Methylsulfonylmethane protects against lethal dose MRSA-induced sepsis through promoting M2 macrophage polarization

The new pattern for dual NOTCH pathway involving nuclear transcription and mitochondrial regulation supports therapeutic mechanism of 4-butyl benzophenone derivatives against SIRS

The systemic inflammatory response syndrome (SIRS) represents a self-amplifying cascade of inflammatory reactions and pathophysiological states triggered by infectious or non-infectious factors. The identification of disease targets and differential proteins in the liver (the unique and important immune organ) of SIRS mice treated with the lead compound D1 was conducted using the Genecards database and proteomic analysis, respectively. Subsequently, NOTCH1 was identified as the potential hub target via an intersection analysis between the aforementioned differentially expressed proteins and disease targets. Based on our previous research on the structure-activity relationship, we designed and synthesized a series of SIRS-related derivatives, wherein butyl, halogen, and ester groups were incorporated into benzophenone, aiming at exploring the anti-inflammatory protective action from the perspective of macrophage polarization. Notably, these derivatives exhibited a direct binding capability to the O-glucosylation site (SER496) or its vicinities (such as SER492, VAL485) of NOTCH1 using docking, SPR, DARTS, and CETSA techniques. Mechanistically, derivative D6 exerted anti-inflammatory effects via the dual NOTCH pathway. Firstly, it could inhibit NOTCH1 nuclear transcriptional activity, attenuate the interaction between NICD and RBPJK, concurrently suppress NF-κB and NLRP3 inflammasome (NLRP3, ASC, and cleaved CASP1) activation, and promote NICD (NOTCH1 active fragments) ubiquitination metabolism (the nuclear transcriptional pathway). Secondly, it might possess the ability to increase PGC1α level, subsequently, enhance ATP and MMP levels, mitigate ROS production, increase mitochondrial numbers, and ameliorate mitochondrial inflammatory damage (the mitochondrial pathway). Importantly, the activator Jagged1 could effectively reverse the aforementioned effects, while the inhibitor DAPT exhibited a synergistic effect, suggesting that the nuclear transcriptional regulation and mitochondrial regulation were both in a NOTCH1-dependent manner. Subsequently, it effectively alleviated the inflammatory response and preserved organ function as evidenced by up-regulating M2-type macrophage-related anti-inflammatory cytokines (IL10, TGFβ, CD206, and ARG1) and down-regulating M1-type macrophage-related pro-inflammatory cytokines (NO, IL6, IL18, iNOS, TNFα, CD86, and IL1β). In a word, derivative D6 modulated macrophage polarization and effectively mitigated SIRS by targeting inhibition of the dual NOTCH pathway.

The relationship and clinical significance of lactylation modification in digestive system tumors

Lactylation, an emerging post-translational modification, plays a pivotal role in the initiation and progression of digestive system tumors. This study presents a comprehensive review of lactylation in digestive system tumors, underscoring its critical involvement in tumor development and progression. By focusing on metabolic reprogramming, modulation of the tumor microenvironment, and the molecular mechanisms regulating tumor progression, the potential of targeting lactylation as a therapeutic strategy is highlighted. The research reveals that lactylation participates in gene expression regulation and cell signaling by affecting the post-translational states of histones and non-histone proteins, thereby influencing metabolic pathways and immune evasion mechanisms in tumor cells. Furthermore, this study assesses the feasibility of lactylation as a therapeutic target, providing insights for clinical treatment of gastrointestinal cancers. Future research should concentrate on elucidating the mechanisms of lactylation, developing efficient lactylation inhibitors, and validating their therapeutic efficacy in clinical trials, which could transform current cancer treatment and immunotherapy approaches. In summary, this review emphasizes the crucial role of lactylation in tumorigenesis and progression through a detailed analysis of its molecular mechanisms and clinical significance.

Lactate and Lactylation in Sepsis: A Comprehensive Review

Sepsis is a disorder of the immune response to infection or infectious factors with high morbidity and mortality in clinical settings. The lactylation of lysine residues, fueled by lactate, plays a pivotal role in its pathophysiology. In conducting a literature review on sepsis-related research, we employed a systematic approach to ensure comprehensiveness and accuracy. Initially, we conducted an extensive literature search through the PubMed database, utilizing a range of keywords including "sepsis", "lactate", "lactylation", and "epigenetic modification". The aim was to capture the most recent research related to the pathophysiological mechanisms of sepsis, metabolic disorders, and the role of lactylation. The results of the literature review revealed a close link between sepsis and metabolic dysfunction, particularly the pivotal role of lactylation in regulating immune responses and inflammatory processes. Lactate, not only an energy metabolic byproduct produced during glycolysis, affects the activity of various proteins, including those involved in immune regulation and cell signaling, through lactylation. In the context of sepsis, changes in the levels of lactylation may be closely associated with the severity and prognosis of the disease. In summary, lactylation, as an emerging type of epigenetic modification, provides a new perspective for the diagnosis and treatment of sepsis. Future research needs to further elucidate the exact mechanisms of lactylation in sepsis and explore its potential as a therapeutic target.

