Dex Treatment Research Articles

A TH17-intrinsic IL-1β-STAT5 axis drives steroid resistance in autoimmune neuroinflammation.

Steroid resistance poses a major challenge for the management of autoimmune neuroinflammation. T helper 17 (TH17) cells are widely implicated in the pathology of steroid resistance; however, the underlying mechanisms are unknown. In this study, we identified that interleukin-1 receptor (IL-1R) blockade rendered experimental autoimmune encephalomyelitis (EAE) mice sensitive to dexamethasone (Dex) treatment. Interleukin-1β (IL-1β) induced a signal transducer and activator of transcription 5 (STAT5)-mediated steroid-resistant transcriptional program in TH17 cells, which promoted inflammatory cytokine production and suppressed Dex-induced anti-inflammatory genes. TH17-specific deletion of STAT5 ablated the IL-1β-induced steroid-resistant transcriptional program and rendered EAE mice sensitive to Dex treatment. IL-1β synergized with Dex to promote the STAT5-dependent expression of CD69 and the development of central nervous system (CNS)-resident CD69+ TH17 cells. Combined IL-1R blockade and Dex treatment ablated CNS-resident TH17 cells, reduced EAE severity, and prevented relapse. CD69+ tissue-resident TH17 cells were also detected in brain lesions of patients with multiple sclerosis. These findings (i) demonstrate that IL-1β-STAT5 signaling in TH17 cells mediates steroid resistance and (ii) identify a therapeutic strategy for reversing steroid resistance in TH17-mediated CNS autoimmunity.

Clinical and economic implications of using daratumubab with lenalidomide in the 1st and 2nd lines of therapy for multiple myeloma patients

Objective: to assess clinical and economic implications of adding daratumumab (Dara) to the “lenalidomide + dexamethasone” (Rd) treatment program in early lines of therapy for patients with multiple myeloma (MM) ineligible for high-dose chemotherapy (HDCT) with subsequent autologous hematopoietic stem cell transplantation (autoHPSCT).Material and methods. Partitioned survival model was developed to compare overall survival in the treatment programs of MM patients in the 1st to 3rd lines of therapy. The following treatment options were included in the analysis: 1st line – Dara+Rd; 2nd line – “carfilzomib + lenalidomide” (K+Rd) or “ixazomib + lenalidomide” (Ixa+Rd) triplets; 3rd line – pomalidomide (Pom+dex) and Rd+(Dara+Rd)+(Pom+dex) versus Rd+(K/Ixa+Rd)+(Pom+dex/Dara). Probabilities of transition between health states (progression-free, progressed disease, and death) were based on published clinical data. Lifetime direct healthcare costs and incremental cost-effectiveness ratios (ICERs) per 1 life year gained were calculated from a Russian health care perspective. The indicator of the difference in costs between current and expected practice was used in budget impact analysis.Results. Dara+Rd combination increased life expectancy by 1.04 years (+16.05%) and 0.95 years (+14.57%) per patient, and in the target population (n=955) by 995.48 and 903.40 years for (Dara+Rd)+(K+Rd)+(Pom+dex) and (Dara+Rd)+(Ixa+Rd)+(Pom+dex) treatment programs, respectively, compared to Rd use in the 1st line. The ICER per 1 life year gained for Dara+Rd in 1st line therapy was 8.95 mln rubles for (Dara+Rd)+(K+Rd)+(Pom+dex) and 8.41 mln rubles for (Dara+Rd)+(Ixa+Rd)+(Pom+dex). It's lower than the median ICER of 13.64 million per 1 life year gained for antitumor drugs used to treat cancer of lymphatic and hematopoietic tissues (reference ICER). Dara+Rd triplet is used in 2nd line therapy after Rd, the number of life years gained in the target population due to greater efficacy is higher by 291.50 years compared with K+Rd and by 203.93 years compared with Ixa+Rd. The ICER per 1 life year gained for Dara+Rd is also lower than the ICER reference value: 9.25 mln rubles versus 13.64 mln rubles. The budget impact analysis showed that using Dara in early stages of MM therapy does not increase drug provision costs in the target population.Conclusion. The obtained results allowed to conclude that it is economically feasible to add Dara to the 1st and 2nd lines of therapy in lenalidomide treatment programs for MM patients who are not candidates for HDCT with autoHPSCT.

Riluzole Reverses a Number of Undesirable Effects of Dexamethasone in Glioblastoma Cells.

Glioblastoma multiforme (GBM)-induced oedema is a major cause of morbidity and mortality among patients with GBM. Dexamethasone (Dex) is the most common corticosteroid used pre-operatively to control cerebral oedema in patients with GBM. Dex is associated with many side effects, and shorter overall survival and progression-free survival of patients with GBM. These negative effects of Dex highlight the need for combinational therapy. Riluzole (Ril), a drug used to treat amyotrophic lateral sclerosis (ALS), is thought to have potential as a treatment for various cancers, with clinical trials underway. Here, we investigated whether Ril could reverse some of the undesirable effects of Dex. The effect of Dex, Ril, and Ril-Dex treatment on cell migration was monitored using the xCELLigence system. Cell viability assays were performed using 3-(4, 5-dimethylthiazol)-2, 5-diphenyltetrazolium bromide (MTT). The expression of genes involved in migration, glucose metabolism, and stemness was examined using real-time polymerase chain reaction (PCR). Pre-treating GBM cells with Ril reduced Dex-induced cell migration and altered Dex-induced effects on cell invasion, stem cell, and glucose metabolism markers. Furthermore, Ril remained effective in killing GBM cells in combination with Dex. Ril, which acts as an anti-tumorigenic drug, mediates some of the negative effects of Dex; therefore, it could be a potential drug to manage the side effects of Dex therapy in GBM.

