Distinct Mechanisms Of Action Research Articles

Role of ventricular tachycardia cycle length in the outcomes after catheter ablation or antiarrhythmic drugs in the SURVIVE-VT trial

Abstract Background It has been suggested that antiarrhythmic drugs (AAD) are less effective and safe in slow ventricular tachycardia (VT) due to their effect on conduction velocity, which could stabilize reentry. Conversely, catheter ablation aims to disrupt the VT circuit. Because of the distinct mechanisms of action of AAD and catheter ablation on the VT circuit, VT cycle length (VT-CL) may play a crucial role in determining their therapeutic efficacy. Therefore, VT-CL could be important in selecting VT treatment. Purpose The aim of this study was to assess the impact of VT-CL on outcomes following catheter ablation or antiarrhythmic drugs in AAD-naïve patients with ischemic cardiomyopathy presenting with VT. Methods This is a post hoc analysis of the previously published Substrate Ablation vs Antiarrhythmic Drug Therapy for Symptomatic Ventricular Tachycardia (SURVIVE-VT) trial. In summary, 144 patients with ischemic cardiomyopathy and symptomatic VT were randomized to receive either catheter ablation (N=71) or AAD (N=73) as first-line therapy. We analyzed VT recurrence, implantable cardioverter-defibrillator (ICD) therapies, and the incidence of slow/incessant VT/VT storm using Cox proportional hazard models, with treatment and VT-CL interaction terms, adjusted for age. Missing VT-CL data for five patients were imputed using the median value. Results In patients with chronic ischemic heart disease and VT treated with either AAD or catheter ablation, a significant interaction was observed between clinical VT-CL and treatment effect on VT recurrence (p=0.016 for the interaction). Specifically, slower VT cycle lengths were associated with higher rates of VT recurrence (hazard ratio per 10 ms [HR] 1.094, 95% confidence interval [CI] 1.015, 1.179; p=0.037) in patients treated with AAD, while no significant effect was observed in those undergoing catheter ablation (see Figure 1). Survival freedom from VT recurrence in patients with VT-CL ≥300ms was significantly higher in patients treated with catheter ablation (78.8% vs 58.1%, log-rank p=0.044, see Figure 2). As expected, VT-CL was significantly associated with a higher risk of slow/incessant VT/VT storm (HR per 10 ms 1.115, 95% CI 1.017-1.222, p=0.047) but was not associated with ICD therapies (HR per 10 ms 1.082, 95% CI 0.994-1.178, p=0.102). Conclusion VT-CL significantly influences treatment outcomes, with slower VT cycles associated with an increased risk of VT recurrence in patients treated with AAD, but not in those undergoing catheter ablation. Therefore, VT-CL should be taken into consideration when selecting the optimal therapy for patients with ischemic cardiomyopathy and VT.Figure 1Figure 2

Micropulse Laser versus Eplerenone for Chronic Central Serous Chorioretinopathy: A 12-Month Comparison.

To compare the long-term efficacy of navigated subthreshold micropulse laser (NSML) and continuous oral eplerenone (EPL) in chronic central serous chorioretinopathy (cCSC). This retrospective observational study included 44 eyes with cCSC (EPL: n = 26; NSML: n = 18). Best-corrected visual acuity (BCVA), central macular thickness (CMT), subretinal fluid (SRF) height, and subfoveal choroidal thickness (SFCT) were evaluated over 12months. Both groups showed significant improvements in BCVA and CMT (p < 0.05). Complete SRF resolution was achieved in both groups by 12months, with NSML showing faster resolution (2.77 ± 1.43 vs. 6.34 ± 2.17months, p < 0.001). The EPL group demonstrated significant SFCT reduction at 6 and 12months (p = 0.001), while the NSML group showed no significant SFCT changes (p > 0.05). Both NSML and EPL improved retinal morphology and visual function in patients with cCSC. NSML achieved faster SRF resolution, while EPL resulted in more significant choroidal thickness reduction. These findings suggest distinct mechanisms of action: NSML primarily affects the retinal pigment epithelium, while EPL modulates choroidal vasculature. Treatment choice may depend on individual patient characteristics and treatment goals.

