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Frontiers in Pharmacology

Frontiers Media SA

Preprints posted in the last 30 days, ranked by how well they match Frontiers in Pharmacology's content profile, based on 100 papers previously published here. The average preprint has a 0.17% match score for this journal, so anything above that is already an above-average fit.

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Application of Engineered NK-92 Cell Extracellular Vesicles in the Treatment of Systemic Lupus Erythematosus

Sun, Y.; Tang, Z.; Guo, M.; Zhai, Z.; Wu, Z.; Wang, X.; Li, F.; An, W.; Dou, X.

2026-04-15 synthetic biology 10.64898/2026.04.14.718139 medRxiv
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IntroductionSystemic Lupus Erythematosus (SLE) is a chronic autoimmune disease characterized by loss of immune tolerance, autoantibody production, and multi-organ damage. Current therapies, including glucocorticoids and CAR-T/CAR-NK cell therapies, are limited by adverse effects, high cost, and safety concerns. ObjectivesTo develop engineered NK-92 cell-derived extracellular vesicles displaying CD19 single-chain variable fragment (V-CD19-Exo) and evaluate their therapeutic efficacy in an MRL/lpr mouse model of SLE. MethodsThe CD19scFv-LAMP-2B fusion construct was stably expressed in NK-92 cells via lentiviral transduction. Extracellular vesicles were isolated by differential centrifugation and characterized by NTA, TEM, and Western Blot. In vivo efficacy was assessed in MRL/lpr mice through B cell depletion analysis, renal function monitoring, cytokine profiling, autoantibody detection, and survival observation. ResultsV-CD19-Exo significantly reduced splenic CD19{square}CD20{square} B cells from 10.53% to 1.51% (p < 0.0001). Treatment attenuated proteinuria, ameliorated lupus nephritis pathology, reversed splenomegaly, and downregulated serum IgE, IL-17A, IFN-{gamma}, anti-dsDNA, and ANA levels. Notably, V-CD19-Exo improved survival to approximately 80% compared to 25% in untreated controls. ConclusionEngineered NK-92 cell-derived extracellular vesicles represent a novel, safe, and effective cell-free therapeutic strategy for SLE, offering advantages over conventional cell therapies including lower immunogenicity, scalable production, and no requirement for lymphodepletion.

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Leronlimab a humanized anti-CCR5 monoclonal antibody ameliorates hepatic fibrosis in two preclinical fibrosis mouse models

Palmer, M.; Hashiguchi, T.; Arman, A. C.; Shirakata, Y.; Buss, N. E.; Lalezari, J. P.

2026-04-21 pharmacology and toxicology 10.64898/2026.04.17.719186 medRxiv
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BackgroundChemokine receptor type 5 (CCR5) is expressed on hepatic stellate cells (HSCs), which, together with fibroblasts, are major producers of extracellular matrix during liver fibrosis. Leronlimab is a humanized IgG4{kappa} monoclonal antibody that binds to CCR5. The objective of the present study was to evaluate the antifibrotic effects of leronlimab in three independent preclinical studies using two mouse models of liver fibrosis. MethodsIn STAM (Stelic Animal Model) model 1, leronlimab was administered at doses of 5 or 10 mg/kg/week for 3 weeks. STAM model 2 was conducted as a confirmatory study to validate the antifibrotic effect observed with the 10 mg/kg/week dose in STAM model 1. In a third study, a carbon tetrachloride (CCl)-induced liver fibrosis mouse model was used to evaluate leronlimab administered at 10 mg/kg/week for 3 weeks. An isotype-matched control antibody was included in all studies for comparison. Evaluations included liver enzymes and histological assessment of liver fibrosis. ResultsIn STAM model 1, leronlimab at 10 mg/kg/week significantly reduced fibrosis area compared with the isotype control (p = 0.0005). These findings were confirmed in STAM model 2 (p < 0.0001). Consistent antifibrotic effects were also observed in the CCl-induced liver fibrosis model (p = 0.0006). ConclusionsCollectively, these preclinical results demonstrate that CCR5 blockade by leronlimab is associated with a significant reduction of established liver fibrosis in multiple mouse models and support further evaluation of leronlimab as a potential therapeutic option, either as monotherapy or in combination regimens, for chronic liver diseases with fibrosis.

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Stability of Oxycodone Solutions Containing S-Ketamine or Dexmedetomidine

Vaisanen, P.; Makela, S.; Siren, S.; Pohjanoksa, K.; Uusalo, P.; Scheinin, M.; Torniainen, K.; Saari, T. I.

