.

Voluntary Exercise Boosts Striatal Dopamine Release: Evidence for the Necessary and Sufficient Role of BDNF

Physical exercise improves motor performance in individuals with Parkinson's disease and elevates mood in those with depression. Although underlying factors have not been identified, clues arise from previous studies showing a link between cognitive benefits of exercise and increases in brain-derived neurotrophic factor (BDNF). Here, we investigated the influence of voluntary wheel-running exercise on BDNF levels in the striatum of young male wild-type (WT) mice, and on the striatal release of a key motor-system transmitter, dopamine (DA). Mice were allowed unlimited access to a freely rotating wheel (runners) or a locked wheel (controls) for 30 d. Electrically evoked DA release was quantified in ex vivo corticostriatal slices from these animals using fast-scan cyclic voltammetry. We found that exercise increased BDNF levels in dorsal striatum (dStr) and increased DA release in dStr and in nucleus accumbens core and shell. Increased DA release was independent of striatal acetylcholine (ACh), and persisted after a week of rest. We tested a role for BDNF in the influence of exercise on DA release using mice that were heterozygous for BDNF deletion (BDNF+/-). In contrast to WT mice, evoked DA release did not differ between BDNF+/- runners and controls. Complementary pharmacological studies using a tropomyosin receptor kinase B (TrkB) agonist in WT mouse slices showed that TrkB receptor activation also increased evoked DA release throughout striatum in an ACh-independent manner. Together, these data support a causal role for BDNF in exercise-enhanced striatal DA release and provide mechanistic insight into the beneficial effects of exercise in neuropsychiatric disorders, including Parkinson's, depression, and anxiety.SIGNIFICANCE STATEMENT Exercise has been shown to improve movement and cognition in humans and rodents. Here, we report that voluntary exercise for 30 d leads to an increase in evoked DA release throughout the striatum and an increase in BDNF in the dorsal (motor) striatum. The increase in DA release appears to require BDNF, indicated by the absence of DA release enhancement with running in BDNF+/- mice. Activation of BDNF receptors using a pharmacological agonist was also shown to boost DA release. Together, these data support a necessary and sufficient role for BDNF in exercise-enhanced DA release and provide mechanistic insight into the reported benefits of exercise in individuals with dopamine-linked neuropsychiatric disorders, including Parkinson's disease and depression.

Effects of low-dose methylcyclopentadienyl manganese tricarbonyl-derived manganese on the development of diencephalic dopaminergic neurons in zebrafish

Fuel additive methylcyclopentadienyl manganese tricarbonyl (MMT) is counted as an organic manganese (Mn)-derived compound. The toxic effects of Mn (alone and complexed) on dopaminergic (DA) neurotransmission have been investigated in both cellular and animal models. However, the impact of environmentally relevant Mn exposure on DA neurodevelopment is rather poorly understood. In the present study, the MMT dose of 100 μM (about 5 mg Mn/L) caused up-regulation of DA-related genes in association with cell body swelling and increase in the number of DA neurons of the ventral diencephalon subpopulation DC2. Furthermore, our analysis identified significant brain Mn bioaccumulation and enhancement of total dopamine levels in association with locomotor hyperactivity. Although DA levels were restored at adulthood, we observed a deficit in the acquisition and consolidation of memory. Collectively, these findings suggest that developmental exposure to low-level MMT-derived Mn is responsible for the selective alteration of diencephalic DA neurons and with long-lasting effects on fish explorative behaviour in adulthood.

Assessing the ability of boys with Duchenne muscular dystrophy age 4-7 years to swallow softgel capsules: Clinical trial experience with edasalonexent

WHAT IS KNOWN AND OBJECTIVE

There is limited information on acceptability of solid dosage forms by young patients with neuromuscular disorders such as Duchenne muscular dystrophy (DMD). Capsule size selection and ability to swallow the NF-κB inhibitor edasalonexent were assessed in males 4-7 years of age with DMD enrolled in clinical trials for a new therapeutic.

METHODS

The Phase 3 PolarisDMD randomized, double-blind, placebo-controlled trial enrolled 131 patients from 8 countries. The Phase 2 MoveDMD trial enrolled 31 patients in the United States. As part of enrolment criteria, these trials assessed the ability to swallow softgel 100 mg (~10 mm) or 250 mg (~15 mm) capsules formulated with a phosphatidylcholine-containing coating. Supportive strategies included pill-swallowing techniques and aids.