Calcium‐Dependent Lipopeptide Antibiotics against Drug‐Resistant Pathogens Discovered via Host‐Dependent Heterologous Expression of a Cloned Biosynthetic Gene Cluster

AbstractHistorically, small molecules biosynthesised by bacteria have been an excellent source for antibacterial drugs. Today, however, the rediscovery of known compounds is a significant hurdle to developing new antimicrobials. Here we use a genome mining and synthetic biology approach to discover the ambocidins: calcium‐dependent lipodepsipeptides that are active against drug‐resistant Gram‐positive pathogens. By cloning a silent biosynthetic gene cluster (the amb cluster) from Streptomyces ambofaciens ATCC 2387 and integrating this into the chromosome of Streptomyces avermitilis we induce expression of ambocidin A and B: two new Nϵ‐hydroxyarginine‐containing cyclic lipodepsipeptides active against drug‐resistant Gram‐positive pathogens. Using a panel of Streptomyces host strains, we show that the choice of heterologous host is critical for producing the biologically active compounds, and that inappropriate host choice leads to aberrant production inactive derivatives. We show that Nϵ‐hydroxyarginine is the product of a heme‐dependent oxygenase and that it enhances biological activity. Ambocidin A inhibits cell wall biosynthesis by binding to Lipid II at a different site than vancomycin. Furthermore, unlike daptomycin, ambocidin A retains potent antimicrobial activity in the presence of lung surfactant, giving it the potential to treat bacterial pneumonia. Our work expands the family of calcium‐dependent lipopeptide antibiotics with a new member exhibiting a distinct mechanism of action.

Antibacterial activity of recombinant liver-expressed antimicrobial peptide-2 derived from olive flounder, Paralichthys olivaceus

Liver-expressed antimicrobial peptide-2 (LEAP-2) is a cysteine-rich peptide that plays a crucial role in the innate immune system of fish. To investigate the molecular function of LEAP-2 from olive flounder, Paralichthys olivaceus, we cloned the gene encoding LEAP-2 using PCR and expressed it in Escherichia coli. Analysis of LEAP-2 expression revealed predominant transcripts in the liver and lower levels in the intestine of olive flounder, whereas their expression levels in the liver and head kidney increased, during the initial stage of infection with the aquapathogenic bacterium Edwardsiella piscicida. Recombinant LEAP-2 (rOfLEAP-2) purified from E. coli exhibited antimicrobial activity, as demonstrated by the ultrasensitive radial diffusion assay, against both Gram-positive (Bacillus subtilis, Streptococcus parauberis, and Lactococcus garvieae) and Gram-negative (Vibrio harveyi and E. coli) bacteria, with minimum inhibitory concentrations ranging from 25 to 100 μg/mL depending on the species tested. The antibacterial activity of rOfLEAP-2 was attributed to its ability to disrupt bacterial membranes, validated by the N-phenylnaphthalen-1-amine uptake assays and scanning electron microscope analysis against E. coli, V. harveyi, B. subtilis, and L. garvieae treated with rOfLEAP-2. Furthermore, a synergistic enhancement of antibacterial activity was observed when rOfLEAP-2 was combined with ampicillin or synthetic LEAP-1 peptide, suggesting a distinct mechanism of action from those of other antimicrobial agents. These findings provide evidence for the antibacterial efficacy of LEAP-2 from olive flounder, highlighting its potential therapeutic application against pathogenic bacteria.

A Comprehensive Review of Moroccan Medicinal Plants for Diabetes Management.

Moroccan flora, renowned for its diverse medicinal plant species, has long been used in traditional medicine to manage diabetes. This review synthesizes ethnobotanical surveys conducted during the last two decades. Among these plants, 10 prominent Moroccan medicinal plants are evaluated for their phytochemical composition and antidiabetic properties through both in vitro and in vivo studies. The review encompasses a comprehensive analysis of the bioactive compounds identified in these plants, including flavonoids, phenolic acids, terpenoids, and alkaloids. Phytochemical investigations revealed a broad spectrum of secondary metabolites contributing to their therapeutic efficacy. In vitro assays demonstrated the significant inhibition of key enzymes α-amylase and α-glucosidase, while in vivo studies highlighted their potential in reducing blood glucose levels and enhancing insulin secretion. Among the ten plants, notable examples include Trigonella foenum-graecum, Nigella Sativa, and Artemisia herba-alba, each showcasing distinct mechanisms of action, such as enzymatic inhibition and the modulation of glucose metabolism pathways. This review underscores the necessity for further chemical, pharmacological, and clinical research to validate the antidiabetic efficacy of these plants and their active compounds, with a view toward their potential integration into therapeutic practices.

