PD Model Research Articles

GLP-1 and GIP receptor agonists in the treatment of Parkinson's disease: Translational systematic review and meta-analysis protocol of clinical and preclinical studies.

BackgroundParkinson’s disease (PD) is a progressive multifactorial neurodegenerative condition. Epidemiological studies have shown that patients with type 2 diabetes mellitus (T2DM2) are at increased risk for developing PD, indicating a possible insulin-modulating role in this latter condition. We hypothesized that drugs similar to glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP), used in the treatment of T2DM2, may play a role in PD.ObjectivesThe purpose of this study is to systematically review and meta-analyze data of preclinical and clinical studies evaluating the efficacy and safety of GLP-1 and GIP drugs in the treatment of PD.MethodsTwo reviewers will independently evaluate the studies available in the Ovid Medline, Ovid Embase, Web of Science, Cochrane Central Register of Controlled Trials, Cinahl, and Lilacs databases. Preclinical rodent or non-human primate studies and randomized controlled human clinical trials will be included, without language or publication period restrictions. Outcomes of interest in preclinical studies will be primarily locomotor improvements and adverse effects in animal models of PD. For clinical trials, we will evaluate clinical improvements rated by the Movement Disorders Society Unified Parkinson’s Disease Rating Scale–parts I, II, III, and IV, and adverse effects. The risk of bias of preclinical studies will be assessed by the SYRCLE tool and CAMARADES checklist and the clinical studies by the Cochrane tool; the certainty of the evidence will be rated by GRADE.Discussion and conclusionThere is an urge for new PD treatments that may slow the progression of the disease rather than just restoring dopamine levels. This study will comprehensively review and update the state of the art of what is known about incretin hormones and PD and highlight the strengths and limitations of translating preclinical data to the clinic whenever possible.Systematic review registrationPROSPERO registration number CRD42020223435.

High-fat diet-induced diabetes leads to vascular alterations, pericyte reduction, and perivascular depletion of microglia in a 6-OHDA toxin model of Parkinson disease

BackgroundDiabetes has been recognized as a risk factor contributing to the incidence and progression of Parkinson’s disease (PD). Although several hypotheses suggest a number of different mechanisms underlying the aggravation of PD caused by diabetes, less attention has been paid to the fact that diabetes and PD share pathological microvascular alterations in the brain. The characteristics of the interaction of diabetes in combination with PD at the vascular interface are currently not known.MethodsWe combined a high-fat diet (HFD) model of diabetes mellitus type 2 (DMT2) with the 6-OHDA lesion model of PD in male mice. We analyzed the association between insulin resistance and the achieved degree of dopaminergic nigrostriatal pathology. We further assessed the impact of the interaction of the two pathologies on motor deficits using a battery of behavioral tests and on microglial activation using immunohistochemistry. Vascular pathology was investigated histologically by analyzing vessel density and branching points, pericyte density, blood–brain barrier leakage, and the interaction between microvessels and microglia in the striatum.ResultsDifferent degrees of PD lesion were obtained resulting in moderate and severe dopaminergic cell loss. Even though the HFD paradigm did not affect the degree of nigrostriatal lesion in the acute toxin-induced PD model used, we observed a partial aggravation of the motor performance of parkinsonian mice by the diet. Importantly, the combination of a moderate PD pathology and HFD resulted in a significant pericyte depletion, an absence of an angiogenic response, and a significant reduction in microglia/vascular interaction pointing to an aggravation of vascular pathology.ConclusionThis study provides the first evidence for an interaction of DMT2 and PD at the brain microvasculature involving changes in the interaction of microglia with microvessels. These pathological changes may contribute to the pathological mechanisms underlying the accelerated progression of PD when associated with diabetes.

IRB PD model accuracy validation in the presence of default correlation: a twin confidence interval approach

The BIS indicated in July 2020 an unprecedented rise in default risk correlation as a result of pandemics-induced credit risks’ accumulation. A third of the world banking assets credit risk measurement depends on the Basel internal-ratings-based (IRB) models. To ensure financial stability, we wish IRB models to be accurate in default probability (PD) forecasting. There naturally arises a question of which model may be deemed accurate if the data demonstrates the presence of the default correlation. The existing prudential IRB validation guidelines suggest a confidence interval of up to 100 percentage points’ length for such a case. Such an interval is useless as any model and any PD forecast seem accurate. The novelty of this paper is the justification for the use of twin confidence intervals to validate PD model accuracy. Those intervals more concentrate around the two extremes (default and its absence), the higher the default correlation is.

