Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) causes seizure activity in larval zebrafish via antagonism of γ-aminobutyric acid type A receptor α1ß2γ2.

Hexahydro-1,3,5-trinitro-1,3,5-triazine, or Royal Demolition Explosive (RDX), is a major component of plastic explosives such as C-4. Acute exposures from intentional or accidental ingestion are a documented clinical concern, especially among young male U.S. service members in the armed forces. When ingested in large enough quantity, RDX causes tonic-clonic seizures. Previous in silico and in vitro experiments predict that RDX causes seizures by inhibiting α1ß2γ2 γ-aminobutyric acid type A (GABAA) receptor-mediated chloride currents. To determine whether this mechanism translates in vivo, we established a larval zebrafish model of RDX-induced seizures. After a 3 h of exposure to 300 µM RDX, larval zebrafish exhibited a significant increase in motility in comparison to vehicle controls. Researchers blinded to experimental group manually scored a 20-min segment of video starting at 3.5 h post-exposure and found significant seizure behavior that correlated with automated seizure scores. Midazolam (MDZ), an nonselective GABAAR positive allosteric modulator (PAM), and a combination of Zolpidem (α1 selective PAM) and compound 2-261 (ß2/3-selective PAM) were effective in mitigating RDX-triggered behavioral and electrographic seizures. These findings confirm that RDX induces seizure activity via inhibition of the α1ß2γ2 GABAAR and support the use of GABAAR-targeted anti-seizure drugs for the treatment of RDX-induced seizures.

GM1 ganglioside modifies microglial and neuroinflammatory responses to α-synuclein in the rat AAV-A53T α-synuclein model of Parkinson's disease.

Among the pathological events associated with the dopaminergic neurodegeneration characteristic of Parkinson's disease (PD) are the accumulation of toxic forms of α-synuclein and microglial activation associated with neuroinflammation. Although numerous other processes may participate in the pathogenesis of PD, the two factors mentioned above may play critical roles in the initiation and progression of dopamine neuron degeneration in PD. In this study, we employed a slowly progressing model of PD using adeno-associated virus-mediated expression of human A53T α-synuclein into the substantia nigra on one side of the brain and examined the microglial response in the striatum on the injected side compared to the non-injected (control) side. We further examined the extent to which administration of the neuroprotective ganglioside GM1 influenced α-synuclein-induced glial responses. Changes in a number of microglial morphological measures (i.e., process length, number of endpoints, fractal dimension, lacunarity, density, and cell perimeter) were indicative of the presence of activated microglial and an inflammatory response on the injected side of the brain, compared to the control side. In GM1-treated animals, no significant differences in microglial morphology were observed between the injected and control striata. Follow-up studies showed that mRNA expression for several inflammation-related genes was increased on the A53T α-synuclein injected side vs. the non-injected side in saline-treated animals and that such changes were not observed in GM1-treated animals. These data show that inhibition of microglial activation and potentially damaging neuroinflammation by GM1 ganglioside administration may be among the many factors that contribute to the neuroprotective effects of GM1 in this model and possibly in human PD.

Molecular determinants of pro-arrhythmia proclivity of d- and l-sotalol via a multi-scale modeling pipeline.

Drug isomers may differ in their proarrhythmia risk. An interesting example is the drug sotalol, an antiarrhythmic drug comprising d- and l- enantiomers that both block the hERG cardiac potassium channel and confer differing degrees of proarrhythmic risk. We developed a multi-scale in silico pipeline focusing on hERG channel - drug interactions and used it to probe and predict the mechanisms of pro-arrhythmia risks of the two enantiomers of sotalol. Molecular dynamics (MD) simulations predicted comparable hERG channel binding affinities for d- and l-sotalol, which were validated with electrophysiology experiments. MD derived thermodynamic and kinetic parameters were used to build multi-scale functional computational models of cardiac electrophysiology at the cell and tissue scales. Functional models were used to predict inactivated state binding affinities to recapitulate electrocardiogram (ECG) QT interval prolongation observed in clinical data. Our study demonstrates how modeling and simulation can be applied to predict drug effects from the atom to the rhythm for dl-sotalol and also increased proarrhythmia proclivity of d- vs. l-sotalol when accounting for stereospecific beta-adrenergic receptor blocking.