2026-04-12 pharmacology and toxicology 10.64898/2026.04.08.717252 medRxiv
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ObjectivesTo determine whether adding S-ketamine or dexmedetomidine to oxycodone affects the microbiological, physical, or chemical stability of patient-controlled analgesia (PCA) solutions prepared in a hospital pharmacy. MethodsOxycodone solution (1 mg/mL) and three oxycodone-S-ketamine mixtures (0.25, 0.50, 0.75 mg/mL) and three oxycodone-dexmedetomidine mixtures (2.5, 5.0, 10 {micro}g/mL) were compounded under validated EU GMP Class A/B aseptic conditions and filled into PCA reservoirs. Reservoirs (n=42 for physicochemical studies; n=21 for sterility; n=4 for antimicrobial activity testing) were stored at 2-8{degrees}C for 28 days, then at 20-25{degrees}C for 2 days. Sterility was assessed by membrane filtration according to Ph. Eur. 2.6.1. Physical stability was evaluated by visual inspection, pH, weight, and osmolality. Chemical stability was assessed using a validated HPLC-UV method developed in accordance with FDA and ICH Q2(R1) guidelines. ResultsAll antimicrobial activity tests showed growth of the six reference strains, indicating no inhibition by the drug mixtures. All 21 sterility-test reservoirs remained free of turbidity throughout 30 days. No visual changes, precipitation, or discolouration were observed. Weight loss was [&le;]0.3%, pH changes were between required range 4,5-7, and osmolality increased by <1.4% during the study. Measured oxycodone, S-ketamine, and dexmedetomidine concentrations remained within {+/-}5% of initial values, and no degradation products were detected. ConclusionsOxycodone PCA solutions containing S-ketamine or dexmedetomidine remained sterile, physically stable, and chemically stable for 28 days at 2-8{degrees}C followed by 2 days at room temperature at 20-25{degrees}C. These findings support extended shelf-life and centralized batch preparation of opioid-adjuvant PCA reservoirs in hospital pharmacy practice. Key MessagesO_ST_ABSWhat is already known on this topicC_ST_ABSOpioid-adjuvant combinations such as oxycodone with S-ketamine or dexmedetomidine are increasingly used in patient-controlled analgesia, but no commercial multi-agent formulations exist. Hospital pharmacies therefore prepare these mixtures as compounded sterile preparations, despite limited data on their chemical and microbiological stability. What this study addsThis study demonstrates that oxycodone PCA solutions containing S-ketamine or dexmedetomidine remain chemically stable and microbiologically sterile for 28 days at 2-8{degrees}C plus 2 days at 20-25{degrees}C, when prepared under validated aseptic conditions. Concentrations of all analytes remained within {+/-}5% of initial values, and no degradation products were detected using a validated HPLC-UV method. How this study might affect research, practice or policyThese stability data support the assignment of extended beyond-use dates and enable centralized batch compounding of PCA reservoirs in hospital pharmacies. The findings have the potential to reduce aseptic workload, improve production efficiency and decrease medication waste while ensuring product quality.

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Study comparing characteristics of ademetionine-containing tablets from different countries

Mato, J. M.; Wong, G. L.; Gooijer, Y.; Safaei, A.

2026-03-30 pharmacology and toxicology 10.64898/2026.03.27.714742 medRxiv
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Background/ObjectivesThe quality and characteristics of approved medicines can vary substantially depending on manufacturing processes and standards within a given country. The aim of the study was to compare the available marketed brands of ademetionine tablets derived from various countries in order to identify potential differences between the different formulations. MethodsWe performed comprehensive analyses of the physical, chemical, and dissolution characteristics of different formulations of ademetionine tablets marketed in China, India, Russia, Ukraine, and Uzbekistan, using the originator formulation of Heptral(R) as the reference standard. The formulations were evaluated at initial analysis and after 3 months at 40{degrees}C/75% relative humidity. Clinical parameters such as ademetionine content, degradation products, S,S-isomer, and water content were assessed using HPLC, and a dissolution profile analysis performed in 2 hours of acid solution followed by 90 minutes in a buffer solution. ResultsThe Nusam (India) and Ximeixin (China) products were the two products most comparable to the Heptral products. Adenomak (Ukraine), the only food-grade product and only one with the tosylate salt showed the most significant quality variations compared to Heptral including dissolution failure as well as considerable variability between batches. ConclusionsThe study highlights the importance of using pharmaceutical-grade ademetionine products to maintain clinical efficacy and ensuring standards are maintained across global markets.

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A Nonsteroidal Reversal Agent Inhibits Allopregnanolone Modulation of α1β3δ GABAA Receptors

Zhou, X.; Youssef, Y.; Miller, K. W.

2026-04-17 pharmacology and toxicology 10.64898/2026.04.14.718525 medRxiv
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The neurosteroid allopregnanolone is a positive allosteric modulator of GABA(A) receptors, which has proved beneficial in the treatment of major depressive disorder and epilepsies. It also has a role in treating the mood swings that are associated with fluctuations in its level during the menstrual cycle. Nonetheless, a subset of women do not tolerate high levels of allopregnanolone. Iso-allopregnanolone, a negative allosteric modulator, as well as synthetic steroid antagonists are used to treat such conditions. However, steroid-based medications are difficult to deliver and their specificity of action can be unclear. Recently introduced novel nonsteroidal agents that, like iso-allopregnanolone, can reverse the action of positive allosteric modulators without changing the positive action of GABA, might provide an alternative. We surveyed a number of them on human 1{beta}3{delta} GABAARs using a [3H]muscimol binding assay. A 6-membered ring spiro-hydantoin, DKD99, allosterically reversed the positive allosteric action of allopregnanolone over a wide concentration range (6 to 1,000 nM). DKD99 shifted allopregnanolones modulation curve 10-fold to the right. Furthermore, it has a much lower affinity when exerting similar actions on 1{beta}3{gamma}2 receptors. Agents such as this have utility for elucidating underlying mechanisms and may offer an alternative pathway for the development of nonsteroidal therapies against the positive allosteric modulatory actions of neurosteroids.