HAGLR promotes neuron differentiation through the miR-130a-3p-MeCP2 axis.

Parkinson’s disease (PD) is a prevalent neurodegenerative disease. Currently, the molecular mechanisms underlying the progressions of PD are not fully understood. The human neuroblastoma cell line SH-SY5Y has been widely used as an in vitro model for PD. This study aims to investigate the molecular mechanisms of the non-coding RNA-mediated SH-SY5Y differentiation induced by retinoic acid (RA). By microArray analysis, lncRNA HAGLR was observed to be significantly upregulated during the RA-induced SH-SY5Y differentiation. Silencing HAGLR blocked the RA-induced SH-SY5Y differentiation. Moreover, bioinformatical analysis illustrated that miR-130a-3p contains binding sites for HAGLR. The RNA-pull down assay and luciferase assay demonstrated that HAGLR functioned as a ceRNA of miR-130a-3p in SH-SY5Y cells. Overexpression of miR-130a-3p effectively inhibited SH-SY5Y differentiation. We identified MeCP2, a vital molecule in neuronal diseases, to be a direct target of miR-130a-3p in SH-SY5Y cells by western blot and luciferase assays. The rescue experiments verified that recovery of miR-130a-3p in HAGLR-overexpressing SH-SY5Y cells could successfully overcome the RA-induced SH-SY5Y differentiation by targeting MeCP2. In summary, this study reveals a potential molecular mechanism for the lncRNA-HAGLR-promoted in vitro neuron differentiation by targeting the miR-130a-3p-MeCP2 axis, contributing to the understanding of the pathogenesis and progression of PD.

Transcriptome profiling of five brain regions in a 6-hydroxydopamine rat model of Parkinson's disease.

BackgroundParkinson's disease (PD) is a neurodegenerative disease, and its pathogenesis is unclear. Previous studies mainly focus on the lesions of substantia nigra (SN) and striatum (Str) in PD. However, lesions are not limited. The olfactory bulb (OB), subventricular zone (SVZ), and hippocampus (Hippo) are also affected in PD.AimTo reveal gene expression changes in the five brain regions (OB, SVZ, Str, SN, and Hippo), and to look for potential candidate genes and pathways that may be correlated with the pathogenesis of PD.Materials and methodsWe established control group and 6‐hydroxydopamine (6‐OHDA) PD model group, and detected gene expressions in the five brain regions using RNA‐seq and real‐time quantitative polymerase chain reaction (RT‐qPCR). We further analyzed the RNA‐seq data by bioinformatics.ResultsWe identified differentially expressed genes (DEGs) in all five brain regions. The DEGs were significantly enriched in the “dopaminergic synapse” and “retrograde endocannabinoid signaling,” and Gi/o‐GIRK is the shared cascade in the two pathways. We further identified Ephx2, Fam111a, and Gng2 as the potential candidate genes in the pathogenesis of PD for further studies.ConclusionOur study suggested that gene expressions change in the five brain regions following exposure to 6‐OHDA. The “dopaminergic synapse,” “retrograde endocannabinoid signaling,” and Gi/o‐GIRK may be the key pathways and cascade of the synaptic damage in 6‐OHDA PD rats. Ephx2, Fam111a, and Gng2 may play critical roles in the pathogenesis of PD.

Marine-Derived Xyloketal Compound Ameliorates MPP+-Induced Neuronal Injury through Regulating of the IRE1/XBP1 Signaling Pathway.