Artificial Intelligence-Based Portable Bioelectronics Platform for SARS-CoV-2 Diagnosis with Multi-nucleotide Probe Assay for Clinical Decisions.

In the context of the recent pandemic, the necessity of inexpensive and easily accessible rapid-test kits is well understood and need not be stressed further. In light of this, we report a multi-nucleotide probe-based diagnosis of SARS-CoV-2 using a bioelectronics platform, comprising low-cost chemiresistive biochips, a portable electronic readout, and an Android application for data acquisition with machine-learning-based decision making. The platform performs the desired diagnosis from standard nasopharyngeal and/or oral swabs (both on extracted and non-extracted RNA samples) without amplifying the viral load. Being a reverse transcription polymerase chain reaction-free hybridization assay, the proposed approach offers inexpensive, fast (time-to-result: ≤ 30 min), and early diagnosis, as opposed to most of the existing SARS-CoV-2 diagnosis protocols recommended by the WHO. For the extracted RNA samples, the assay accounts for 87 and 95.2% test accuracies, using a heuristic approach and a machine-learning-based classification method, respectively. In case of the non-extracted RNA samples, 95.6% decision accuracy is achieved using the heuristic approach, with the machine-learning-based best-fit model producing 100% accuracy. Furthermore, the availability of the handheld readout and the Android application-based simple user interface facilitates easy accessibility and portable applications. Besides, by eliminating viral RNA extraction from samples as a pre-requisite for specific detection, the proposed approach presents itself as an ideal candidate for point-of-care SARS-CoV-2 diagnosis.

Cryptography in Hierarchical Coded Caching: System Model and Cost Analysis.

The idea behind network caching is to reduce network traffic during peak hours via transmitting frequently-requested content items to end users during off-peak hours. However, due to limited cache sizes and unpredictable access patterns, this might not totally eliminate the need for data transmission during peak hours. Coded caching was introduced to further reduce the peak hour traffic. The idea of coded caching is based on sending coded content which can be decoded in different ways by different users. This allows the server to service multiple requests by transmitting a single content item. Research works regarding coded caching traditionally adopt a simple network topology consisting of a single server, a single hub, a shared link connecting the server to the hub, and private links which connect the users to the hub. Building on the results of Sengupta et al. (IEEE Trans. Inf. Forensics Secur., 2015), we propose and evaluate a yet more complex system model that takes into consideration both throughput and security via combining the mentioned ideas. It is demonstrated that the achievable rates in the proposed model are within a constant multiplicative and additive gap with the minimum secure rates.

SKA-31, an activator of Ca2+-activated K+ channels, improves cardiovascular function in aging.

Aging represents an independent risk factor for the development of cardiovascular disease, and is associated with complex structural and functional alterations in the vasculature, such as endothelial dysfunction. Small- and intermediate-conductance, Ca2+-activated K+ channels (KCa2.3 and KCa3.1, respectively) are prominently expressed in the vascular endothelium, and pharmacological activators of these channels induce robust vasodilation upon acute exposure in isolated arteries and intact animals. However, the effects of prolonged in vivo administration of such compounds are unknown. In our study, we hypothesized that such treatment would ameliorate aging-related cardiovascular deficits. Aged (∼18 months) male Sprague Dawley rats were treated daily with either vehicle or the KCa channel activator SKA-31 (10 mg/kg, intraperitoneal injection; n = 6/group) for 8 weeks, followed by echocardiography, arterial pressure myography, immune cell and plasma cytokine characterization, and tissue histology. Our results show that SKA-31 administration improved endothelium-dependent vasodilation, reduced agonist-induced vascular contractility, and prevented the aging-associated declines in cardiac ejection fraction, stroke volume and fractional shortening, and further improved the expression of endothelial KCa channels and associated cell signalling components to levels similar to those observed in young male rats (∼5 months at end of study). SKA-31 administration did not promote pro-inflammatory changes in either T cell populations or plasma cytokines/chemokines, and we observed no overt tissue histopathology in heart, kidney, aorta, brain, liver and spleen. SKA-31 treatment in young rats had little to no effect on vascular reactivity, select protein expression, tissue histology, plasma cytokines/chemokines or immune cell properties. Collectively, these data demonstrate that administration of the KCa channel activator SKA-31 improved aging-related cardiovascular function, without adversely affecting the immune system or promoting tissue toxicity.