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Apelin inhibits cyst growth and improves kidney function in mice with polycystic kidney disease

Nyimanu, D.; Chakraborty, A.; Parnell, S.; Wallace, D.; Yu, A.

2026-03-30 pharmacology and toxicology 10.64898/2026.03.26.714294 medRxiv
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BackgroundAutosomal dominant polycystic kidney disease (ADPKD) is a common inherited disorder marked by numerous renal cysts that impair kidney function, with about half of affected individuals progressing to kidney failure by midlife. Patients exhibit reduced circulating apelin, a ligand of the apelin receptor, known to regulate cardiovascular function including hypertension. We tested whether diminished apelin signaling contributes to cystogenesis and if exogenous apelin receptor activation can improve disease outcomes. MethodsPlasma samples from age- and sex-matched healthy controls and ADPKD participants were analyzed for circulating apelin peptides. To assess direct cystic effects, primary ADPKD renal epithelial cells were grown as 3D collagen-embedded cysts and treated with apelin agonists. Male and female Pkd1RC/RC; Pkd2+/- (PKD) mice were treated for 27 days with apelin agonists, vehicle, or the standard of care drug, Mozavaptan. Kidney and heart weight ratios, BUN, renal cAMP, and kidney transcriptional profiles were evaluated. ResultsCirculating apelin peptides were significantly reduced in ADPKD patients despite normal kidney function (eGFR, BUN, and creatinine). In vitro, both apelin and the small molecule apelin receptor agonist Azelaprag inhibited cyst growth. Apelin and Mozavaptan reduced kidney weight, cystic index, blood urea nitrogen and renal cAMP in PKD mice, whereas Azelaprag did not. Apelin downregulated expression of genes associated with cyst progression, including Lcn2 (Ngal), Postn, and Havcr1 (Kim-1). Mozavaptan, but not apelin, induced diuresis and reduced urinary concentration. ConclusionApelin receptor activation by exogenous apelin inhibited cAMP synthesis and cyst growth and improved kidney function in an orthologous mouse model of ADPKD. We propose that the apelin receptor may be a potential therapeutic target in ADPKD.

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Treatment of murine autoimmune myocarditis with a novel monoclonal antibody that targets multiple inflammatory pathways

Toldo, S.; Luger, D.; Vozenilek, A.; Abbate, A.; Kelly, J.; Mezzaroma, E.; Shibao, C. A.; Abd-ElDayem, M. A.; Klenerman, P.; Waksman, R.; Virmani, R.; Maynard, J. A.; Harrison, D.; Flugelman, M. Y.; Epstein, S. E.

2026-03-31 systems biology 10.64898/2026.03.27.714891 medRxiv
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Severe forms of inflammation-induced acute and chronic myocarditis have a poor prognosis. Promising therapeutic efforts focused on monoclonal antibodies (mAbs) inhibiting inflammation-inducing molecules. However, most mAbs target only one or a limited number of such molecules. Since inflammation involves multiple redundant pathways, we postulated that an mAb inhibiting multiple inflammatory pathways would be a potent therapeutic agent. We initially tested the commercially available anti-natural killer (NK) cell mAb (anti-NK1.1), which binds a receptor expressed on NK cells and depletes them. Since NK cells are key cellular orchestrators of inflammation, by reducing their number, we aimed to inhibit multiple inflammatory pathways. Our initial studies demonstrated that administration of this antibody significantly improved myocardial outcomes in mouse models of acute myocardial infarction and of heart failure. Since NK1.1 is not expressed in human cells, we built on these promising preclinical results by developing a novel mAb targeting CD160 on human NK cells for evaluation as an immunosuppressive therapy. We found that the anti-CD160 mAb depletes both murine and human NK cells. We also found that, while CD160+ cells were largely present in the NK population, they also occurred among CD8+ and {gamma}/{delta} T cell subsets in human cells. Anti-CD160 therapy entirely prevented the deterioration of the myocardial function of mice with autoimmune-induced acute myocarditis. This outcome suggests our novel approach for inhibiting multiple inflammatory pathways may provide a potent strategy for improving outcomes of inflammation-driven myocarditis, as well as of other inflammation-driven diseases. Key PointsO_ST_ABSQuestionC_ST_ABSCan the depletion of CD160+ cells prevent autoimmune-induced myocarditis? FindingsIn this study we found that CD160 is expressed by mouse and human natural killer cells and other subtypes of cytotoxic T cells, and that a monoclonal antibody targeting CD160 depletes NK cells. In a preclinical model of experimental autoimmune myocarditis, administration of the anti-CD160 monoclonal antibody prevented myocardial dysfunction and systemic inflammation. MeaningOur results are compatible with the hypothesis that early autoimmune-induced myocardial dysfunction is promoted by CD160+ cells, which elevate inflammation-induced circulating factors (or factors released by tissue-resident cytotoxic immune cells) that cause myocardial dysfunction in the absence of myocardial necrosis or fibrosis, and further, that targeting CD160+cells with a mAb that depletes NK cells (and probably CD160 expressing cytotoxic T cells) entirely prevents the deterioration of myocardial function in such mice. This outcome suggests our novel approach for inhibiting multiple inflammatory pathways may provide a potent strategy for improving outcomes of inflammation-driven myocarditis, as well as of other inflammation-driven diseases.