α2-macroglobulin alleviates glucocorticoid-induced avascular necrosis of the femoral head in mice by promoting proliferation, migration and angiogenesis of vascular endothelial cells

To explore the mechanism underlying the protective effect of α2-macroglobulin (A2M) against glucocorticoid-induced femoral head necrosis. In a human umbilical vein endothelial cell (HUVEC) model with injuries induced by gradient concentrations of dexamethasone (DEX; 10-8-10-5 mol/L), the protective effects of A2M at 0.05 and 0.1 mg/mL were assessed by examining the changes in cell viability, migration, and capacity of angiogenesis using CCK-8 assay, Transwell and scratch healing assays and angiogenesis assay. The expressions of CD31 and VEGF-A proteins in the treated cells were detected using Western blotting. In BALB/c mouse models of avascular necrosis of the femoral head induced by intramuscular injections of methylprednisolone, the effects of intervention with A2M on femoral trabecular structure, histopathological characteristics, and CD31 expression were examined with Micro-CT, HE staining and immunohistochemical staining. In cultured HUVECs, DEX treatment significantly reduced cell viability, migration and angiogenic ability in a concentration- and time-dependent manner (P<0.05), and these changes were obviously reversed by treatment with A2M in positive correlation with A2M concentration (P<0.05). DEX significantly reduced the expression of CD31 and VEGF-A proteins in HUVECs, while treatment with A2M restored CD31 and VEGF-A expressions in the cells (P<0.05). The mouse models of femoral head necrosis showed obvious trabecular damages in the femoral head, where a large number of empty lacunae and hypertrophic fat cells could be seen and CD31 expression was significantly decreased (P<0.05). A2M treatment of the mouse models significantly improved trabecular damages, maintained normal bone tissue structures, and increased CD31 expression in the femoral head (P<0.05). A2M promotes proliferation, migration, and angiogenesis of DEX-treated HUVECs and alleviates methylprednisolone-induced femoral head necrosis by improving microcirculation damages and maintaining microcirculation stability in the femoral head.

Mechanism of dexmedetomidine protection against cisplatin induced acute kidney injury in rats

Objective This study explored the molecular mechanisms by which dexmedetomidine (Dex) alleviates cisplatin (CP)-induced acute kidney injury (AKI) in rats. Methods CP-induced AKI models were established, and Dex was intraperitoneally injected at different concentrations into rats in the model groups. Subsequently, rats were assigned to the control, CP, CP + Dex 10 μg/kg, and CP + Dex 25 μg/kg groups. After weighing the kidneys of the rats, the kidney arterial resistive index was calculated, and CP-induced AKI was evaluated. In addition, four serum biochemical indices were measured: histopathological damage in rat kidneys was detected; levels of inflammatory factors, interleukin (IL)-1β, IL-18, IL-6, and tumor necrosis factor alpha, in kidney tissue homogenate of rats were assessed through enzyme-linked immunosorbent assay (ELISA); and levels of NLRP-3, caspase-1, cleaved caspase-1, gasdermin D (GSDMD), and GSDMD-N in kidney tissues of rats were determined via western blotting. Results Dex treatment reduced nephromegaly and serum clinical marker upregulation caused by CP-induced AKI. In addition, hematoxylin and eosin staining revealed that Dex treatment relieved CP-induced kidney tissue injury in AKI rats. ELISA analyses demonstrated that Dex treatment reduced the upregulated levels of proinflammatory cytokines in the kidney tissue of AKI rats induced by CP, thereby alleviating kidney tissue injury. Western blotting indicated that Dex alleviated CP-induced AKI by inhibiting pyroptosis mediated by NLRP-3 and caspase-1. Conclusion Dex protected rats from CP-induced AKI, and the mechanism may be related to NLRP-3/Caspase-1-mediated pyroptosis.

