PD Model Research Articles

Dimethyl fumarate ameliorates parkinsonian pathology by modulating autophagy and apoptosis via Nrf2-TIGAR-LAMP2/Cathepsin D axis

Mounting evidence suggests a role for oxidative stress and accumulation of dysfunctional organelle and misfolded proteins in PD. Autophagosomes mediate the clearance of these cytoplasmic proteins via delivery to lysosomes to form autophagolysosomes, followed by degradation of the protein by lysosomal enzymes. In PD, autophagolysosome accumulation occurs initiating a plethora of events resulting in neuronal death by apoptosis. This study evaluated the effect of Dimethylfumarate (DMF), an Nrf2 activator in the rotenone-induced mouse PD model. In PD mice, there was decreased expression of LAMP2 and LC3, which resulted in inhibition of autophagic flux and increased expression of cathepsin D, which mediated apoptosis. The role of Nrf2 activation in alleviating oxidative stress is well known. Our study elucidated the novel mechanism underlying the neuroprotective effect of DMF. The loss of dopaminergic neurons induced by rotenone was lessened to a significant extent by pre-treatment with DMF. DMF promoted autophagosome formation and inhibited apoptosis by removing the inhibitory effect of p53 on TIGAR. TIGAR expression upregulated LAMP2 expression and downregulated Cathepsin D, promoting autophagy and inhibiting apoptosis. Thus, it was proved that DMF confers neuroprotection against rotenone-induced dopaminergic neurodegeneration and could be used as a potential therapeutic agent for PD and its progression.

The use of the ECHO model™ for education as an innovative approach to educator professional development

After entering the workforce, educators may face novel problems of practice that require additional training. Ongoing professional learning and development (PD) is meant to provide the additional training necessary to ensure educators are prepared to meet those challenges. PD offerings should meet the recommendations of Adult Learning Theory, the Model for Teacher Change, and recommended best practices for adult learning and PD. The ECHO Model for Education is an effective, high-quality model of educator PD that satisfies such recommendations. Practical issues are discussed, and recommendations are made for those interested in implementing this innovative model for PD.

0258 Altered sleep regulation in a mouse model of Parkinson’s disease

Abstract Introduction Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by pathognomonic motor abnormalities that lead to significant disability and morbidity in advanced stages. PD is also associated with sleep abnormalities such as increased fragmentation, insomnia, and excessive daytime sleepiness. Little is known of the underlying mechanisms, in part due to the limited ability of existing mouse models to adequately replicate human PD patient sleep phenotypes. Here we characterize sleep-wake behavior in an innovative genetic mouse model of PD (MCI-Park) targeting a mitochondrial complex I gene (Ndufs2), which experiences progressive dopaminergic neuron loss and displays motor phenotypes resembling those seen in human PD. Methods Undisturbed sleep-wake behavior during 12 hr light: 12 hr dark cycles was evaluated in MCI-Park mice during prodromal stages (6-8 weeks of age) and later parkinsonian stages (14-18 weeks of age) as well as in age-matched wildtype littermate controls. Electroencephalographic (EEG) and electromyographic (EMG) recording electrodes were surgically implanted using sterile technique in male and female MCI-Park and wildtype mice. After one week of recovery and acclimation to recording chambers, EEG and EMG were recorded continuously and sleep phenotypes were analyzed. Results In prodromal stages, MCI-Park mice exhibited similar overall sleep state amounts compared to wildtype mice, however there were significantly more state shifts as well as longer bouts of wakefulness and shorter bouts of non-REM (NREM) sleep. As mice progressed to parkinsonian stages, these fragmentation measures worsened. In addition, parkinsonian MCI-Park mice experienced a significant increase in wakefulness, a significant reduction in NREM sleep amount, and alterations in REM sleep, with pronounced reductions in REM sleep amount and number of REM bouts. Power spectral analysis revealed consistent decreases in theta2 (also known as alpha) power across all sleep-wake states in MCI-Park mice. Conclusion These results indicate that mice harboring a genetic defect causing selective disruption of dopaminergic neurons exhibit progressive sleep abnormalities that resemble sleep disturbances in PD patients. This model thus offers an opportunity to evaluate mechanisms underlying and therapeutic strategies targeting altered sleep in PD patients. Support (if any) This work was supported by the Department of Defense award number W81XWH-21-0582 (F.W.T. and D.J.S.).