The IRE1/XBP1 signaling pathway is the most conserved component of the endoplasmic reticulum unfolded protein response (UPRER). Activating this branch to correct defects in ER proteostasis is regarded as a promising anti-Parkinson's disease (PD) strategy. P-53 is a marine-derived xyloketal B analog which exhibited potential neuroprotective activities in previous research studies; however, the molecular mechanism underneath its protective effect remains unknown. Herein, a transcriptomic approach was introduced to explore the protective mechanism of P-53. RNA microarray profiling was conducted based on an MPP+-induced C. elegans PD model, and bioinformatics analyses including GO enrichment and PPI network analysis were subsequently performed. In particular, the recovery of the impaired UPRER was highlighted as a main physiological change caused by P-53, and a cluster of genes including abu and hsp family genes which are involved in the IRE1/XBP1 branch of the UPRER were identified as the key genes related to its neuroprotective effect. The transcription levels of these key genes were validated by RT-qPCR assays. Further results showed that P-53 enhanced the phosphorylation of IRE1, the splicing of xbp-1 mRNA, and the translation of XBP1S and boosted the expression level of the downstream targets of the IRE1/XBP1 signaling pathway. Moreover, it was also demonstrated that P-53 accelerated the scavenging of misfolded α-synuclein and attenuated the correlative mitochondrial dysfunction. Finally, the protective effect of P-53 against MPP+-induced dopaminergic neuronal loss was assessed. Taken together, these results revealed that P-53 plays its neuroprotective role through regulating of the IRE1/XBP1 signaling pathway and laid the foundation for its further development as an ER proteostasis-regulating agent.

TNF\u03b1 increases tyrosine hydroxylase expression in human monocytes

Most, if not all, peripheral immune cells in humans and animals express tyrosine hydroxylase (TH), the rate limiting enzyme in catecholamine synthesis. Since TH is typically studied in the context of brain catecholamine signaling, little is known about changes in TH production and function in peripheral immune cells. This knowledge gap is due, in part, to the lack of an adequately sensitive assay to measure TH in immune cells expressing lower TH levels compared to other TH expressing cells. Here, we report the development of a highly sensitive and reproducible Bio-ELISA to quantify picogram levels of TH in multiple model systems. We have applied this assay to monocytes isolated from blood of persons with Parkinson’s disease (PD) and to age-matched, healthy controls. Our study unexpectedly revealed that PD patients’ monocytes express significantly higher levels of TH protein in peripheral monocytes relative to healthy controls. Tumor necrosis factor (TNFα), a pro-inflammatory cytokine, has also been shown to be increased in the brains and peripheral circulation in human PD, as well as in animal models of PD. Therefore, we investigated a possible connection between higher levels of TH protein and the known increase in circulating TNFα in PD. Monocytes isolated from healthy donors were treated with TNFα or with TNFα in the presence of an inhibitor. Tissue plasminogen activator (TPA) was used as a positive control. We observed that TNFα stimulation increased both the number of TH+ monocytes and the quantity of TH per monocyte, without increasing the total numbers of monocytes. These results revealed that TNFα could potentially modify monocytic TH production and serve a regulatory role in peripheral immune function. The development and application of a highly sensitive assay to quantify TH in both human and animal cells will provide a novel tool for further investigating possible PD immune regulatory pathways between brain and periphery.

Small heterodimer partner (SHP) aggravates ER stress in Parkinson\u2019s disease-linked LRRK2 mutant astrocyte by regulating XBP1 SUMOylation

BackgroundEndoplasmic reticulum (ER) stress is a common feature of Parkinson’s disease (PD), and several PD-related genes are responsible for ER dysfunction. Recent studies suggested LRRK2-G2019S, a pathogenic mutation in the PD-associated gene LRRK2, cause ER dysfunction, and could thereby contribute to the development of PD. It remains unclear, however, how mutant LRRK2 influence ER stress to control cellular outcome. In this study, we identified the mechanism by which LRRK2-G2019S accelerates ER stress and cell death in astrocytes.MethodsTo investigate changes in ER stress response genes, we treated LRRK2-wild type and LRRK2-G2019S astrocytes with tunicamycin, an ER stress-inducing agent, and performed gene expression profiling with microarrays. The XBP1 SUMOylation and PIAS1 ubiquitination were performed using immunoprecipitation assay. The effect of astrocyte to neuronal survival were assessed by astrocytes-neuron coculture and slice culture systems. To provide in vivo proof-of-concept of our approach, we measured ER stress response in mouse brain.ResultsMicroarray gene expression profiling revealed that LRRK2-G2019S decreased signaling through XBP1, a key transcription factor of the ER stress response, while increasing the apoptotic ER stress response typified by PERK signaling. In LRRK2-G2019S astrocytes, the transcriptional activity of XBP1 was decreased by PIAS1-mediated SUMOylation. Intriguingly, LRRK2-GS stabilized PIAS1 by increasing the level of small heterodimer partner (SHP), a negative regulator of PIAS1 degradation, thereby promoting XBP1 SUMOylation. When SHP was depleted, XBP1 SUMOylation and cell death were reduced. In addition, we identified agents that can disrupt SHP-mediated XBP1 SUMOylation and may therefore have therapeutic activity in PD caused by the LRRK2-G2019S mutation.ConclusionOur findings reveal a novel regulatory mechanism involving XBP1 in LRRK2-G2019S mutant astrocytes, and highlight the importance of the SHP/PIAS1/XBP1 axis in PD models. These findings provide important insight into the basis of the correlation between mutant LRRK2 and pathophysiological ER stress in PD, and suggest a plausible model that explains this connection.

