Mechanisms Of Interplay Research Articles

Solvent-assisted thermogalvanic cell for enhanced low-grade heat harvesting over an extended temperature range

In the pursuit of sustainable energy harvesting from low-grade heat, thermogalvanic cells (TGCs) have received considerable attention, but still confront profound challenges in efficiency and cost-effectiveness, limiting their real-world applications. To expedite the deployment of TGCs, this study delves into the mechanistic interplay of three crucial determinants: intrinsic temperature coefficient, concentration gradient, and activity coefficient of redox couples, elucidating their impact on TGCs' thermoelectric performance. We report a solvent-assisted liquid-state thermogalvanic cell (SA-LTC) by incorporating organic solvents into the sodium ferrocyanide-based TGCs system. With ethanol as a regulator to the concentration gradient and solvation structure, the temperature coefficient of [Fe(CN)6]3-/4- can be enhanced from − 1.39 to − 4.32 mV K−1, leading to a five-fold increase in thermoelectric power and efficiency. Meanwhile, ethanol imparts a lower freezing point and wider working temperature range to the system, showing its better environmental adaptability. In particular, SA-LTC performs better at lower temperatures, at which it achieved a record-high temperature coefficient of − 5.26 mV K−1 and a power density of 2.17 mW m−2 K−2 at 10–20 °C. This study not only provides useful guidance to the optimization of electrolyte design, but also highlights the potential of TGCs for sustainable energy conversion in varied thermal conditions for practical applications.

ABA and Melatonin: Players on the Same Field?

In plants, abscisic acid (ABA) and melatonin (MT) are conventionally treated as molecules mitigating stress responses. To understand the mechanisms of ABA-MT interplay, we examined the effects of ABA and MT treatment in ABA and MT loss-of-function mutants of Arabidopsis thaliana exposed to high light (HL) stress. ABA constantly suppressed ASMT encoding N-acetylserotonin methyltransferase in the context of differential responses of other MT biosynthesis genes in both the wild type (WT) and mutants. However, this response was absent in the mutant with the disrupted ABI4. Given that the ASMT promoter region contains several potential ABI4-binding elements, these data suggest that ASMT can be a potential target gene for ABI4. A role for ABI4 in the interactions between ABA and MT is supported by the finding that ABI4 is constitutively derepressed in the MT signaling mutants cand2 and gpa1, which exhibited elevated steady state levels of ABI4 transcripts and were not regulated by either stress or melatonin. In addition, the abi4 mutant showed increased modulations in the expression of the MT catabolic genes M2H and M3H in response to ABA treatment, inferring that this transcription factor is a negative regulator of ABA-dependent changes in MT content. Furthermore, all tested mutants with impaired ABA synthesis or signaling displayed elevated steady state MT levels compared to WT, while MT treatment contributed to the downregulation of key ABA synthesis and signaling genes. Collectively, our results suggest that ABA and melatonin act antagonistically, modulating the expression of ABA and MT signaling and metabolism genes. To understand the mechanisms of ABA-MT interactions, we studied the effects of ABA and MT treatment in ABA and MT loss-of-function mutants of Arabidopsis thaliana exposed to severe light stress (SLS).

A novel 3D cardiac microtissue model for investigation of cardiovascular complications in rheumatoid arthritis

BackgroundRheumatoid arthritis (RA) is a chronic inflammatory disease that affects not only the joints but also has significant cardiovascular (CV) manifestations. The mechanistic interplay between RA and cardiovascular complications is not yet well understood due to the lack of relevant in vitro models. In this study, we established RA cardiac microtisses (cMTs) from iPSC-derived cardiomyocytes (CMs), endothelial cells (ECs) and cardiac fibroblasts (CFs) to investigate whether this fully human 3D multicellular system could serve as a platform to elucidate the connection between RA and CV disorders.MethodsPBMC and FLS from healthy and RA donors were reprogrammed to hiPSCs with Sendai vectors. hiPSCs pluripotency was assessed by IF, FACS, spontaneous embryoid bodies formation and teratoma assay. hiPSCs were differentiated to cardiac derivatives such as CMs, ECs and CFs, followed by cell markers characterizations (IF, FACS, qRT-PCR) and functional assessments. 3D cMTs were generated by aggregation of 70% CMs, 15% ECs and 15% CFs. After 21 days in culture, structural and metabolic properties of 3D cMTs were examined by IF, qRT-PCR and Seahorse bioanalyzer.ResultshiPSCs demonstrated typical colony-like morphology, normal karyotype, presence of pluripotency markers, and ability to differentiate into cells originating from all three germ layers. hiPSC-CMs showed spontaneous beating and expression of cardiac markers (cTnT, MYL7, NKX2.5, MYH7). hiPSC-ECs formed sprouting spheres and tubes and expressed CD31 and CD144. hiPSC-CFs presented spindle-shaped morphology and expression of vimentin, collagen 1 and DDR2. Self-aggregation of CMs/ECs/CFs allowed development of contracting 3D cMTs, demonstrating spherical organization of the cells, which partially resembled the cardiac muscle, both in structure and function. IF analysis confirmed the expression of cTnT, CD31, CD144 and DDR2 in generated 3D cMTs. RA cMTs exhibited significantly greater formation of capillary-like structures, mimicking enhanced vascularization—key RA feature—compared to control cMTs. Seahorse examination of cMTs revealed changes in mitochondrial and glycolytic rates in the presence of metabolic substrates and inhibitors.ConclusionsThe cMTs model may represent an advanced human stem cell-based platform for modeling CV complications in RA. The highly developed capillary-like structures observed within RA cMTs highlight a critical feature of inflammation-induced CV dysfunction in chronic inflammatory diseases.

