scholarly journals 5-LO-derived LTB4 plays a key role in MCP-1 expression in HMGB1-exposed VSMCs via a BLTR1 signaling axis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jong Min Choi ◽  
Seung Eun Baek ◽  
Ji On Kim ◽  
Eun Yeong Jeon ◽  
Eun Jeong Jang ◽  
...  

AbstractMonocyte chemoattractant protein-1 (MCP-1) plays an important role in initiating vascular inflammation; however, its cellular source in the injured vasculatures is unclear. Given the importance of high mobility group box 1 (HMGB1) in tissue injury, we investigated the role of vascular smooth muscle cells (VSMCs) in MCP-1 production in response to HMGB1. In primary cultured rat aortic VSMCs stimulated with HMGB1, the expression of MCP-1 and 5-lipoxygenase (LO) was increased. The increased MCP-1 expression in HMGB1 (30 ng/ml)-stimulated cells was significantly attenuated in 5-LO-deficient cells as well as in cells treated with zileuton, a 5-LO inhibitor. Likewise, MCP-1 expression and production were also increased in cells stimulated with exogenous leukotriene B4 (LTB4), but not exogenous LTC4. LTB4-induced MCP-1 expression was attenuated in cells treated with U75302, a LTB4 receptor 1 (BLTR1) inhibitor as well as in BLTR1-deficient cells, but not in 5-LO-deficient cells. Moreover, HMGB1-induced MCP-1 expression was attenuated in BLTR1-deficient cells or by treatment with a BLTR1 inhibitor, but not other leukotriene receptor inhibitors. In contrast to MCP-1 expression in response to LTB4, the increased MCP-1 production in HMGB1-stimulated VSMC was markedly attenuated in 5-LO-deficient cells, indicating a pivotal role of LTB4-BLTR1 signaling in MCP-1 expression in VSMCs. Taken together, 5-LO-derived LTB4 plays a key role in MCP-1 expression in HMGB1-exposed VSMCs via BLTR1 signaling, suggesting the LTB4-BLTR1 signaling axis as a potential therapeutic target for vascular inflammation in the injured vasculatures.

2022 ◽  
Vol 20 ◽  
Author(s):  
Fathimath Zaha Ikram ◽  
Alina Arulsamy ◽  
Thaarvena Retinasamy ◽  
Mohd. Farooq Shaikh

Background: High mobility group box 1 (HMGB1) protein is a damage-associated molecular pattern (DAMP) molecule that plays an important role in the repair and regeneration of tissue injury. It also acts as a pro-inflammatory cytokine through the activation of toll-like receptor 4 (TLR4) and receptor for advanced glycation end products (RAGE), to elicit the neuroinflammatory response. HMGB1 may aggravate several cellular responses which may lead to pathological inflammation and cellular death. Thus, there have been a considerable amount of research into the pathological role of HMGB1 in diseases. However, whether the mechanism of action of HMGB1 is similar in all neurodegenerative disease pathology remains to be determined. Objective: Therefore, this systematic review aimed to critically evaluate and elucidate the role of HMGB1 in the pathology of neurodegeneration based on the available literature. Methods: A comprehensive literature search was performed on four databases; EMBASE, PubMed, Scopus, and CINAHL Plus. Results: A total of 85 articles were selected for critical appraisal, after subjecting to the inclusion and exclusion criteria in this study. The selected articles revealed that HMGB1 levels were found elevated in most neurodegeneration except in Huntington’s disease and Spinocerebellar ataxia, where the levels were found decreased. This review also showcased that HMGB1 may act on distinctive pathways to elicit its pathological response leading to the various neurodegeneration processes/diseases. Conclusion: While there have been promising findings in HMGB1 intervention research, further studies may still be required before any HMGB1 intervention may be recommended as a therapeutic target for neurodegenerative diseases.


2019 ◽  
Vol 47 (03) ◽  
pp. 613-633 ◽  
Author(s):  
Sumin Yang ◽  
Wonhwa Lee ◽  
Bong-Seon Lee ◽  
Changhun Lee ◽  
Eui Kyun Park ◽  
...  