RESULTS

Most (97%; 175/181) patients screened were able to swallow capsules. In Phase 2 and 3, respectively, 77% (24/31) and 61% (80/131) of enrolled patients selected the larger capsule and among those selecting the smaller capsule, most transitioned to the larger capsule. There were no obvious geographical differences in ability to swallow capsules and size selection was not correlated with age. Compliance was high (92%-98%) through 52 weeks of dosing with no discontinuations due to capsule burden.

WHAT IS NEW AND CONCLUSION

Swallowing of capsules was not a barrier for drug administration in young patients with DMD. Capsule formulations may be an acceptable alternative to liquid formulations for children as young as 4 years of age.

A Randomized, Double-Blind, Placebo-Controlled, Global Phase 3 Study of Edasalonexent in Pediatric Patients with Duchenne Muscular Dystrophy: Results of the PolarisDMD Trial

Background:

Edasalonexent (CAT-1004) is an orally-administered novel small molecule drug designed to inhibit NF-κB and potentially reduce inflammation and fibrosis to improve muscle function and thereby slow disease progression and muscle decline in Duchenne muscular dystrophy (DMD).

Objective:

This international, randomized 2 : 1, placebo-controlled, phase 3 study in patients ≥4 – < 8 years old with DMD due to any dystrophin mutation examined the effect of edasalonexent (100 mg/kg/day) compared to placebo over 52 weeks.

Methods:

Endpoints were changes in the North Star Ambulatory Assessment (NSAA; primary) and timed function tests (TFTs; secondary). Assessment of health-related function used the Pediatric Outcomes Data Collection tool (PODCI).

Results:

One hundred thirty one patients received edasalonexent (n = 88) and placebo (n = 43). At week 52, differences between edasalonexent and placebo for NSAA total score and TFTs were not statistically significant, although there were consistently less functional declines in the edasalonexent group. A pre-specified analysis by age demonstrated that younger patients (≤6.0 years) showed more robust and statistically significant differences between edasalonexent and placebo for some assessments. Treatment was well-tolerated and the majority of adverse events were mild, and most commonly involved the gastrointestinal system (primarily diarrhea).

Conclusions:

Edasalonexent was generally well-tolerated with a manageable safety profile at the dose of 100 mg/kg/day. Although edasalonexent did not achieve statistical significance for improvement in primary and secondary functional endpoints for assessment of DMD, subgroup analysis suggested that edasalonexent may slow disease progression if initiated before 6 years of age. (NCT03703882)

Domestic trauma with penile and scrotum skin degloving and testicular avulsion

Traumatic lesions of male external genitalia are certainly less frequent than the other body sites and in the majority of cases they are caused by work accidents in the metalworking environment or by gunshot wounds. We present a rare case of traumatic degloving lesion of the male external genitalia with avulsion of the left testis caused by an accidental fall from the ladder. Reconstructive surgery was carried out in a single procedure, obtaining an excellent esthetic and functional result.

Involvement of transcribed lncRNA uc.291 and SWI/SNF complex in cutaneous squamous cell carcinoma

While non-melanoma skin cancers (NMSCs) are the most common tumours in humans, only the sub-type cutaneous squamous cell carcinoma (cSCC), might become metastatic with high lethality. We have recently identified a regulatory pathway involving the lncRNA transcript uc.291 in controlling the expression of epidermal differentiation complex genes via the interaction with ACTL6A, a component of the chromatin remodelling complex SWI/SNF. Since transcribed ultra-conserved regions (T-UCRs) are expressed in normal tissues and are deregulated in tumorigenesis, here we hypothesize a potential role for dysregulation of this axis in cSCC, accounting for the de-differentiation process observed in aggressive poorly differentiated cutaneous carcinomas. We therefore analysed their expression patterns in human tumour biopsies at mRNA and protein levels. The results suggest that by altering chromatin accessibility of the epidermal differentiation complex genes, down-regulation of uc.291 and BRG1 expression contribute to the de-differentiation process seen in keratinocyte malignancy. This provides future direction for the identification of clinical biomarkers in cutaneous SCC. Analysis of publicly available data sets indicates that the above may also be a general feature for SCCs of different origins.

