A novel MyD88 inhibitor LM9 prevents atherosclerosis by regulating inflammatory responses and oxidative stress in macrophages

MyD88 and Its Inhibitors in Cancer: Prospects and Challenges

The interplay between the immune system and cancer underscores the central role of immunotherapy in cancer treatment. In this context, the innate immune system plays a critical role in preventing tumor invasion. Myeloid differentiation factor 88 (MyD88) is crucial for innate immunity, and activation of MyD88 promotes the production of inflammatory cytokines and induces infiltration, polarization, and immune escape of immune cells in the tumor microenvironment. Additionally, abnormal MyD88 signaling induces tumor cell proliferation and metastasis, which are closely associated with poor prognosis. Therefore, MyD88 could serve as a novel tumor biomarker and is a promising target for cancer therapy. Current strategies targeting MyD88 including inhibition of signaling pathways and protein multimerization, have made substantial progress, especially in inflammatory diseases and chronic inflammation-induced cancers. However, the specific role of MyD88 in regulating tumor immunity and tumorigenic mechanisms remains unclear. Therefore, this review describes the involvement of MyD88 in tumor immune escape and disease therapy. In addition, classical and non-classical MyD88 inhibitors were collated to provide insights into potential cancer treatment strategies. Despite several challenges and complexities, targeting MyD88 is a promising avenue for improving cancer treatment and has the potential to revolutionize patient outcomes.

Nanoremediation and Antioxidant Potential of Biogenic Silver Nanoparticles Synthesized Using Leucena's Leaves, Stem, and Fruits

Synthetic dyes are persistent organic environmental pollutants that can cause extensive damage to living beings and to the ecosystem as a whole. Cost-effective, sustainable, and efficient strategies to deal with this type of pollution are necessary as it commonly resists conventional water treatment methods. Silver nanoparticles (AgNPs) synthesized using the aqueous extract from the leaves, stem, and fruits of Leucaena leucocephala (Leucena) were produced and characterized through UV-vis, TEM, EDS, SDL, XPS, XRD, and zeta potential, and they proved to be able to promote adsorption to remediate methylene blue and tartrazine pollution in water. The nanoremediation was performed and did not require direct exposure to sunlight or any special lamp or a specific reduction agent. The AgNPs produced using the extract from the leaves exhibited the best performance in nanoremediation and also presented antioxidant activity that surpassed the one from butylated hydroxytoluene (BHT). Consequently, it is an interesting nanotool to use in dye nanoremediation and/or as an antioxidant nanostructure.

The role of immune system in atherosclerosis: Molecular mechanisms, controversies, and future possibilities

Numerous cardiovascular disorders have atherosclerosis as their pathological underpinning. Numerous studies have demonstrated that, with the aid of pattern recognition receptors, cytokines, and immunoglobulins, innate immunity, represented by monocytes/macrophages, and adaptive immunity, primarily T/B cells, play a critical role in controlling inflammation and abnormal lipid metabolism in atherosclerosis. Additionally, the finding of numerous complement components in atherosclerotic plaques suggests yet again how heavily the immune system controls atherosclerosis. Therefore, it is essential to have a thorough grasp of how the immune system contributes to atherosclerosis. The specific molecular mechanisms involved in the activation of immune cells and immune molecules in atherosclerosis, the controversy surrounding some immune cells in atherosclerosis, and the limitations of extrapolating from relevant animal models to humans were all carefully reviewed in this review from the three perspectives of innate immunity, adaptive immunity, and complement system. This could provide fresh possibilities for atherosclerosis research and treatment in the future.

Corilagin relieves atherosclerosis via the toll-like receptor 4 signaling pathway in vascular smooth muscle cells

INTRODUCTION

Corilagin possesses a diverse range of pharmacologic bioactivities. However, the specific protective effects and mechanisms of action of corilagin in the context of atherosclerosis remain unclear. In this study, we investigated the impact of corilagin on the toll-like receptor (TLR)4 signaling pathway in a mouse vascular smooth muscle cell line (MOVAS) stimulated by oxidized low-density lipoprotein (ox-LDL). Additionally, we examined the effects of corilagin in Sprague-Dawley rats experiencing atherosclerosis.