9198 Dimeric [Cys25]PTH(1-34) Induces Differential Transcriptional Responses Versus Monomeric PTH(1-34)

Abstract Disclosure: M. Noh: None. H.J. Kim: None. J. Kim: None. M. Kang: None. S. Lee: None. H. Lee: None. S. Lee: None. Introduction: Patients with hypoparathyroidism caused by the homozygous mutation that changes arginine to cysteine at position 25 in parathyroid hormone (PTH) exhibit high bone densities, which suggests a potential influence of the mutant hormone on bone formation. We also have found that [Cys25]PTH forms homodimers, and that the dimeric peptide exhibits altered functionality versus monomeric PTH. Dimeric [Cys25]PTH(1-34) (Dimer) thus displays selective binding to the G protein-coupled PTH1R conformation (RG) in vitro and markedly diminished cAMP-inducing capability in vivo. Despite these alterations, Dimer induced bone anabolic effects in both calvarial injection assays and after injection in ovariectomized osteoporotic mice, closely mimicking the effects of PTH(1-34) (wtPTH). Our current objective is to explore the downstream signaling pathways activated by Dimer vs wtPTH to help elucidate the bone anabolic effects of the Dimeric analog and its therapeutic potential. Methods: A phospho-protein antibody array assay developed for G protein-coupled receptor (GPCR) downstream target proteins was employed in HEK293/hPTH1R (GP-2.3) cells following treatment with chemically synthesized wtPTH or Dimer. We further conducted RNA-seq analysis of transcriptome changes in primary cells collected from calvarial bones of mice treated with wtPTH or Dimer at 6, 12, and 24-hours post-injection. Finally, we used quantitative reverse transcription PCR (qRT-PCR) to analyze changes in specific marker genes in tibiae and kidney isolated from mice after treatment with Dimer vs. wtPTH. Results: The number of phosphorylated proteins significantly regulated by PTH1R upon exposure to Dimer was remarkably enhanced, relative to the number regulated upon exposure to wtPTH. RNA-seq analysis revealed that the early effects of wtPTH and Dimer on transcriptional regulation were similar, whereas marked differences in expression levels became apparent over time. qRT-PCR analyses of RNA expression levels in kidneys versus tibiae from mice treated with wtPTH or Dimer revealed in bone that the expression of genes associated with bone catabolism, particularly RANKL, was significantly lower in response to Dimer as compared to wtPTH treatment, while in kidney there was an overall reduced response to Dimer as compared to wtPTH. Conclusions: Our study supports the hypothesis that as compared to PTH(1-34), dimeric [Cys25]PTH (1-34) induces altered signaling responses in vivo and has a lower effect on bone catabolism. Dimeric [Cys25]PTH(1-34) thus holds interest as a potential bone anabolic agent that utilizes a distinct mechanism of action. Presentation: 6/3/2024