Comparison of the toxicokinetics of the convulsants picrotoxinin and tetramethylenedisulfotetramine (TETS) in mice.

Acute intoxication with picrotoxin or the rodenticide tetramethylenedisulfotetramine (TETS) can cause seizures that rapidly progress to status epilepticus and death. Both compounds inhibit γ-aminobutyric acid type-A (GABAA) receptors with similar potency. However, TETS is approximately 100 × more lethal than picrotoxin. Here, we directly compared the toxicokinetics of the two compounds following intraperitoneal administration in mice. Using LC/MS analysis we found that picrotoxinin, the active component of picrotoxin, hydrolyses quickly into picrotoxic acid, has a short in vivo half-life, and is moderately brain penetrant (brain/plasma ratio 0.3). TETS, in contrast, is not metabolized by liver microsomes and persists in the body following intoxication. Using both GC/MS and a TETS-selective immunoassay we found that mice administered TETS at the LD50 of 0.2 mg/kg in the presence of rescue medications exhibited serum levels that remained constant around 1.6 µM for 48 h before falling slowly over the next 10 days. TETS showed a similar persistence in tissues. Whole-cell patch-clamp demonstrated that brain and serum extracts prepared from mice at 2 and 14 days after TETS administration significantly blocked heterologously expressed α2ß3γ2 GABAA-receptors confirming that TETS remains pharmacodynamically active in vivo. This observed persistence may contribute to the long-lasting and recurrent seizures observed following human exposures. We suggest that countermeasures to neutralize TETS or accelerate its elimination should be explored for this highly dangerous threat agent.

Kv1.3 inhibition as a potential microglia-targeted therapy for Alzheimer's disease: preclinical proof of concept.

Microglia significantly contribute to the pathophysiology of Alzheimer's disease but an effective microglia-targeted therapeutic approach is not yet available clinically. The potassium channels Kv1.3 and Kir2.1 play important roles in regulating immune cell functions and have been implicated by in vitro studies in the 'M1-like pro-inflammatory' or 'M2-like anti-inflammatory' state of microglia, respectively. We here found that amyloid-ß oligomer-induced expression of Kv1.3 and Kir2.1 in cultured primary microglia. Likewise, ex vivo microglia acutely isolated from the Alzheimer's model 5xFAD mice co-expressed Kv1.3 and Kir2.1 as well as markers traditionally associated with M1 and M2 activation suggesting that amyloid-ß oligomer induces a microglial activation state that is more complex than previously thought. Using the orally available, brain penetrant small molecule Kv1.3 blocker PAP-1 as a tool, we showed that pro-inflammatory and neurotoxic microglial responses induced by amyloid-ß oligomer required Kv1.3 activity in vitro and in hippocampal slices. Since we further observed that Kv1.3 was highly expressed in microglia of transgenic Alzheimer's mouse models and human Alzheimer's disease brains, we hypothesized that pharmacological Kv1.3 inhibition could mitigate the pathology induced by amyloid-ß aggregates. Indeed, treating APP/PS1 transgenic mice with a 5-month oral regimen of PAP-1, starting at 9 months of age, when the animals already manifest cognitive deficits and amyloid pathology, reduced neuroinflammation, decreased cerebral amyloid load, enhanced hippocampal neuronal plasticity, and improved behavioural deficits. The observed decrease in cerebral amyloid deposition was consistent with the in vitro finding that PAP-1 enhanced amyloid-ß uptake by microglia. Collectively, these results provide proof-of-concept data to advance Kv1.3 blockers to Alzheimer's disease clinical trials.

Structural Insights into the Atomistic Mechanisms of Action of Small Molecule Inhibitors Targeting the KCa3.1 Channel Pore.