METHODS

The cytotoxicity of corilagin was assessed using the CCK8 assay. MOVAS cells, pre-incubated with ox-LDL, underwent treatment with varying concentrations of corilagin. TLR4 expression was modulated by either downregulation through small interfering (si)RNA or upregulation via lentivirus transfection. Molecular expression within the TLR4 signaling pathway was analyzed using real-time polymerase chain reaction (PCR) and Western blotting. The proliferation capacity of MOVAS cells was determined through cell counting. In a rat model, atherosclerosis was induced in femoral arteries using an improved guidewire injury method, and TLR4 expression in plaque areas was assessed using immunofluorescence. Pathological changes were examined through hematoxylin and eosin staining, as well as Oil-Red-O staining.

RESULTS

Corilagin demonstrated inhibitory effects on the TLR4 signaling pathway in MOVAS cells pre-stimulated with ox-LDL, consequently impeding the proliferative impact of ox-LDL. The modulation of TLR4 expression, either through downregulation or upregulation, similarly influenced the expression of downstream molecules. In an in vivo context, corilagin exhibited the ability to suppress TLR4 and MyD88 expression in the plaque lesion areas of rat femoral arteries, thereby alleviating the formation of atherosclerotic plaques.

CONCLUSION

Corilagin can inhibit the TLR4 signaling pathway in VSMCs, possibly by downregulating TLR4 expression and, consequently, relieving atherosclerosis.

Protective effect of scorpion venom oligopeptides in human umbilical vein endothelial cells under benzo(α)pyrene exposure

Inflammation and oxidative stress play pivotal role in the process of atherosclerosis. Scorpion venom is widely used as anti-cancer agent, however, the anti-inflammatory and antioxidant activities of scorpion venom peptides (SVPs) are rarely explored. In the current study, seven novel SVPs were isolated in a protective activity tracking isolation method in a cell model of benzo(α)pyrene (BaP)-induced human umbilical vein endothelial cells (HUVECs). The current study showed that SVP-1 [Tyr-Thr-Trp-Glu-Ala] significantly attenuated BaP-induced reactive oxygen species (ROS) over-production and inflammatory cytokines (IL-6, IL-1β, TNF-α, NO and PGE2) over-expression. Furthermore, SVP-1 attenuated BaP-induced adhesion molecules over-expression and inhibited the NF-κB and AhR signalling pathways activation. Collectively, the present study, for the first time, shows that SVPs inhibit the NF-κB and AhR signalling pathways in HUVECs under BaP-exposure, which strongly suggests the therapeutic potential of SVPs against atherosclerosis.

Ishige okamurae Attenuates Neuroinflammation and Cognitive Deficits in Mice Intracerebroventricularly Injected with LPS via Regulating TLR-4/MyD88-Dependent Pathways

Neuroinflammation is one of the critical causes of neuronal loss and cognitive impairment. We aimed to evaluate the anti-neuroinflammatory properties of Ishige okamuae using mice intracerebroventricularly injected with lipopolysaccharides (LPS) and LPS-treated C6 glioma cells. We found that the short- and long-term memory deficits of LPS-injected mice were improved by oral administration of Ishige okamurae extracts (IOE). LPS-induced neuronal loss, increase in amyloid-β plaque, and expression of COX-2 and iNOS were restored by IOE. In addition, LPS-induced activation of Toll-like receptor-4 (TLR-4) and its downstream molecules, such as MyD88, NFκB, and mitogen-activated protein kinases (MAPKs), were significantly attenuated in the brains of mice fed with IOE. We found that pretreatment of IOE to C6 glioma cells ameliorated LPS-induced expression of TLR-4 and its inflammatory cascades, such as MyD88 expression, reactive oxygen species production, MAPKs phosphorylation, and NFκB phosphorylation with consequent downregulation of COX-2, iNOS, proinflammatory cytokines, and nitric oxide expression. Furthermore, IOE (0.2 µg/mL) was found to have equivalent efficacy with 10 μM of MyD88 inhibitor in preventing LPS-induced inflammatory responses in C6 glioma cells. Taken together, these results strongly suggest that IOE could be developed as a promising anti-neuroinflammatory agent which is able to control the TLR-4/MyD88-dependent signaling pathways.