Treating LRRK2‐Related Parkinson's Disease by Inhibiting the mTOR Signaling Pathway to Restore Autophagy

AbstractParkinson's disease (PD) is the most common chronic neurodegenerative disease and is characterized by motor dysfunctions. Pathogenic mutations in leucine‐rich repeat kinase 2 (LRRK2) are a major cause of the neurotoxicity that causes PD. As an inhibitor of LRRK2 activity, vitamin B12 (VB12) is a promising therapeutic option for PD and is shown to restore autophagy in PD models. However, the dependence on transporters and the extremely low brain tissue utilization of VB12 limit its therapeutic effects. Based on this, VB12‐loaded tetrahedral framework nucleic acid (TVC) is synthesized and its effectiveness in the model of PD induced with 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine is evaluated. TVC provides better recovery of autophagy than free VB12 did both in vivo and in vitro, leading to enhanced clearing of abnormal protein accumulations and restoration of PD motor symptoms. It is believed that TVC has broad therapeutic potential in the treatment of PD and similar neurodegenerative diseases.

MOST EFFECTIVE INTERNATIONALLY EMERGING IMPLEMENTATION MODELS IN TEACHER PROFESSIONAL DEVELOPMENT PROGRAMS OVER THE LAST DECADE

<p>This study aims to identify effective internationally emerging implementation models in teacher professional development. Several trends in teacher Professional Development are influencing the nature and quality of teacher professional development. The meta-analysis method was used in this study by identifying, collecting, and analysis potential studies to reach the findings. The results show that professional development has the potential to transform the education scene when supported by all industry players. Policy plays a vital role in the success of programs like PD programs. Policies surrounding the government of this model should be carefully structured to guide the PD programs appropriately as well as formulators should be industry players who understand the drivers that affect the education sector and in particular the educators. Good policy choices will mean that the PD stands a chance to be effective. The PD program should be provided with all the necessary resources for it to be effective and to enable smooth running. Educators should be facilitated with the necessary materials they require for the program. Lack of resources means that the PD program will not achieve its intended goals. Resources might be learning resources for the educator, allowances among many others. Extensive collaborations should be done by the sectors that could play a strong role in affecting the education, stakeholders, investors and other parties related in order to reach an agreement on the best model of PD. Additionally, there is a need to determine how best to run the PD programs to be beneficial to the education system.</p><p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/edu_01/0781/a.php" alt="Hit counter" /></p>

Therapeutic potential of pluripotent stem cell-derived dopaminergic progenitors in Parkinson\u2019s disease: a systematic review protocol