ECM1 and KRT6A are involved in tumor progression and chemoresistance in the effect of dexamethasone on pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) has a very poor prognosis. Neoadjuvant chemotherapy is an effective PDAC treatment option, but chemotherapy causes unfavorable side effects. Glucocorticoids (e.g., dexamethasone [DEX]) are administered to reduce side effects of chemotherapy for solid tumors, including pancreatic cancer. Glucocorticoids have both beneficial and detrimental effects, however. We investigated the functional changes and gene-expression profile alterations induced by DEX in PDAC cells. PDAC cells were treated with DEX, and the cell proliferation, migration, invasion, and chemosensitivity to gemcitabine (GEM) were evaluated. The results demonstrated decreased cell proliferative capacity, increased cell migration and invasion, and decreased sensitivity to GEM. A comprehensive genetic analysis revealed marked increases in ECM1 and KRT6A in DEX-treated PDAC cells. We evaluated the effects of ECM1 and KRT6A expression by using PDAC cells transfected with those genes. Neither ECM1 nor KRT6A changed the cells' proliferation, but each enhanced cell migration and invasion. ECM1 decreased sensitivity to GEM. We also assessed the clinicopathological significance of the expressions of ECM1 and KRT6A in 130 cases of PDAC. An immunohistochemical analysis showed that KRT6A expression dominated the poorly differentiated areas. High expressions of these two proteins in PDAC were associated with a poorer prognosis. Our results thus demonstrated that DEX treatment changed PDAC cells' functions, resulting in decreased cell proliferation, increased cell migration and invasion, and decreased sensitivity to GEM. The molecular mechanisms of these changes involve ECM1 and KRT6A, whose expressions are induced by DEX.

The Efficacy & Molecular Mechanisms of a Terpenoid Compound Ganoderic Acid C1 on Corticosteroid-Resistant Neutrophilic Airway Inflammation: In vivo and in vitro Validation.

Neutrophil predominant airway inflammation is associated with severe and steroid-resistant asthma clusters. Previously, we reported efficacy of ASHMI, a three-herb TCM asthma formula in a steroid-resistant neutrophil-dominant murine asthma model and further identified Ganoderic Acid C1 (GAC1) as a key ASHMI active compound in vitro. The objective of this study is to investigate GAC1 effect on neutrophil-dominant, steroid-resistant asthma in a murine model. In this study, Balb/c mice were systematically sensitized with ragweed (RW) and alum and intranasally challenged with ragweed. Unsensitized/PBS challenged mice served as normal controls. Post sensitization, mice were given 4 weeks of oral treatment with GAC1 or acute dexamethasone (Dex) treatment at 48 hours prior to challenge. Pulmonary cytokines were measured by ELISA, and lung sections were processed for histology by H&E staining. Furthermore, GAC1 effect on MUC5AC expression and on reactive oxygen species (ROS) production in human lung epithelial cell line (NCI-H292) was determined by qRT-PCR and ROS assay kit, respectively. Computational analysis was applied to select potential targets of GAC1 in steroid-resistant neutrophil-dominant asthma. Molecular docking was performed to predict binding modes between GAC1 and Dex with TNF-α. The result of the study showed that chronic GAC1 treatment, significantly reduced pulmonary inflammation (P < 0.01-0.001 vs Sham) and airway neutrophilia (P < 0.01 vs Sham), inhibited TNF-α, IL-4 and IL-5 levels (P < 0.05-0.001 vs Sham). Acute Dex treatment reduced eosinophilic inflammation and IL-4, IL-5 levels, but had no effect on neutrophilia and TNF-α production. GAC1 treated H292 cells showed decreased MUC5AC gene expression and production of ROS (P < 0.001 vs stimulated/untreated cells). Molecular docking results showed binding energy of complex GAC1-TNF was -10.8 kcal/mol. GAC1 may be a promising anti-asthma botanical drug for treatment of steroid-resistant asthma.

Exploring vaginal discharge scoring to assess clinical metritis severity: Comparison between intrauterine dextrose and systemic antibiotics treatments

The objectives of this study were to assess: 1) differences in the metabolic status, systemic inflammation, daily milk yield, and daily rumination time between Holstein dairy cows with different vaginal discharge scores (VDS) in the first 7±3 DIM, and 2) effects of intrauterine dextrose infusion on metabolic status, systemic inflammation, daily milk yield and daily rumination time in dairy cows with VDS4 and VDS5. Cows (n=641) from a farm located in central Pennsylvania were screened at 7±3 DIM (study d 0) to assess vaginal discharge scores. Vaginal discharge was scored using a five-point scale (i.e., 1- clear fluid, 2- <50% white purulent fluid, 3- >50% white purulent fluid, 4- red-brownish fluid without fetid smell, and 5- fetid red-brownish watery fluid). Cows with VDS4 and VDS5 were blocked by parity and randomly assigned to one of two treatment groups: 1) CONV (VDS4 n=15; VDS5 n= 23): two injections of ceftiofur (per label; 6.6 mg/Kg) 72 h apart; and 2) DEX (VDS4 n=15; VDS5 n=22): three intrauterine infusions of a 50% dextrose solution (1 L/cow) every 24 h. Cows that presented a VDS 1, 2, and 3 were categorized as normal vaginal discharge animals (NOMVDS; n=35) and were randomly selected and matched by parity to CONV and DEX cows. Daily milk yield and rumination time for the first 150 DIM were collected from on-farm computer records. Blood samples were collected to assess haptoglobin (HP) and β-hydroxybutyrate (BHB) concentrations at study d 0, d 7, and d 14 relative to enrollment. Subclinical ketosis was defined as having a BHB concentration >1.2 mmol/dL at any of the sampling points. The data were analyzed using the MIXED and GLIMMIX procedures of SAS as a randomized complete block design. When comparing cows with different VDS (i.e., NOMVDS, VDS4, VDS5) separately, cows with VDS5 had the highest concentration of HP at enrollment compared to cows with VDS4 and NOMVDS; however, cows with VDS4 had higher concentrations of HP compared to cows with NOMVDS. Cows with VDS4 or VDS5 had a higher incidence of subclinical ketosis compared to cows with NOMVDS (p=0.005; VDS4= 62.08±9.16%; VDS5=74.44±6.74%; NOMVDS=34.36±8.53%). Similarly, daily milk yield (p<.0001; VDS4=30.17±1.32 kg/d; VDS5=27.40±1.27 kg/d; NOMVDS=35.14±1.35 kg/d) and daily rumination time (p=0.001; VDS4=490.77±19.44 min; VDS5=465±16.67 min; NOMVDS=558.29±18.80 min) was lower for cows with VDS4 and VDS5 compared to cows with NOMVDS at 7±3 days in milk. When analyzing HP concentration between treatment groups in cows with VDS4 (p=0.70), VDS5 (p=0.25), or VDS4 and VDS5 combined (p=0.31), there was no difference in HP concentration by study d 14 between treatment groups. Interestingly, when only cows with VDS4 were considered for treatment, both treatments, DEX and CONV, increased the daily milk yield to the levels of NOMVDS cows by 14 days in milk. On the other hand, when only cows with VDS5 were considered for treatment, cows treated with DEX produced, on average, 4.48 kg/d less milk in the first 150 days in milk compared to cows treated with CONV or cows that had NOMVDS. Similarly, when cows with either VDS4 or VDS5 were considered for treatment, DEX treatment also impaired milk yield. These results suggest that cows with either VDS 4 or 5 have an altered inflammatory status, and decreased milk yield and rumination compared to cows with NOMVDS. Furthermore, DEX treatment may have similar effects on daily milk yield and metabolic status compared to CONV in cows with VDS4, while DEX is not recommended for cows with VDS5.