Guanmaitong Granule Attenuates Atherosclerosis by Inhibiting Inflammatory Immune Response in ApoE−/− Mice Fed High-Fat Diet

Background

Atherosclerosis (AS) is the leading cause of cardiovascular diseases, such as myocardial infarction and stroke. Guanmaitong granule (GMTG) is a TCM (Traditional Chinese medicine) prescribed to treat AS. However, its mechanism remains unclear.

Methods

We obtained reliable ingredients and targets of GMTG using the HERB database. AS-related targets were obtained from HERB and GeneCards databases. The target database was constructed by intersecting the ingredients of GMTG with the AS-related targets. STRING and Cytoscape were used to create protein-protein interaction (PPI) network and screen core targets. GO enrichment analysis and KEGG pathway analyses were performed using R. Finally, the ApoE^−/− mice AS model was induced by a high-fat diet (HFD) for in vivo validation of core pathways and targets.

Results

A total of 124 ingredients and 418 potential targets of GMTG for treating AS were obtained. Numerous ingredients and targets were related to Panax notoginseng, Salvia miltiorrhiza, and Astragalus. Most core targets and pathways were involved in the inflammatory immune response. GMTG could decrease serum triglycerides, total cholesterol, low-density lipoprotein-cholesterol, and oxidized low-density lipoprotein level and increase the serum high-density lipoprotein-cholesterol level. Furthermore, GMTG reduced the plaque burden and promoted plaque remodeling by reducing plaque area, lipid deposition, foam cell content, and collagen fiber content in the plaque in the aortic root of ApoE^−/− mice. GMTG inhibited systemic and plaque inflammatory immune response and increased plaque stability by inhibiting the excessive release of the TLR4/MyD88/NF-κB pathway-induced inflammatory cytokines, tumor necrosis factor, interleukin-6, and interleukin-1 beta.

Conclusion

Radix notoginseng, Radix salviae liguliobae, and Radix astragali are the main ingredients of GMTG for treating AS. Further, GMTG could regulate the level of serum lipids and inhibit inflammatory immune response, which resulted in anti-AS effects such as plaque stabilization, reduction of plaque burden, and plaque remodeling. GMTG is a promising multi-target treatment for AS.

Therapeutic potential of traditional Chinese medicine in atherosclerosis: A review

Atherosclerosis is the onset of endothelial cell damage and is characterized by abnormal accumulation of fibrinogen and lipid in large and middle arteries. Recent researches indicate that traditional Chinese medicine including Notoginseng Radix et Rhizoma, Astragali Radix, Salviae Miltiorrhizae Radix et Rhizoma, Ginseng Radix et Rhizoma, Fructus Crataegi, Glycyrrhizae Radix et Rhizoma, Polygoni Multiflori Radix, Fructus Lycii, and Coptidis Rhizoma have therapeutic effects on atherosclerosis. Furthermore, the pharmacological roles of these kinds of traditional Chinese medicine in atherosclerosis refer to endothelial function influences, cell proliferation and migration, platelet aggregation, thrombus formation, oxidative stress, inflammation, angiogenesis, apoptosis, autophagy, lipid metabolism, and the gut microbiome. Traditional Chinese medicine may serve as potential and effective anti-atherosclerosis drugs. However, a critical study has shown that Notoginseng Radix et Rhizoma may also have toxic effects including pustules, fever, and elevate circulating neutrophil count. Further high-quality studies are still required to determine the clinical safety and efficacy of traditional Chinese medicine and its active ingredients.