Cardiac care of Non-COVID-19 patients during the SARS-CoV-2 pandemic: The pivotal role of CCTA

Funding Acknowledgements

Type of funding sources: None.

Aims

To describe the role of coronary CT angiography (CCTA) as the sole available non-invasive diagnostic test for symptomatic patients with suspected CAD in a hub center for cardiovascular emergencies in the presence of limited access to hospital facilities during the COVID-19 pandemic.

Methods and Results

From March 9th to April 30th, during the peak of the COVID-19 pandemic, a consecutive cohort of symptomatic patients with high clinical suspicion of CAD and clinical indication to CCTA were enrolled in a hub hospital in Milan, Italy. When obstructive coronary artery disease was detected (>70% diameter stenosis in a proximal coronary segment or >90% stenosis in any coronary segment) patients were referred to invasive coronary angiography (ICA). Clinical follow-up was assessed in patients in whom ICA was considered deferrable.

Overall, 58 consecutive patients were included. Ten (17.2%) symptomatic patients underwent ICA according to CCTA findings, while in 48 (82.8%) patients ICA was deferred. No clinical events were recorded after a mean follow-up of 49.7 ± 16.8 days. In nine out of ten patients referred to ICA, severe coronary artery disease was confirmed and treated accordingly. Changes in medical therapy were significantly more prevalent in patients with vs. those without CAD at CCTA.

Conclusion

We report a potential pivotal role for CCTA in the triage of non-COVID-19 patients with suspected  CAD during the SARS-CoV-2 pandemic. CCTA may be helpful for identifying patients who necessitate ICA, ensuring adequate resource utilization during the pandemic.

Rapamycin, by Inhibiting mTORC1 Signaling, Prevents the Loss of Striatal Bidirectional Synaptic Plasticity in a Rat Model of L-DOPA-Induced Dyskinesia

Levodopa (L-DOPA) treatment is the main gold-standard therapy for Parkinson disease (PD). Besides good antiparkinsonian effects, prolonged use of this drug is associated to the development of involuntary movements known as L-DOPA-induced dyskinesia (LID). L-DOPA-induced dyskinesia is linked to a sensitization of dopamine (DA) D1 receptors located on spiny projection neurons (SPNs) of the dorsal striatum. Several evidences have shown that the emergence of LID can be related to striatal D1/cAMP/PKA/DARPP-32 and extracellular signal-regulated kinases (ERK1/2) pathway overactivation associated to aberrant N-methyl-d-aspartate (NMDA) receptor function. In addition, within striatum, ERK1/2 is also able to modulate in a D1 receptor-dependent manner the activity of the mammalian target of rapamycin complex 1 (mTORC1) pathway under DA depletion and L-DOPA therapy. Consistently, increased mTORC1 signaling appears during chronic administration of L-DOPA and shows a high correlation with the severity of dyskinesia. Furthermore, the abnormal activation of the D1/PKA/DARPP-32 cascade is paralleled by increased phosphorylation of the GluA1 subunit of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor at the PKA Ser845 site. The GluA1 promotes excitatory AMPA receptor-mediated transmission and may be implicated in the alterations found at the corticostriatal synapses of dyskinetic animals. In our study, we investigated the role of mTORC1 pathway activation in modulating bidirectional striatal synaptic plasticity in L-DOPA-treated parkinsonian rats. Inhibition of mTORC1 by coadministration of rapamycin to L-DOPA was able to limit the magnitude of LID expression, accounting for a therapeutic effect of this drug. In particular, behavioral data showed that, in L-DOPA-treated rats, rapamycin administration induced a selective decrease of distinct components of abnormal involuntary movements (i.e., axial and orolingual dyskinesia). Furthermore, ex vivo patch clamp and intracellular recordings of SPNs revealed that pharmacological inhibition of mTORC1 also resulted associated with a physiological bidirectional plasticity, when compared to dyskinetic rats treated with L-DOPA alone. This study uncovers the important role of mTORC1 inhibition to prevent the loss of striatal bidirectional plasticity under chronic L-DOPA treatment in rodent models of PD.