The intermediate-conductance Ca2+-activated K+ channel (KCa3.1) constitutes an attractive pharmacological target for immunosuppression, fibroproliferative disorders, atherosclerosis, and stroke. However, there currently is no available crystal structure of this medically relevant channel that could be used for structure-assisted drug design. Using the Rosetta molecular modeling suite we generated a molecular model of the KCa3.1 pore and tested the model by first confirming previously mapped binding sites and visualizing the mechanism of TRAM-34 (1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole), senicapoc (2,2-bis-(4-fluorophenyl)-2-phenylacetamide), and NS6180 (4-[[3-(trifluoromethyl)phenyl]methyl]-2H-1,4-benzothiazin-3(4H)-one) inhibition at the atomistic level. All three compounds block ion conduction directly by fully or partially occupying the site that would normally be occupied by K+ before it enters the selectivity filter. We then challenged the model to predict the receptor sites and mechanisms of action of the dihydropyridine nifedipine and an isosteric 4-phenyl-pyran. Rosetta predicted receptor sites for nifedipine in the fenestration region and for the 4-phenyl-pyran in the pore lumen, which could both be confirmed by site-directed mutagenesis and electrophysiology. While nifedipine is thus not a pore blocker and might be stabilizing the channel in a nonconducting conformation or interfere with gating, the 4-phenyl-pyran was found to be a classical pore blocker that directly inhibits ion conduction similar to the triarylmethanes TRAM-34 and senicapoc. The Rosetta KCa3.1 pore model explains the mechanism of action of several KCa3.1 blockers at the molecular level and could be used for structure-assisted drug design.

Rapid Throughput Analysis of GABAA Receptor Subtype Modulators and Blockers Using DiSBAC1(3) Membrane Potential Red Dye.

Fluorometric imaging plate reader membrane potential dye (FMP-Red-Dye) is a proprietary tool for basic discovery and high-throughput drug screening for G-protein-coupled receptors and ion channels. We optimized and validated this potentiometric probe to assay functional modulators of heterologous expressed GABAA receptor (GABAAR) isoforms (synaptic α1ß3γ2, extrasynaptic α4ß3δ, and ß3 homopentomers). High-resolution mass spectrometry identified FMP-Red-Dye as 5,5'-(1-propen-1-yl-3-ylidene)bis[1,3-dimethyl-2-thio-barbituric acid]. GABAAR-expressing cells equilibrated with FMP-Red-Dye exhibited depolarized equilibrium membrane potentials compared with GABAAR-null cells. The channel blockers picrotoxin, fipronil, and tetramethylenedisulfotetramine, and the competitive antagonist bicuculline reduced fluorescence near the levels in GABAAR-null cells indicating that FMR-Red-Dye, a barbiturate derivative, activates GABAAR-mediated outward Cl- current in the absence of GABA. GABA caused concentration-dependent increases in fluorescence with rank order of potencies among GABAAR isoforms consistent with results from voltage-clamp experiments (EC50 values for α4ß3δ, α1ß3γ2, and ß3 homopentamers were 6 ± 1, 40 ± 11, and >18 mM, respectively), whereas GABAAR-null cells were unresponsive. Neuroactive steroids (NAS) increased fluorescence of GABAAR expressing cells in the absence of GABA and demonstrated positive allosteric modulation in the presence of GABA, whereas benzodiazepines only exhibited positive allosteric modulator (PAM) activity. Of 20 NAS tested, allopregnanolone, (3α,5α,20E)-3-hydroxy-13,24-cyclo-18-norcholan-20-ene-21-carbonitrile, eltanolone, 5ß-pregnan-3α,21-diol-20-one, and ganaxolone showed the highest potency. The FMP-Red-Dye-based assay described here provides a sensitive and quantitative method of assessing the activity of GABAAR agonists, antagonists, and PAMs on diverse GABAAR isoforms. The assay has a wide range of applications, including screening for antiseizure agents and identifying channel blockers of interest to insecticide discovery or biosecurity.

A multi-walled carbon nanotube-zinc oxide nanofiber based flexible chemiresistive biosensor for malaria biomarker detection.