Synergistic Effect of Polydatin and Polygonatum sibiricum Polysaccharides in Combating Atherosclerosis via Suppressing TLR4-Mediated NF-κB Activation in ApoE-Deficient Mice

Objective

Atherosclerosis is a chronic inflammatory disease, which is closely related to hyperlipidemia, inflammatory responses, and oxidative stress. As natural products, polydatin (PD) and Polygonatum sibiricum polysaccharides (PSP) have remarkable pharmacological effects in anti-inflammatory, antioxidant stress, and lipid regulation. In this study, we sought to investigate whether the combination of polydatin and P. sibiricum polysaccharides play an anti-atherosclerotic role in alleviating inflammatory responses by inhibiting the toll-like receptor4 (TLR4)/myeloid differentiation factor88(MyD88)/nuclear factor-kappa B(NF-κB) signaling pathway.

Methods

Thirty-two ApoE-/- mice were fed with a high-fat diet (HFD) starting at the age of 8 weeks. Mice were randomly divided into four groups; (1) model group, (2) PD (100 mg/kg) + PSP (50 mg/kg) group, (3) TAK-242 (3 mg/kg) (TLR4 inhibitor) group, (4) PD (100 mg/kg) + PSP (50 mg/kg) + TAK-242 (3 mg/kg) group. Eight age-matched wild-type C57BL/6J mice fed an ordinary diet were used as a control group. Blood lipid levels were measured with an automatic biochemical analyzer. The lipid accumulation and histopathological changes in the aorta and liver were observed by Oil Red O and hematoxylin and eosin (H&E) staining, respectively. ELISA was performed to measure the serum levels of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). Western blot analysis was performed to analyze the expression of key proteins in the TLR4/MyD88/NF-κB signaling pathway.

Results

Compared with the model group, the combination of PD and PSP significantly inhibit serum lipids (low-density lipoprotein cholesterol, total cholesterol, and triglyceride) and cell adhesion molecules (VCAM-1, ICAM-1). Oil Red O staining indicated that the combination of PD and PSP decrease lipid accumulation in the aorta and liver. Moreover, H&E staining suggested that the combination of PD and PSP alleviate aortic intimal hyperplasia, inflammatory cell infiltration, and hepatic steatosis. Finally, the combination of PD and PSP inhibit the expression of TLR4, MyD88, and the phosphorylation level of NF-κB p65 protein in the aorta.

Conclusions

Polydatin synergizes with P. sibiricum polysaccharides in preventing the development of atherosclerosis in ApoE-/- mice by inhibiting the TLR4/MyD88/NF-κB signaling pathway.

Inhalation of Salvianolic Acid B Prevents Fine Particulate Matter-Induced Acute Airway Inflammation and Oxidative Stress by Downregulating the LTR4/MyD88/NLRP3 Pathway

Air pollution is a serious threat to human health. Inhaled fine particulate matter (PM2.5) can cause inflammation and oxidative stress in the airway; however, the mechanisms responsible for this effect have yet to be elucidated and there are no specific drugs that can prevent and treat this condition. In the present study, we investigated the effects and mechanisms underlying the inhalation of salvianolic acid B (SalB) on PM2.5-induced airway inflammation and oxidative stress. We used a PM2.5-induced mouse model of airway inflammation and oxidative stress, along with a human epithelial cell model, to study the action and mechanisms of SalB by histopathology, real-time PCR, enzyme-linked immunosorbent assays, flow cytometry, and western blotting. SalB treatment markedly inhibited the PM2.5-induced increase in the number of neutrophils and macrophages in bronchoalveolar lavage fluid, improved the infiltration of inflammatory cells in lung tissue, and reduced injury in the alveolar septum. Furthermore, SalB reduced the mRNA and protein levels of interleukin- (IL-) 1β, tumor necrosis factor- (TNF-) α, keratinocyte (KC), and transforming growth factor- (TGF-) β1 in lung tissues and the protein levels of IL-1β, TNF-α, IL-8, IL-6, and TGF-β1 in human epithelial cells. SalB treatment also significantly prevented the reduction of levels of superoxide dismutase, catalase, glutathione, and glutathione peroxidase in lung tissue and reduced the levels of reactive oxygen species in human epithelial cells induced by PM2.5. Furthermore, SalB and the myeloid differentiation primary response 88 (MyD88) inhibitor ST2825 inhibited the expression levels of toll-like receptor 4 (TLR4), MyD88, tumor necrosis factor receptor associated factor 6 (TRAF-6), and NOD-like receptor protein 3 (NLRP3), as well as the phosphorylation of downstream Erk1/2 and P38 in lung tissue and epithelial cells. SalB protects against PM2.5-induced airway inflammation and oxidative stress in a manner that is associated with the inhibition of the TLR4/MyD88/TRAF-6/NLRP3 pathway and downstream signals ERK1/2 and P38.