Abstract 660: OPN-6602, a potent dual EP300/CBP bromodomain inhibitor, targets multiple myeloma through concomitant suppression of IRF4 and c-MYC

Abstract Multiple myeloma (MM) is an aggressive hematological cancer derived from malignant plasma cells in the bone marrow. E1A-binding protein (EP300) and CREB-binding protein (CBP) are transcription coactivators that contain both epigenetic writer histone acetyltransferase (HAT) and reader bromo- (BRD) domains that regulate transcription of genes via chromatin remodeling. EP300/CBP inhibition causes cell cycle arrest and apoptosis in MM through suppression of interferon regulatory factor (IRF4) and concomitant repression of c-MYC, rendering EP300/CBP as a novel target for MM. OPN-6602 is a potent, selective, and orally active small molecule dual EP300/CBP inhibitor discovered through structure guided drug design. Its binding interaction exhibits low nM activity on EP300 (Kd= 1.5 nM) and CREBBP (Kd= 1 nM), with &amp;gt; 200-fold less activity against BRD4. OPN-6602 binding to EP300 is particularly potent by Surface Plasmon Resonance analysis, displaying a Kd of 0.87 nM, with a fast association rate (1.5 E+06/Ms) and a slow dissociation rate (1.3 E-03/s) with a residence time of 13 min. It potently inhibits cell growth in MM cell lines OPM-2 (IC50 ~ 4 nM) and MM.1S (IC50 ~ 47 nM) as well as histone acetylation (IC50 ~ 2 nM) via BRD intramolecular modulation of HAT activity. OPN-6602 demonstrated potent inhibition of H3K27Ac in both LK2 (CBP-deficient lung cancer cells, IC50 = 11 nM) and in OPM-2 (IC50 = 1.6 nM). OPN-6602 also potently inhibited H3K27ac expression in PBMCs with IC50s of 0.75 and 1.4 nM, respectively. The effects of OPN-6602 with dexamethasone (dex) or lenalidomide (len) on the growth of OPM-2 and MM1.S cells were evaluated in a matrix combination study. As single agents, maximal growth inhibition reached 60-75% following dex treatment and only 30-40% following len treatment. In vitro combination studies utilizing a systematic assessment of a broad range of OPN-6602 concentrations in combination with dex or len demonstrated strong synergy. Synergy was observed between OPN-6602 at 3.7 nM and len through a concentration range from 0.027 to 20 µM. Synergy was observed with 1.2 or 3.7 nM of OPN-6602 in combo with dex concentrations from 0.055 to 40 µM. In the OPM-2 xenograft model, OPN-6602 inhibits tumor growth by 30-111% at doses from 2.5-60 mg/kg QD. This growth inhibition correlated with downregulation of IRF4 and cMYC in tumor samples analyzed by QPCR analysis. The pharmacokinetic profile is favorable for oral QD dose administration due to a high Cmax (19 µg/mL at 24 mg/kg) and short half-life (T1/2 = 1.5 hr). A first-in-human study of OPN-6602 in patients with MM is planned for 2024. Citation Format: Bernice Matusow, Wayne Spevak, Chao Zhang, Yan Ma, Rafe Shellooe, James Tsai, Pei Pei Li, Pan Yu Chen, Gaston Habets, Christine Nichols, Parmveer Singh, Kerry Inokuchi, Jackie Walling, Jason Halladay, Gideon Bollag. OPN-6602, a potent dual EP300/CBP bromodomain inhibitor, targets multiple myeloma through concomitant suppression of IRF4 and c-MYC [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 660.