Synergistic phenotypic adaptations of motile purple sulphur bacteria Chromatium okenii during lake-to-laboratory domestication.

Isolating microorganisms from natural environments for cultivation under optimized laboratory settings has markedly improved our understanding of microbial ecology. Artificial growth conditions often diverge from those in natural ecosystems, forcing wild isolates into distinct selective pressures, resulting in diverse eco-physiological adaptations mediated by modification of key phenotypic traits. For motile microorganisms we still lack a biophysical understanding of the relevant traits emerging during domestication and their mechanistic interplay driving short-to-long-term microbial adaptation under laboratory conditions. Using microfluidics, atomic force microscopy, quantitative imaging, and mathematical modeling, we study phenotypic adaptation of Chromatium okenii, a motile phototrophic purple sulfur bacterium from meromictic Lake Cadagno, grown under laboratory conditions over multiple generations. Our results indicate that naturally planktonic C. okenii leverage shifts in cell-surface adhesive interactions, synergistically with changes in cell morphology, mass density, and distribution of intracellular sulfur globules, to suppress their swimming traits, ultimately switching to a sessile lifeform. A computational model of cell mechanics confirms the role of such phenotypic shifts in suppressing the planktonic lifeform. By investigating key phenotypic traits across different physiological stages of lab-grown C. okenii, we uncover a progressive loss of motility during the early stages of domestication, followed by concomitant deflagellation and enhanced surface attachment, ultimately driving the transition of motile sulfur bacteria to a sessile state. Our results establish a mechanistic link between suppression of motility and surface attachment via phenotypic changes, underscoring the emergence of adaptive fitness under laboratory conditions at the expense of traits tailored for natural environments.

Association of Obesity, Inflammation, and Hypogonadism: A Cross-Sectional Study in Males Under 60 Years of Age.

Background Obesity is a significant global health issue closely associated with numerous metabolic disorders, including hypogonadism. Male obesity-related secondary hypogonadism (MOSH) is characterized by reduced testosterone levels, leading to various health complications. The bidirectional relationship between obesity and hypogonadism creates a vicious cycle, with obesity exacerbating hypogonadism and hypogonadism contributing to further obesity. Chronic inflammation, indicated by elevated C-reactive protein (CRP) levels, plays a crucial role in this interplay. The primary aim of this study is to investigate the role of obesity as an isolated factor contributing to hypogonadism. Materials and methods This observational, cross-sectional study was conducted from September 2022 to July 2024 at Dr. D.Y. Patil Medical College and Hospitals in Pune, India. A total of 80 male participants, all under 60 years of age with a BMI greater than 25 kg/m², were included in the study and classified as overweight or obese according to WHO criteria. Exclusion criteria included diabetes, age over 60 years, a BMI less than 25 kg/m², any testicular pathologies, and significant risk factors. After obtaining informed consent, participants underwent thorough clinical examinations and laboratory investigations. Patients who met the criteria were included in the study, with measurements taken for central obesity (waist circumference (WC) and waist-hip ratio (WHR)) and BMI. CRP levels were measured as an inflammatory marker indicative of chronic disease states. Statistical analyses, including correlation and regression analyses, were performed using SPSS software, version 22 (IBM SPSS Statistics, Version 22). Statistical significance was set at p < 0.05. Results The majority of participants fell within the 50-59 age group, with a mean age of 45.95 years. The study found strong positive correlations between BMI (r = 0.76), WC (r = 0.81), and WHR (r = 0.78) with CRP levels, indicating that central obesity is closely linked to systemic inflammation. Additionally, there were significant negative correlations between free testosterone and these anthropometric measures: BMI (r = -0.65), WC (r = -0.70), and WHR (r = -0.67), suggesting that increased adiposity is associated with lower testosterone levels. The strongest negative correlation observed was between CRP and free testosterone (r = -0.82), highlighting the impact of chronic inflammation on hypogonadism. Regression analysis further confirmed that CRP was a significant predictor of free testosterone levels (R-squared = 0.674), emphasizing the crucial role of inflammation in the pathophysiology of hypogonadism in obese individuals. Conclusion This study underscores the intricate relationship between obesity, chronic inflammation, and hypogonadism in men. The bidirectional nature of this relationship suggests that managing obesity and reducing systemic inflammation could potentially alleviate hypogonadism. Interventions focusing on weight loss, improving insulin sensitivity, and anti-inflammatory treatments may thus hold promise in restoring normal testosterone levels in obese men. Understanding and addressing the impact of obesity on male reproductive health is crucial, given the rising prevalence of obesity worldwide. Future research should explore therapeutic avenues and further elucidate the underlying mechanisms of this complex interplay.