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Differential effects of fenofibrate and fenofibric acid on the regulation of liver endothelial permeability

Luty, M. T.; Borah, D.; Szafranska, K.; Giergiel, M.; Trzos, K.; McCourt, P.; Lekka, M.; Kotlinowski, J.; Zapotoczny, B.

2026-04-20 cell biology 10.64898/2026.04.16.718907 medRxiv
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Background and AimsFenofibrate is widely prescribed for hyperlipidaemia and has been associated with rare but severe cases of drug-induced liver injury (DILI), yet its effects on liver sinusoidal endothelial cells (LSECs) remain to be investigated. LSECs maintain a highly permeable specialized sinusoidal barrier characterized by transcellular pores (fenestrations), regulating the bidirectional transfer of circulating compounds to and from the hepatocytes. As drug-induced alterations in fenestration architecture could influence xenobiotic access to hepatocytes, these changes may modulate pathways associated with DILI. Understanding the effects of fenofibrate on LSEC ultrastructure may therefore provide insights into previously underexplored endothelial contributions to hepatic drug responses. MethodsBoth fenofibrate and its active metabolite, fenofibric acid, were evaluated for their effects on LSEC ultrastructure, mechanical properties, and functional markers. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) and were used to quantify fenestration architecture. AFM was additionally used to measure cellular mechanical properties, which were interpreted in the context of fluorescence-based quantification of cytoskeletal organization. Gene expression, viability, and cytotoxicity were assessed using PCR-based and biochemical assays. ResultsFenofibrate reduced fenestration number and porosity at both tested concentration (10, and 25 {micro}M). It also decreased the apparent Youngs modulus of LSECs, accompanied by changes in tubulin and actin architecture, without detectable cytotoxicity. In contrast, treatment with fenofibric acid did not result in significant structural or mechanical effects on LSECs, even at higher concentrations. ConclusionsTogether, these data identify LSECs as a drug-responsive hepatic cell type for fenofibrate, suggesting that LSECs could represent an underrecognized contributor to the complex, multifactorial processes underlying DILI. This work provides a framework for evaluating endothelial contributions to fenofibrate-associated liver effects in more complex models. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=105 SRC="FIGDIR/small/718907v1_ufig1.gif" ALT="Figure 1"> View larger version (51K): org.highwire.dtl.DTLVardef@1d3f60corg.highwire.dtl.DTLVardef@bea13aorg.highwire.dtl.DTLVardef@14b27d8org.highwire.dtl.DTLVardef@124e0d3_HPS_FORMAT_FIGEXP M_FIG Fenofibrate reduces LSEC fenestrations and metabolic activity at higher concentrations, while its metabolite, fenofibric acid, does not affect LSEC, regardless of its concentration. C_FIG

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Do drugs with biliary toxicity cause cholangiocarcinoma?

Zong, C.; Lim, K.; Walker, S. A.; Dai, R.; Jeong, M. H.; George, R.; Jo, J. H.; Iqbal, S.; Im, H.; Weissleder, R.

2026-04-03 cancer biology 10.64898/2026.03.31.715688 medRxiv
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AO_SCPLOWBSTRACTC_SCPLOWMany commonly used therapeutic drugs cause biliary toxicity, but it is unclear if they are directly responsible for the increasing incidence of cholangiocarcinoma (CCA). We tested experimentally and analyzed through a cohort approach whether drugs, such as the commonly used antibiotic Augmentin, which is a poster-child of biliary toxicity, are causally linked to CCA development. Using sophisticated analytical tools in cholangiocytes, including single extracellular vesicle (EV) analysis, we found no evidence that Augmentin increases the cholangiocyte malignancy marker YAP1 or phospho-YAP1. Furthermore, we analyzed the CCA incidence in our healthcare system and determined it to be 0.0932% (Augmentin group) and 0.0799% (amoxicillin control group). Although the Augmentin group showed a numerically higher CCA incidence, the association did not reach statistical significance (RR = 1.1669, 95% CI 0.6200-2.1961; Fishers exact test, P = 0.7493). Similarly, we found no evidence for cholangiocarcinoma development with other commonly used drugs, including chlorpromazine, floxuridine, 5-fluorouracil, flucloxacillin and terbinafine. We conclude that there is no direct causal relationship between clinical Augmentin doses and CCA development.

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Comparative LUSZ Therapeutic Study (LUSZ_AVIST) of Antiviral, Antiretroviral, and Immunosuppressive Treatments in Hospitalized COVID-19 Patients with High-Risk Factors, Biomarkers, and Disease Progression.

Makdissy, N.; Makdessi, E. W.; Fenianos, F.; Nasreddine, N.; Daher, W.; El Hamoui, S.