Prolonged exposure to dexamethasone alters the proteome and cellular phenotype of human testicular peritubular cells.

Human testicular peritubular cells (HTPCs) are smooth muscle cells, which in the testis form a small compartment surrounding the seminiferous tubules. Contractions of HTPCs are responsible for sperm transport, HTPCs contribute to spermatogenesis, have immunological roles and are a site of glucocorticoid receptor expression. Importantly, HTPCs maintain their characteristics in vitro, and thus can serve as an experimental window into the male gonad. Previously we reported consequences of 3-day treatment with Dexamethasone (Dex), a synthetic glucocorticoid and multi-purpose anti-inflammatory drug. However, as glucocorticoid therapies in man often last longer, we now studied consequences of a prolonged 7-day exposure to 1 µM Dex. Combining live cell imaging with quantative proteomics of samples taken from men, we confirmed our recent findings but more importantly, found numerous novel proteomic alterations induced by prolonged Dex treatment. The comparison of the 7-day treatment with the 3-day treatment dataset revealed that extracellular matrix- and focal adhesion-related proteins become more prominent after 7 days of treatment. In contrast, extended stimulation is, for example, associated with a decrease of proteins related to cholesterol and steroid metabolism. Our dataset, which describes phenotypic and proteomic alterations, is a valuable resource for further research projects investigating effects of Dex on human testicular cells.

Dexamethasone Induced Osteocyte Apoptosis in Steroid-Induced Femoral Head Osteonecrosis through ROS-Mediated Oxidative Stress.

Glucocorticoid (GC) overuse is strongly associated with steroid-induced osteonecrosis of the femoral head (SINFH). However, the underlying mechanism of SINFH remains unclear. This study aims to investigate the effect of dexamethasone (Dex)-induced oxidative stress on osteocyte apoptosis and the underlying mechanisms. Ten patients with SINFH and 10 patients with developmental dysplasia of the hips (DDH) were enrolled in our study. Sixty rats were randomly assigned to the Control, Dex, Dex + N-Acetyl-L-cysteine (NAC), Dex + Dibenziodolium chloride (DPI), NAC, and DPI groups. Magnetic resonance imaging (MRI) was used to examine edema in the femoral head of rats. Histopathological staining was performed to assess osteonecrosis. Immunofluorescence staining with TUNEL and 8-OHdG was conducted to evaluate osteocyte apoptosis and oxidative damage. Immunohistochemical staining was carried out to detect the expression of NOX1, NOX2, and NOX4. Viability and apoptosis of MLO-Y4 cells were measured using the CCK-8 assay and TUNEL staining. 8-OHdG staining was conducted to detect oxidative stress. 2',7'-Dichlorodihydrofluorescein diacetate (DCFH-DA) staining was performed to measure reactive oxygen species (ROS). The expression of NOX1, NOX2, and NOX4 in MLO-Y4 cells was analyzed by Western blotting. Multiple comparisons were performed using one-way analysis of variance (ANOVA). In patients and the rat model, hematoxylin-eosin (HE) staining revealed a significantly higher rate of empty lacunae in the SINFH group than in the DDH group. Immunofluorescence staining indicated a significant increase in TUNEL-positive cells and 8-OHdG-positive cells in the SINFH group compared to the DDH group. Immunohistochemical staining demonstrated a significant increase in the expression of NOX1, NOX2, and NOX4 proteins in SINFH patients compared to DDH patients. Moreover, immunohistochemical staining showed a significant increase in the proportion of NOX2-positive cells compared to the Control group in the femoral head of rats. In vitro, Dex significantly inhibited the viability of osteocyte cells and induced apoptosis. After Dex treatment, the intracellular ROS level increased. However, Dex treatment did not alter the expression of NOX proteins in vitro. Additionally, NAC and DPI inhibited the generation of intracellular ROS and partially alleviated osteocyte apoptosis in vivo and in vitro. This study demonstrates that GC promotes apoptosis of osteocyte cells through ROS-induced oxidative stress. Furthermore, we found that the increased expression of NOXs induced by GC serves as an important source of ROS generation.