We report the fabrication of a flexible, lightweight and disposable multi walled carbon nanotube (MWCNT)-zinc oxide (ZnO) nanofiber based chemiresistive biosensor for label free detection of the malaria biomarker, histidine rich protein II (HRP2). The sensing platform is formed by depositing nanofibers in between the source and drain electrodes patterned on a thin, flexible polyethylene terephthalate (PET) substrate. MWCNT-ZnO nanofibers are synthesized via the electrospinning technique followed by a calcination process. This approach creates functional groups on the nanofiber surface that are used for the one step immobilization of HRP2 antibodies without further surface modification. The device exhibits a good sensitivity of 8.29 kΩ g-1 mL and a wide detection range of 10 fg mL-1-10 ng mL-1, and it is specific towards the targeted HRP2 biomarker. To the best of our knowledge, this is the first report on a flexible chemiresistive biosensor explored for the detection of the malaria biomarker and can be extended in the future to several other biomarker detection systems towards smart point-of-care (POC) diagnostics.

Neuronal Atrophy Early in Degenerative Ataxia Is a Compensatory Mechanism to Regulate Membrane Excitability.

Neuronal atrophy in neurodegenerative diseases is commonly viewed as an early event in a continuum that ultimately results in neuronal loss. In a mouse model of the polyglutamine disorder spinocerebellar ataxia type 1 (SCA1), we tested the hypothesis that cerebellar Purkinje neuron atrophy serves an adaptive role rather than being simply a nonspecific response to injury. In acute cerebellar slices from SCA1 mice, we find that Purkinje neuron pacemaker firing is initially normal but, with the onset of motor dysfunction, becomes disrupted, accompanied by abnormal depolarization. Remarkably, subsequent Purkinje cell atrophy is associated with a restoration of pacemaker firing. The early inability of Purkinje neurons to support repetitive spiking is due to unopposed calcium currents resulting from a reduction in large-conductance calcium-activated potassium (BK) and subthreshold-activated potassium channels. The subsequent restoration of SCA1 Purkinje neuron firing correlates with the recovery of the density of these potassium channels that accompanies cell atrophy. Supporting a critical role for BK channels, viral-mediated increases in BK channel expression in SCA1 Purkinje neurons improves motor dysfunction and partially restores Purkinje neuron morphology. Cerebellar perfusion of flufenamic acid, an agent that restores the depolarized membrane potential of SCA1 Purkinje neurons by activating potassium channels, prevents Purkinje neuron dendritic atrophy. These results suggest that Purkinje neuron dendritic remodeling in ataxia is an adaptive response to increases in intrinsic membrane excitability. Similar adaptive remodeling could apply to other vulnerable neuronal populations in neurodegenerative disease. SIGNIFICANCE STATEMENT: In neurodegenerative disease, neuronal atrophy has long been assumed to be an early nonspecific event preceding neuronal loss. However, in a mouse model of spinocerebellar ataxia type 1 (SCA1), we identify a previously unappreciated compensatory role for neuronal shrinkage. Purkinje neuron firing in these mice is initially normal, but is followed by abnormal membrane depolarization resulting from a reduction in potassium channels. Subsequently, these electrophysiological effects are counteracted by cell atrophy, which by restoring normal potassium channel membrane density, re-establishes pacemaker firing. Reversing the initial membrane depolarization improved motor function and Purkinje neuron morphology in the SCA1 mice. These results suggest that Purkinje neuron remodeling in ataxia is an active compensatory response that serves to normalize intrinsic membrane excitability.

Diisopropylfluorophosphate Impairs the Transport of Membrane-Bound Organelles in Rat Cortical Axons.