8279 Dimeric [Cys25]PTH(1-34) Induces Differential Transcriptional Responses Versus Monomeric PTH(1-34)

Abstract Disclosure: M. Noh: None. H.J. Kim: None. J. Kim: None. M. Kang: None. S. Lee: None. H. Lee: None. S. Lee: None. Introduction: Patients with hypoparathyroidism caused by the homozygous mutation that changes arginine to cysteine at position 25 in parathyroid hormone (PTH) exhibit high bone densities, which suggests a potential influence of the mutant hormone on bone formation. We also have found that [Cys25]PTH forms homodimers, and that the dimeric peptide exhibits altered functionality versus monomeric PTH. Dimeric [Cys25]PTH(1-34) (Dimer) thus displays selective binding to the G protein-coupled PTH1R conformation (RG) in vitro and markedly diminished cAMP-inducing capability in vivo. Despite these alterations, Dimer induced bone anabolic effects in both calvarial injection assays and after injection in ovariectomized osteoporotic mice, closely mimicking the effects of PTH(1-34) (wtPTH). Our current objective is to explore the downstream signaling pathways activated by Dimer vs wtPTH to help elucidate the bone anabolic effects of the Dimeric analog and its therapeutic potential. Methods: A phospho-protein antibody array assay developed for G protein-coupled receptor (GPCR) downstream target proteins was employed in HEK293/hPTH1R (GP-2.3) cells following treatment with chemically synthesized wtPTH or Dimer. We further conducted RNA-seq analysis of transcriptome changes in primary cells collected from calvarial bones of mice treated with wtPTH or Dimer at 6, 12, and 24-hours post-injection. Finally, we used quantitative reverse transcription PCR (qRT-PCR) to analyze changes in specific marker genes in tibiae and kidney isolated from mice after treatment with Dimer vs. wtPTH. Results: The number of phosphorylated proteins significantly regulated by PTH1R upon exposure to Dimer was remarkably enhanced, relative to the number regulated upon exposure to wtPTH. RNA-seq analysis revealed that the early effects of wtPTH and Dimer on transcriptional regulation were similar, whereas marked differences in expression levels became apparent over time. qRT-PCR analyses of RNA expression levels in kidneys versus tibiae from mice treated with wtPTH or Dimer revealed in bone that the expression of genes associated with bone catabolism, particularly RANKL, was significantly lower in response to Dimer as compared to wtPTH treatment, while in kidney there was an overall reduced response to Dimer as compared to wtPTH. Conclusions: Our study supports the hypothesis that as compared to PTH(1-34), dimeric [Cys25]PTH (1-34) induces altered signaling responses in vivo and has a lower effect on bone catabolism. Dimeric [Cys25]PTH(1-34) thus holds interest as a potential bone anabolic agent that utilizes a distinct mechanism of action. Presentation: 6/3/2024

Non-cyclic nucleotide EPAC1 activators suppress lipopolysaccharide-regulated gene expression, signalling and intracellular communication in differentiated macrophage-like THP-1 cells

This study explores the anti-inflammatory effects of non-cyclic nucleotide EPAC1 activators, PW0577 and SY007, on lipopolysaccharide (LPS)-induced responses in differentiated THP-1 macrophage-like cells. Both activators were found to selectively activate EPAC1 in THP-1 macrophages, leading to the activation of the key down-stream effector, Rap1. RNA sequencing analysis of LPS-stimulated THP-1 macrophages, revealed that treatment with PW0577 or SY007 significantly modulates gene expression related to fibrosis and inflammation, including the suppression of NLRP3, IL-1β, and caspase 1 protein expression in LPS-stimulated cells. Notably, these effects were independent of p65 NFκB phosphorylation at Serine 536, indicating a distinct mechanism of action. The study further identified a shared influence of both activators on LPS signalling pathways, particularly impacting extracellular matrix (ECM) components and NFκB-regulated genes. Additionally, in a co-culture model involving THP-1 macrophages, vascular smooth muscle cells, and human coronary artery endothelial cells, EPAC1 activators modulated immune-vascular interactions, suggesting a broader role in regulating cellular communication between macrophages and endothelial cells. These findings enhance our understanding of EPAC1's role in inflammation and propose EPAC1 activators as potential therapeutic agents for treating inflammatory and fibrotic conditions through targeted modulation of Rap1 and associated signalling pathways.