Hijacking the BAF complex: the mechanistic interplay of ARID1A and EWS::FLI1 in Ewing sarcoma.

Ewing sarcoma, an aggressive pediatric cancer, is driven by the EWS::FLI1 fusion protein, which disrupts gene expression by hijacking the BAF chromatin remodeling complex. Central to this mechanism is the formation of biomolecular condensates, mediated by the prion-like domains (PrLDs)of EWS and ARID1A, a core BAF subunit. ARID1A serves as a critical interface between EWS::FLI1 and the BAF complex, with its condensate-forming ability essential for the aberrant gene expression that drives tumor growth. The loss of condensate-competent ARID1A significantly impairs tumor progression, identifying it as a potential therapeutic target. However, targeting condensate formation is challenging due to the transient nature of the interactions involved, complicating the development of effective inhibitors. This work underscores the importance of further investigation into therapeutic strategies aimed at disrupting condensate formation in Ewing sarcoma and other related malignancies.

Spatial proteomic profiling elucidates immune determinants of neoadjuvant chemo-immunotherapy in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) presents significant clinical and therapeutic challenges due to its aggressive nature and generally poor prognosis. We initiated a Phase II clinical trial (ChiCTR1900027160) to assess the efficacy of a pioneering neoadjuvant chemo-immunotherapy regimen comprising programmed death-1 (PD-1) blockade (Toripalimab), nanoparticle albumin-bound paclitaxel (nab-paclitaxel), and the oral fluoropyrimidine derivative S-1, in patients with locally advanced ESCC. This study uniquely integrates clinical outcomes with advanced spatial proteomic profiling using Imaging Mass Cytometry (IMC) to elucidate the dynamics within the tumor microenvironment (TME), focusing on the mechanistic interplay of resistance and response. Sixty patients participated, receiving the combination therapy prior to surgical resection. Our findings demonstrated a major pathological response (MPR) in 62% of patients and a pathological complete response (pCR) in 29%. The IMC analysis provided a detailed regional assessment, revealing that the spatial arrangement of immune cells, particularly CD8+ T cells and B cells within tertiary lymphoid structures (TLS), and S100A9+ inflammatory macrophages in fibrotic regions are predictive of therapeutic outcomes. Employing machine learning approaches, such as support vector machine (SVM) and random forest (RF) analysis, we identified critical spatial features linked to drug resistance and developed predictive models for drug response, achieving an area under the curve (AUC) of 97%. These insights underscore the vital role of integrating spatial proteomics into clinical trials to dissect TME dynamics thoroughly, paving the way for personalized and precise cancer treatment strategies in ESCC. This holistic approach not only enhances our understanding of the mechanistic basis behind drug resistance but also sets a robust foundation for optimizing therapeutic interventions in ESCC.

Unraveling the mechanistic interplay between CO and CO2 hydrogenation over Ni, Co, and NiCo catalysts