High mobility group box 1 (HMGB1) is recognized as a late mediator of sepsis, and the inhibition of HMGB1 release and recovery of vascular barrier integrity have emerged as attractive therapeutic strategies for the management of sepsis. We tested the hypothesis that aloin induces sirtuin 1 (SIRT1) and heme oxygenase (HO)-1, which inhibit HMGB1 release in lipopolysaccharide (LPS)-stimulated cells, thereby inhibiting HMGB1-induced hyperpermeability and increasing the survival of septic mice. Aloin was administered after LPS or HMGB1 challenge, and the antiseptic activity of aloin was determined from measurements of permeability, activation of pro-inflammatory proteins and production of markers for tissue injury in HMGB1-activated human umbilical vein endothelial cells (HUVECs) and a cecal ligation and puncture (CLP)-induced sepsis mouse model. Aloin significantly reduced HMGB1 release in LPS-activated HUVECs via SIRT1-mediated HMGB1 deacetylation and the PI3K/Nrf2/heme oxygenase (HO)-1 signaling axis. Aloin also suppressed the production of tumor necrosis factor (TNF)-[Formula: see text] and interleukin (IL)-6, as well as the activation of nuclear factor (NF)-[Formula: see text]B and extracellular signal-regulated kinase 1/2 (ERK 1/2) by HMGB1. Moreover, aloin restored HMGB1-mediated vascular disruption and inhibited vascular hyperpermeability in mice. In addition, treatment with aloin reduced the CLP-induced release of HMGB1, sepsis-related mortality and tissue injury in vivo. Our results suggest that aloin reduces HMGB1 release and sepsis-related mortality by activating SIRT1 and PI3K/Nrf2/HO-1 signals, indicating that aloin has potential for the treatment of sepsis.


2020 ◽  
Vol 12 (539) ◽  
pp. eaaz3833 ◽  
Author(s):  
Weiqiang Chen ◽  
Xiaoling Qiang ◽  
Yongjun Wang ◽  
Shu Zhu ◽  
Jianhua Li ◽  
...  

For the clinical management of sepsis, antibody-based strategies have only been attempted to antagonize proinflammatory cytokines but not yet been tried to target harmless proteins that may interact with these pathogenic mediators. Here, we report an antibody strategy to intervene in the harmful interaction between tetranectin (TN) and a late-acting sepsis mediator, high-mobility group box 1 (HMGB1), in preclinical settings. We found that TN could bind HMGB1 to reciprocally enhance their endocytosis, thereby inducing macrophage pyroptosis and consequent release of lactate dehydrogenase and apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain. The genetic depletion of TN expression or supplementation of exogenous TN protein at subphysiological doses distinctly affected the outcomes of potentially lethal sepsis, revealing a previously underappreciated beneficial role of TN in sepsis. Furthermore, the administration of domain-specific polyclonal and monoclonal antibodies effectively inhibited TN/HMGB1 interaction and endocytosis and attenuated the sepsis-induced TN depletion and tissue injury, thereby rescuing animals from lethal sepsis. Our findings point to a possibility of developing antibody strategies to prevent harmful interactions between harmless proteins and pathogenic mediators of human diseases.


Author(s):  
J. R. Hully ◽  
K. R. Luehrsen ◽  
K. Aoyagi ◽  
C. Shoemaker ◽  
R. Abramson

The development of PCR technology has greatly accelerated medical research at the genetic and molecular levels. Until recently, the inherent sensitivity of this technique has been limited to isolated preparations of nucleic acids which lack or at best have limited morphological information. With the obvious exception of cell lines, traditional PCR or reverse transcription-PCR (RT-PCR) cannot identify the cellular source of the amplified product. In contrast, in situ hybridization (ISH) by definition, defines the anatomical location of a gene and/or it’s product. However, this technique lacks the sensitivity of PCR and cannot routinely detect less than 10 to 20 copies per cell. Consequently, the localization of rare transcripts, latent viral infections, foreign or altered genes cannot be identified by this technique. In situ PCR or in situ RT-PCR is a combination of the two techniques, exploiting the sensitivity of PCR and the anatomical definition provided by ISH. Since it’s initial description considerable advances have been made in the application of in situ PCR, improvements in protocols, and the development of hardware dedicated to in situ PCR using conventional microscope slides. Our understanding of the importance of viral latency or viral burden in regards to HIV, HPV, and KSHV infections has benefited from this technique, enabling detection of single viral copies in cells or tissue otherwise thought to be normal. Clearly, this technique will be useful tool in pathobiology especially carcinogenesis, gene therapy and manipulations, the study of rare gene transcripts, and forensics.


2019 ◽  
Vol 24 (39) ◽  
pp. 4605-4610 ◽  
Author(s):  
Atena Soleimani ◽  
Farzad Rahmani ◽  
Gordon A. Ferns ◽  
Mikhail Ryzhikov ◽  
Amir Avan ◽  
...  

