5,2'-dibromo-2,4',5'-trihydroxydiphenylmethanone attenuates LPS-induced inflammation and ROS production in EA.hy926 cells via HMBOX1 induction

Marine bromophenols suppressed choroidal neovascularization by targeting HUWE1 through NF-κb signaling pathway

Inflammation plays a key role in the progression of choroidal neovascularization (CNV). Regular intravitreal injection of anti-VEGF medication is required for many patients to sustain eye condition as CNV always recurs due to persistent chronic inflammation in the retina and choroid. Marine bromophenols (BDB) have been widely studied due to their diverse bioactivities, including anti-inflammatory effect, though the mechanism of which remained unclear. Our study demonstrated that BDB could restricted endothelial cells' function and suppressed choroidal explants both in vitro and in vivo without out affecting the cells viability. BDB also significantly reduced numerous inflammatory cytokines in both raw cells and choroidal tissue, including IL-1β, IL-6, TNF-α, IL-4 and MMP-9. Moreover, we demonstrated that BDB down regulated phosphorylation of NF-κB p65 in the raw cells. By Co-IP assay, HUWE1 was found to be bound with BDB and the binding location was at sequences position 4214. When overexpressed HUWE1 in HUVECs, the suppression of endothelial cells' function by BDB became more significant. Taken together, the findings in this study showed that BDB suppressed endothelial cells' function and choroidal neovascularization by targeting HUWE1 through NF-κB pathway, which suggested that BDB could be a potential therapeutic candidate in treating chronic inflammation in choroidal neovascularization.

GSK3β-dependent lysosome biogenesis: An effective pathway to mitigate renal fibrosis with LM49

Renal fibrosis is an incurable disorder characterised by an imbalance of the extracellular matrix (ECM) favouring excess production over degradation. The identification of actionable pathways and agents that promote ECM degradation to restore ECM homeostasis may help mitigate renal fibrosis. In this study, we identified 5,2′-dibromo-2,4′,5′-trihydroxydiphenylmethanone (LM49), a compound we previously synthesised, as a small-molecule inducer of ECM degradation. LM49 administration efficiently reduced ECM deposition in renal tissue of diabetic nephropathy rats and in transforming growth factor β-treated renal fibroblast cells. LM49 promoted the cytosol-to-nucleus translocation of transcription factor EB (TFEB) to increase lysosome biogenesis, leading to lysosome-based degradation of the ECM. TFEB-mediated lysosome biogenesis was induced by LM49 directly inhibiting the activity of glycogen synthase kinase 3β (GSK3β) rather than mammalian target of rapamycin complex 1. LM49 inhibited GSK3β kinase activity concentration-dependently via competing with ATP. Direct binding between LM49 and GSK3β was confirmed by the bio-layer interferometry assay, cellular thermal shift assay, and drug affinity responsive target stability. A molecular docking and molecular dynamic simulation revealed that LM49 occupied the ATP pocket of GSK3β, which was consistent with the kinase activity assay. In summary, LM49 enhances TFEB-mediated lysosome biogenesis by directly inhibiting GSK3β, leading to the degradation of the ECM by lysosomes. The enhancement of GSK3β-dependent lysosome biogenesis to rebalance the ECM may be a novel strategy to counteract renal fibrosis, and LM49 may be a viable clinical candidate for treating this disorder.

ptk2 and mt2a Genes Expression in Gastritis and Gastric Cancer Patients with Helicobacter pylori Infection

BACKGROUND

ptk2 and mt2a genes contribute to the cell cycle during proliferation and apoptosis, respectively. Designing a case-control study including gastric adenocarcinoma and gastritis patients with and without Helicobacter pylori infection would lead to determinate of the correlations between ptk2 and mt2a genes expression with H. pylori infection in gastric antral epithelial cells.

METHODS

Overall, 50 and 30 gastric antral biopsy samples of gastric cancer (case group) and gastritis (control group) patients were included into study, respectively. All biopsy samples were collected considering the exclusion criteria including patients with a history of consumption of tobacco, alcohol, and anti-H. pylori drugs. Each patient group is divided into with and without H. pylori infection to detect cDNA fold changes of ptk2 and mt2a genes by using Real Time RT PCR. Furthermore, the presence of H. pylori virulence genes was detected directly by using specific primers and simple PCR on cDNA synthesized from total RNA of gastric antral biopsy samples.