BackgroundParkinson’s disease (PD) is the second most common age-dependent neurodegenerative disease that causes motor and cognitive disabilities. This disease is associated with a loss of dopamine content within the putamen, which stems from the degeneration of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNc). Several approved drugs are available that can effectively treat symptoms of PD. However, long-term medical management is often complicated and does not delay or halt disease progression. Alternatively, cell replacement strategies can address these shortcomings and provide dopamine where it is needed. Although using human pluripotent stem cells (hPSCs) for treatment of PD is a promising alternative, no consensus in the literature pertains to efficacy concerns of hPSC-based therapy for PD. This systematic review aims to investigate the efficacy of primate PSC-derived DA progenitor transplantation to treat PD in preclinical studies.MethodsThis is a systematic review of preclinical studies in animal models of PD. We intend to use the following databases as article sources: MEDLINE (via PubMed), Web of Science, and SCOPUS without any restrictions on language or publication status for all related articles published until the end of April 2021. Two independent reviewers will select the titles and abstracts, extract data from qualifying studies, and assess the risk of bias using the SYstematic Review Centre for Laboratory animal Experimentation (SYRCLE) risk of bias tool and the Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies (CAMARADES) checklist. Apomorphine-induced rotation test (APO-IR) and amphetamine-induced rotation test (AMP-IR) are defined as the primary outcomes. The standardized mean difference (SMD) by Hedges’ g method (r) and odds ratio (OR) and related 95% confidence interval (CI) will be calculated to determine the size effect of the treatment. The heterogeneity between studies will be calculated by “I2 inconsistency of values and Cochran’s Q statistical test,” where I2 > 50% and/or p < 0.10 suggests high heterogeneity. Meta-analyses of random effects will be run when appropriate.DiscussionThis study will present an overview of preclinical research on PSCs and their therapeutic effects in PD animal models. This systematic review will point out the strengths and limitations of studies in the current literature while encouraging the funding of new studies by public health managers and governmental bodies.

Developing pharmacokinetics-pharmacodynamics model of valproic acid syrup based on prediction of population pharmacokinetics parameter and seizure frequency in Indonesian pediatric epilepsy outpatients.

Valproic acid (VPA) is a broad-spectrum antiepileptic drug with known efficacy profile in pediatric patients, despite of its narrow therapeutic index. There is lack of VPA's pharmacokinetics profile in Indonesian pediatric subjects, partly due to limited pediatric blood volume taken for conducting therapeutic drug monitoring. This study aimed to determine the correlation between VPA pharmacokinetics parameters based on population data and seizure frequency in pediatric epilepsy outpatients. This observational study was conducted at Sanglah General Hospital during June-December 2019. The subjects of this research were 38 pediatric epilepsy patients who adhered to VPA syrup monotherapy for at least 3weeks. Five subjects randomly selected for blood sample collection. Thus, VPA concentration level in the blood being analysed as a comparison to its concentration predicted from Yukawa's steady state equation. Monolix2019R2® software was used to identify VPA population pharmacokinetics-pharmacodynamics (PK-PD) parameters at steady state level. Population PK-PD of VPA syrup at steady state levelwere ka_pop = 6.25/h, Vd_pop = 3.36L, Cl_pop = 3.17·e-11mL/min, IC50_pop = 1.85·e-6, correlation of Vd_pop and Cl_pop = 0.966. Kendall Tau Correlation of predicted VPA steady state concentration and frequency of seizure was-0.66. Mean prediction error between predicted steady state concentration of five subjects and their related blood levels was≤25% and considered as within clinically acceptable limit. It needs further study to develop best matched PK-PD model of VPA syrup at steady state condition in pediatric epilepsy.

Peridynamic analysis of fatigue crack growth in fillet welded joints

Fatigue assessment is one of the significant factors to be considered for estimating design life of structures and structural reliability during operation. Especially, for welded structures, high stress concentration, residual stresses, weld geometry and weld quality make the structure more vulnerable to fatigue failures. Therefore, approaches that are more effective are required for estimating fatigue performances of welded structures. Existing classical methods to predict the crack propagation under cyclic loadings have some difficulties in treating complicated patterns of crack growth. However, peridynamic theory has advantages on dealing with discontinuities. In this study, a peridynamic fatigue model, which is a bond damage model of remaining life, is validated by considering ASTM E647 standard compact tension test for the crack growth. After validating the PD model, the fatigue performance of the fillet welded joint is presented by predicting the fatigue crack growth under cyclic loading conditions.