Although CO and CO2 hydrogenation reactions have been extensively studied, there is still significant controversy regarding the mechanism of methane formation and the routes for byproducts, especially when both carbon sources are simultaneously present. This work combines kinetic, operando-spectroscopic, isotopic techniques and DFT calculations to elucidate the relationships between CO and CO2 hydrogenation over mono Ni, Co and bimetallic NiCo catalysts with similar metal dispersion. The bimetallic catalysts showed a slight synergistic effect for methane formation from CO, while from CO2 the effect was opposite, showing a negative shift of activity as compared with those observed on the monometallic catalysts. The kinetic analysis shows similar apparent order with respect to H2 (∼0.5) and an inverse secondary isotope kinetic effect (<1) for both methanation reactions, suggesting that CH4 formation proceeds via C-O bond breaking in an H*-assisted mechanism, where the rate-determining step was not shown to be sensitive to the carbon source. The anti-synergistic effect observed on the bimetallic catalysts during CO2 hydrogenation is explained by the formation of unreactive HCOO* species (spectator), which generate a lower density of methane intermediates. On the other hand, the formation of the undesired products, i.e., CO or CO2 during CO2 or CO hydrogenation, respectively, shows relevant differences since the CO formation during CO2 hydrogenation proceeds through the desorption of the carbonyl species adsorbed on weak sites, meanwhile the CO2 formation from CO hydrogenation is due to a minority route of direct dissociation of CO, allowing the rejection of O* with CO* to produce CO2. This study contributes to elucidate the routes that determine the selectivity and reactivity for CO and CO2 hydrogenation and their mechanistic relationship. This information is valuable for the rational design and development of new materials with high performance during hydrogenation processes.

Daidzein's potential in halting neurodegeneration: unveiling mechanistic insights.

Neurological conditions encompassing a wide range of disorders pose significant challenges globally. The complex interactions among signaling pathways and molecular elements play pivotal roles in the initiation and progression of neurodegenerative diseases. Isoflavones have emerged as a promising candidate to fight against neurodegenerative diseases. Daidzein, a 7-hydroxy-3-(4-hydroxyphenyl)-chromen-4-one, belongs to the isoflavone class and exhibits a diverse pharmacological profile. It is found primarily in soybeans and soy products, as well as in some other legumes and herbs. Investigations into daidzein have revealed that it confers neuroprotection by inhibiting oxidative stress, inflammation, and apoptosis, which are key contributors to neuronal damage and degeneration. Activating pathways like PI3K/Akt/mTOR and promoting neurotrophic factors like BDNF by daidzein underscore its potential in supporting neuronal function and combating neurodegeneration. Daidzein's effects on dopamine provide further avenues for intervention in conditions like Parkinson's disease. Additionally, the modulation of inflammatory and NRF-2-antioxidant signaling by daidzein reinforces its neuroprotective role. Moreover, daidzein's interaction with receptors and cellular processes like ER-β, GPR30, MAO, VEGF, and GnRH highlights its multifaceted effects across multiple pathways involved in neuroprotection and neuronal function. This review article delves into the mechanistic interplay of various mediators in mediating the neuroprotective effects of daidzein. The review article consolidates and analyzes research published over nearly two decades (2005-2024) from various databases, including PubMed, Scopus, ScienceDirect, and Web of Science, to provide a comprehensive understanding of daidzein's effects and mechanisms in neuroprotection.

Intrinsic link between PGRN and Gba1 D409V mutation dosage in potentiating Gaucher disease.

Gaucher disease (GD) is caused by biallelic GBA1/Gba1 mutations that encode defective glucocerebrosidase (GCase). Progranulin (PGRN, encoded by GRN/Grn) is a modifier of GCase, but the interplay between PGRN and GCase, specifically GBA1/Gba1 mutations, contributing to GD severity is unclear. Mouse models were developed with various dosages of Gba1 D409V mutation against the PGRN deficiency (Grn-/-) [Grn-/-;Gba1D409V/WT (PG9Vwt), Grn-/-;Gba1D409V/D409V (PG9V), Grn-/-;Gba1D409V/Null (PG9VN)]. Disease progression in those mouse models was characterized by biochemical, pathological, transcriptomic, and neurobehavioral analyses. Compared to PG9Vwt, Grn-/-;Gba1WT/Null and Grn-/- mice that had a higher level of GCase activity and undetectable pathologies, homozygous or hemizygous D409V in PG9V or PG9VN, respectively, resulted in profound inflammation and neurodegeneration. PG9VN mice exhibited much earlier onset, shorter life span, tissue fibrosis, and more severe phenotypes than PG9V mice. Glycosphingolipid accumulation, inflammatory responses, lysosomal-autophagy dysfunction, microgliosis, retinal gliosis, as well as α-Synuclein increases were much more pronounced in PG9VN mice. Neurodegeneration in PG9VN was characterized by activated microglial phagocytosis of impaired neurons and programmed cell death due to necrosis and, possibly, pyroptosis. Brain transcriptomic analyses revealed the intrinsic relationship between D409V dosage, and the degree of altered gene expression related to lysosome dysfunction, microgliosis, and neurodegeneration in GD, suggesting the disease severity is dependent on a GCase activity threshold related to Gba1 D409V dosage and loss of PGRN. These findings contribute to a deeper understanding of GD pathogenesis by elucidating additional underlying mechanisms of interplay between PGRN and Gba1 mutation dosage in modulating GCase function and disease severity in GD and GBA1-associated neurodegenerative diseases.