A Modified Bond-Associated Non-Ordinary State-Based Peridynamic Model for Impact Problems of Quasi-Brittle Materials.

In this work, we have developed a novel bond-associated non-ordinary state-based peridynamic (BA-NOSB PD) model for the numerical modeling and prediction of the impact response and fracture damage of quasi-brittle materials. First, the improved Johnson-Holmquist (JH2) constitutive relationship is implemented in the framework of BA-NOSB PD theory to describe the nonlinear material response, which also helps to eliminate the zero-energy mode. Afterwards, the volumetric strain in the equation of state is redefined by the introduction of the bond-associated deformation gradient, which can effectively improve the stability and accuracy of the material model. Then, a new general bond-breaking criterion is proposed in the BA-NOSB PD model, which is capable of covering various failure modes of quasi-brittle materials, including the tensile-shear failure that is not commonly considered in the literature. Subsequently, a practical bond-breaking strategy and its computational implementation are presented and discussed by means of energy convergence. Finally, the proposed model is verified by two benchmark numerical examples and demonstrated by the numerical simulation of edge-on impact and normal impact experiments on ceramics. The comparison between our results and references shows good capability and stability for impact problems of quasi-brittle materials. Numerical oscillations and unphysical deformation modes are effectively eliminated, showing strong robustness and bright prospects for relevant applications.

Selenium mitigates ferroptosis-mediated dopaminergic cell death by regulating the Nrf2/GPX4 pathway

• Selenium protects against MPP+-induced neuronal toxicity in SH-SY5Y cells. • Selenium rescues the toxic effect of MPP+ by inhibiting ferroptosis in SH-SY5Y cells. • GPX4 and Nrf2 silencing abrogates selenium-mediated protective effects on the MPP+-induced PD model. • The Nrf2/GPX4 pathway might play an essential role in selenium-induced inhibition of ferroptosis in the MPP+-induced PD model.

Integrated insight into the molecular mechanisms of selenium-modulated, MPP+-induced cytotoxicity in a Parkinson’s disease model

ObjectiveParkinson’s disease (PD) is a neurodegenerative disease that is associated with oxidative stress. Due to the anti-inflammatory and antioxidant functions of Selenium (Se), this molecule may have neuroprotective functions in PD; however, the involvement of Se in such a protective function is unclear. Methods1-methyl-4-phenylpyridinium (MPP+), which inhibits mitochondrial respiration, is generally used to produce a reliable cellular model of PD. In this study, a MPP+-induced PD model was used to test if Se could modulate cytotoxicity, and we further capture gene expression profiles following PC12 cell treatment with MPP+ with or without Se by genome wide high-throughput sequencing. ResultsWe identified 351 differentially expressed genes (DEGs) and 14 differentially expressed long non-coding RNAs (DELs) in MPP+-treated cells when compared to controls. We further document 244 DEGs and 27 DELs in cells treated with MPP+ and Se vs. cells treated with MPP+ only. Functional annotation analysis of DEGs and DELs revealed that these groups were enriched in genes that respond to reactive oxygen species (ROS), metabolic processes, and mitochondrial control of apoptosis. Thioredoxin reductase 1 (Txnrd1) was also identified as a biomarker of Se treatment. ConclusionsOur data suggests that the DEGs Txnrd1, Siglec1 and Klf2, and the DEL AABR07044454.1 which we hypothesize to function in cis on the target gene Cdkn1a, may modulate the underlying neurodegenerative process, and act a protective function in the PC12 cell PD model. This study further systematically demonstrated that mRNAs and lncRNAs induced by Se are involved in neuroprotection in PD, and provides novel insight into how Se modulates cytotoxicity in the MPP+-induced PD model.