Directed differentiation of porcine induced pluripotent stem cells into forebrain GABAergic neuron progenitors

To establish an efficient protocol for directed differentiation of miniature-swine induced pluripotent stem cells (iPSCs) into GABAergic progenitors in a chemically defined system. We adopted a two-stage protocol for inducing the differentiation of porcine iPSCs. In the first stage, embryoid bodies (EBs) derived from porcine iPSCs after 3 days of suspension culture were induced in neural induction medium (containing SB431542, DMH1 and FGF2) till day 12 to differentiate into primitive neuroepithelia cells (NECs). In the second stage, the primitive NECs were induced in neural induction medium (containing Pur and B27) to obtain neural rosettes, which further differentiated into GABAergic neuron progenitors on day 21. After labeling with CM-DiI, the progenitor cells were stereotactically transplanted into the substantia nigra (SN) of 6-OHDA-lesioned PD model rats, and the cell survival, migration and differentiation in vivo were observed. Porcine iPSCs could be passaged stably on the feeder cell layer and expressed the pluripotent stem cell markers OCT4, Nanog, SSEA1and TRA-160. Karyotype analysis demonstrated the absence of contamination by cells from other species. On day 12 of induced differentiation, the cells formed adherent colonies containing NECs in the form of neural rosettes, which expressed the neuroepithelial markers PAX6, SOX2 and Nestin and the neurite marker beta Ⅲ Tubulin (Tuj1). After induction for 21 days, the NECs differentiated into GABAergic neural progenitors highly expressing NKX2.1 and FOXG1. Eight weeks after transplantation, the iPSCs-iGABA progeniters survived in the striatum of the PD rats, where they differentiate into GABAergic neurons and TH+ neurons and significantly improved dyskinesia of the rats. The miniature-swine iPSCsderived GABA progenitors may serve as promising donor cells for neural grafting for treatment of neurodegenerative diseases.

Differential Effects of Psychological Interventions in Online and Face-to-Face Settings on DSM-5 and ICD-11 Maladaptive Trait Domains: An Exploratory Pilot Study.

While mental health treatments have proven to be effective for a range of mental health problems, there is comparably little research on its effects on personality disorders or difficulty (PD). New dimensional conceptualizations of PD such as the ICD-11 PD model enable the cost- and time-effective dimensional assessment of severity and style of PD. Furthermore, they constitute a promising tool to investigate PD, not only as a treatment endpoint but also as a predictive or influencing factor for mental health treatments. In this study, we investigated the effects in two different mental health treatment settings [online (N = 38); face-to-face and blended [FTF/blended] (N = 35)] on the reduction of maladaptive personality traits as well as the interaction between maladaptive personality patterns and the response on primary endpoints (i.e., mental distress). Results indicate that both treatment settings have comparable within-group effects on the reduction of distress symptoms, while the treatment in the FTF/blended setting seems to have a stronger impact on the reduction of maladaptive traits. Further, reduction of maladaptive trait expressions was a reliable predictor of treatment response in the FTF/blended setting while explaining less variance in the online setting. Beyond the promising findings on the utility of maladaptive trait change as an outcome measure, we discuss possible applications as an information source for treatment decisions.

Characterization of substantia nigra neurogenesis in homeostasis and dopaminergic degeneration: beneficial effects of the microneurotrophin BNN-20

BackgroundLoss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) underlines much of the pathology of Parkinson’s disease (PD), but the existence of an endogenous neurogenic system that could be targeted as a therapeutic strategy has been controversial. BNN-20 is a synthetic, BDNF-mimicking, microneurotrophin that we previously showed to exhibit a pleiotropic neuroprotective effect on the dopaminergic neurons of the SNpc in the “weaver” mouse model of PD. Here, we assessed its potential effects on neurogenesis.MethodsWe quantified total numbers of dopaminergic neurons in the SNpc of wild-type and “weaver” mice, with or without administration of BNN-20, and we employed BrdU labelling and intracerebroventricular injections of DiI to evaluate the existence of dopaminergic neurogenesis in the SNpc and to assess the origin of newborn dopaminergic neurons. The in vivo experiments were complemented by in vitro proliferation/differentiation assays of adult neural stem cells (NSCs) isolated from the substantia nigra and the subependymal zone (SEZ) stem cell niche to further characterize the effects of BNN-20.ResultsOur analysis revealed the existence of a low-rate turnover of dopaminergic neurons in the normal SNpc and showed, using three independent lines of experiments (stereologic cell counts, BrdU and DiI tracing), that the administration of BNN-20 leads to increased neurogenesis in the SNpc and to partial reversal of dopaminergic cell loss. The newly born dopaminergic neurons, that are partially originated from the SEZ, follow the typical nigral maturation pathway, expressing the transcription factor FoxA2. Importantly, the pro-cytogenic effects of BNN-20 were very strong in the SNpc, but were absent in other brain areas such as the cortex or the stem cell niche of the hippocampus. Moreover, although the in vitro assays showed that BNN-20 enhances the differentiation of NSCs towards glia and neurons, its in vivo administration stimulated only neurogenesis.ConclusionsOur results demonstrate the existence of a neurogenic system in the SNpc that can be manipulated in order to regenerate the depleted dopaminergic cell population in the “weaver” PD mouse model. Microneurotrophin BNN-20 emerges as an excellent candidate for future PD cell replacement therapies, due to its area-specific, pro-neurogenic effects.