Telmisartan and candesartan promote browning of white adipose tissue and reverse fatty liver changes in high fat diet fed male albino rats

Obesity is a key risk factor for many diseases, as cardiovascular disorders, diabetes, infertility, osteoarthritis, sleep apnea, non-alcoholic fatty liver disease (NAFLD) as well as increased risk for many cancers. Telmisartan and Candesartan cilexetil are angiotensin II receptor blockers which had proven to involve in pathogenesis of obesity and NAFLD.

AIMS

This work is designed to explore the possible mitigated effects of Telmisartan and Candesartan cilexetil on weight gain and fatty liver in high fat diet (HFD) fed rats.

MAIN METHODS

The HFD rat model was achieved with induction of NAFLD. For Seven weeks either telmisartan or candesartan were orally administered at doses of 5 and 10 mg/kg respectively once daily. The effects of both drugs were evaluated by measurements of rat's body weight, food intakes, length, body mass index (BMI), liver weight, inguinal and interscapular fat weights. In addition, we assayed lipid profile, liver functions tests, serum inflammatory cytokines, adipokine and leptin. Lastly, liver and adipose tissue histopathological structures were evaluated.

KEY FINDINGS

at end of experiment, telmisartan and candesartan were highly effective in decreasing rat's body weight from (213.1±2.68 to 191.2±2.54 and 203.5±5.89 gm , respectively), BMI, liver weight, fat weights in addition reduced serum levels of lipid and liver enzymes. Also, inflammatory cytokines were reduced with repaired histopathological insults in liver by significantly damped NAFLD score from (6.5 ±0.17 to 1±0 and 4 ±0, respectively) and decreased areas of adipocytes from (21239.12 to 5355.7 and 11607.1 um2 , respectively).

SIGNIFICANCE

Telmisartan and candesartan have therapeutic potential against obesity and NAFLD induced by HFD in rats. All the previous indices showed more improvement in telmisartan than candesartan group.

Malvidin promotes PGC-1α/Nrf2 signaling to attenuate the inflammatory response and restore mitochondrial activity in septic acute kidney injury

Acute kidney injury (AKI) in sepsis is a vital and dangerous organ failure caused by an infection-induced dysregulation of the host reaction. Malvidin possesses significant anti-inflammatory and antioxidant bioactivities. This study explored the critical roles of malvidin in sepsis AKI and the crosstalk among mitochondrial function, nucleotide-binding oligomerization-like receptor 3 (NLRP3) inflammasome and nuclear factor erythroid 2 (Nrf2) signaling pathway. First, C57BL/6 mice were administered lipopolysaccharide intraperitoneally for 6 h to create an AKI model of sepsis. Hematoxylin-eosin staining and serum biomarker assays showed that malvidin protected from AKI in sepsis. Real-time fluorescence quantitative polymerase chain reaction analysis revealed that malvidin was able to inhibit inflammatory cytokines and mediators. Western blot assays indicated that malvidin suppressed NLRP3 inflammasome activation and enhanced antioxidant properties. Additionally, human renal tubular epithelial cells were stimulated by lipopolysaccharide/adenosine triphosphate to establish an NLRP3 inflammasome activation model in vitro, and in line with findings in vivo, malvidin significantly inhibited NLRP3 inflammasome activation. Furthermore, our data indicate that malvidin restored mitochondrial quality and function, reduced reactive oxygen species production, increased mitochondrial membrane potential, enhanced mitochondrial DNA copy number, and promoted peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) nuclear translocation. Moreover, inhibitor blockade assays indicated that both PGC-1α and Nrf2 affected the inhibition of the NLRP3 inflammasome by malvidin. Finally, immunoprecipitation assays showed that malvidin promoted PGC-1α and Nrf2 interactions. Overall, malvidin alleviated lipopolysaccharide-induced sepsis AKI, improved mitochondrial function and mitochondrial biogenesis, and inhibited the NLRP3 inflammasome through the PGC-1α/Nrf2 signaling pathway, suggesting that malvidin might translate into clinical applications for sepsis AKI therapy.