RESULTS

A negative correlation was revealed between age and clinical manifestations with the ΔCt value of the ptk2 gene (P < 0.05). The H. pylori iceA1/2 and cagE genes revealed positive and negative correlations with the ΔCt value of the ptk2 gene (P < 0.05), respectively. Furthermore, a weak correlation was detectable between H. pylori babA2/B, oipA, and cagY genes and the ΔCt value of the mt2a gene in gastric antral epithelial cells of patients (P < 0.1).

CONCLUSIONS

The results of the current study opened a view for more investigation on the stunning roles of H. pylori infection in clinical outcomes through mt2a and ptk2 gene expression in gastric antral epithelial cells.

5,2′-Dibromo-2,4′,5′-trihydroxydiphenylmethanone Inhibits LPS-Induced Vascular Inflammation by Targeting the Cav1 Protein

Vascular inflammation is directly responsible for atherosclerosis. 5,2′-Dibromo-2,4′,5′-trihydroxydiphenylmethanone (TDD), a synthetic bromophenol derivative, exhibits anti-atherosclerosis and anti-inflammatory effects. However, the underlying pathways are not yet clear. In this study, we first examined the effects of TDD on toll-like receptor-4 (TLR4) activity, the signaling receptor for lipopolysaccharide (LPS), and found that TDD does not inhibit LPS-induced TLR4 expression in EA.hy926 cells and the vascular wall in vivo. Next, we investigated the global protein alterations and the mechanisms underlying the action of TDD in LPS-treated EA.hy926 cells using an isobaric tag for the relative and absolute quantification technique. Western blot analysis revealed that TDD inhibited NF-κB activation by regulating the phosphorylation and subsequent degradation IκBα. Among the differentially expressed proteins, TDD concentration-dependently inhibited Caveolin 1(Cav1) expression. The interaction between Cav1 and TDD was determined by using biolayer interference assay, UV-vis absorption spectra, fluorescence spectrum, and molecular docking. We found that TDD can directly bind to Cav1 through hydrogen bonds and van der Waals forces. In conclusion, our results showed that TDD inhibited LPS-induced vascular inflammation and the NF-κB signaling pathway by specifically targeting the Cav1 protein. TDD may be a novel anti-inflammatory compound, especially for the treatment of atherosclerosis.

Quercetin Mitigates Endothelial Activation in a Novel Intestinal-Endothelial-Monocyte/Macrophage Coculture Setup

Atherosclerosis initiation is associated with a pro-inflammatory state of the endothelium. Quercetin is a flavonoid abundantly present in plant-based foods, with a possible impact on cardiovascular health. In this study, the effects of quercetin on lipopolysaccharide (LPS)-mediated endothelial inflammation and monocyte adhesion and migration, which are initial steps of the atherogenic process, are studied. Novel in vitro multicellular models simulating the intestinal-endothelial-monocytes/macrophages axis allowed to combine relevant intestinal flavonoid absorption, metabolism and efflux, and the consequent bioactivity towards peripheral endothelial cells. In this triple coculture, quercetin exposure decreased monocyte adhesion to and macrophage migration through an LPS-stressed endothelium, and this was associated with significantly lower levels of soluble vascular cell adhesion molecule-1 (sVCAM-1). Furthermore, quercetin decreased the pro-inflammatory cell environment upon LPS-induced endothelial activation, in terms of tumor necrosis factor- α (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), and sVCAM-1 expression. These findings highlight a mode-of-action by which quercetin may positively impact the initial states of atherosclerosis under more physiologically relevant conditions in terms of quercetin concentrations, metabolites, and intercellular crosstalk.

HMBOX1 attenuates LPS-induced periodontal ligament stem cell injury by inhibiting CXCL10 expression through the NF-κB signaling pathway