Case report for an adolescent with germline RET mutation and alveolar rhabdomyosarcoma

In this case report we evaluate the genetics of and scientific basis of therapeutic options for a 14-yr-old male patient diagnosed with metastatic PAX3–FOXO1 fusion positive alveolar rhabdomyosarcoma. A distinguishing genetic feature of this patient was a germline RET C634F mutation, which is a known driver of multiple endocrine neoplasia type 2A (MEN2A) cancer. Through sequential DNA and RNA sequencing analyses over the patient's clinical course, a set of gene mutations, amplifications, and overexpressed genes were identified and biological hypotheses generated to explore the biology of RET and coexisting signaling pathways in rhabdomyosarcoma. Somatic genetic abnormalities identified include CDK4 amplification and FGFR4 G388R polymorphism. Because of the initial lack of patient-derived primary cell cultures, these hypotheses were evaluated using several approaches including western blot analysis and pharmacological evaluation with molecularly similar alveolar rhabdomyosarcoma cell lines. Once a primary cell culture became available, the RET inhibitor cabozantinib was tested but showed no appreciable efficacy in vitro, affirming with the western blot negative for RET protein expression that RET germline mutation could be only incidental. In parallel, the patient was treated with cabozantinib without definitive clinical benefit. Parallel chemical screens identified PI3K and HSP90 as potential tumor-specific biological features. Inhibitors of PI3K and HSP90 were further validated in drug combination synergy experiments and shown to be synergistic in the patient-derived culture. We also evaluated the use of JAK/STAT pathway inhibitors in the context of rhabdomyosarcomas bearing the FGFR4 G388R coding variant. Although the patient succumbed to his disease, study of the patient's tumor has generated insights into the biology of RET and other targets in rhabdomyosarcoma.

Phase 1 Study of Edasalonexent (CAT-1004), an Oral NF-κB Inhibitor, in Pediatric Patients with Duchenne Muscular Dystrophy

Background:

Edasalonexent is an orally administered small molecule designed to inhibit NF-κB, which is activated from infancy in Duchenne muscular dystrophy and is central to causing muscle damage and preventing muscle regeneration.

Objective:

Evaluate the safety, tolerability, pharmacokinetics and exploratory pharmacodynamics of three doses of edasalonexent in ambulatory males ≥4 to <8 years of age with genetically confirmed Duchenne muscular dystrophy.

Methods:

This was a 1-week, open-label, multiple-dose study with 3 sequential ascending doses (33, 67 and 100 mg/kg/day) of edasalonexent administered under different dietary conditions to 17 males with a mean age of 5.5 years.

Results:

All doses of edasalonexent were well tolerated, with no serious adverse events, no drug discontinuations and no dose reductions. The majority of adverse events were mild, and the most common adverse events were gastrointestinal (primarily diarrhea). Edasalonexent was rapidly absorbed with peak levels observed 2–6 hours after dosing and exposures appeared to increase nearly proportionally to dose for the 2 lower and all 3 doses under low-fat and high-fat meal conditions, respectively. Only minor plasma accumulation of edasalonexent was observed with 7 days of dosing. After treatment with edasalonexent for 7 days, levels of NF-κB-regulated genes and serum proteins were decreased.

Conclusions:

This first report of edasalonexent oral administration for one week in male pediatric patients with Duchenne muscular dystrophy showed that treatment was well tolerated and inhibited NF-kB pathways.

Costs and Resource Use Associated with Alzheimer's Disease in Italy: Results from an Observational Study

BACKGROUND

The GERAS II study aimed to assess societal costs and resource use associated with Alzheimer's disease (AD) for patients and their primary caregivers in Italy and Spain, stratified for different severity stages of AD at baseline. This report presents baseline results for Italy.

DESIGN

GERAS II was a prospective, multicentre, observational study of routine care in AD.

SETTING

Community-dwelling patients attending specialist secondary care centres (memory clinics/Alzheimer's Evaluation Units) and their primary informal caregivers were recruited into the study.

PARTICIPANTS

Patients were aged ≥55 years, presented within the normal course of care, had a diagnosis of probable AD and a Mini-Mental State Examination (MMSE) score of ≤26. Patients and caregivers were stratified according to patient AD dementia severity at baseline: mild, MMSE score 21-26; moderate, MMSE score 15-20; or moderately severe/severe, MMSE score <15.

MEASUREMENTS

Data collected for patients and caregivers included demographics/clinical characteristics; current medication; patient cognitive, functional and behavioural assessments; patient and caregiver health-related quality of life (HRQoL); and patient and caregiver resource use. The costs associated with the resources used were calculated. Costs were broken down into patient healthcare costs, patient social care costs and caregiver informal care costs.