Modulation of Comorbid Chronic Neuropathic Pain and Anxiety-Like Behaviors by Glutamatergic Neurons in the vlPAG and the Analgesic and Anxiolytic Effects of EA.

Comorbid chronic neuropathic pain and anxiety is a common disease that represents a major clinical challenge. The underlying mechanisms of chronic neuropathic pain and anxiety are not entirely understood, which limits the exploration of effective treatment methods. Glutamatergic neurons in the ventrolateral periaqueductal gray (vlPAG) have been implicated in regulating pain, but the potential roles of the vlPAG in neuropathic pain-induced anxiety have not been investigated. Herein, whole-cell recording and immunofluorescence showed that the excitability of CamkIIα neurons in the vlPAG (vlPAGCamkIIα+ neurons) was decreased in mice with spared nerve injury (SNI), while electroacupuncture (EA) activated these neurons. We also showed that chemogenetic inhibition of vlPAGCamkIIα+ neurons resulted in allodynia and anxiety-like behaviors in naive mice. Furthermore, chemogenetic activation of vlPAGCamkIIα+ neurons reduced anxiety-like behaviors and allodynia in mice with SNI, and EA had a similar effect in alleviating these symptoms. Nevertheless, EA combined with chemogenetic activation failed to further relieve allodynia and anxiety-like behaviors. Artificial inhibition of vlPAGCamkIIα+ neurons abolished the analgesic and anxiolytic effects of EA. Overall, our study reveals a novel mechanism of neuropathic pain-induced anxiety and shows that EA may relieve comorbid chronic neuropathic pain and anxiety by activating vlPAGCamkIIα+ neurons.Significance Statement Neuropathic pain is clinically accompanied by anxiety. Both glutamatergic neurons in the ventrolateral periaqueductal gray (vlPAG) and electroacupuncture (EA) have demonstrated analgesic properties. However, the efficacy of these interventions in addressing neuropathic pain and its concomitant anxiety has yet to be fully elucidated. In a mice model of spared nerve injury (SNI), we observed a decreased excitability of vlPAG CamkIIα neurons. Remarkably, EA treatment significantly enhanced the excitability of these neurons. Further, chemogenetic activation of vlPAGCamkIIα+ neurons not only resulted in analgesia but also mitigated anxiety-like behaviors in SNI mice, mirroring the effects observed with EA treatment. Conversely, inhibition of vlPAGCamkIIα+ neurons activity in naive mice reduced pain thresholds and induced anxiety-like behavior, while also negating the beneficial effects of EA. These findings provide novel insights into the mechanistic interplay between chronic neuropathic pain and anxiety, highlighting the therapeutic potential of targeting vlPAG glutamatergic neurons in these conditions.

Copper-Graphene Composite (CGC) Conductors: Synthesis, Microstructure, and Electrical Performance.

Improving the electrical performance of copper, the most widely used electrical conductor in the world is of vital importance to the progress of key technologies, including electric vehicles, portable devices, renewable energy, and power grids. Copper-graphene composite (CGC) stands out as the most promising candidate for high-performance electrical conductor applications. This can be attributed to the superior properties of graphene fillers embedded in CGC, including excellent electrical and thermal conductivity, corrosion resistance, and high mechanical strength. This review highlights the recent progress of CGC conductors, including their fabrication processes, electrical performances, mechanisms of copper-graphene interplay, and potential applications.

Phytochemical-mediated modulation of autophagy and endoplasmic reticulum stress as a cancer therapeutic approach.

Autophagy and endoplasmic reticulum (ER) stress are conserved processes that generally promote survival, but can induce cell death when physiological thresholds are crossed. The pro-survival aspects of these processes are exploited by cancer cells for tumor development and progression. Therefore, anticancer drugs targeting autophagy or ER stress to induce cell death and/or block the pro-survival aspects are being investigated extensively. Consistently, several phytochemicals have been reported to exert their anticancer effects by modulating autophagy and/or ER stress. Various phytochemicals (e.g., celastrol, curcumin, emodin, resveratrol, among others) activate the unfolded protein response to induce ER stress-mediated apoptosis through different pathways. Similarly, various phytochemicals induce autophagy through different mechanisms (namely mechanistic target of Rapamycin [mTOR] inhibition). However, phytochemical-induced autophagy can function either as a cytoprotective mechanism or as programmed cell death type II. Interestingly, at times, the same phytochemical (e.g., 6-gingerol, emodin, shikonin, among others) can induce cytoprotective autophagy or programmed cell death type II depending on cellular contexts, such as cancer type. Although there is well-documented mechanistic interplay between autophagy and ER stress, only a one-way modulation was noted with some phytochemicals (carnosol, capsaicin, cryptotanshinone, guangsangon E, kaempferol, and δ-tocotrienol): ER stress-dependent autophagy. Plant extracts are sources of potent phytochemicals and while numerous phytochemicals have been investigated in preclinical and clinical studies, the search for novel phytochemicals with anticancer effects is ongoing from plant extracts used in traditional medicine (e.g., Origanum majorana). Nonetheless, the clinical translation of phytochemicals, a promising avenue for cancer therapeutics, is hindered by several limitations that need to be addressed in future studies.