2026-04-13 respiratory medicine 10.64898/2026.04.10.26350587 medRxiv
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COVID-19 has spread rapidly and caused a global pandemic making it one of the deadliest in history. Early identification of patients with coronavirus disease 2019 who may develop critical illness is of immense importance. Therefore, novel biomarkers were needed to identify patients who will suffer rapid disease progression to severe complications and death. Many treatments were adopted including the antiviral Remdesivir, the antiretroviral Lopinavir /Ritonavir and Tocilizumab. Our study aimed not only to specify high-risk factors and biomarkers of fatal outcome in hospitalized subjects with coronavirus but also to compare the efficacy of the three considered treatments to help clinicians better choose a therapeutic strategy and reduce mortality. We divided the population (n=711) into four main groups based according to the WHO ordinal severity scale. The percentage of mortality, in and out the hospital, the length of stay in the hospital, the pulmonary inflammatory lesion and its distribution, the SARS-CoV-2 IgM and IgG variations at admission, the inflammatory markers, the complete blood count, the coagulation factors and enzymes, proteins and electrolytes profile, glucose and lipid profile, and other relevant markers were measured. The significance of the observed variation was assessed by multivariate and ANOVA analyses. We succeeded to establish a novel predictive scoring model of disease progression based on a cohort of Lebanese hospitalized patients relying on the pulmonary inflammatory lesions, inflammation biomarkers such as LDH, D-Dimer, CRP, IL-6 and the lymphocyte count, the number of comorbidities and the age of the patient which all were significantly correlated with the illness severity showing best outcomes with immunomodulatory and anticoagulant treatments by the results. As top tier, Tocilizumab was more efficient than the two other treatments in non-severe cases but none of the used treatments was insanely effective alone to reduce mortality in severe cases.

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Minoxidil hydrochloride impedes NLRP3 inflammasome activation via upregulation of AMPK-mediated autophagy

Kaur, S.; Ali, M.; Shafeeq, A.; Ahmed, Z.; Kumar, A.

2026-04-08 immunology 10.64898/2026.04.06.716638 medRxiv
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NLRP3 inflammasome is a cytosolic multi-protein complex that plays a crucial role in the immune system, responding to various exogenous and endogenous stimuli by triggering protective inflammatory responses. However, aberrant NLRP3 inflammasome activation is implicated in numerous inflammatory diseases. Therefore, the NLRP3 inflammasome is an important pharmacological target for the treatment of multiple diseases. In this context, we screened various US-FDA-approved drugs for NLRP3 inflammasome inhibition. We found that among various drugs, minoxidil hydrochloride (MXL) effectively inhibits NLRP3 inflammasome, evidenced by reduced secretion of IL-1{beta} and IL-18 in J774A.1 cells treated with MXL. The IC50 values of MXL for inhibition of IL-1{beta} and IL-18 were calculated to be 1.2 and 1.06 {micro}M, respectively. MXL was found to prevent ASC oligomerization, thereby inhibiting the NLRP3 inflammasome and leading to CASP1 cleavage. Further investigation revealed that MXL also utilizes AMPK-mediated autophagy to modulate NLRP3 inflammasome activity. Using siAMPK and bafilomycin A1, an end-stage autophagy inhibitor, we elucidated crosstalk between the NLRP3 inflammasome and autophagic pathways, which was modulated by MXL. Furthermore, we demonstrated the efficacy of MXL in two different mouse models of inflammation, involving the NLRP3 inflammasome. MXL at doses of 10 and 20 mg/kg effectively inhibited the activation of NLRP3 inflammasome by monosodium urate in the air pouch model and by ATP in the peritoneal inflammation model, as evidenced by reduced secretion of 1{beta} and IL-18 in the lavage. Our study identifies MXL as a potent NLRP3 inflammasome inhibitor, warranting further investigation as a potential therapeutic agent for inflammatory diseases.

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The structure-interaction model of polymyxin lipopeptides with human oligopeptide transporter 2

Jiang, X.; Luo, Y.; Azad, M. A. K.; Xu, L.; Xiao, M.; Velkov, T.; Roberts, K. D.; Thamlikitkul, V.; Zhou, Q. T.; Zhou, F.; Li, J.

2026-04-02 biochemistry 10.64898/2026.04.01.715775 medRxiv
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BackgroundMultidrug-resistant (MDR) Gram-negative bacteria have triggered a critical global health crisis. Polymyxin lipopeptide antibiotics are used as a last-line therapy against these problematic pathogens, but their clinical use is largely limited by severe nephrotoxicity. Human oligopeptide transporter 2 (hPepT2) is a membrane transporter mediating the reabsorption of polymyxins in renal proximal tubular cells, substantially contributing to their nephrotoxicity. However, it remains unclear how polymyxins interact with hPepT2. MethodsIn this study, we investigated the structure-interaction relationship (SIR) of polymyxins with hPepT2 by integrating computational, chemical and cell biology approaches. Bioinformatic modelling predicted the residues essential for the binding of polymyxins with hPepT2. Transporter mutagenesis and molecular analysis were employed to explore the role of each residue in the interaction of hPepT2 and polymyxins. Moreover, we synthesised a series of polymyxin-like analogues with altering the moieties that are critical for binding with hPepT2. The antibacterial activity and nephrotoxicity of these analogues were subsequently assessed. ResultsOur bioinformatic modelling proposed an outward-facing structure of hPepT2 with a possible transport pathway that polymyxins bind to the lateral opening site of hPepT2 (e.g. E214, D215, D317, D342, E622). Molecular assays for transporter function and expression confirmed that D215 residue of hPepT2 is critical for polymyxin binding, while several other residues significantly impact on transporter turnover rate and/or protein expression. Our experimental validations showed that the lipopeptide analogues with altering the Dab1, Dab3, Dab5 and Dab9 moieties of polymyxins demonstrated decreased interactions with hPepT2. Among these synthetic analogues, alanine substitution at Dab3 showed reduced nephrotoxicity in mice while reserved antibacterial activity against a range of bacterial strains. ConclusionsOverall, this proof-of-concept study demonstrated that the computationally predicted and experimentally validated polymyxin-hPepT2 SIR model provides a viable approach for the discovery of novel, safer lipopeptide antibiotics.