A Simplified Protocol for Permanent Deformation Characterization of Asphalt Concrete

Abstract Permanent deformation (PD; or rutting) is one of the major distresses in flexible pavements. To predict PD in asphalt concrete, repeated and recovery load tests are usually conducted in the laboratory. The full-blown repeated load permanent deformation (RLPD) is time-consuming, limiting its use in research programs and developing correlations. Therefore, a quicker yet reliable procedure is needed for use in performance prediction programs. This paper presents a simplified and quicker procedure to obtain PD model parameters. It is illustrated using laboratory tests on field specimens. The procedure uses one specimen, compared with three specimens in the full-blown RLPD test, to be tested at two temperatures, the highest and lowest in the RLPD test, under the same conditions as in the RLPD test. The results of any intermediate temperature are obtained from the calibrated model. Two approaches are presented for analyzing the test results: the power equation in the AASHTOWare program, and the construction of a master curve. In the full-blown testing program with three specimens and three temperatures, the master curve approach fitted the results better than the power law. In the simplified procedure, the fitting of the two approaches is almost identical. Results obtained from tests conducted on six mixes show (1) testing one specimen at the highest temperature only and extrapolating the results overpredicts the material behavior at intermediate and low temperatures, and (2) the master curve from the simplified procedure compares very well with the one from the full-blown RLPD program.

(227) Analysis of Gene Expression of Vitamin D in Rats in Experimental Model of Peyronie's Disease and Human Penile Tunica Albuginea

Abstract Introduction Peyronie's disease (PD) is a penile connective tissue disorder that results in an inflammatory process, fibrotic plaque in the tunica albuginea (TA) and penile curvature. The molecular changes of fibrotic plaque formation are complex and include different cellular/protein mechanisms. Vitamin D (vitD) is a steroid hormone that has unconventional pathways of action, and among its effects it has already been described that it plays a role in extracellular matrix remodeling, in the immune response and in fibrosis. The literature regarding the action of vitD in the male genital system is scarce, and the gene expression of its receptors has not yet been demonstrated in penile TA. Objective To identify the gene expression of the vitD receptor in penile TA of rats submitted to the experimental model of PD and human penile TA. Methods The experimental model in rats divided into 2 groups (case and control) described before by Cohen et al. Human penile TA was achieved from Peyronie´s surgery cases and cadaveric controls. The antibody anti vitD (VDR D-6: sc-13133, Santa Cruz Biotechnology®, CA, USA) was used. Immunolabeling was carried out using the avidin-biotin-peroxidase complex method, and 3,3′-diaminobenzidine as liquid chromogen. In each case, the immunolabeling was quantified by computer-assisted digital image analysis following the methodology described by Matos et al. PCR real-time analyses followed the MIQE guideline10. One of the fractions of the tissue samples of the TA was stored in RNAholder. The extraction of total RNA from the samples was carried out using the reagent TRIzol®. The reverse transcription was performed using the reverse transcriptase enzyme ImPromII™ to obtain complementary DNA (cDNA). Messenger RNA expression of vitD was obtained by RT-PCR. Quantitative RT-PCR was carried out using pair of oligonucleotides endogenous RPL13a (human samples) and GAPDH (rat samples), known commercially as forward and reverse primers. It was performed statistical analysis with SPSS® version 17.0 (SPSS® Inc; Illinois, USA). Values were expressed as a mean and standard error with a significance level of 95% (p ≤ 0.05). The tests applied were One-Way ANOVA and unpaired t-test with Welch's correction, confirming the similarity between the variances. Sensitivity and specificity analysis was calculated following the Youden index. Ethical approval local committee number 06/2016. Results The vitD mRNA amplifications demonstrated the presence of its receptors in the penile TA in both the control and the case groups, and the expression of the control group was statistically higher (p < 0,0001) when compared to the case group in rats. In human samples, mRNA amplifications demonstrated the presence of its receptors in the penile TA in both the control and the case groups, and the expression of the control group was statistically lower (p < 0,0001) when compared to the case group. Conclusions The presence of vitD receptors (genic and proteic expression) in penile TA of rats Peyronies´ models and human TA was demonstrated and allows future studies regarding its regulation and modulation according to the evolution and phase of PD and vitD serum levels. Disclosure No

(080) Exploring the Effects of Actinidin as a Novel Collagenase on Human Peyronie’s Disease Cells