Homeobox containing 1 (HMBOX1) is a member of the homeobox transcription factor family that has been reported to serve an important role in numerous biological processes. The present study aimed to determine the role of HMBOX1 in the pathogenesis of periodontitis. Human periodontal ligament stem cells (hPDLSCs) were treated with liposaccharide (LPS) and transfected with a HMBOX1 overexpression (Ov-HMBOX1) plasmid or small interfering (si)-C-X-C motif chemokine ligand 10 (CXCL10) plasmids. The effects of Ov-HMBOX1 on cell proliferation, inflammation and apoptosis were subsequently investigated using Cell Counting Kit-8, ELISA for analysis of IL-6, TNF-α and IL-1β levels, TUNEL and western blotting assays for analysis of Bcl-2, Bax, cleaved caspase-3 and caspase-3 levels, respectively. Furthermore, the potential effects of HMBOX1 on the mRNA and protein levels of CXCL10 and the NF-κB signaling pathway were investigated by using reverse transcription-quantitative PCR and western blotting. Finally, the physiological processes of lipopolysaccharide (LPS)-induced hPDLSCs overexpressing HMBOX1 were assessed following treatment with phorbol 12-myristate 13-acetate (PMA), a NF-κB agonist. The results revealed that Ov-HMBOX1 transfection promoted proliferation whilst alleviating inflammation and apoptosis in LPS-induced hPDLSCs. Ov-HMBOX1 reduced the expression of CXCL10 by suppressing the NF-κB signaling pathway. PMA treatment inhibited the proliferation of LPS-induced hPDLSCs transfected with Ov-HMBOX1, which was reversed by transfection with si-CXCL10. In conclusion, results of the present study provided evidence that HMBOX1 can attenuate LPS-induced hPDLSC injury by downregulating CXCL10 expression via the NF-κB signaling pathway, which may provide a novel insight into the development of potentially novel treatment strategies for periodontitis.

Perspectives in the Cell-Based Therapies of Various Aspects of the Spinal Cord Injury-Associated Pathologies: Lessons from the Animal Models

Traumatic injury of the spinal cord (SCI) is a devastating neurological condition often leading to severe dysfunctions, therefore an improvement in clinical treatment for SCI patients is urgently needed. The potential benefits of transplantation of various cell types into the injured spinal cord have been intensively investigated in preclinical SCI models and clinical trials. Despite the many challenges that are still ahead, cell transplantation alone or in combination with other factors, such as artificial matrices, seems to be the most promising perspective. Here, we reviewed recent advances in cell-based experimental strategies supporting or restoring the function of the injured spinal cord with a particular focus on the regenerative mechanisms that could define their clinical translation.

Protease-Activated Receptor 2 (PAR-2) Antagonist AZ3451 Mitigates Oxidized Low-Density Lipoprotein (Ox-LDL)-Induced Damage and Endothelial Inflammation

Oxidized low-density lipoprotein (ox-LDL)-induced endothelial dysfunction plays an important role in the initiation and development of cardiovascular diseases, especially atherosclerosis (AS). Protease-activated receptor 2 (PAR-2) is a receptor for inflammatory proteases. However, the biological function of PAR-2 in endothelial cells and the pathophysiological process of AS are still unknown. In the current study, we found that treatment with ox-LDL increased the gene and protein expressions of PAR-2 in EA.hy926 endothelial cells. Interestingly, we found that antagonism of PAR-2 with its specific antagonist AZ3451 could ameliorate ox-LDL-induced lactate dehydrogenase (LDH) release. Treatment with AZ3451 considerably improved the mitochondrial function by restoring the mitochondrial membrane potential and increasing the levels of intracellular adenosine triphosphate (ATP). Also, we found that AZ3451 attenuated ox-LDL-induced expression and production of pro-inflammatory cytokines such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-8 (IL-8). Treatment with AZ3451 also mitigated the expression of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). Notably, our results demonstrated that the presence of AZ3451 alleviated ox-LDL-induced expression of the endothelial cell adhesion molecules vascular cell adhesion molecule-1 (VCAM-1) and intercellular cell adhesion molecule-1 (ICAM-1). Mechanistically, we found that AZ3451 attenuated ox-LDL-induced activation of nuclear factor-κB (NF-κB) by reducing the levels of intracellular NF-κB p65 and the luciferase activity of NF-κB promoter. Based on these findings, we conclude that PAR-2 might become a novel therapeutic target for the treatment of AS.