Potential biomarker for diagnosis and therapy of sepsis: Lactylation

INTRODUCTION

As a disease that has plagued human health for decades, sepsis has so far had no specific diagnostic or therapeutic indicators. The discovery of lactylation modifications not only uncovered the deep-rooted causes of changing between lactate level and pathophysiology and immunology of sepsis, but also reaffirmed the inevitable link between metabolic reprogramming and epigenetic reprogramming in sepsis. Lactylation modification became a potential marker for diagnosis and guiding the treatment of sepsis.

AIM

In this paper, we will summarize the discovery and regulation of lactylation modifications, discuss the study of lactylation modifications in sepsis, and evaluate their possibility and potential as diagnostic and therapeutic indicators of sepsis.

CONCLUSION

Lactylation modification is directly regulated by glycolysis and lactate, and inhibition of glycolytic pathway-related enzymes can regulate the level of lactylation modification, and more importantly, lactylation modification can act on these enzymes to regulate their functions and feedback regulate the level of glycolysis, this finding provides more ideas for clinical treatment of sepsis. We use "epigenetic modification", "glycolysis", "lactate", "lactylaiton" and "sepsis" as keywords and search the relevant literature through Pubmed and Web of science up to 2023.

Lactate and Lactylation: Clinical Applications of Routine Carbon Source and Novel Modification in Human Diseases

Cell metabolism generates numerous intermediate metabolites that could serve as feedback and feed-forward regulation substances for posttranslational modification. Lactate, a metabolic product of glycolysis, has recently been conceptualized to play a pleiotropic role in shaping cell identities through metabolic rewiring and epigenetic modifications. Lactate-derived carbons, sourced from glucose, mediate the crosstalk among glycolysis, lactate, and lactylation. Furthermore, the multiple metabolic fates of lactate make it an ideal substrate for metabolic imaging in clinical application. Several studies have identified the crucial role of protein lactylation in human diseases associated with cell fate determination, embryonic development, inflammation, neoplasm, and neuropsychiatric disorders. Herein, this review will focus on the metabolic fate of lactate-derived carbon to provide useful information for further research and therapeutic approaches in human diseases. We comprehensively discuss its role in reprogramming and modification during the regulation of glycolysis, the clinical translation prospects of the hyperpolarized lactate signal, lactyl modification in human diseases, and its application with other techniques and omics.

Metabolic Reprogramming and Its Regulatory Mechanism in Sepsis-Mediated Inflammation

Sepsis is a systemic inflammatory disease caused by an infection that can lead to multiple organ failure. Sepsis alters energy metabolism, leading to metabolic reprogramming of immune cells, which consequently disrupts innate and adaptive immune responses, triggering hyperinflammation and immunosuppression. This review summarizes metabolic reprogramming and its regulatory mechanism in sepsis-induced hyperinflammation and immunosuppression, highlights the significance and intricacies of immune cell metabolic reprogramming, and emphasizes the pivotal role of mitochondria in metabolic regulation and treatment of sepsis. This review provides an up-to-date overview of the relevant literature to inform future research directions in understanding the regulation of sepsis immunometabolism. Metabolic reprogramming has great promise as a new target for sepsis treatment in the future.

Systematic analysis of lysine crotonylation in human macrophages responding to MRSA infection

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most commonly encountered bacteria found in healthcare clinics and has been ranked a priority 2 pathogen. Research is urgently needed to develop new therapeutic approaches to combat the pathogen. Variations in the pattern of protein posttranslational modifications (PTMs) of host cells affect physiological and pathological events, as well as therapeutic effectiveness. However, the role of crotonylation in MRSA-infected THP1 cells remains unknown. In this study, we found that crotonylation profiles of THP1 cells were altered after MRSA infection. It was then confirmed that lysine crotonylation profiles of THP1 cells and bacteria were different; MRSA infection inhibited global lysine crotonylation (Kcro) modification but partially elevated Kcro of host proteins. We obtained a proteome-wide crotonylation profile of THP1 cells infected by MRSA further treated by vancomycin, leading to the identification of 899 proteins, 1384 sites of which were down-regulated, and 160 proteins with 193 sites up-regulated. The crotonylated down-regulated proteins were mainly located in cytoplasm and were enriched in spliceosome, RNA degradation, protein posttranslational modification, and metabolism. However, the crotonylated up-regulated proteins were mainly located in nucleus and significantly involved in nuclear body, chromosome, ribonucleoprotein complex, and RNA processing. The domains of these proteins were significantly enriched on RNA recognition motif, and linker histone H1 and H5 families. Some proteins related to protecting against bacterial infection were also found to be targets of crotonylation. The present findings point to a comprehensive understanding of the biological functions of lysine crotonylation in human macrophages, thereby providing a certain research basis for the mechanism and targeted therapy on the immune response of host cells against MRSA infection.