Abstract Introduction Peyronie’s Disease (PD) is a connective tissue disorder of the penile tunica albuginea that affects approximately 10% of men. The plaques that hallmark PD contain excessive amounts of collagen and can result in penile curvature, painful erections, and/or erectile dysfunction. Intralesional Collagenase Clostridium histolyticum injection for PD are no longer available in Canada, making treatment options limited. Hayward kiwi fruit are rich in natural actinidin, a soluble enzyme that has the unique ability to hydrolyze various types of collagen and fibrinogen. Actinidin is considered a collagenase alternative; however, there have been no studies evaluating the application of actinidin on in vitro cellular PD models. Objective To determine the effectiveness of actinidin at reducing the collagen component of a 2D human PD cell model. Secondly, to determine the cytotoxicity of kiwifruit extract on human PD cells. Methods Human PD tissues obtained during penile prosthesis implantation were isolated for fibroblast cells and cultured using complete media. The cells were plated on a 96-well plate and treated with one of 4 treatment groups: media, saline, and low and high concentration actinidin treatment (0.5 mg/ml to 37.5 mg/ml). The actinidin treatments were prepared by dissolving freeze-dried kiwi powder in saline and then filtered; the low concentration was further diluted with saline. Cells were incubated at 37°C for 24 hours and then collagen was extracted and measured using a soluble collagen quantification assay kit and a fluorescent microplate reader. To measure cytotoxicity, cells were stained for the nucleus and actin filaments using DAPI and Phalloidin-conjugated FITC, respectively. A twelve-hour timelapse capturing images of FITC and DAPI fluorescein were carried through using a fluorescent confocal microscope. The total fluorescent area of each well was measured using ImageJ. Actin signals were normalized by DAPI signals, and all values were analyzed using Python and Prism10. Results The higher concentration of actinidin treatment significantly reduced cellular collagen of human PD fibroblasts compared to the media treatment (P < 0.05). The high concentration actinidin treatment had a significantly higher normalized actin signal than other treatment groups (P < 0.0001). This ratio allows us to observe the treated cells with compromised plasma membranes. The low concentration of actinidin did not have any significant difference from media and saline treatment groups. A significant increased level of normalized actin indicated that actinidin may have mechanisms to disturb the plasma membrane. Conclusions Our preliminary study suggests that the natural collagenase actinidin can break down PD cells by reducing the extracellular collagen content and compromising the cellular membrane. Further studies are underway to investigate treatment in 3D models and to determine the optimal actinidin concentration that can further reduce the collagen composition in human PD cell models. Actinidin has the potential to be a novel treatment option for patients suffering from PD. Disclosure Yes, this is sponsored by industry/sponsor: KiwiEnzyme.com Ltd Clarification No industry support in study design or execution

Physiologically-based pharmacokinetic pharmacodynamic parent-metabolite model of edoxaban to predict drug-drug-disease interactions: M4 contribution.

This study aimed to develop a physiologically-based pharmacokinetic pharmacodynamic (PBPK/PD) parent-metabolite model of edoxaban, an oral anticoagulant with a narrow therapeutic index, and to predict pharmacokinetic (PK)/PD profiles and potential drug-drug-disease interactions (DDDIs) in patients with renal impairment. A whole-body PBPK model with a linear additive PD model of edoxaban and its active metabolite M4 was developed and validated in SimCYP for healthy adults with or without interacting drugs. The model was extrapolated to situations including renal impairment and drug-drug interactions (DDIs). Observed PK and PD data in adults were compared with predicted data. The effect of several model parameters on the PK/PD response of edoxaban and M4 was investigated in sensitivity analysis. The PBPK/PD model successfully predicted PK profiles of edoxaban and M4 as well as anticoagulation PD responses with or without the influence of interacting drugs. For patients with renal impairment, the PBPK model successfully predicted the fold change in each impairment group. Inhibitory DDI and renal impairment had a synergistic effect on the increased exposure of edoxaban and M4, and their downstream anticoagulation PD effect. Sensitivity analysis and DDDI simulation show that renal clearance, intestinal P-glycoprotein activity, and hepatic OATP1B1 activity are the major factors affecting edoxaban-M4 PK profiles and PD responses. Anticoagulation effect induced by M4 cannot be ignored when OATP1B1 is inhibited or downregulated. Our study provides a reasonable approach to adjust the dose of edoxaban in several complicated scenarios especially when M4 cannot be ignored due to decreased OATP1B1 activity.