RESULTS

Of 198 patients enrolled from Italy, 29 (15%) had mild AD dementia, 80 (40%) had moderate AD dementia, and 89 (45%) had moderately severe/severe AD dementia. Patient and caregiver characteristics showed some differences between AD dementia severity groups; for example, a numerically higher proportion of patients with mild and moderately severe/severe AD dementia were taking memantine compared with those with moderate AD dementia. Patient functioning and behavioural and psychological symptoms worsened with increasing AD dementia severity (p<0.05 between groups for all measures). No significant difference between the disease severity groups was observed in patient HRQoL, and there was no clear pattern in resource use. However, all measures of caregiver time spent helping the patient differed significantly between groups (p<0.05) and were highest in patients with moderately severe/severe AD dementia. Mean (standard deviation) total monthly societal costs per patient (2013 values) were €1850 (1901), €1552 (1322) and €2728 (2184) for patients with mild, moderate and moderately severe/severe AD dementia, respectively (p<0.001 between groups). Caregiver informal care costs were the greatest contributor to total societal costs and amounted to €1370, €1223 and €2223 per patient per month for mild, moderate and moderately severe/severe AD dementia groups, respectively (p<0.001 between groups).

CONCLUSION

Total Italian societal costs generally increased with increasing AD dementia severity. However, costs were slightly lower for moderate than for mild AD dementia, possibly reflecting the observed unusual trend of greater caregiver time and higher memantine use in patients with mild versus moderate AD dementia.

Oral management of adult patients undergoing hematopoietic stem cell transplantation

Chemotherapy and hematopoietic stem cell transplantation (HSCT) are the current treatments for patients with hematological diseases; they result in myelosuppression, and increase the susceptibility of patients to severe infections. The oral cavity is a potential site of complications in HSCT patients, because it is the entrance for agents that can cause systemic infections; it is one of the most frequent locations for side effects deriving from conditioning therapy. The importance of dental pre-chemotherapy and transplant prescription is often stressed, since both therapies depress the immune system and platelets, making each intervention at this stage a high risk. The aim of this article is to review the potential complications of HSCT, and to extrapolate from the scientific literature the treatments and timeframes in which dental therapies can be performed, avoiding important risks for patients.

Cerebellar rTMS for motor control in progressive supranuclear palsy

BACKGROUND

Stimulatory cerebellar TMS is a promising tool to improve motor control in neurodegenerative disorders.

OBJECTIVE/HYPOTHESIS

Our goal was to use 10Hz cerebellar rTMS to augment cerebellar-brain inhibition (CBI) for improved postural stability and speech in patients with progressive supranuclear palsy (PSP).

METHODS

We performed CBI assessments with neuronavigation before and after high frequency cerebellar rTMS or sham TMS in two patients with PSP, using a double cone coil for the conditioning pulse and a figure-of-eight coil for the test pulse and treatments. We collected posturography data and speech samples before and after treatment.

RESULTS

After treatment, CBI increased by 50% in subject 1 and by 32% in subject 2, and postural stability and speech improved. The protocol was well tolerated, but the sham was not consistently believable.

CONCLUSION

Cerebellar rTMS may improve postural stability and speech in PSP, but cooled coils with vibrotactile sham capability are needed for larger future studies.

Motor learning and metaplasticity in striatal neurons: relevance for Parkinson's disease

Nigro-striatal dopamine transmission is central to a wide range of neuronal functions, including skill learning, which is disrupted in several pathologies such as Parkinson's disease. The synaptic plasticity mechanisms, by which initial motor learning is stored for long time periods in striatal neurons, to then be gradually optimized upon subsequent training, remain unexplored. Addressing this issue is crucial to identify the synaptic and molecular mechanisms involved in striatal-dependent learning impairment in Parkinson's disease. In this study, we took advantage of interindividual differences between outbred rodents in reaching plateau performance in the rotarod incremental motor learning protocol, to study striatal synaptic plasticity ex vivo. We then assessed how this process is modulated by dopamine receptors and the dopamine active transporter, and whether it is impaired by overexpression of human α-synuclein in the mesencephalon; the latter is a progressive animal model of Parkinson's disease. We found that the initial acquisition of motor learning induced a dopamine active transporter and D1 receptors mediated long-term potentiation, under a protocol of long-term depression in striatal medium spiny neurons. This effect disappeared in animals reaching performance plateau. Overexpression of human α-synuclein reduced striatal dopamine active transporter levels, impaired motor learning, and prevented the learning-induced long-term potentiation, before the appearance of dopamine neuronal loss. Our findings provide evidence of a reorganization of cellular plasticity within the dorsolateral striatum that is mediated by dopamine receptors and dopamine active transporter during the acquisition of a skill. This newly identified mechanism of cellular memory is a form of metaplasticity that is disrupted in the early stage of synucleinopathies, such as Parkinson's disease, and that might be relevant for other striatal pathologies, such as drug abuse.