The extensive use of organophosphates (OPs) is an ongoing environmental health concern due to multiple reports of OP-related neurologic abnormalities. The mechanism of the acute toxicity of OPs has been attributed to inhibition of acetylcholinesterase (AChE), but there is growing evidence that this may not account for all the long-term neurotoxic effects of OPs. In previous experiments (using ex vivo and in vitro model systems) we observed that the insecticide OP chlorpyrifos impaired the movements of vesicles and mitochondria in axons. Here, using a time-lapse imaging technique, we evaluated the OP-nerve agent diisopropylfluorophosphate (DFP) across a wide range of concentrations (subnanomolar to micromolar) for effects on fast axonal transport of membrane-bound organelles (MBOs) that contain the amyloid precursor protein (APP) tagged with the fluorescent marker Dendra2 (APPDendra2). Both 1 and 24 hours of exposure to DFP and a positive control compound, colchicine, resulted in a decrease in the velocity of anterograde and retrograde movements of MBOs and an increase in the number of stationary MBOs. These effects occurred at picomolar (100 pM) to low nanomolar (0.1 nM) concentrations that were not associated with compromised cell viability or cytoskeletal damage. Moreover, the effects of DFP on axonal transport occurred at concentrations that did not inhibit AChE activity, and they were not blocked by cholinergic receptor antagonists. Given the fundamental importance of axonal transport to neuronal function, these observations may explain some of the long-term neurologic deficits that have been observed in humans who have been exposed to OPs.

Chasing the Elusive Benzofuran Impurity of the THR Antagonist NH-3: Synthesis, Isotope Labeling, and Biological Activity.

We have synthesized and established the structure of a long-suspected, but hitherto unknown, benzofuran side product (EBI) formed during the synthesis of NH-3. Understanding the mechanism of its formation has enabled isotope (D) labeling. We further developed a highly efficient method for separating EBI from NH-3. Interestingly, EBI was found to be a very potent thyroid hormone receptor (THR) agonist, while NH-3 is an antagonist. In this process, we have also achieved a significantly improved synthesis of NH-3.

New positive Ca2+-activated K+ channel gating modulators with selectivity for KCa3.1.

Small-conductance (KCa2) and intermediate-conductance (KCa3.1) calcium-activated K(+) channels are voltage-independent and share a common calcium/calmodulin-mediated gating mechanism. Existing positive gating modulators like EBIO, NS309, or SKA-31 activate both KCa2 and KCa3.1 channels with similar potency or, as in the case of CyPPA and NS13001, selectively activate KCa2.2 and KCa2.3 channels. We performed a structure-activity relationship (SAR) study with the aim of optimizing the benzothiazole pharmacophore of SKA-31 toward KCa3.1 selectivity. We identified SKA-111 (5-methylnaphtho[1,2-d]thiazol-2-amine), which displays 123-fold selectivity for KCa3.1 (EC50 111 ± 27 nM) over KCa2.3 (EC50 13.7 ± 6.9 µM), and SKA-121 (5-methylnaphtho[2,1-d]oxazol-2-amine), which displays 41-fold selectivity for KCa3.1 (EC50 109 nM ± 14 nM) over KCa2.3 (EC50 4.4 ± 1.6 µM). Both compounds are 200- to 400-fold selective over representative KV (KV1.3, KV2.1, KV3.1, and KV11.1), NaV (NaV1.2, NaV1.4, NaV1.5, and NaV1.7), as well as CaV1.2 channels. SKA-121 is a typical positive-gating modulator and shifts the calcium-concentration response curve of KCa3.1 to the left. In blood pressure telemetry experiments, SKA-121 (100 mg/kg i.p.) significantly lowered mean arterial blood pressure in normotensive and hypertensive wild-type but not in KCa3.1(-/-) mice. SKA-111, which was found in pharmacokinetic experiments to have a much longer half-life and to be much more brain penetrant than SKA-121, not only lowered blood pressure but also drastically reduced heart rate, presumably through cardiac and neuronal KCa2 activation when dosed at 100 mg/kg. In conclusion, with SKA-121, we generated a KCa3.1-specific positive gating modulator suitable for further exploring the therapeutical potential of KCa3.1 activation.

Alterations in cerebellar physiology are associated with a stiff-legged gait in Atcay(ji-hes) mice.