Protective effect of surfactin on copper sulfate-induced inflammation, oxidative stress, and hepatic injury in zebrafish

Surfactin, an antibacterial peptide, produced by various Bacillus subtilis strains, have broad-spectrum antibacterial and immune-enhancing functions. In this study, we investigated the anti-inflammatory, antioxidant, and hepatoprotective effect of surfactin on zebrafish (Danio rerio) larvae following their exposure to copper sulfate (CuSO₄ ). The mature AB wild-type and a transgenic line of zebrafish larvae that expressed enhanced GFP (EGFP) named Tg (Lyz:EGFP) were exposed to 0, 20, 40, and 60 μg/mL surfactin after incubation with 3.2 μg/mL CuSO₄ for 2 h from 72 h postfertilization (hpf). Different endpoints, such as migration of GFP-labeled neutrophils, analysis of inflammatory cytokines and transaminases, markers of oxidation, expression of certain genes, and histological changes of liver, were studied to evaluate the function of surfactin. The protein expression levels of NF-κBp65, TNF-α, cyclooxygenase-2 (COX-2), and iNOS were determined in murine macrophage RAW 264.7 cells by western blotting. Our results show that surfactin reduced migration of neutrophils and relieved hepatic injury. In addition, surfactin reduced the index levels of inflammatory factors, oxidative stress response, and improved hepatic function. Surfactin also significantly inhibited the expression of IL-1β, IL-8, TNF-α, nitric oxide, NF-κBp65, COX-2, and iNOS, and increased the expression of IL-10. Thus, our results demonstrate that surfactin has anti-inflammatory, antioxidant, and hepatoprotective activities. Surfactin has potential as a novel inflammation and immune adjustment.

The Role of Chronic Inflammation in Various Diseases and Anti-inflammatory Therapies Containing Natural Products

Chronic inflammation represents a long-term reaction of the body's immune system to noxious stimuli. Such a sustained inflammatory response sometimes results in lasting damage to healthy tissues and organs. In fact, chronic inflammation is implicated in the development and progression of various diseases, including cardiovascular diseases, respiratory diseases, metabolic diseases, neurodegenerative diseases, and even cancers. Targeting nonresolving inflammation thus provides new opportunities for treating relevant diseases. In this review, we will go over several chronic inflammation-associated diseases first with emphasis on the role of inflammation in their pathogenesis. Then, we will summarize a number of natural products that exhibit therapeutic effects against those diseases by acting on different markers in the inflammatory response. We envision that natural products will remain a rich resource for the discovery of new drugs treating diseases associated with chronic inflammation.

Loss of HMBOX1 promotes LPS-induced apoptosis and inhibits LPS-induced autophagy of vascular endothelial cells in mouse

Our previous study revealed that Homeobox containing 1 (HMBOX1), essential for the survival of vascular endothelial cells (VECs), was involved in the progression of atherosclerosis. Knockdown of HMBOX1 promoted apoptosis and inhibited autophagy through regulating intracellular free zinc level in cultured VECs. In current study, in order to investigate the roles of HMBOX1 in vivo and in endothelium, we generated a knockout (KO) mouse for HMBOX1 by using transcription activator-like effector nucleases (TALENs) technology. Herein, we reported that the protein level of HMBOX1 was gradually increased during mouse development. The HMBOX1 KO mouse was viable and fertile. There existed no differences in apoptosis and autophagy of aortic endothelial cells between wild type and KO mouse. Whereas, loss of HMBOX1 promoted apoptosis and inhibited autophagy of aortic endothelial cells under lipopolysaccharide (LPS) stimulation in mouse. We also demonstrated that HMBOX1 deletion had no influence on the secretion of inflammatory cytokines TNF-α and IL-6. Moreover, overexpression or knockdown of HMBOX1 failed to regulate multiple pro-apoptotic genes expression in vitro. In conclusion, HMBOX1 participated in the functional maintenance of mouse aortic endothelial cells, the aortic endothelial cells of HMBOX1 KO mouse showed increased apoptosis and decreased autophagy with LPS treatment.

A novel marine halophenol derivative attenuates lipopolysaccharide-induced inflammation in RAW264.7 cells via activating phosphoinositide 3-kinase/Akt pathway

BACKGROUND

2,4',5'-Trihydroxyl-5,2'-dibromo diphenylmethanone (LM49), a novel active halophenol derivative synthesized by our group from marine plants, exhibits strong anti-inflammatory activities. However, molecular machineries involved in its effect have not been fully identified. The study was aimed to investigate the anti-inflammatory effect of LM49 on lipopolysaccharide (LPS)-stimulated RAW264.7 cells and its underlying mechanism.

METHODS

RAW264.7 cells were treated with LPS (10 μg/mL) and then exposed to different concentrations of LM49 (i.e., 5, 10, and 15 μM) for 24 h. Cytokine release in culture medium of RAW264.7 cells was measured by enzyme-linked immunosorbent assay (ELISA). Phagocytic capacity (FITC-dextran uptake) was determined by flow cytometry. The protein level of phosphoinositide 3-kinase (PI3K), AKT and p-AKT was measured by western blot analysis.