Mastering the complex time-scale interaction during Stress Corrosion Cracking phenomena through an advanced coupling scheme

Stress corrosion cracking (SCC) failure is a multi-physics phenomena and is usually modelled at the microstructural level, which includes mechanical, chemical, and electrochemical contributions. In aggressive corrosive environments, materials prone to localized corrosion, can suffer heavy pitting corrosion. Subsequently, pit-to-crack transition events might be initiated. Respective mechanical assisted pitting corrosion propagation processes are determined by mechanical, chemical, and electrochemical properties as well as transport properties of ions at grain boundaries. Variations in the electrolyte exposure conditions (including the kinetics at the solid–liquid interface), different mechanical loading scenarios, grain-specific crystal anisotropies, and other local factors combine to produce a highly complex SCC-type interaction scenario at various time and length scales. Since corrosion is a slow process whereas brittle fracture is a rapid failure mechanism, the individual domain discretization-based solvers need to use distinct time steps and appropriate solver settings to become capable to accurately simulate such coupled events. In order to address the issues that arise while accounting for scaling effects in both time and space, and retaining coupled mechanistic interplay and including the aspects specified earlier, a sophisticated modelling method is necessary for the analysis of structural failure by SCC. In this work, a partitioned multi-physics computational approach is presented, using two separate single physics solvers coupled by the open-source coupling library preCICE. In the proposed computational setup, two separate software environments are used, with dedicated solver settings and different time steps, to simulate the mechanical fracture and dissolution-driven pitting corrosion for various loading and corrosion conditions, while also taking into account the effects of microstructural anisotropy. For a 2D polycrystalline model representing face-centered-cubic (fcc) material systems, selected numerical experiments are conducted that predict the evolution of fracture and crack path resulting from SCC. The framework has been further extended to simulate 3D problems as well. The corresponding results are evaluated to show the applicability of the proposed methodology.

Unraveling the mechanistic interplay of mediators orchestrating the neuroprotective potential of harmine.

Neurodegenerative diseases (NDDs) encompass a range of conditions characterized by the specific dysfunction and continual decline of neurons, glial cells, and neural networks within the brain and spinal cord. The majority of NDDs exhibit similar underlying causes, including oxidative stress, neuroinflammation, and malfunctioning of mitochondria. Elevated levels of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), alongside decreased expression of brain-derived neurotrophic factor (BDNF) and glutamate transporter subtype 1 (GLT-1), constitute significant factors contributing to the pathogenesis of NDDs. Additionally, the dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) gene has emerged as a significant target for the treatment of NDDs at the preclinical level. It significantly contributes to developmental brain defects, early onset neurodegeneration, neuronal loss, and dementia in Down syndrome. Moreover, an impaired ubiquitin-proteosome system (UPS) also plays a pathological role in NDDs. Malfunctioning of UPS leads to abnormal protein buildup or aggregation of α-synuclein. α-Synuclein is a highly soluble unfolded protein that accumulates in Lewy bodies and Lewy neurites in Parkinson's disease and other synucleinopathies. Recent research highlights the promising potential of natural products in combating NDDs relative to conventional therapies. Alkaloids have emerged as promising candidates in the fight against NDDs. Harmine is a tricyclic β-carboline alkaloid (harmala alkaloid) with one indole nucleus and a six-membered pyrrole ring. It is extracted from Banisteria caapi and Peganum harmala L. and exhibits diverse pharmacological properties, encompassing neuroprotective, antioxidant, anti-inflammatory, antidepressant, etc. Harmine has been reported to mediate its neuroprotective via reducing the level of inflammatory mediators, NADPH oxidase, AChE, BChE and reactive oxygen species (ROS). Whereas, it has been observed to increase the levels of BDNF, GLT-1 and anti-oxidant enzymes, along with protein kinase-A (PKA)-mediated UPS activation. This review aims to discuss the mechanistic interplay of various mediators involved in the neuroprotective effect of harmine.