A192 'GLYCOCAGED' DRUGS: PHARMACOKINETICS AND TRANSLATIONAL POTENTIAL FOR PEOPLE WITH IBD

Abstract Background Inflammatory bowel disease (IBD) is characterized by chronic inflammation in the gastrointestinal tract. Despite the alarming global increase in IBD burden with 1 in 121 Canadians affected, no cure exists. Systemic administration of anti-inflammatory drugs like corticosteroids is a front-line therapy for inducing remission. However, these drugs are limited in their application by deleterious off-target side effects. To target the drug to sites of inflammation and reduce systemic uptake, we developed a microbiome-cleavable, glycoconjugate drug delivery system, termed GlycoCage. We have demonstrated that GlycoCaged dexamethasone (Dex, a potent steroid), is effective at reducing inflammation at 10-fold lower doses than its uncaged counterpart in the SHIP-deficient (SHIP-/-) mouse model of CD-like intestinal inflammation. We hypothesize that GlycoCaged technology can expand the therapeutic window of IBD drugs by lowering effective doses and eliminating side effects. Aims: 1) Quantify Dex in systemic circulation. 2) Assess status of inflammation outside of the gut in SHIP-/- mice treated with caged Dex. 3) Measure decaging activity in people with IBD. Methods To compare systemic distribution of Dex to caged Dex, we orally gavaged SHIP+/+ and SHIP-/- mice with 3 mg/kg of Dex or the molar equivalent of caged Dex and collected serum for LC-MS/MS analysis at multiple timepoints post oral gavage. In addition to CD-like ileitis, SHIP-/- mice spontaneously develop enlarged mesenteric lymph nodes (MLNs) and inflamed lungs. After daily treatment of Dex or caged Dex for 2 weeks, MLNs and lungs were collected and analyzed for size and histopathology. We also obtained stool samples from healthy control participants and people with IBD to investigate the prevalence of prodrug-cleaving activity by direct enzymatic activity assay using fluorogenic resorufin as a prodrug proxy. Data from people with IBD were stratified to fecal calprotectin. Results Unlike free dexamethasone, caged dexamethasone did not enter systemic circulation or impact inflammation outside of the gut in SHIP-/- mice. All people have decaging activity that is not affected by IBD or the individual’s disease activity. Conclusions Our results highlight a novel glycoconjugated prodrug strategy to improve and broaden treatment options for people with IBD. In the future, we will evaluate GlycoCaged Dex in a mouse model of colitis and test the efficacy of other GlycoCaged drugs. Funding Agencies CCCGlycoNet

Dexmedetomidine Alleviates Brain Ischemia/Reperfusion Injury by Regulating Metastasis-associated Lung Adenocarcinoma Transcript 1/MicroRNA-140-5p/ Nuclear Factor Erythroid-derived 2-like 2 Axis.

Dexmedetomidine (Dex) is widely used in perioperative anesthesia, and recent studies have reported that it protects organs from ischemia/reperfusion (I/R) injury. This study was performed to investigate the role of Dex in alleviating cerebral I/R injury and its regulatory effects on metastasis-associated lung adenocarcinoma transcript 1 (MALAT1)/microRNA-140-5p (miR-140-5p)/nuclear factor erythroid-derived 2-like 2 (Nrf2) axis. In vivo rat middle cerebral artery occlusion (MCAO) model and in vitro oxygen-glucose deprivation/re-oxygenation (OGD/R)-induced neuronal injury model were constructed. Dex was injected into the animals or used to culture HT22 cells to observe the pharmacological effects. The neurological defect, brain water content, infarct volume of the rats, and neuron viability were evaluated. The levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) were detected. Besides, the regulatory effects of Dex on MALAT1, miR-140-5p, and Nrf2 expression levels and regulatory relationships among them were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, and dual- luciferase reporter assay. Dex significantly alleviated the neurological injury of rats with MCAO and promoted the viability of neurons. Dex treatment suppressed miR-140-5p expression, but elevated MALAT1 and Nrf2 expressions. MALAT1 knockdown down-regulated Nrf2 expression and promoted oxidative stress in neurons. Additionally, miR-140-5p directly targeted Nrf2, and it also functioned as a downstream target miRNA of MALAT1. Dex, via regulating MALAT1/miR-140-5p/Nrf2 axis, plays a neuroprotective role against I/R-induced brain injury.

Dexamethasone targets actin cytoskeleton signaling and inflammatory mediators to reverse sulfur mustard-induced toxicity in rabbit corneas

PurposeSulfur mustard (SM), a bi-functional alkylating agent, was used during World War I and the Iran-Iraq war. SM toxicity is ten times higher in eyes than in other tissues. Cornea is exceptionally susceptible to SM-injuries due to its anterior positioning and mucous-aqueous interphase. Ocular SM exposure induces blepharitis, photosensitivity, dry eye, epithelial defects, limbal ischemia and stem cell deficiency, and mustard gas keratopathy leading to temporary or permanent vision impairments. We demonstrated that dexamethasone (Dex) is a potent therapeutic intervention against SM-induced corneal injuries; however, its mechanism of action is not well known. Investigations employing proteomic profiling (LC-MS/MS) to understand molecular mechanisms behind SM-induced corneal injury and Dex efficacy were performed in the rabbit cornea exposed to SM and then received Dex treatment. PEAKS studio was used to extract, search, and summarize peptide identity. Ingenuity Pathway Analysis was used for pathway identification. Validation was performed using immunofluorescence. One-Way ANOVA (FDR < 0.05; p < 0.005) and Student's t-test (p < 0.05) were utilized for analyzing proteomics and IF data, respectively. Proteomic analysis revealed that SM-exposure upregulated tissue repair pathways, particularly actin cytoskeleton signaling and inflammation. Prominently dysregulated proteins included lipocalin2, coronin1A, actin-related protein2, actin-related protein2/3 complex subunit2, actin-related protein2/3 complex subunit4, cell division cycle42, ezrin, bradykinin/kininogen1, moesin, and profilin. Upregulated actin cytoskeleton signaling increases F-actin formation, dysregulating cell shape and motility. Dex reversed SM-induced increases in the aforementioned proteins levels to near control expression profiles. Dex aids corneal wound healing and improves corneal integrity via actin cytoskeletal signaling and anti-inflammatory effects following SM-induced injuries.