Diagnostic and evaluative efficiency of 68Ga-FAPI-04 in skeletal muscle injury

BackgroundSkeletal muscles are vital for daily function, yet assessing their injuries remain challenging. We aimed to elucidate the effectiveness of 68Ga-FAPI-04 in evaluating skeletal muscle remodeling.ResultsC2C12 cells were subjected to graded H2O2 stimulation in vitro, revealing an initial rise and subsequent decline in fibroblast activation protein (FAP) expression as H2O2 concentration increased. In vivo, a murine triceps surae injury model was created using various solutions to simulate normal repair, mild repair failure, and severe repair failure. Assessments were conducted on days 1, 3, 7, and 14 using PET, MRI, and ultrasound. With 68Ga-FAPI-04, the normal and mild repair failure groups showed significantly higher SUVmax and T/B ratios on day 1 compared to the severe repair failure group. These values gradually decreased in the normal repair group, becoming negligible after day 7. MRI results for the normal repair group showed low to moderate signal intensity by day 7. A clinical study retrospectively evaluated post-hip arthroplasty patient images at intervals of 1 month, 2–3 months, 5–6 months, and over 7 months. In these patients, 18F-FDG SUVmax and volume remained relatively stable over time, while 68Ga-FAPI-04 SUVmax initially increased, then decreased, with a consistent reduction in volume.ConclusionIn skeletal muscle injuries, FAP demonstrates a distinctive mechanism of action, and 68Ga-FAPI-04, in comparison to other tests, more precisely captures alterations in lesion site uptake intensity and volume.Trial registrationTrial registration: ChiCTR2000041204. Registered 22 December 2020, https://www.chictr.org.cn/showproj.html?proj=66211

Clinical Benefits and Safety of Medical Cannabis Products: A Narrative Review on Natural Extracts.

Interest in medical cannabis and cannabis-based medicinal products (CBMPs) has increased greatly in recent years. Two cannabinoids are of principal importance; delta-9-tetrahydrocannabinol (∆9-THC), the primary psychoactive component, and also cannabidiol (CBD), considered non-intoxicating. Each has distinct mechanisms of action and different therapeutic potentials. CBMPs differ in their ∆9-THC and CBD components; predominantly ∆9-THC, balanced formulations with equivalent ∆9-THC and CBD elements, and CBD-predominant products. In this narrative review, we evaluate the published evidence for the clinical benefits of CBMPs and overall benefits in well-being. We also review the overall safety profile and discuss the potential for dependence with CBMPs. Evidence can be drawn from a wide range of randomized and other controlled studies and from observational real-world studies. Most data from observational registry studies are supportive of ∆9-THC-based products (∆9-THC-predominant or balanced CBMPs) in the management of chronic neuropathic pain. Balanced products are also effective in reducing spasticity in multiple sclerosis. Most CBMPs show benefit in providing symptomatic benefits in reducing anxiety, nausea, and in improving sleep, but the place of specific products is more subtle, and choice guided by specific circumstances. Symptomatic improvements are accompanied by improved quality of life and well-being. Safety data indicate that CBMPs are generally well tolerated in most patients without specific contraindications. The majority of adverse effects are non-serious, and transient; most are principally associated with ∆9-THC and are dose-dependent. In contrast to recreational cannabis use, there is little evidence from clinical studies that CBMPs have any potential for dependence.

Design and development of a series of 4-(piperazin-1-yl)pyrimidines as irreversible menin inhibitors

The interaction between menin and MLL1 protein plays an important role in AML with MLL rearrangement and NPM1 mutation. Blocking the formation of menin-MLL complex can inhibit proliferation and induce differentiation in these cancer subtypes. In development of anticancer drugs, irreversible inhibitors are gaining spotlight as they may have better activities than the reversible analogs. Therefore, we designed and developed a novel series of covalent menin inhibitors. Among these compounds, 37 emerges as a selective and potent inhibitor of MLL fusion protein-expressing leukemic cells. The cellular study indicates 37 has a distinct mechanism of action, in both reducing menin protein levels and downregulating MEN1 transcription. This effect of 37 is not involved in proteasomal degradation, and may directly affect the synthesis of menin protein, which offers a significant advantage in addressing acquired resistance to menin inhibitors. Further study showed that compound 37 has prolonged anti-leukemic action and exhibits promising in vivo efficacy, making it a valuable probe for further menin-MLL interaction studies.

New anti-ovarian cancer quinolone derivatives acting by modulating microRNA processing machinery.