Colorectal cancer (CRC) is the leading cause of cancer death worldwide and its incidence is increasing. In most patients with CRC, the PI3K/AKT signaling axis is over-activated. Regulatory oncogenic or tumor suppressor microRNAs (miRNAs) for PI3K/AKT signaling regulate cell proliferation, migration, invasion, angiogenesis, as well as resistance to chemo-/radio-therapy in colorectal cancer tumor tissues. Thus, regulatory miRNAs of PI3K/AKT/mTOR signaling represent novel biomarkers for new patient diagnosis and obtaining clinically invaluable information from post-treatment CRC patients for improving therapeutic strategies. This review summarizes the current knowledge of miRNAs’ regulatory roles of PI3K/AKT signaling in CRC pathogenesis.


2019 ◽  
Vol 20 (14) ◽  
pp. 1474-1485 ◽  
Author(s):  
Eyaldeva C. Vijayakumar ◽  
Lokesh Kumar Bhatt ◽  
Kedar S. Prabhavalkar

High mobility group box-1 (HMGB1) mainly belongs to the non-histone DNA-binding protein. It has been studied as a nuclear protein that is present in eukaryotic cells. From the HMG family, HMGB1 protein has been focused particularly for its pivotal role in several pathologies. HMGB-1 is considered as an essential facilitator in diseases such as sepsis, collagen disease, atherosclerosis, cancers, arthritis, acute lung injury, epilepsy, myocardial infarction, and local and systemic inflammation. Modulation of HMGB1 levels in the human body provides a way in the management of these diseases. Various strategies, such as HMGB1-receptor antagonists, inhibitors of its signalling pathway, antibodies, RNA inhibitors, vagus nerve stimulation etc. have been used to inhibit expression, release or activity of HMGB1. This review encompasses the role of HMGB1 in various pathologies and discusses its therapeutic potential in these pathologies.


2019 ◽  
Vol 20 (9) ◽  
pp. 2066 ◽  
Author(s):  
Namrata Khurana ◽  
Suresh C. Sikka

Androgen receptor (AR) signaling plays a key role not only in the initiation of prostate cancer (PCa) but also in its transition to aggressive and invasive castration-resistant prostate cancer (CRPC). However, the crosstalk of AR with other signaling pathways contributes significantly to the emergence and growth of CRPC. Wnt/β-catenin signaling facilitates ductal morphogenesis in fetal prostate and its anomalous expression has been linked with PCa. β-catenin has also been reported to form complex with AR and thus augment AR signaling in PCa. The transcription factor SOX9 has been shown to be the driving force of aggressive and invasive PCa cells and regulate AR expression in PCa cells. Furthermore, SOX9 has also been shown to propel PCa by the reactivation of Wnt/β-catenin signaling. In this review, we discuss the critical role of SOX9/AR/Wnt/β-catenin signaling axis in the development and progression of CRPC. The phytochemicals like sulforaphane and curcumin that can concurrently target SOX9, AR and Wnt/β-catenin signaling pathways in PCa may thus be beneficial in the chemoprevention of PCa.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Maria Cecilia Oliveira-Nunes ◽  
Glaucia Julião ◽  
Aline Menezes ◽  
Fernanda Mariath ◽  
John A. Hanover ◽  
...  

AbstractGlioblastoma (GBM) is a grade IV glioma highly aggressive and refractory to the therapeutic approaches currently in use. O-GlcNAcylation plays a key role for tumor aggressiveness and progression in different types of cancer; however, experimental evidence of its involvement in GBM are still lacking. Here, we show that O-GlcNAcylation plays a critical role in maintaining the composition of the GBM secretome, whereas inhibition of OGA activity disrupts the intercellular signaling via microvesicles. Using a label-free quantitative proteomics methodology, we identified 51 proteins in the GBM secretome whose abundance was significantly altered by activity inhibition of O-GlcNAcase (iOGA). Among these proteins, we observed that proteins related to proteasome activity and to regulation of immune response in the tumor microenvironment were consistently downregulated in GBM cells upon iOGA. While the proteins IGFBP3, IL-6 and HSPA5 were downregulated in GBM iOGA cells, the protein SQSTM1/p62 was exclusively found in GBM cells under iOGA. These findings were in line with literature evidence on the role of p62/IL-6 signaling axis in suppressing tumor aggressiveness and our experimental evidence showing a decrease in radioresistance potential of these cells. Taken together, our findings provide evidence that OGA activity may regulate the p62 and IL-6 abundance in the GBM secretome. We propose that the assessment of tumor status from the main proteins present in its secretome may contribute to the advancement of diagnostic, prognostic and even therapeutic tools to approach this relevant malignancy.


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