Characterization of GABAergic marker expression in prefrontal cortex in dexamethasone induced depression/anxiety model.

The pivotal responsibility of GABAergic interneurons is inhibitory neurotransmission; in this way, their significance lies in regulating the maintenance of excitation/inhibition (E/I) balance in cortical circuits. An abundance of glucocorticoids (GCs) exposure results in a disorder of GABAergic interneurons in the prefrontal cortex (PFC); the relationship between this status and an enhanced vulnerability to neuropsychiatric ailments, like depression and anxiety, has been identified, but this connection is still poorly understood because systematic and comprehensive research is lacking. Here, we aim to investigate the impact of dexamethasone (DEX, a GC receptor agonist) on GABAergic interneurons in the PFC of eight-week-old adult male mice. A double-blind study was conducted where thirty-two mice were treated subcutaneously either saline or DEX (0.2 mg/10 ml per kg of body weight) dissolved in saline daily for 21 days. Weight measurements were taken at five-day intervals to assess the emotional changes in mice as well as the response to DEX treatment. Following the 21-day regimen of DEX injections, mice underwent examinations for depression/anxiety-like behaviours and GABAergic marker expression in PFC. In a depression/anxiety model generated by chronic DEX treatment, we found that our DEX procedure did trigger depression/anxiety-like behaviors in mice. Furthermore, DEX treatment reduced the expression levels of a GABA-synthesizing enzyme (GAD67), Reelin, calcium-binding proteins (parvalbumin and calretinin) and neuropeptides co-expressed in GABAergic neurons (somatostatin, neuropeptide Y and vasoactive intestinal peptide) in the PFC were reduced after 21 days of DEX treatment; these reductions were accompanied by decreases in brain size and cerebral cortex thickness. Our results indicate that a reduction in the number of GABAergic interneurons may result in deficiencies in cortical inhibitory neurotransmission, potentially causing an E/I imbalance in the PFC; this insight suggests a potential breakthrough strategy for the treatment of depression and anxiety.

Dexmedetomidine regulates exosomal miR-29b-3p from macrophages and alleviates septic myocardial injury by promoting autophagy in cardiomyocytes via targeting glycogen synthase kinase 3β.

Our previous research suggested that dexmedetomidine (Dex) promotes autophagy in cardiomyocytes, thus safeguarding them against apoptosis during sepsis. However, the underlying mechanisms of Dex-regulated autophagy have remained elusive. This study aimed to explore the role of exosomes and how they participate in Dex-induced cardioprotection in sepsis. The underlying microRNA (miRNA) mechanisms and possible therapeutic targets for septic myocardial injury were identified. We first collected plasma exosomes from rats with sepsis induced by caecal ligation and puncture (CLP) with or without Dex treatment, and then incubated them with H9c2 cells to observe the effect on cardiomyocytes. Subsequently, the differential expression of miRNAs in plasma exosomes from each group of rats was identified through miRNA sequencing. miR-29b-3p expression in circulating exosomes of septic or non-septic patients, as well as in lipopolysaccharide-induced macrophages after Dex treatment, was analysed by quantitative real-time polymerase chain reaction (qRT-PCR). The autophagy level of cardiomyocytes after macrophage-derived exosome treatment was assessed by an exosome tracing assay, western blotting, and an autophagic flux assay. Specific miRNA mimics and inhibitors or small interfering RNAs were used to predict and evaluate the function of candidate miRNA and its target genes by qRT-PCR, annexin V/propyl iodide staining, autophagy flux analysis, and western blotting. We found that plasma-derived exosomes from Dex-treated rats promoted cardiomyocyte autophagy and exerted antiapoptotic effects. Additionally, they exhibited a high expression of miRNA, including miR-29b-3p. Conversely, a significant decrease in miR-29b-3p was observed in circulating exosomes from CLP rats, as well as in plasma exosomes from sepsis patients. Furthermore, Dex upregulated the lipopolysaccharide-induced decrease in miR-29b-3p expression in macrophage-derived exosomes. Exosomal miR-29b-3p from macrophages is thought to be transferred to cardiomyocytes, thus leading to the promotion of autophagy in cardiomyocytes. Database predictions, luciferase reporter assays, and small interfering RNA intervention confirmed that glycogen synthase kinase 3β (GSK-3β) is a target of miR-29b-3p. miR-29b-3p promotes cardiomyocyte autophagy by inhibiting GSK-3β expression and activation. These findings demonstrate that Dex attenuates sepsis-associated myocardial injury by modulating exosome-mediated macrophage-cardiomyocyte crosstalk and that the miR-29b-3p/GSK-3β signaling pathway represents a hopeful target for the treatment of septic myocardial injury.

Selenium-mediated alleviation of skeletal muscle atrophy through enterotype modulation in mice.