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Assessment of Repurposed Compounds for Antiviral Activity Against Measles Virus

Rossler, A.; Ayala-Bernot, J.; Mohammadabadi, S.; Lasrado, N.; Warke, S.; Flaumenhaft, R.; Barouch, D.

2026-04-01 microbiology 10.64898/2026.03.31.715719 medRxiv
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BackgroundThere is currently no approved antiviral therapy against measles virus (MeV). Repurposing available compounds with broad antiviral activity may rapidly identify candidate drugs for clinical evaluation. Here we evaluated the antiviral activity of the clinically approved drugs azelastine hydrochloride and zafirlukast as well as the flavonoids quercetin and isoquercetin against MeV in preventative and therapeutic in vitro studies. MethodsCompounds were tested for antiviral activity against MeV in preventative (prophylactic and virucidal) and therapeutic (steady-state and persistent) assays in Vero/hSLAM cells. Viral loads and cell viability were measured 48h post-infection, and dose-response curves were used to calculate EC50 values. Flavonoids were also tested in the presence of 1 mM ascorbic acid. ResultsAzelastine hydrochloride did not show evidence of antiviral activity against MeV under these conditions, whereas zafirlukast, quercetin, and isoquercetin showed therapeutic activity against MeV. The addition of ascorbic acid enhanced the therapeutic potency of quercetin to 4.2-4.8 {micro}M and of isoquercetin to 10.7-10.9 {micro}M. Antiviral activity was dose-dependent when administered post-infection. ConclusionAmong the four compounds tested, quercetin showed the most potent therapeutic antiviral activity against MeV in vitro. Isoquercetin and zafirkulast also showed therapeutic activity. These findings support further evaluation of quercetin, isoquercetin, and zafirlukast as candidate antiviral drugs for MeV and highlight the utility of in vitro platforms for rapid antiviral drug screening.

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In vivo pharmacokinetics and tissue distribution profile of a Wnt/β-catenin pathway-targeting anticancer cassane diterpene isolated from Caesalpinia pulcherrima

De Vass Gunawardane, S.; Epitawala Arachchige, O. V.; Wijerathne, S. K.; Punyasiri, P. A. N.; Murugananthan, A.; Samarakoon, S. R.; Senathilake, K. S.

2026-04-01 pharmacology and toxicology 10.64898/2026.03.30.715187 medRxiv
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A cassane diterpene, 6{beta}-cinnamoyl-7-hydroxyvouacapen-5-ol (6{beta}CHV), isolated from Caesalpinia pulcherrima, has emerged as a promising anticancer drug lead with reported Wnt/{beta}-catenin pathway inhibitory activity and in vivo safety. The present study reports the in vivo pharmacokinetics and tissue distribution of 6{beta}CHV in Wistar rats following a single oral dose of 200 mg/kg. A reproducible RP-HPLC-UV method was developed and validated for quantifying 6{beta}CHV in rat plasma and tissues. Chromatographic separation was achieved using a gradient elution of methanol and water. The method was subsequently applied to investigate the pharmacokinetics and tissue distribution of 6{beta}CHV. Plasma pharmacokinetic analysis revealed delayed and moderate absorption, with a Tmax of 4 h and a Cmax of 1314.12 ng/mL. Following absorption, 6{beta}CHV is distributed widely across peripheral tissues, including the liver, heart, lungs, spleen, and kidneys, as well as pharmacological sanctuary sites such as the brain and testes. The highest concentrations were observed in the stomach, small intestine, and liver, with detectable levels persisting up to 24 h, reflecting extensive tissue partitioning and retention. Overall, these findings demonstrate that oral administration of 6{beta}CHV is feasible. However, the delayed absorption suggests that further optimization of formulation or alternative administration routes may enhance systemic exposure. This study provides the first comprehensive pharmacokinetic and tissue distribution profile of 6{beta}CHV, supporting its continued preclinical development as a potential anticancer therapeutic. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=125 SRC="FIGDIR/small/715187v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@4ae86forg.highwire.dtl.DTLVardef@1e1e51aorg.highwire.dtl.DTLVardef@1881c43org.highwire.dtl.DTLVardef@f7789f_HPS_FORMAT_FIGEXP M_FIG C_FIG

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sPRR signaling in macrophages via the AT1R/Yap/Taz axis to induce renal fibrosis

Feng, Y.; Zheng, H.; Xie, S.; Wang, F.; Luo, R.; Yang, T.