Recent evidence suggests that dystonia, a movement disorder characterized by sustained involuntary muscle contractions, can be associated with cerebellar abnormalities. The basis for how functional changes in the cerebellum can cause dystonia is poorly understood. Here we identify alterations in physiology in Atcay(ji-hes) mice which in addition to ataxia, have an abnormal gait with hind limb extension and toe walking, reminiscent of human dystonic gait. No morphological abnormalities in the brain accompany the dystonia, but partial cerebellectomy causes resolution of the stiff-legged gait, suggesting that cerebellar dysfunction contributes to the dystonic gait of Atcay(ji-hes) mice. Recordings from Purkinje and deep cerebellar nuclear (DCN) neurons in acute brain slices were used to determine the physiological correlates of dystonia in the Atcay(ji-hes) mice. Approximately 50% of cerebellar Purkinje neurons fail to display the normal repetitive firing characteristic of these cells. In addition, DCN neurons exhibit increased intrinsic firing frequencies with a subset of neurons displaying bursts of action potentials. This increased intrinsic excitability of DCN neurons is accompanied by a reduction in after-hyperpolarization currents mediated by small-conductance calcium-activated potassium (SK) channels. An activator of SK channels reduces DCN neuron firing frequency in acute cerebellar slices and improves the dystonic gait of Atcay(ji-hes) mice. These results suggest that a combination of reduced Purkinje neuron activity and increased DCN intrinsic excitability can result in a combination of ataxia and a dystonia-like gait in mice.

Nexus of NFκB/VEGF/MMP9 signaling in diabetic retinopathy-linked dementia: Management by phenolic acid-enabled nanotherapeutics.

AIMS: The purpose of this review is to highlight the therapeutic effectiveness of phenolic acids in slowing the progression of diabetic retinopathy (DR)-linked dementia by addressing the nuclear factor kappa B (NFκB)/matrix metalloproteinase-9 (MMP9)/vascular endothelial growth factor (VEGF) interconnected pathway. MATERIALS AND METHODS: We searched 80 papers published in the last 20 years using terms like DR, dementia, phenolic acids, NFkB/VEFG/MMP9 signaling, and microRNAs (miRs) in databases including Pub-Med, WOS, and Google Scholar. By encasing phenolic acid in nanoparticles and then controlling its release into the targeted tissues, nanotherapeutics can increase their effectiveness. Results were summarized, and compared, and research gaps were identified throughout the data collection and interpretation. KEY FINDINGS: Amyloid beta (Aß) deposition in neuronal cells and drusen sites of the eye leads to the activation of NFkB/VEGF/MMP9 signaling and microRNAs (miR146a and miR155), which in turn energizes the accumulation of pro-inflammatory and pro-angiogenic microenvironments in the brain and retina leading to DR-linked dementia. This study demonstrates the potential of phenolic acid-enabled nanotherapeutics as a functional food or supplement for preventing and treating DR-linked dementia, and oxidative stress-related diseases. SIGNIFICANCE: The retina has mechanisms to clear metabolic waste including Aß, but the activation of NFkB/ MMP9/ VEGF signaling leads to fatal pathological consequences. Understanding the role of miR146a and miR155 provides potential therapeutic avenues for managing the complex pathology shared between DR and dementia. In particular, phenolic acid nanotherapeutics offer a dual benefit in retinal regeneration and dementia management.

Participation of Lens Proteins and miRs in Traumatic and Inheritance Cataract: A Review on Diagnostic and Therapeutic Approaches for Cataract Management.

Traumatic and inherited cataract spiking blindness is caused by accumulated deposition of mutant eye lens protein or lens microarchitecture alteration. A traumatic cataract is a clouding of the eye's natural lens that occurs as a result of physical trauma to the eye. This trauma can be caused by various incidents such as blunt force injury, penetration by a foreign object, or a significant impact on the eye area. Inheritance cataracts or hereditary cataracts are cataracts that are genetically inherited from one or both parents. Complications following cataract surgery encompass various adverse outcomes such as inflammation, infection, bleeding, swelling, drooping eyelid, glaucoma, secondary cataracts, and complete loss of vision. The main purpose of the review is to highlight common pathophysiology associated with traumatic and inherited cataracts. Also, the review discusses diagnosis and treatment strategies for such cataract types by targeting their key pathological hallmarks. γD-crystallin plays a crucial role in maintaining the optical properties of the lens during the life span of an individual. Carbamazepine, Resveratrol, and Myricetin (CRM) are effectively bound at the γD-crystallin binding site and thereby could minimize misfolding and aggregation of γD-crystallin. miR-202, miR-193b, miR-135a, miR365, and miR-376a had the highest levels of abundance in the aqueous humor of individuals diagnosed with cataracts. The validation of these miRs will provide more insights into their functional roles and may be used for diagnostic purposes. The effective CRM combination as a multidrug formulation may postpone both traumatic and inherited cataracts and protect the eye from blindness.