RESULTS

Our findings revealed that LM49 reduced the production and mRNA levels of cytokines related to inflammation such as interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α), and increased the level of IL-10, an anti-inflammatory cytokine. In addition, LM49 decreased the production of nitric oxide and reactive oxygen species. Moreover, flow cytometry showed that LM49 significantly enhanced the phagocytic capacity (FITC-dextran uptake) of macrophages. The effects of LM49 were significantly inhibited by the phosphoinositide 3-kinase (PI3K) inhibitor, LY294002. In particular, LY294002 attenuated the phagocytic capacity of RAW264.7 cells induced by LM49 and prevented the effects on cytokines.

CONCLUSION

These findings suggest that LM49 possesses anti-inflammatory activity on LPS-stimulated RAW264.7 cells, in which the PI3K/Akt pathway plays an essential role. LM49 may have clinical utility as an anti-inflammatory agent. In this study, we demonstrated that a halophenol derivative (LM49) could possess anti-inflammatory activity on LPS-stimulated RAW264.7 cells by reducing pro-inflammatory cytokines and enhancing the phagocytic capacity, in which the PI3K/Akt pathway plays an essential role. LM49 may have clinical utility as an anti-inflammatory agent.

Process Development and Synthesis of Process-Related Impurities of an Efficient Scale-Up Preparation of 5,2'-Dibromo-2,4',5'-Trihydroxy Diphenylmethanone as a New Acute Pyelonephritis Candidate Drug

Based on a foregoing gram-scale laboratory process, an efficient scale-up preparation process of 5,2'-dibromo-2,4',5'-trihydroxydiphenylmethanone (LM49-API), a new acute pyelonephritis candidate drug, was developed and validated aiming to reduce by-products and achieve better impurity profiles. Meanwhile, the polymorph of LM49-API and process-related impurities were also investigated. Ultimately, the optimal reaction conditions were verified by evaluating the impurity profiles and their formation during the synthesis. Six process-related impurities were synthesized and identified, being useful for the quality control of LM49-API. Its finalized preparation process was further validated at 329-410 g scale-up production in 53.4-57.1% overall yield with 99.95-99.98% high-performance liquid chromatography (HPLC) purity, and it is currently viable for commercial production. LM49-API-imC and LM49-API-imX were identified as the main single impurities in LM49-API, with the content controlled to be less than 0.03%.

5,2'-dibromo-2,4',5'-trihydroxydiphenylmethanone attenuates LPS-induced inflammation and ROS production in EA.hy926 cells via HMBOX1 induction

Inflammation and reactive oxygen species (ROS) are important factors in the pathogenesis of atherosclerosis (AS). 5,2′‐dibromo‐2,4′,5′‐trihydroxydiphenylmethanone (TDD), possess anti‐atherogenic properties; however, its underlying mechanism of action remains unclear. Therefore, we sought to understand the therapeutic molecular mechanism of TDD in inflammatory response and oxidative stress in EA.hy926 cells. Microarray analysis revealed that the expression of homeobox containing 1 (HMBOX1) was dramatically upregulated in TDD‐treated EA.hy926 cells. According to the gene ontology (GO) analysis of microarray data, TDD significantly influenced the response to lipopolysaccharide (LPS); it suppressed the LPS‐induced adhesion of monocytes to EA.hy926 cells. Simultaneously, TDD dose‐dependently inhibited the production or expression of IL‐6, IL‐1β, MCP‐1, TNF‐α, VCAM‐1, ICAM‐1 and E‐selectin as well as ROS in LPS‐stimulated EA.hy926 cells. HMBOX1 knockdown using RNA interference attenuated the anti‐inflammatory and anti‐oxidative effects of TDD. Furthermore, TDD inhibited LPS‐induced NF‐κB and MAPK activation in EA.hy926 cells, but this effect was abolished by HMBOX1 knockdown. Overall, these results demonstrate that TDD activates HMBOX1, which is an inducible protective mechanism that inhibits LPS‐induced inflammation and ROS production in EA.hy926 cells by the subsequent inhibition of redox‐sensitive NF‐κB and MAPK activation. Our study suggested that TDD may be a potential novel agent for treating endothelial cells dysfunction in AS.