Physiological changes in advanced Parkinson's disease: Altered motor cortical plasticity and its significance in pathophysiology and clinical symptoms

AbstractParkinson's disease (PD) is a progressive neurodegenerative disorder characterized by dopaminergic neurodegeneration in the substantia nigra. Dopamine plays an important role in the induction of synaptic plasticity, and plastic changes in the brain have been broadly investigated in PD. In humans, non‐invasive transcranial magnetic stimulation (TMS) has been widely used for plasticity induction in the motor cortex. In this review, we will discuss how dopamine receptors are involved in the induction of neuroplasticity, changes in corticostriatal plasticity in PD model animals, effects of dopamine on motor cortical plasticity in healthy humans, changes in motor cortical plasticity in PD patients including its relationship to motor symptoms, and, finally, altered plasticity in levodopa‐induced dyskinesia.

Towards a population pharmacokinetic/pharmacodynamic model of anti-VEGF therapy in patients with age-related macular degeneration

PurposeTo develop a population pharmacokinetic/pharmacodynamic model (popPKPD) of intravitreal bevacizumab treatment for neovascular age-related macular degeneration (nAMD) patients to learn about the PK/PD relationship and utilise it for dosing regimen decisions on future nAMD patients. MethodsThe Greater Manchester Avastin for Neovascularisation (GMAN) randomised clinical trial data was retrospectively utilised, and the best-corrected visual acuity (BCVA) and central macular retinal thickness (CRT, measured by optical coherence tomography) were the PD inputs to the model. Using the nonlinear mixed-effects method, the best PKPD structural model was investigated, and the clinical significance of the two different dosing treatment regimens (as-needed versus routine) was evaluated. ResultsA structural model to describe the change of BCVA from the baseline of nAMD patients was successfully obtained based on the turnover PD model concept (drug stimulates the “visual acuity response production”). The popPKPD model and simulation indicate that the routine regimen protocol improves patient visual outcome compared to the as–needed protocol.For the change in CRT, the turnover structural PKPD model was too demanding to fit to the given clinical data. ConclusionsThis is the first popPKPD attempt in nAMD treatment that shows the potential of this strategy to understand/inform the dosing regimen. Clinical trials with richer PD data will provide the means to build more robust models.

Purine derivatives and creatinine urine excretion as a tool to estimate sheep feed intake

Dry matter intake is a key variable in animal nutritional evaluation. Purine derivates excretion is used to estimate microbial protein synthesis and could be used to estimate DMI. The present study aimed to evaluate PD models to estimate DMI and digestible DMI and access endogenous excretion of PD using regression analysis. Nine trials and 158 experimental units (animal or animal within the period) where DMI, dry matter apparent digestibility (n = 122), and PD urinary excretion were evaluated. Models were evaluated using PROC MIXED of SAS and considering the random effect of the trial. The PDC index was the better single variable to estimate sheep DMI. More complex models considering PD to creatinine ratio and metabolic weight (BW0.75) showed the lowest error. Quadratic terms of PDC index, PD: creatinine ratio, and allantoin to creatinine ratio did not improve DMI estimation. Similar results were observed comparing different models to estimate digestible DMI, however, with lower R2. In addition, endogenous excretion of PD estimated by linear regression was 0.286 mmol/kg of BW0.75. Thus, the PDC index is the best variable to estimate feed intake and digestible DMI from PD excretion.

Retinal alpha-synuclein accumulation correlates with retinal dysfunction and structural thinning in the A53T mouse model of Parkinson's disease.

Abnormal alpha-synuclein (α-SYN) protein deposition has long been recognized as one of the pathological hallmarks of Parkinson's disease's (PD). This study considers the potential utility of PD retinal biomarkers by investigating retinal changes in a well characterized PD model of α-SYN overexpression and how these correspond to the presence of retinal α-SYN. Transgenic A53T homozygous (HOM) mice overexpressing human α-SYN and wildtype (WT) control littermates were assessed at 4, 6, and 14 months of age (male and female, n = 15-29 per group). In vivo retinal function (electroretinography, ERG) and structure (optical coherence tomography, OCT) were recorded, and retinal immunohistochemistry and western blot assays were performed to examine retinal α-SYN and tyrosine hydroxylase. Compared to WT controls, A53T mice exhibited reduced light-adapted (cone photoreceptor and bipolar cell amplitude, p < 0.0001) ERG responses and outer retinal thinning (outer plexiform layer, outer nuclear layer, p < 0.0001) which correlated with elevated levels of α-SYN. These retinal signatures provide a high throughput means to study α-SYN induced neurodegeneration and may be useful in vivo endpoints for PD drug discovery.