The Dysregulated MAD in Mad: A Neuro-theranostic Approach Through the Induction of Autophagic Biomarkers LC3B-II and ATG.

The word mad has historically been associated with the psyche, emotions, and abnormal behavior. Dementia is a common symptom among psychiatric disorders or mad (schizophrenia, depression, bipolar disorder) patients. Autophagy/mitophagy is a protective mechanism used by cells to get rid of dysfunctional cellular organelles or mitochondria. Autophagosome/mitophagosome abundance in autophagy depends on microtubule-associated protein light chain 3B (LC3B-II) and autophagy-triggering gene (ATG) which functions as an autophagic biomarker for phagophore production and quick mRNA disintegration. Defects in either LC3B-II or the ATG lead to dysregulated mitophagy-and-autophagy-linked dementia (MAD). The impaired MAD is closely associated with schizophrenia, depression, and bipolar disorder. The pathomechanism of psychosis is not entirely known, which is the severe limitation of today's antipsychotic drugs. However, the reviewed circuit identifies new insights that may be especially helpful in targeting biomarkers of dementia. Neuro-theranostics can also be achieved by manufacturing either bioengineered bacterial and mammalian cells or nanocarriers (liposomes, polymers, and nanogels) loaded with both imaging and therapeutic materials. The nanocarriers must cross the BBB and should release both diagnostic agents and therapeutic agents in a controlled manner to prove their effectiveness against psychiatric disorders. In this review, we highlighted the potential of microRNAs (miRs) as neuro-theranostics in the treatment of dementia by targeting autophagic biomarkers LC3B-II and ATG. Focus was also placed on the potential for neuro-theranostic nanocells/nanocarriers to traverse the BBB and induce action against psychiatric disorders. The neuro-theranostic approach can provide targeted treatment for mental disorders by creating theranostic nanocarriers.

Riluzole and novel naphthalenyl substituted aminothiazole derivatives prevent acute neural excitotoxic injury in a rat model of temporal lobe epilepsy.

Epileptogenic seizures, or status epilepticus (SE), leads to excitotoxic injury in hippocampal and limbic neurons in the kainic acid (KA) animal model of temporal lobe epilepsy (TLE). Here, we have further characterized neural activity regulated methylaminoisobutryic acid (MeAIB)/glutamine transport activity in mature rat hippocampal neurons in vitro that is inhibited by riluzole (IC50 = 1 µM), an anti-convulsant benzothiazole agent. We screened a library of riluzole derivatives and identified SKA-41 followed by a second screen and synthesized several novel chlorinated aminothiazoles (SKA-377, SKA-378, SKA-379) that are also potent MeAIB transport inhibitors in vitro, and brain penetrant following systemic administration. When administered before KA, SKA-378 did not prevent seizures but still protected the hippocampus and several other limbic areas against SE-induced neurodegeneration at 3d. When SKA-377 - 379, (30 mg/kg) were administered after KA-induced SE, acute neural injury in the CA3, CA1 and CA4/hilus was also largely attenuated. Riluzole (10 mg/kg) blocks acute neural injury. Kinetic analysis of SKA-378 and riluzoles' blockade of Ca2+-regulated MeAIB transport in neurons in vitro indicates that inhibition occurs via a non-competitive, indirect mechanism. Sodium channel NaV1.6 antagonism blocks neural activity regulated MeAIB/Gln transport in vitro (IC50 = 60 nM) and SKA-378 is the most potent inhibitor of NaV1.6 (IC50 = 28 µM) compared to NaV1.2 (IC50 = 118 µM) in heterologous cells. However, pharmacokinetic analysis suggests that sodium channel blockade may not be the predominant mechanism of neuroprotection here. Riluzole and our novel aminothiazoles are agents that attenuate acute neural hippocampal injury following KA-induced SE and may help to understand mechanisms involved in the progression of epileptic disease.