TurboID mapping reveals the exportome of secreted intrinsically disordered proteins in the transforming parasite Theileria annulata.

Theileria annulata is a tick-transmitted apicomplexan parasite that gained the unique ability among parasitic eukaryotes to transform its host cell, inducing a fatal cancer-like disease in cattle. Understanding the mechanistic interplay between the host cell and malignant Theileria species that drives this transformation requires the identification of responsible parasite effector proteins. In this study, we used TurboID-based proximity labeling, which unbiasedly identified secreted parasite proteins within host cell compartments. By fusing TurboID to nuclear export or localization signals, we biotinylated proteins in the vicinity of the ligase enzyme in the nucleus or cytoplasm of infected macrophages, followed by mass spectrometry analysis. Our approach revealed with high confidence nine nuclear and four cytosolic candidate parasite proteins within the host cell compartments, eight of which had no orthologs in non-transforming T. orientalis. Strikingly, all eight of these proteins are predicted to be highly intrinsically disordered proteins. We discovered a novel tandem arrayed protein family, nuclear intrinsically disordered proteins (NIDP) 1-4, featuring diverse functions predicted by conserved protein domains. Particularly, NIDP2 exhibited a biphasic host cell-cycle-dependent localization, interacting with the EB1/CD2AP/CLASP1 parasite membrane complex at the schizont surface and the tumor suppressor stromal antigen 2 (STAG2), a cohesion complex subunit, in the host nucleus. In addition to STAG2, numerous NIDP2-associated host nuclear proteins implicated in various cancers were identified, shedding light on the potential role of the T. annulata exported protein family NIDP in host cell transformation and cancer-related pathways.IMPORTANCETurboID proximity labeling was used to identify secreted proteins of Theileria annulata, an apicomplexan parasite responsible for a fatal, proliferative disorder in cattle that represents a significant socio-economic burden in North Africa, central Asia, and India. Our investigation has provided important insights into the unique host-parasite interaction, revealing secreted parasite proteins characterized by intrinsically disordered protein structures. Remarkably, these proteins are conspicuously absent in non-transforming Theileria species, strongly suggesting their central role in the transformative processes within host cells. Our study identified a novel tandem arrayed protein family, with nuclear intrinsically disordered protein 2 emerging as a central player interacting with established tumor genes. Significantly, this work represents the first unbiased screening for exported proteins in Theileria and contributes essential insights into the molecular intricacies behind the malignant transformation of immune cells.

Applying Dynamical Systems Theory to Improve Personalized Medicine Following Mild Traumatic Brain Injury.

A sizable proportion of patients with mild traumatic brain injury (mTBI) have persistent symptoms and functional impairments months to years following injury. This phenomenon is continually observed despite an explosion of research and interest in improving mTBI clinical outcomes over the last two decades. All pharmacological clinical trials to date have failed to demonstrate improved outcomes for mTBI. One possible explanation for these continued failures is an overly myopic approach to treating mTBI (i.e., testing the effect of a single drug with a specific mechanism on a group of people with highly heterogenous injuries). Clinical presentation and prognosis of mTBI vary considerably between patients, and yet we continue to assess group-level effects of a homogenized treatment. We need to utilize an equally complex treatment approach to match the extraordinary complexity of the human brain. Dynamical systems theory has been used to describe systems composed of multiple subsystems who function somewhat independently but are ultimately interconnected. This theory was popularized in the motor control literature as an overarching framework for how the mind and body connect to interact and move through the environment. However, the human body can be viewed as a dynamical system composed of multiple subsystems (i.e., organ systems) who have isolated functions, which are also codependent on the health and performance of other interconnected organ systems. In this perspective piece, we will use the example of mTBI in the obese patient to demonstrate how broadening our approach to treatment of the individual (and not necessarily the injury) may ultimately yield improved outcomes. Furthermore, we will explore clinical and pre-clinical evidence demonstrating multiple system interactions in the context of obesity and TBI and discuss how expanding our understanding of the mechanistic interplay between multiple organ systems may ultimately provide a more personalized treatment approach for this mTBI patient subpopulation.