Hyper-activation of Aurora kinase a-polo-like kinase 1-FOXM1 axis promotes chronic myeloid leukemia resistance to tyrosine kinase inhibitors

BACKGROUND

Chronic myeloid leukemia (CML) is a myeloproliferative disease caused by the constitutive tyrosine kinase (TK) activity of the BCR-ABL1 fusion protein. Accordingly, TK inhibitors have drastically changed the disease prognosis. However, persistence of the transformed hematopoiesis even in patients who achieved a complete response to TK inhibitors and the disease relapse upon therapy discontinuation represent a major obstacle to CML cure.

METHODS

Thiostrepton, Danusertib and Volasertib were used to investigate the effects of FOXM1, AKA and Plk1 inhibition in K562-S and K562-R cells. Apoptotic cell death was quantified by annexin V/propidium iodide staining and flow cytometry. Quantitative reverse transcription (RT)-PCR was used to assess BCR-ABL1, FOXM1, PLK1 and AURKA expression. Protein expression and activation was assessed by Western Blotting (WB). Clonogenic assay were performed to confirm K562-R resistance to Imatinib and to evaluate cells sensitivity to the different drugs.

RESULTS

Here we proved that BCR-ABL1 TK-dependent hyper-activation of Aurora kinase A (AURKA)-Polo-like kinase 1 (PLK1)-FOXM1 axis is associated with the outcome of Imatinib (IM) resistance in an experimental model (K562 cell line) and bone marrow hematopoietic cells. Notably, such a biomolecular trait was detected in the putative leukemic stem cell (LSC) compartment characterized by a CD34+ phenotype. Constitutive phosphorylation of FOXM1 associated with BCR-ABL1 TK lets FOXM1 binding with β-catenin enables β-catenin nuclear import and recruitment to T cell factor/lymphoid enhancer-binding factor (TCF/LEF) transcription complex, hence supporting leukemic cell proliferation and survival. Lastly, the inhibition of single components of AURKA-PLK1-FOXM1 axis in response to specific drugs raises the expression of growth factor/DNA damage-inducible gene a (GADD45a), a strong inhibitor of AURKA and, as so, a critical component whose induction may mediate the eradication of leukemic clone.

CONCLUSIONS

Our conclusion is that AURKA, PLK1 and FOXM1 inhibition may be considered as a promising therapeutic approach to cure CML.

Preclinical rationale for entinostat in embryonal rhabdomyosarcoma

Background

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in the pediatric cancer population. Survival among metastatic RMS patients has remained dismal yet unimproved for years. We previously identified the class I-specific histone deacetylase inhibitor, entinostat (ENT), as a pharmacological agent that transcriptionally suppresses the PAX3:FOXO1 tumor-initiating fusion gene found in alveolar rhabdomyosarcoma (aRMS), and we further investigated the mechanism by which ENT suppresses PAX3:FOXO1 oncogene and demonstrated the preclinical efficacy of ENT in RMS orthotopic allograft and patient-derived xenograft (PDX) models. In this study, we investigated whether ENT also has antitumor activity in fusion-negative eRMS orthotopic allografts and PDX models either as a single agent or in combination with vincristine (VCR).

Methods

We tested the efficacy of ENT and VCR as single agents and in combination in orthotopic allograft and PDX mouse models of eRMS. We then performed CRISPR screening to identify which HDAC among the class I HDACs is responsible for tumor growth inhibition in eRMS. To analyze whether ENT treatment as a single agent or in combination with VCR induces myogenic differentiation, we performed hematoxylin and eosin (H&E) staining in tumors.