Skeletal muscle is crucial for health, and glucocorticoid-induced atrophy poses a significant clinical challenge. This study utilized a dexamethasone (Dex)-induced mouse model to assess the impact of selenium supplementation on skeletal muscle atrophy during and after Dex treatment. Increasing evidence suggests the existence of a 'gut-muscle axis', where gut microbiota plays a regulatory role in muscle metabolism and function. We also examined changes in gut microbiota during selenium supplementation and applied the PAM (Partitioning Around Medoids, PAM) algorithm to identify key enterotypes influencing muscle health. Our findings show that selenium supplementation significantly mitigated Dex-induced muscle atrophy and hastened recovery post-treatment. Selenium intervention not only restructured the gut microbiota, enhancing diversity and promoting short-chain fatty acid producers, but also favored the Lactobacillus and Dubosiella enterotypes. These enterotypes are linked to improved amino acid and energy utilization, beneficial for muscle function. This study suggests that selenium may be a valuable nutritional supplement for combating Dex-induced skeletal muscle atrophy.

Establishment of a glucocorticoid inducible system for regulating somatic embryogenesis in Liriodendron hybrids.

The precise expression of transcription factors (TFs) is crucial for plant growth and development, especially during somatic embryogenesis. However, conventional overexpression approaches, commonly used for functional genetics, can lead to deleterious effects. Therefore, it is imperative to ensure that TFs are expressed in a controlled and timely manner when aiming to enhance the efficiency of somatic embryogenesis. In this study, a dexamethasone/glucocorticoid receptor (DEX/GR) inducible expression system was employed to modulate the protein expression levels of target TFs within the nucleus during somatic embryogenesis in Liriodendron hybrids. We selected the WUSCHEL (WUS) gene, a well-established functional TF known for its vital role in somatic embryogenesis, as a model to assess the effectiveness of this system. Through DEX treatment, we induced the translocation of LhWUS-GR/LhWUS-GFP-GR fusion proteins from the cytoplasm to the nucleus, consequently leading to WUS-driven somatic embryogenesis. As the DEX concentration increased, there was a corresponding increase in the migration of the LhWUS-GFP-GR fusion protein into the nucleus. Additionally, we observed a higher proliferation ratio of callus expressing LhWUS-GR when exposed to varying DEX concentrations. Notably, the efficiency of somatic embryogenesis exhibited significant improvement under optimal DEX concentration. In conclusion, our study successfully utilizes the DEX/GR inducible system in Liriodendron hybrids, offering a valuable tool for the precise control and utilization of TFs at the desired levels. This innovative approach holds promise for advancing our understanding of TF function and enhancing plant development through the regulated manipulation of TF expression.

Dexpanthenol ameliorates lipopolysaccharide-induced cardiovascular toxicity by regulating the IL-6/HIF1α/VEGF pathway

IntroductionLipopolysaccharide (Lps) is an essential component responsible for the virulence of gram-negative bacteria. Lps can cause damage to many organs, including the heart, kidneys, and lungs. Dexpanthenol (Dex) is an agent that exhibits anti-oxidative and anti-inflammatory effects and stimulates epithelialization. In this study, we aimed to investigate the effects of Dex on Lps-induced cardiovascular toxicity. MethodsRats were divided into four groups: control, Lps (5 mg/kg, intraperitoneal), Dex (500 mg/kg, intraperitoneal), and Lps + Dex. The control group received saline intraperitoneally (i.p.) once daily for three days. The Lps group received saline i.p. once daily for three days and a single dose of Lps i.p. was administered on the third day. The Dex group received Dex i.p. once daily for three days and saline on the third day. The Lps + Dex group received Dex i.p. once daily for three days and a single dose of Lps i.p. on the third day. Heart and aortic tissues were taken for biochemical, histopathological, immunohistochemical, and genetic analysis. ResultsLps injection caused histopathological changes in both heart and aortic tissues and significantly increased total oxidant status and oxidative stress index levels. Interleukin-6, and Tumor necrosis factor-α mRNA expressions were significantly altered in heart and aorta, likely do to the anti-inflammatory and antioxidative effects of Dex. Furthermore, Dex affected Caspase-3 and Hypoxia-inducible factor 1-α staining patterns. ConclusionsOur results show that Dex treatment has a protective effect on Lps-induced cardiac and endothelial damage in rats by reducing inflammation, oxidative stress, and apoptosis.

Dexamethasone potentiates chimeric antigen receptor T cell persistence and function by enhancing IL-7Rα expression

Dexamethasone (dex) is a glucocorticoid that is a mainstay for the treatment of inflammatory pathologies, including immunotherapy-associated toxicities, yet the specific impact of dex on the activity of CAR Tcells is not fully understood. We assessed whether dex treatment given exvivo or as an adjuvant invivo with CAR Tcells impacted the phenotype or function of CAR Tcells. We demonstrated that CAR Tcell expansion and function were not inhibited by dex. We confirmed this observation using multiple CAR constructs and tumor models, suggesting that this is a general phenomenon. Moreover, we determined that dex upregulated interleukin-7 receptor α on CAR Tcells and increased the expression of genes involved in activation, migration, and persistence when supplemented exvivo. Direct delivery of dex and IL-7 into tumor-bearing mice resulted in increased persistence of adoptively transferred CAR Tcells and complete tumor regression. Overall, our studies provide insight into the use of dex to enhance CAR Tcell therapy and represent potential novel strategies for augmenting CAR Tcell function during production as well as following infusion into patients.