RBC aggregation, deformation and adhesion to endothelium: Role of nitric oxide derived from L-Arginine and sodium nitroprusside

Red blood cells (RBCs) are the most abundant human blood cells. RBC aggregation and deformation strongly determine blood viscosity which impacts hemorheology and microcirculation. In turn, RBC properties depend on different endogenous and exogenous factors. One such factor is nitric oxide (NO), which is mainly produced by endothelial cells (EC) from L-arginine amino acid in the circulatory system. Since the mechanisms of the RBC-endothelium interplay are not clear up to date and considering its possible clinical importance, the aims of this study are to investigate in vitro: (1) The effect of L-arginine induced NO on RBC aggregation and adhesion to endothelium; (2) the NO effect on RBC aggregation and deformation induced by L-arginine and sodium nitroprusside without the presence of endothelium in the samples. The RBC aggregation and adhesion to a monolayer of EC were studied using optical tweezers (OT). The RBC deformability and aggregation without endothelium in the samples were studied using the flow chamber method and Myrenne aggregometer. We confirmed that NO increases deformability and decreases aggregation of RBCs. We showed that the soluble guanylate cyclase pathway appears to be the only NO signaling pathway involved. In the samples with the endothelium, the “bell-shaped” dependence of RBC aggregation force on L-arginine concentration was observed, which improves our knowledge about the process of NO production by endothelium. Additionally, data related to L-arginine accumulation by endothelium were obtained: Necessity of the presence of extracellular L-arginine stated by other authors was put under question. In our study, NO decreased the RBC-endothelium adhesion, however, the tendency appeared to be weak and was not confirmed in another set of experiments. To our knowledge, this is the first attempt to measure the forces of RBC adhesion to endothelium monolayer with OT.

Abstract 7270: Combination targeting of SKP2 and KDM5B induces senescence in castration-resistant prostate cancer cells via AKT signaling

Abstract Prostate cancer (PCa) is the second-leading cause of cancer mortalities and morbidities in the United States and is the most commonly diagnosed malignancy in men. Despite the fact that androgen deprivation therapy is the first-line option to initial responses, most PCa patients invariably develop castration-resistant prostate cancer (CRPC). CRPC is a lethal type of malignancy, therefore, novel and effective treatment strategies are needed. The goal of this study was to evaluate the combination treatment of small molecule inhibitors, SZL-P1-41, a SKP2 target and PBIT, a KDM5B target on PCa growth and progression; as well as to delineate the underlying mechanisms of suppressing CRPC. Literature reports that S-Phase Kinase Associated Protein 2 (SKP2) is upregulated in PCa and Lysine-specific demethylase 5B (KDM5B) serves as a histone demethylase with a crucial role in cancers. Studies showed that KDM5B is increased in human PCa and KDM5B knockout decreases carcinogenic properties of PCa cells. We previously reported that SKP2 loss partially decreases the growth of prostate tumors and that KDM5B levels are reversely regulated by SKP2 in PCa cells. However, the mechanisms of KDM5B and SKP2 interplay on PCa malignancy is unknown. We hypothesize that combination of PBIT and SZL-P1-41 treatment will enhance anti-cancer effects on PCa progression by inducing cellular senescence. Here, we showed that inhibition of KDM5B and SKP2 decreased the proliferation of PCa cells, and KDM5B KO cells were more vulnerable to SKP2 inhibition. More importantly, a combined inhibition of KDM5B and SKP2 significantly blocked malignant progression and migration of PCa cells. Mechanistically, combined inhibition of KDM5B and SKP2 in PCa cells abrogated AKT activation, resulting in an induction of cellular senescence, which was measured via Western blot analysis and senescence-associated β-galactosidase (SA-β-Gal) staining. Taken together, our results show that combined inhibition of KDM5B and SKP2 is more efficacious in inhibiting proliferation and migration in CRPC cells, and this regimen would be an ideal therapeutic approach for treating CRPC. Citation Format: LaKendria K. Brown, Thanigaivelan Kanagasabai, Guoliang Li, Sherly I. Celada, Zhenbang Chen. Combination targeting of SKP2 and KDM5B induces senescence in castration-resistant prostate cancer cells via AKT signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7270.

Structural and mechanistic insights into activation of the human RNA ligase RTCB by Archease

RNA ligases of the RTCB-type play an essential role in tRNA splicing, the unfolded protein response and RNA repair. RTCB is the catalytic subunit of the pentameric human tRNA ligase complex. RNA ligation by the tRNA ligase complex requires GTP-dependent activation of RTCB. This active site guanylylation reaction relies on the activation factor Archease. The mechanistic interplay between both proteins has remained unknown. Here, we report a biochemical and structural analysis of the human RTCB-Archease complex in the pre- and post-activation state. Archease reaches into the active site of RTCB and promotes the formation of a covalent RTCB-GMP intermediate through coordination of GTP and metal ions. During the activation reaction, Archease prevents futile RNA substrate binding to RTCB. Moreover, monomer structures of Archease and RTCB reveal additional states within the RNA ligation mechanism. Taken together, we present structural snapshots along the reaction cycle of the human tRNA ligase.