Results

ENT in combination with the chemotherapy VCR has synergistic antitumor activity in a subset of fusion-negative eRMS in orthotopic “allografts,” although PDX mouse models were too hypersensitive to the VCR dose used to detect synergy. Mechanistic studies involving CRISPR suggest that HDAC3 inhibition is the primary mechanism of cell-autonomous cytoreduction in eRMS. Following cytoreduction in vivo, residual tumor cells in the allograft models treated with chemotherapy undergo a dramatic, entinostat-induced (70–100%) conversion to non-proliferative rhabdomyoblasts.

Conclusion

Our results suggest that the targeting class I HDACs may provide a therapeutic benefit for selected patients with eRMS. ENT’s preclinical in vivo efficacy makes ENT a rational drug candidate in a phase II clinical trial for eRMS.

Electronic supplementary material

The online version of this article (10.1186/s13395-019-0198-x) contains supplementary material, which is available to authorized users.

Variability and trends in corticosteroid use by male United States participants with Duchenne muscular dystrophy in the Duchenne Registry

Background

Treatment options for Duchenne muscular dystrophy remain limited, although consensus treatment guidelines recommend corticosteroid use.

Methods

This retrospective analysis assessed corticosteroid use in ambulatory and nonambulatory US males with Duchenne, age 35 and under, or Becker muscular dystrophy, who enrolled in The Duchenne Registry from 2007 to 2016 (formerly DuchenneConnect).

Results

The mean (SD) age of corticosteroid use initiation was 5.9 (2.5) years, and deflazacort use (54%) was slightly more common than prednisone/prednisolone (46%). Among all responses from those with Duchenne, 63% were currently on corticosteroids, 12% were no longer on corticosteroids, and 25% had never been on corticosteroids. Among those who were nonambulatory, 49% were currently on corticosteroids, 28% had discontinued corticosteroids, and 23% had never used corticosteroids. Primary reasons for never initiating therapy were that corticosteroids were not prescribed or recommended and concerns about side effects. Corticosteroid use was maximal at age 8 (84% on corticosteroids) and gradually declined from age 10 to 19. The primary reasons for corticosteroid discontinuation were problems with side effects (65%) or not enough benefit (28%). Average doses of corticosteroids were below recommended doses. In the 159 responses with Becker muscular dystrophy, 20% were currently using corticosteroids.

Conclusions

Recognizing the self-selected nature of participation, it appears that a considerable proportion of US participants registered with The Duchenne Registry were either not on corticosteroids or not on recommended doses despite consensus recommendations. Side effects were a consideration in initiating and discontinuing treatment.

These data reinforce the need for additional treatment options for those affected by Duchenne.

Dopamine drives binge-like consumption of a palatable food in experimental Parkinsonism

BACKGROUND

Prolonged dopaminergic replacement therapy in PD results in pulsatile dopamine receptors stimulation in both dorsal and ventral striatum causing wearing off, motor fluctuations, and nonmotor side effects such as behavioral addictions. Among impulse control disorders, binge eating can be easily modeled in laboratory animals.

OBJECTIVES

We hypothesize that manipulation of dopamine levels in a 6-hydroxydopamine-lesioned rats, as a model of PD characterized by a different extent of dopamine denervation between dorsal and ventral striatum, would influence both synaptic plasticity of the nucleus accumbens and binge-like eating behavior.

METHODS

Food preference, food intake, and weight gain were monitored in sham-operated and unilaterally lesioned rats, subjected to a modified version of Corwin's limited access protocol, modelling binge eating disorder. Electrophysiological properties and long-term potentiation of GABAergic spiny projection neurons of the nucleus accumbens core were studied through ex vivo intracellular and patch-clamp recordings from corticostriatal slices of naïve and l-dopa-treated rats.

RESULTS

Sham-operated animals with intact nucleus accumbens core plasticity reliably developed food-addiction-like behavior when exposed to intermittent access to a highly palatable food. In contrast, parkinsonian rats were unresponsive to such restriction regimens, and also plasticity was lost in ventral spiny neurons. Chronic l-dopa reestablished long-term potentiation and compulsive eating, but with a different temporal dynamic that follows that of drug administration.

CONCLUSIONS

Our data indicate that endogenous and exogenous dopamine drive binge-like consumption of a palatable food in healthy and parkinsonian rats with distinct temporal dynamics, providing new insights into the complexity of l-dopa effects on the mesolimbic dopaminergic system. © 2019 International Parkinson and Movement Disorder Society.