Discovery and characterization of novel inhibitors of CTP synthase 1 (CTPS1) for the treatment of autoimmune and inflammatory disease

Abstract The de novo pyrimidine biosynthetic pathway is an inducible cellular program which allows the rapid synthesis of pyrimidine nucleotides in proliferating cells, and the final rate-limiting step is catalyzed by cytidine triphosphate synthase (CTPS1 or CTPS2). A CTPS1 loss-of-function mutation in humans has illustrated the essential and non-redundant role of CTPS1 in activated lymphocyte proliferation. Therefore, selective CTPS1 inhibition is an attractive approach to specifically target pathological immune activity in autoimmune and inflammatory disease. Using cryo-EM and structure-based drug design, we have identified a series of potent, orally bioavailable, CTPS1-specific inhibitors, exemplified by the compound NTX-871. In-vitro, NTX-871 significantly inhibits the proliferation of T-cell derived lines and activated primary T-cells. These inhibitory effects are reversed by the addition of exogenous cytidine, illustrating the specificity of NTX-871 for CTPS1 and the de novo pyrimidine synthesis program. NTX-871 was also tested in several mouse in-vivo PD and autoimmune disease models. Oral dosing of NTX-871 significantly reduced T-cell proliferation in an ovalbumin-induced T-cell proliferation model, and QD or BID dosing of NTX-871 significantly improved disease phenotypes in models of delayed-type hypersensitivity, collagen-induced arthritis, and experimental autoimmune encephalomyelitis.

Treadmill Exercise Alleviates Cognition Disorder by Activating the FNDC5: Dual Role of Integrin αV/β5 in Parkinson's Disease.

Parkinson's disease with cognitive impairment (PD-CI) results in several clinical outcomes for which specific treatment is lacking. Although the pathogenesis of PD-CI has not yet been fully elucidated, it is related to neuronal plasticity decline in the hippocampus region. The dopaminergic projections from the substantia nigra to the hippocampus are critical in regulating hippocampal plasticity. Recently, aerobic exercise has been recognized as an effective therapeutic strategy for enhancing plasticity through the secretion of various muscle factors. The exact role of FNDC5-an upregulated, newly identified myokine produced after exercise-in mediating hippocampal plasticity and regional dopaminergic projections in PD-CI remains unclear. In this study, the effect of treadmill exercise on hippocampal synaptic plasticity was evaluated in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced chronic PD models. The results showed that treadmill exercise substantially alleviated the motor dysfunction, cognition disorder, and dopaminergic neuron degeneration induced by MPTP. Here, we discovered that the quadriceps, serum, and brain FNDC5 levels were lower in PD mice and that intervention with treadmill exercise restored FNDC5 levels. Moreover, treadmill exercise enhanced the synaptic plasticity of hippocampal pyramidal neurons via increased dopamine levels and BDNF in the PD mice. The direct protective effect of FNDC5 is achieved by promoting the secretion of BDNF in the hippocampal neurons via binding the integrin αVβ5 receptor, thereby improving synaptic plasticity. Regarding the indirect protection effect, FNDC5 promotes the dopaminergic connection from the substantia nigra to the hippocampus by mediating the interaction between the integrin αVβ5 of the hippocampal neurons and the CD90 molecules on the membrane of dopaminergic terminals. Our findings demonstrated that treadmill exercise could effectively alleviate cognitive disorders via the activation of the FNDC5-BDNF pathway and enhance the dopaminergic synaptic connection from SNpc to the hippocampus in the MPTP-induced chronic PD model.