Incorporating shear stress ratio and load cycle number in a simple permanent deformation model for unbound material

A power model (ε = A. NB) to estimate permanent strain (ε) from single-stage repeated load triaxial (RLT) tests can simulate both shakedown and incremental collapse. When the exponent B < 1, the ε versus load cycle number (N) plot concaves downwards, resembling that of a material that shakes down. When B > 1, the same plot concaves upwards, mimicking that of a material that incrementally collapses. A power model that relates A and B to the shear stress ratio (SR = 1/factor of safety), a measure of how far the RLT specimen is away from static failure, is proposed. Use of SR as an independent variable in a PD model is advantageous because it embodies the geomaterial’s gradation, physical state, suction, stress level, shear strength and margin of safety against static failure. No other parameters bar N and SR are needed, enabling the number of independent variables and hence model complexity to be kept low. This model was applied to a virgin and a recycled concrete aggregate utilizing 2 independent variables (N and SR) with A and B both functions of SR. A rational procedure to estimate the mobilized shear stress is presented and a methodology to quantify SR that considers non-linearity of the Mohr-Coulomb failure envelope and cohesion due to suction in the unsaturated RLT specimens is proposed; such considerations have been absent in previous models. For the materials tested, A was found to decrease non-linearly with increasing SR while the relationship between B and SR is quite linear. The resulting model was able to simulate the RLT test data quite well with four fitting parameters. The fitting parameters can be easily derived using linear regression on a spreadsheet and were all statistically significant with a confidence level exceeding 95%. Once B is known, the shakedown limit can be estimated by setting B < 1. An appropriate margin of safety can be incorporated on the shakedown load to limit the permanent strain.

Early glycolytic reprogramming controls microglial inflammatory activation

BackgroundMicroglial activation-mediated neuroinflammation plays an important role in the progression of neurodegenerative diseases. Inflammatory activation of microglial cells is often accompanied by a metabolic switch from oxidative phosphorylation to aerobic glycolysis. However, the roles and molecular mechanisms of glycolysis in microglial activation and neuroinflammation are not yet fully understood.MethodsThe anti-inflammatory effects and its underlying mechanisms of glycolytic inhibition in vitro were examined in lipopolysaccharide (LPS) activated BV-2 microglial cells or primary microglial cells by enzyme-linked immunosorbent assay (ELISA), quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot, immunoprecipitation, flow cytometry, and nuclear factor kappa B (NF-κB) luciferase reporter assays. The anti-inflammatory and neuroprotective effects of glycolytic inhibitor, 2-deoxoy-d-glucose (2-DG) in vivo were measured in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-or LPS-induced Parkinson’s disease (PD) models by immunofluorescence staining, behavior tests, and Western blot analysis.ResultsWe found that LPS rapidly increased glycolysis in microglial cells, and glycolysis inhibitors (2-DG and 3-bromopyruvic acid (3-BPA)), siRNA glucose transporter type 1 (Glut-1), and siRNA hexokinase (HK) 2 abolished LPS-induced microglial cell activation. Mechanistic studies demonstrated that glycolysis inhibitors significantly inhibited LPS-induced phosphorylation of mechanistic target of rapamycin (mTOR), an inhibitor of nuclear factor-kappa B kinase subunit beta (IKKβ), and NF-kappa-B inhibitor alpha (IκB-α), degradation of IκBα, nuclear translocation of p65 subunit of NF-κB, and NF-κB transcriptional activity. In addition, 2-DG significantly inhibited LPS-induced acetylation of p65/RelA on lysine 310, which is mediated by NAD-dependent protein deacetylase sirtuin-1 (SIRT1) and is critical for NF-κB activation. A coculture study revealed that 2-DG reduced the cytotoxicity of activated microglia toward MES23.5 dopaminergic neuron cells with no direct protective effect. In an LPS-induced PD model, 2-DG significantly ameliorated neuroinflammation and subsequent tyrosine hydroxylase (TH)-positive cell loss. Furthermore, 2-DG also reduced dopaminergic cell death and microglial activation in the MPTP-induced PD model.ConclusionsCollectively, our results suggest that glycolysis is actively involved in microglial activation. Inhibition of glycolysis can ameliorate microglial activation-related neuroinflammatory diseases.