MicroRNAs (miRNAs) play a crucial role in ovarian cancer (OC) pathogenesis and miRNA processing can be the object of pharmacological intervention. By exploiting our in-house quinolone library, we combined a cell-based screening with medicinal chemistry efforts, ultimately leading to derivative 33 with anti-OC activity against distinct cell lines (GI50 values 13.52-31.04 μM) and CC50 Wi-38 = 142.9 μM. Compound 33 retained anticancer activity against additional cancer cells and demonstrated a synergistic effect with cisplatin against cisplatin-resistant A2780 cells. Compound 33 bound TRBP by SPR (K D = 4.09 μM) and thermal shift assays and its activity was TRBP-dependent, leading to modulation of siRNA and miRNA maturation. Derivative 33 exhibited augmented potency against OC cells and a stronger binding affinity for TRBP compared to enoxacin, the sole quinolone identified as a modulator of miRNA maturation. Consequently, 33 represents a promising template for developing novel anti-OC agents with a distinctive mechanism of action.

Does each Component of Reactive Oxygen Species have a Dual Role in the Tumor Microenvironment?

Reactive oxygen species (ROS) are a class of highly reactive oxidizing molecules, including superoxide anion (O2 •-) and hydrogen peroxide (H2O2), among others. Moderate levels of ROS play a crucial role in regulating cellular signaling and maintaining cellular functions. However, abnormal ROS levels or persistent oxidative stress can lead to changes in the tumor microenvironment (TME) that favor cancer development. This review provides an overview of ROS generation, structure, and properties, as well as their effects on various components of the TME. Contrary to previous studies, our findings reveal a dual effect of ROS on different components of the TME, whereby ROS can either enhance or inhibit certain factors, ultimately leading to the promotion or suppression of the TME. For example, H2O2 has dual effects on immune cells and non-- cellular components within the TME, while O2 •- has dual effects on T cells and fibroblasts. Furthermore, each component demonstrates distinct mechanisms of action and ranges of influence. In the final section of the article, we summarize the current clinical applications of ROS in cancer treatment and identify certain limitations associated with existing therapeutic approaches. Therefore, this review aims to provide a comprehensive understanding of ROS, highlighting their dual effects on different components of the TME, and exploring the potential clinical applications that may pave the way for future treatment and prevention strategies.

Novel platinum therapeutics induce rapid cancer cell death through triggering intracellular ROS storm

Induction of reactive oxygen species (ROS) production in cancer cells plays a critical role for cancer treatment. However, therapeutic efficiency remains challenging due to insufficient ROS production of current ROS inducers. We designed a novel platinum (Pt)-based drug named “carrier-platin” that integrates ultrasmall Pt-based nanoparticles uniformly confined within a poly(amino acids) carrier. Carrier-platin dramatically triggered a burst of ROS in cancer cells, leading to cancer cell death as quick as 30 min. Unlike traditional Pt-based drugs which induce cell apoptosis through DNA intercalation, carrier-platin with superior ROS catalytic activities induces a unique pattern of cancer cell death that is neither apoptosis nor ferroptosis and operates independently of DNA damage. Importantly, carrier-platin demonstrates superior anti-tumor efficacy against a broad spectrum of cancers, particularly those with multidrug resistance, while maintaining minimal systemic toxicity. Our findings reveal a distinct mechanism of action of Pt in cancer cell eradication, positioning carrier-platin as a novel category of anti-cancer chemotherapeutics.

Preventive and Therapeutic Effects of Lactiplantibacillus plantarum HD02 and MD159 through Mast Cell Degranulation Inhibition in Mouse Models of Atopic Dermatitis.

As the relationship between the gut microbiome and allergies becomes better understood, targeted strategies to prevent and treat allergies through gut microbiome modulation are being increasingly developed. In the study presented herein, we screened various probiotics for their ability to inhibit mast cell degranulation and identified Lactiplatibacillus plantarum HD02 and MD159 as effective candidates. The two strains significantly attenuated vascular permeability induced by mast cell degranulation in a passive cutaneous anaphylaxis (PCA) model and, in the MC903-induced murine atopic dermatitis (AD) model, demonstrated comparable preventive effects against allergies, reducing blood levels of MCPT-1 (mast cell protease-1) and total IgE. In the house dust mite (HDM)-induced murine AD model, both L. plantarum HD02 and MD159 showed therapeutic effects, with L. plantarum HD02 demonstrating superior efficacy. Nevertheless, L. plantarum MD159 better suppressed transepidermal water loss (TEWL). Furthermore, L. plantarum HD02 and MD159 significantly increased the number of splenic Foxp3+ regulatory T cells, with L. plantarum MD159 having a more pronounced effect. However, only L. plantarum HD02 achieved a reduction in immune cells in the draining lymph nodes. Our findings highlight L. plantarum HD02 and MD159 as promising candidates for the prevention and treatment of allergies, demonstrating significant efficacy in suppressing mast cell degranulation, reducing the number of allergy biomarkers, and modulating immune responses in experimental models of AD. Their distinct mechanisms of action suggest potential complementary roles in addressing allergic diseases, underscoring their therapeutic promise in clinical applications.