NLRP3 mediates the neuroprotective effects of SVHRSP derived from scorpion venom in rotenone-induced experimental Parkinson’s disease model

Ethnopharmacological relevanceIn traditional Chinese medicine, scorpion is used to treat diseases with symptoms such as trembling, convulsion and dementia. Our laboratory employs patented technology to extract and purify the active single component from scorpion venom. We then utilize mass spectrometry to determine the amino acid sequence of the polypeptide and synthesize it artificially to acquire the polypeptide with a purity of 99.3%, named SVHRSP (Scorpion Venom Heat-Resistant Peptide). SVHRSP has been demonstrated to display potent neuroprotective efficacy in Parkinson’s disease. Aim of the studyTo explore the molecular mechanisms and potential molecular targets of SVHRSP-afforded neuroprotection in PD mouse models, as well as to investigate the role of NLRP3 in SVHRSP-mediated neuroprotection. Materials and methodsThe PD mouse model was induced by rotenone and the neuroprotective role of SVHRSP on the PD mouse model was measured using the gait test, rotarod test, the number of dopaminergic neurons, and the activation of microglia. RNA sequencing and GSEA analysis were performed to find the differentially biological pathways regulated by SVHRSP. Primary mid-brain neuron-glial cultures and NLRP3−/− mice were applied to verify the role of NLRP3 by using qRT-PCR, western blotting, enzyme-linked immunosorbent assay (ELISA) and immunostaining. ResultsSVHRSP-afforded dopaminergic neuroprotection was accompanied with inhibition of microglia-mediated neuroinflammatory pathways. Importantly, depletion of microglia markedly reduced the neuroprotective efficacy of SVHRSP against rotenone-induced dopaminergic neurotoxicity in vitro. SVHRSP inhibited microglial NOD-like receptor pathway, mRNA expression and protein level of NLRP3 in rotenone PD mice. SVHRSP also reduced rotenone-induced caspse-1 activation and IL-1β maturation, indicating that SVHRSP mitigated activation of NLRP3 inflammasome. Moreover, inactivation of NLRP3 inflammasome by MCC950 or genetic deletion of NLRP3 almost abolished SVHRSP-afforded anti-inflammatory, neuroprotective effects and improvement of motor performance in response to rotenone. ConclusionsNLRP3 mediated the neuroprotective effects of SVHRSP in rotenone-induced experimental PD model, providing additional evidence for the mechanisms of SVHRSP-afforded anti-inflammatory and neuroprotective effects in PD.

Novel Mutation in the Feline GAA Gene in a Cat with Glycogen Storage Disease Type II (Pompe Disease).

Glycogen storage disease type II (Pompe disease: PD) is an autosomal recessively inherited fatal genetic disorder that results from the deficiency of a glycogen hydrolyzing enzyme, acid α-glucosidase encoded by the GAA gene. Here, we describe the molecular basis of genetic defects in an 8-month-old domestic short-haired cat with PD. The cat was previously diagnosed with PD based on the clinical and pathological findings of hypertrophic cardiomyopathy and excessive accumulation of glycogen in the cardiac muscles. Sanger sequencing was performed on 20 exons of the feline GAA gene using genomic DNA extracted from paraffin-embedded liver tissues. The affected cat was found to be homozygous for the GAA:c.1799G>A mutation resulting in an amino acid substitution (p.R600H) of acid α-glucosidase, a codon position of which is identical with three missense mutations (p.R600C, p.R600L, and p.R600H) causing human infantile-onset PD (IOPD). Several stability and pathogenicity predictors have also shown that the feline mutation is deleterious and severely decreases the stability of the GAA protein. The clinical, pathological, and molecular findings in the cat were similar to those of IOPD in humans. To our knowledge, this is the first report of a pathogenic mutation in a cat. Feline PD is an excellent model for human PD, especially IOPD.