Pharmacokinetics and pharmacodynamics of enrofloxacin treatment of Escherichia coli in a murine thigh infection modeling

BackgroundEnrofloxacin is an antibacterial drug with broad-spectrum activity that is widely indicated for veterinary use. We aim to develop the clinical applications of Enrofloxacin against colibacillosis by using the neutropenic mice thigh infection model.ResultsThe minimum inhibitory concentration (MIC) distribution of 67 isolated E. coli strains to ENR was calculated using CLSI guidelines. Whereas, the MIC50 value calculation was considered as the population PD parameter for ENR against E. coli strains. The MIC values of 15 E. coli strains were found to be nearest to the MIC50 i.e., 0.25 μg/mL. Of all the tested strains, the PK-PD and E. coli disease model was established via selected E. coli strain i.e., Heilong 15. We analyzed the PK characteristics of ENR and its metabolite ciprofloxacin (CIP) following a single subcutaneous (s.c.) injection of ENR (1.25, 2.5, 5, 10 mg/kg). The concentration-time profiling of ENR within the plasma specimens was determined by considering the non-compartmental analysis (NCA). The basic PK parameters of ENR for the peak drug concentration (Cmax) and the area under the concentration-time curve (AUC) values were found to be in the range of 0.27–1.97 μg/mL and 0.62–3.14 μg.h/mL, respectively. Multiple s.c. injection over 24 h (1.25, 2.5, 5, 10 mg/kg at various time points i.e., 6, 8, 12, and 24 h respectively) were administered to assess the targeted PD values. The Akaike Information Criterion (AIC) was used to choose PD models, and the model with the lowest AIC was chosen. The inhibitory Emax model was employed to calculate the related PK-PD parameters. The results of our study indicated that there was a strong correlation between the AUC/MIC and various antibacterial activities (R2 = 0.9928). The target values of dividing AUC/MIC by 24 h for bacteriostatic action were 1-log10 reduction, 2-log10 reduction, and 3-log10 reduction 0.325, 0.4375, 0.63, and 0.95 accordingly.ConclusionThe identified pharmacodynamics targets for various antibacterial effects will be crucial in enhancing ENR clinical applications and serving as a key step in reducing bacterial resistance.

Development of a physiologically relevant and easily scalable LUHMES cell-based model of G2019S LRRK2-driven Parkinson's disease.

ABSTRACTParkinson's disease (PD) is a fatal neurodegenerative disorder that is primarily caused by the degeneration and loss of dopaminergic neurons of the substantia nigra in the ventral midbrain. Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common genetic cause of late-onset PD identified to date, with G2019S being the most frequent LRRK2 mutation, which is responsible for up to 1-2% of sporadic PD and up to 6% of familial PD cases. As no treatment is available for this devastating disease, developing new therapeutic strategies is of foremost importance. Cellular models are commonly used for testing novel potential neuroprotective compounds. However, current cellular PD models either lack physiological relevance to dopaminergic neurons or are too complex and costly for scaling up the production process and for screening purposes. In order to combine biological relevance and throughput, we have developed a PD model in Lund human mesencephalic (LUHMES) cell-derived dopaminergic neurons by overexpressing wild-type (WT) and G2019S LRRK2 proteins. We show that these cells can differentiate into dopaminergic-like neurons and that expression of mutant LRRK2 causes a range of different phenotypes, including reduced nuclear eccentricity, altered mitochondrial and lysosomal morphologies, and increased dopaminergic cell death. This model could be used to elucidate G2019S LRRK2-mediated dopaminergic neural dysfunction and to identify novel molecular targets for disease intervention. In addition, our model could be applied to high-throughput and phenotypic screenings for the identification of novel PD therapeutics.