2026-04-07 pathology 10.64898/2026.04.03.716436 medRxiv
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BackgroundWithin the kidney, (pro) renin receptor (PRR) is abundantly expressed in the collecting duct (CD) and modulate physiological and pathophysiological processes. We have recently reported that activation of CD PRR mediates obstructive renal fibrosis in a mouse model of unilateral ureteral obstruction (UUO). The current study addresses the underlying mechanisms by examining the profibrotic pathway mediated by soluble PRR (sPRR)-dependent alternative macrophage activation. MethodsWe performed UUO or sham surgery on mice with CD-specific deletion of PRR (CD PRR KO) and floxed controls. After 7 days, we assessed fibrosis-related parameters, inflammatory cytokines, M1/M2 macrophage markers, other gene expression markers of kidney injury, and the concentration of plasma sPRR. We also administered vehicle or site-1 protease (S1P) inhibitor PF-429242 (PF) to C57BL/6 mice with UUO to determine the role of sPRR. Experiments were performed in vitro to examine the mechanism of sPRR-His-mediated macrophage M2 polarization and activation of potential target genes in bone-marrow-derived macrophages (BMDMs). ResultsCompared with the floxed control, CD PRR KO decreased macrophage accumulation, M2 polarization, and Yap/Taz expression while improving renal fibrosis and suppressing plasma sPRR levels following UUO. In BMDMs, sPRR-His treatment promoted macrophage M2 polarization, fibrosis, and Yap/Taz expression, which was dependent on angiotensin type 1 receptor (AT1R). ConclusionCD PRR-derived sPRR acts via ATR to promote macrophage M2 polarization and stimulates the AT1R/Yap/Taz axis, which leads to renal fibrosis during UUO.

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The Effect of Vitamin-D Supplementation on HDAC2 Levels in Stable COPD Patients

Donastin, A.; Irawan, D.; Effendy, E.; Iryawan, R. D. A.; Nuari, N.; Oktaviana, B. M.; Yahya, D.; Muhammad, A. R.

2026-04-08 respiratory medicine 10.64898/2026.04.05.26348641 medRxiv
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Background: Chronic Obstructive Pulmonary Disease (COPD) is the third leading cause of global mortality, with persistent lung inflammation contributing to disease progression. This inflammation is partly associated with reduced levels of histone deacetylase 2 (HDAC2). Previous studies suggest that Vitamin D may modulate HDAC2 levels. This study aimed to evaluate the effect of Vitamin D supplementation on HDAC2 expression in stable COPD patients. This experimental study aimed to evaluate the effect of vitamin D supplementation on HDAC2 expression in stable COPD patients at Jemursari Islamic Hospital. Methods: Five COPD patients received a daily dose of 5000 IU of Vitamin D for three months. Serum levels of 25(OH)D3 and HDAC2 were measured before and after the intervention. Results: Vitamin D supplementation resulted in a significant increase in both 25(OH)D and HDAC2 levels. Pulmonary function parameters showed an increasing trend, however, no statistically significant differences were observed. Conclusion: Vitamin D supplementation was associated with increased HDAC2 levels, suggesting a potential anti-inflammatory effect. However, no significant improvement in pulmonary function was observed. Further studies are needed to determine its clinical impact.

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An Integrated Analysis of GLP-1R Agonist Mechanisms: Addressing Study Variations in Heterogeneous Cell Systems

Silfvergren, O.; Rigal, S.; Schimek, K.; Simonsson, C.; Kanebratt, K. P.; Forschler, F.; Yesildag, B.; Marx, U.; Vilen, L.; Gennemark, P.; Cedersund, G.

2026-03-27 systems biology 10.64898/2026.03.25.714139 medRxiv
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Experimental cell systems support the development of pharmacological therapies such as glucagon-like peptide-1 receptor agonists (GLP-1RAs). However, their utility in drug discovery is limited due to study variability, which complicates formation of unified conclusions based on all available data. To address this, we conducted a comprehensive analysis of the GLP-1RA exenatide, incorporating 16 new and five pre-existing mono- or co-culture studies of human liver and pancreatic models. We employed a new pragmatic model-based approach designed to handle the common situation of heterogeneous in vitro datasets with few replicates per condition. All studies are jointly explained (disagreement<{chi}{superscript 2}-limit; 542<732), thereby providing a unified conclusion based on all studies. This work links in vitro biology to clinically relevant mechanisms, such as exenatides effect on glucose-insulin interplay, and predicts previously undescribed inter-study variabilities. Independent validation confirms predictive performance (64<83). Our new integrative approach enhances the utility of experimental cell systems in preclinical drug discovery.

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Targeting Protease-activated Receptor 4 (PAR4) Protects Against Acute Kidney Injury (AKI) in Ischemia Reperfusion Injury

Webb, E. M.; Cao, S.; Pan, Y.; Zhang, M.-Z.; Harris, R.; Boutaud, O.; Bouchard, J. L.; Jones, C. K.; Lindsley, C. W.; Hamm, H. E.

2026-03-30 pharmacology and toxicology 10.64898/2026.03.27.714572 medRxiv
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Acute kidney injury (AKI) is a serious and common clinical syndrome that currently has no effective treatment. Emerging evidence links coagulation pathways to kidney injury, particularly through coagulation proteases. Protease-activated receptors (PARs) are a family of G-protein coupled receptors (GPCRs) that are activated by proteolytic cleavage of their N termini, exposing a tethered ligand that initiates receptor signaling. PARs have been shown to play a major role in inflammation, vascular regulation, and tissue injury. PARs play key roles in inflammation, vascular regulation, and tissue injury. Previous work from the Hamm laboratory demonstrated that PAR4 contributes to AKI progression, as PAR4 knockout mice were protected in both unilateral ureteral obstruction and ischemia-reperfusion-based models of kidney disease. In this study, we investigated the potential of a PAR4 antagonist, VU6073819, at mitigating AKI progression in an ischemia-reperfusion injury (IRI) mouse model. PAR4 antagonism not only alleviated kidney injury and inflammatory response, but it significantly improved the survival. These findings identify PAR4 as a promising therapeutic target for AKI.