A Bond-Based Peridynamic Model with Matrix Plasticity for Impact Damage Analysis of Composite Materials

The prediction of damage and failure to fiber-reinforced polymer composites in extreme environments, particularly when subjected to impact loading, is a crucial issue for the application and design of protective structures. In this paper, based on the prototype microelastic brittle (PMB) model and the LaRC05 composite materials failure model, we proposed a bond-based peridynamic (BB-PD) model with the introduction of plastic hardening of the resin matrix for fiber-reinforced polymer composites. The PD constitutive relationships of the matrix bond and interlayer bond under compressive loading are considered to include two stages of linear elasticity and plastic hardening, according to the stress-strain relationship of the resin matrix in the LaRC05 failure model. The proposed PD model is employed to simulate the damage behaviors of laminated composites subjected to impact loading. The corresponding ballistic impact tests of composite laminates were carried out to observe their damage behaviors. The PD prediction results are in good agreement with the ballistic experimental results, which can verify the correctness and accuracy of the PD model developed in this study in describing the impact damage behaviors of composite materials. In addition, the characteristics and degree of damage in composite laminates are analyzed and discussed based on this PD model. The difference in the impact resistance of composite laminates with different stacking sequences is also studied using the numerical simulation results.

Abstract 6180: Antitumor activity of the ATR inhibitor Elimusertib in patient-derived xenograft models with DNA damage response pathway alterations

Abstract Introduction: The ataxia telangiectasia and RAD3-related (ATR) kinase is a key component of the DNA damage response (DDR) and functions in conjunction with ataxia telangiectasia mutated (ATM). ATM loss or functional deficiency may enhance reliance on ATR signaling. Preclinical and clinical studies have pointed to a potential synthetic lethality of ATR inhibition and ATM loss. In this study, we sought to further elaborate potential candidates for ATR inhibition by testing the anti-tumor effect of elimusertib (BAY 1895344) in patient-derived tumor xenograft (PDX) models with DDR alterations including ATM loss. Methods: Patient derived xenograft (PDX) models were implanted into athymic nu/nu mice. Once tumors reached an appropriate size of approximately 200-400mm3 treatments were started. Mice were randomized (N= 3-8) to different treatment arms for assessment of anti-tumor activity of elimusertib as monotherapy and in combination therapy with copanlisib. Monotherapy treatment was performed with 20 mg/kg and 40 mg/kg doses, applied twice daily for 3 days with 4 days treatment break (BID 3 days on/4 days off). Efficacy read-out was either Event-Free Survival (EFS-2), defined as time for doubling of tumor volume relative to baseline, or response based on RECIST criteria:(partial response [PR]= &amp;gt;30% decrease, stable disease [SD]= between 20% increase and 30% decrease, and progressive disease [PD]= &amp;gt;20% increase). For assessment of pharmacodynamic effects, tumors were harvested 10 days after treatment start and analyzed by immunohistochemistry (IHC) and RPPA (Reverse Phase Proteomics Array). Results: Elimusertib was tested in 21 PDX models with various DDR alterations. Of those 11 showed a statistically significant prolongation of event free survival compared to control. In 4 PDX models elimusertib reached a partial response (PR), and another 4 models showed stable disease (SD). Amongst the 5 models with ATM protein Ioss (IHC), one was PR and another one SD. In 3 of 5 PARP inhibitor resistant there was statistically significant prolongation of EFS upon elimusertib treatment vs control. We found an increase in DNA damage in tumors, as indicated by increased level of ƳH2AX (on IHC and RPPA). We also detected an increase in PI3K/mTOR pathway signaling as determined by p-MTOR and pS6 (RPPA) in 2 of 4 models (PR and PD model) with different sensitivity to ATRi and PARPi alone. We tested the combination of elimusertib with the PI3K inhibitor copanlisib achieved a statistically significant increase of EFS compared to monotherapy in 3 of 11 models tested. Conclusion ATR inhibition shows potent monotherapy activity in selected PDX models that harbor DDR defects, including models with intrinsic and acquired PARPi resistance. Further work is needed to identify markers predicting sensitivity or resistance that providing rationale for synergistic combination therapies. Citation Format: Kaushik Varadarajan, Christian X. Pico, Kurt Evans, Maria G. Raso, Yasmeen Rizvi, Xiaofeng Zheng, Timothy P. Diperi, Bailiang Wang, Stephen Scott, Ming Zhao, Argun Akcakanat, Antje M. Wengner, Timothy A. Yap, Funda Meric-Bernstam. Antitumor activity of the ATR inhibitor Elimusertib in patient-derived xenograft models with DNA damage response pathway alterations. [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 6180.