Pharmacological Modulation of BET Family in Sepsis

Integrated Lactylome Characterization Reveals the Molecular Dynamics of Protein Regulation in Gastrointestinal Cancers

Lysine lactylation (Kla) plays a vital role in several physiological processes. However, the cancer-specific modulation of Kla in gastrointestinal (GI) tumors requires systematic elucidation. Here, global lactylome profiling of cancerous and adjacent tissues is conducted from 40 patients with GI cancer and identified 11698 Kla sites. Lactylome integration revealed that Kla affects proteins involved in hallmark cancer processes, including epigenetic rewiring, metabolic perturbations, and genome instability. Moreover, the study revealed pan-cancer patterns of Kla alterations, among which 37 Kla sites are consistently upregulated in all four GI cancers and are involved in gene regulation. It is further verified that lactylation of CBX3 at K10 mediates its interaction of CBX3 with the epigenetic marker H3K9me3 and facilitates GI cancer progression. Overall, this study provides an invaluable resource for understanding the lactylome landscape in GI cancers, which may provide new paths for drug discovery for these devastating diseases.

BET-inhibitor DYB-41 reduces pulmonary inflammation and local and systemic cytokine levels in LPS-induced acute respiratory distress syndrome: an experimental rodent study

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a form of respiratory failure stemming from various underlying conditions that ultimately lead to inflammation and lung fibrosis. Bromodomain and Extra-Terminal motif (BET) inhibitors are a class of medications that selectively bind to the bromodomains of BET motif proteins, effectively reducing inflammation. However, the use of BET inhibitors in ARDS treatment has not been previously investigated. In our study, we induced ARDS in rats using endotoxin and administered a BET inhibitor. We evaluated the outcomes by examining inflammation markers and lung histopathology.

RESULTS

Nine animals received treatment, while 12 served as controls. In the lung tissue of treated animals, we observed a significant reduction in TNFα levels (549 [149-977] pg/mg vs. 3010 [396-5529] pg/mg; p = 0.009) and IL-1β levels (447 [369-580] pg/mg vs. 662 [523-924] pg/mg; p = 0.012), although IL-6 and IL-10 levels showed no significant differences. In the blood, treated animals exhibited a reduced TNFα level (25 [25-424] pg/ml vs. 900 [285-1744] pg/ml, p = 0.016), but IL-1β levels were significantly higher (1254 [435-2474] pg/ml vs. 384 [213-907] pg/ml, p = 0.049). No differences were observed in IL-6 and IL-10 levels. There were no significant variations in lung tissue levels of TGF-β, SP-D, or RAGE. Histopathological analysis revealed substantial damage, with notably less perivascular edema (3 vs 2; p = 0.0046) and visually more inflammatory cells. However, two semi-quantitative histopathologic scoring systems did not indicate significant differences.

CONCLUSIONS

These preliminary findings suggest a potential beneficial effect of BET inhibitors in the treatment of acute lung injury and ARDS. Further validation and replication of these results with a larger cohort of animals, in diverse models, and using different BET inhibitors are needed to explore their clinical implications.

Commonly disrupted pathways in brain and kidney in a pig model of systemic endotoxemia

Sepsis is a life-threatening state that arises due to a hyperactive inflammatory response stimulated by infection and rarely other insults (e.g., non-infections tissue injury). Although changes in several proinflammatory cytokines and signals are documented in humans and small animal models, far less is known about responses within affected tissues of large animal models. We sought to understand the changes that occur during the initial stages of inflammation by administering intravenous lipopolysaccharide (LPS) to Yorkshire pigs and assessing transcriptomic alterations in the brain, kidney, and whole blood. Robust transcriptional alterations were found in the brain, with upregulated responses enriched in inflammatory pathways and downregulated responses enriched in tight junction and blood vessel functions. Comparison of the inflammatory response in the pig brain to a similar mouse model demonstrated some overlapping changes but also numerous differences, including oppositely dysregulated genes between species. Substantial changes also occurred in the kidneys following LPS with several enriched upregulated pathways (cytokines, lipids, unfolded protein response, etc.) and downregulated gene sets (tube morphogenesis, glomerulus development, GTPase signal transduction, etc.). We also found significant dysregulation of genes in whole blood that fell into several gene ontology categories (cytokines, cell cycle, neutrophil degranulation, etc.). We observed a strong correlation between the brain and kidney responses, with significantly shared upregulated pathways (cytokine signaling, cell death, VEGFA pathways) and downregulated pathways (vasculature and RAC1 GTPases). In summary, we have identified a core set of shared genes and pathways in a pig model of systemic inflammation.

Immune dysregulation and RNA N6-methyladenosine modification in sepsis

Sepsis is defined as life-threatening organ dysfunction caused by the host immune dysregulation to infection. It is a highly heterogeneous syndrome with complex pathophysiological mechanisms. The host immune response to sepsis can be divided into hyper-inflammatory and immune-suppressive phases which could exist simultaneously. In the initial stage, systemic immune response is activated after exposure to pathogens. Both innate and adaptive immune cells undergo epigenomic, transcriptomic, and functional reprogramming, resulting in systemic and persistent inflammatory responses. Following the hyper-inflammatory phase, the body is in a state of continuous immunosuppression, which is related to immune cell apoptosis, metabolic failure, and epigenetic reprogramming. Immunosuppression leads to increased susceptibility to secondary infections in patients with sepsis. RNA N6-Methyladenosine (m6A) has been recognized as an indispensable epitranscriptomic modification involved in both physiological and pathological processes. Recent studies suggest that m6A could reprogram both innate and adaptive immune cells through posttranscriptional regulation of RNA metabolism. Dysregulated m6A modifications contribute to the pathogenesis of immune-related diseases. In this review, we summarize immune cell changes and the potential role of m6A modification in sepsis. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > RNA Editing and Modification.

Discovery of Potent and Novel Dual PARP/BRD4 Inhibitors for Efficient Treatment of Pancreatic Cancer

Targeting poly(ADP-ribose) polymerase1/2 (PARP1/2) is a promising strategy for the treatment of pancreatic cancer with breast cancer susceptibility gene (BRCA) mutation. Inducing the deficiency of homologous recombination (HR) repair is an effective way to broaden the indication of PARP1/2 inhibitor for more patients with pancreatic cancer. Bromodomain-containing protein 4 (BRD4) repression has been reported to elevate HR deficiency. Therefore, we designed, synthetized, and optimized a dual PARP/BRD4 inhibitor III-16, with a completely new structure and high selectivity against PARP1/2 and BRD4. III-16 showed favorable synergistic antitumor efficacy in pancreatic cancer cells and xenografts by arresting cell cycle progression, inhibiting DNA damage repair, and promoting autophagy-associated cell death. Moreover, III-16 reversed Olaparib-induced acceleration of cell cycle progression and recovery of DNA repair. The advantages of III-16 over Olaparib suggest that dual PARP/BRD4 inhibitors are novel and promising agents for the treatment of advanced pancreatic cancer.