The occurrence, role, and management strategies for phytic acid in foods.

Phytic acid, a naturally occurring compound predominantly found in cereals and legumes, is the focus of this review. This review investigates its distribution across various food sources, elucidating its dual roles in foods. It also provides new insights into the change in phytic acid level during food storage and the evolving trends in phytic acid management. Although phytic acid can function as a potent color stabilizer, flavor enhancer, and preservative, its antinutritional effects in foods restrict its applications. In terms of management strategies, numerous treatments for degrading phytic acid have been reported, each with varying degradation efficacies and distinct mechanisms of action. These treatments encompass traditional methods, biological approaches, and emerging technologies. Traditional processing techniques such as soaking, milling, dehulling, heating, and germination appear to effectively reduce phytic acid levels in processed foods. Additionally, fermentation and phytase hydrolysis demonstrated significant potential for managing phytic acid in food processing. In the future, genetic modification, due to its high efficiency and minimal environmental impact, should be prioritized to downregulate the biosynthesis of phytic acid. The review also delves into the biosynthesis and metabolism of phytic acid and elaborates on the mitigation mechanism of phytic acid using biotechnology. The challenges in the application of phytic acid in the food industry were also discussed. This study contributes to a better understanding of the roles phytic acid plays in food and the sustainability and safety of the food industry.

Discovery of natural product derivative triptolidiol as a direct NLRP3 inhibitor by reducing K63-specific ubiquitination.

NLRP3 is up-regulated in inflammatory and autoimmune diseases. The development of NLRP3 inhibitors is challenged by the identification of compounds with distinct mechanisms of action avoiding side effects and toxicity. Triptolide is a natural product with multiple anti-inflammatory activities, but a narrow therapeutic window. Natural product triptolide derivatives were screened for NLRP3 inhibitors in human THP-1 and mouse bone marrow-derived macrophages. The efficacy of potent NLRP3 inhibitors was evaluated in LPS-induced acute lung injury and septic shock models. Triptolidiol was identified as a selective inhibitor of NLRP3 with high potency. Triptolidiol inactivated the NLRP3 inflammasome in human THP-1 and mouse primary macrophages primed with LPS. Triptolidiol specifically inhibited pro-caspase 1 cleavage downstream of NLRP3, but not AIM2 or NLRC4 inflammasomes. Based on the structure-activity relationship study, the C8-β-OH group was critical for its binding to NLRP3. Triptolidiol exhibited a submicromolar KD for NLRP3, binding to residue C280. This binding prevented the interaction of NLRP3 with NEK7, the key regulator of NLRP3 inflammasome oligomerization and assembly, but not with the inflammasome adaptor protein ASC. Triptolidiol decreased the K63-specific ubiquitination of NLRP3, leading NLRP3 to a "closed" inactive conformation. Intraperitoneal administration of triptolidiol significantly attenuated LPS-induced acute lung injury and lethal septic shock. Triptolidiol is a novel NLRP3 inhibitor that regulates inflammasome assembly and activation by decreasing K63-linked ubiquitination. Triptolidiol has novel structural features that make it distinct from reported NLRP3 inhibitors and represents a viable therapeutic lead for inflammatory diseases.

Neuronal Membrane-Derived Nanodiscs for Broad-Spectrum Neurotoxin Detoxification.