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Multicenter preclinical validation of next-generation CAR T cells: a strategy for harmonization, reproducibility, and its feasibility in clinical translation

Dalloul, I.; Barden, M.; Wilcke, J.; Bernhard, S.; Ellenbach, N.; Boulesteix, A.-L.; Abken, H.; Kobold, S.

2026-04-10 synthetic biology 10.64898/2026.04.10.717659 medRxiv
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PurposeClinical translation of CAR T cell therapies has accelerated, yet preclinical evidence still often originates from single-center studies lacking sufficient robustness. Preclinical confirmatory multicenter studies have been proposed to improve the translational success, but their feasibility in cellular therapies remains unexplored. MethodsWe performed a confirmatory multicenter study validating C-C-motive-receptor-8 (CCR8) overexpression in CAR T cells--a strategy previously shown to enhance solid tumor infiltration. In vitro experiments covering activation, cytotoxicity, and migration using three CAR constructs were conducted across two centers with harmonized materials, preregistered protocols, randomization, and blinding. ResultsThe data from the two centers confirmed key findings of the exploratory study: CCR8 overexpression in anti-EpCAM and anti-mesothelin CAR T cells leads to enhanced selective migration towards a CCL1-gradient, while not compromising antigen-specific T cell activatory capacity and cytotoxicity in vitro. The study furthermore broadened the applicability of CCR8 overexpression to anti-CEA CAR T cells. ConclusionsThis first-of-its-kind preclinical confirmatory CAR T study demonstrates the feasibility of a multicenter confirmation in cellular therapy, with technical and logistical challenges resolved through transparent communication between all parties involved. Both exploratory and confirmatory studies aim to downselect CAR candidates with the highest clinical success potential, as they compete for limited resources in preclinical research. It is therefore mandatory to clarify the extent of replications required to validate the experimental methodology and identify CAR candidates with most likelihood of success. TRANSLATIONAL RELEVANCEPreclinical evidence for novel CAR T cell therapeutic strategies relies mostly on exploratory single-center studies lacking robustness, with recent findings substantiating their limited predictive value for cellular therapies tested outside hematology. Here, the function of CCR8-armored CARs in vitro was confirmed in a preclinical confirmatory multicenter study, demonstrating the feasibility of such studies in adding value to the transition of preclinical concepts to clinical development. Our first-of-its-kind study may contribute to define new routes for preclinical testing and further raises the general question of what level of preclinical evidence is reasonably achievable in an academic context. It indicates the need for strong collaborative efforts to realize dedicated preclinical infrastructure for clinical translation of reprogrammed immune cellular therapeutics.

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Anti-HIV Immunotoxin and Antibody-Drug Conjugate Display Both Common and Distinct Effects in Killing Target Cells

PINCUS, S.; Peters, T.; Stackhouse, M. S.; O'Shea-Stone, G.; Cole, F. M.; Tripet, B.; Copie, V.

2026-04-10 immunology 10.64898/2026.04.07.717054 medRxiv
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BackgroundIn the course of testing mAb-based therapies to eradicate the persistent reservoir of HIV infection, we investigated the efficacy and mode of killing of HIV-infected cells by two categories of cytotoxic immunoconjugates (CICs) targeted by the same mAb, an immunotoxin (IT) and antibody-drug conjugate (ADC). MethodsWe performed metabolic and transcriptional analyses of treatment effects on the persistently-infected cell line H9/NL4-3. Cells were treated with CICs consisting of the anti-gp41 mAb 7B2 conjugated to either deglycosylated ricin A chain (dgA) or to the highly cytotoxic anthracycline derivative PNU-159682. At intervals up to 24 hr, intracellular metabolites were quantified by 1H nuclear magnetic resonance spectroscopy, and the transcriptome analyzed by RNA-Seq. ResultsSix hr post treatment, 7B2-dgA elicited both metabolic and transcriptional alterations, whereas 7B2-PNU treated cells did not differ from untreated cells. 7B2-dgA treated cells exhibited elevated intracellular levels of many amino acids, and activation of gene pathways for apoptosis, intracellular signaling, and immune activation. By 24 hr, both 7B2-dgA and 7B2-PNU treated cells differed markedly from untreated. Many of the changes observed following 7B2-PNU treatment at 24 hr were similar to those observed at 6hr following 7B2-dgA, likely indicating processes involved in cell death, but a number of alterations were unique to either IT or ADC treated cells. ConclusionsAn IT and ADC showed both similarities and differences in their cytotoxic effects. These results raise the question of whether the mode of cell killing could be a determinant of clinical efficacy. Although these studies were aimed at targeting the persistent reservoir of HIV infection, they have relevance for the design of CICs to treat cancer and other conditions. SUMMARYThe use of cytotoxic immunoconjugates, wherein an antibody is attached to a cellular poison, is effective in the treatment of cancer and other conditions. We seek to extend these results to treating HIV and other chronic viral infections. We analyzed the molecular mechanisms of cell killing when the same antibody was attached to different toxic structures. We report that each immunoconjugate induced both common and distinct patterns of killing. Such differences may have clinical relevance.