Neurotoxins pose significant challenges in defense and healthcare due to their disruptive effects on nervous tissues. Their extreme potency and enormous structural diversity have hindered the development of effective antidotes. Motivated by the properties of cell membrane-derived nanodiscs, such as their ultrasmall size, disc shape, and inherent cell membrane functions, here, we develop neuronal membrane-derived nanodiscs (denoted "Neuron-NDs") as a countermeasure nanomedicine for broad-spectrum neurotoxin detoxification. We fabricate Neuron-NDs using the plasma membrane of human SH-SY5Y neurons and demonstrate their effectiveness in detoxifying tetrodotoxin (TTX) and botulinum toxin (BoNT), two model toxins with distinct mechanisms of action. Cell-based assays confirm the ability of Neuron-NDs to inhibit TTX-induced ion channel blockage and BoNT-mediated inhibition of synaptic vesicle recycling. In mouse models of TTX and BoNT intoxication, treatment with Neuron-NDs effectively improves survival rates in both therapeutic and preventative settings. Importantly, high-dose administration of Neuron-NDs shows no observable acute toxicity in mice, indicating its safety profile. Overall, our study highlights the facile fabrication of Neuron-NDs and their broad-spectrum detoxification capabilities, offering promising solutions for neurotoxin-related challenges in biodefense and therapeutic applications.

SARS-CoV-2 Mpro inhibitor identification using a cellular gain-of-signal assay for high-throughput screening

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2, SARS2) is responsible for the COVID-19 pandemic and infections that continue to affect the lives of millions of people worldwide, especially those who are older and/or immunocompromised. The SARS2 main protease enzyme, Mpro (also called 3C-like protease, 3CLpro), is a bona fide drug target as evidenced by potent inhibition with nirmatrelvir and ensitrelvir, the active components of the drugs Paxlovid and Xocova, respectively. However, the existence of nirmatrelvir and ensitrelvir-resistant isolates underscores the need to develop next-generation drugs with different resistance profiles and/or distinct mechanisms of action. Here, we report the results of a high-throughput screen of 649,568 compounds using a cellular gain-of-signal assay. In this assay, Mpro inhibits expression of a luciferase reporter, and 8,777 small molecules were considered hits by causing a gain in luciferase activity 3x SD above the sample field activity (6.8% gain-of-signal relative to 100 µM GC376). Single concentration and dose-response gain-of-signal experiments confirmed 3,522/8,762 compounds as candidate inhibitors. In parallel, all initial high-throughput screening hits were tested in a peptide cleavage assay with purified Mpro and only 39/8,762 showed inhibition. Importantly, 19/39 compounds (49%) re-tested positive in both SARS2 assays, including two previously reported Mpro inhibitors, demonstrating the efficacy of the overall screening strategy. This approach led to the rediscovery of known Mpro inhibitors such as calpain inhibitor II, as well as to the discovery of novel compounds that provide chemical information for future drug development efforts.

Calcium-Dependent Lipopeptide Antibiotics against Drug-Resistant Pathogens Discovered via Host-Dependent Heterologous Expression of a Cloned Biosynthetic Gene Cluster.

Historically, small molecules biosynthesised by bacteria have been an excellent source for antibacterial drugs. Today, however, the rediscovery of known compounds is a significant hurdle to developing new antimicrobials. Here we use a genome mining and synthetic biology approach to discover the ambocidins: calcium-dependent lipodepsipeptides that are active against drug-resistant Gram-positive pathogens. By cloning a silent biosynthetic gene cluster (the amb cluster) from Streptomyces ambofaciens ATCC 2387 and integrating this into the chromosome of Streptomyces avermitilis we induce expression of ambocidin A and B: two new Nε-hydroxyarginine-containing cyclic lipodepsipeptides active against drug-resistant Gram-positive pathogens. Using a panel of Streptomyces host strains, we show that the choice of heterologous host is critical for producing the biologically active compounds, and that inappropriate host choice leads to aberrant production inactive derivatives. We show that Nε-hydroxyarginine is the product of a haem-dependent oxygenase and that it enhances biological activity. Ambocidin A inhibits cell wall biosynthesis by binding to Lipid II at a different site than vancomycin. Unlike daptomycin, ambocidin A retains antimicrobial activity in the presence of lung-surfactant, giving it the potential to treatbacterial pneumonia. Our work expands the family of calcium-dependent lipopeptide antibiotics withnew members exhibiting a distinct mechanism of action.