ST2825, a Small Molecule Inhibitor of MyD88, Suppresses NF-κB Activation and the ROS/NLRP3/Cleaved Caspase-1 Signaling Pathway to Attenuate Lipopolysaccharide-Stimulated Neuroinflammation

Neuroinflammation characterized by microglia activation is the mechanism of the occurrence and development of various central nervous system diseases. ST2825, as a peptide-mimetic MyD88 homodimerization inhibitor, has been identified as crucial molecule with an anti-inflammatory role in several immune cells, especially microglia. The purpose of the study was to investigate the anti-neuroinflammatory effects and the possible mechanism of ST2825. Methods: Lipopolysaccharide (LPS) was used to stimulate neuroinflammation in male BALB/c mice and BV2 microglia cells. The NO level was determined by Griess Reagents. The levels of pro-inflammatory cytokines and chemokines were determined by ELISA. The expressions of inflammatory proteins were determined by real-time PCR and Western blotting analysis. The level of ROS was detected by DCFH-DA staining. Results: In vivo, the improved levels of LPS-induced pro-inflammatory factors, including TNF-α, IL-6, IL-1β, MCP-1 and ICAM-1 in the cortex and hippocampus, were reduced after ST2825 treatment. In vitro, the levels of LPS-induced pro-inflammatory factors, including NO, TNF-α, IL-6, IL-1β, MCP-1, iNOS, COX2 and ROS, were remarkably decreased after ST2825 treatment. Further research found that the mechanism of its anti-neuroinflammatory effects appeared to be associated with inhibition of NF-κB activation and down-regulation of the NLRP3/cleaved caspase-1 signaling pathway. Conclusions: The current findings provide new insights into the activity and molecular mechanism of ST2825 for the treatment of neuroinflammation.

Hovenia Monofloral Honey can Attenuate Enterococcus faecalis Mediated Biofilm Formation and Inflammation

We evaluated the anti-biofilm formation and anti-inflammatory activity of Hovenia monofloral honey (HMH) against Enterococcus faecalis. Co-culture of HMH with E. faecalis attenuated the biofilm formation of E. faecalis on a polystyrene surface. In addition, HMH effectively eradicated the established E. faecalis biofilm. HMH significantly attenuated E. faecalis growth but did not affect the production of extracellular polymeric substances on E. faecalis, indicating that reduction of E. faecalis biofilm is a result of HMH-mediated killing of E. faecalis. Furthermore, we found that HMH can effectively attenuate E. faecalis-induced expression of a proinflammatory interleukin-8 (IL-8) in HT-29 cells. Interestingly, treatment of HMH significantly attenuated the E. faecalis-mediated expression of Toll-like receptor-2 (TLR-2) and its adaptor molecules, myeloid differentiation primary response 88 (MyD88), in HT-29 cells. In addition, E. faecalis-induced mitogen-activated protein kinases (MAPKs) phosphorylation was significantly attenuated by HMH administration. Furthermore, HMH-mediated anti-inflammatory efficacy (0.2 mg/mL of HMHs) had an equal extent of inhibitory efficacy as 5 μM of MyD88 inhibitor to attenuate E. faecalis-mediated IL-8 expression in HT-29 cells. These results suggest that HMH could effectively inhibit E. faecalis-mediated gastrointestinal inflammation through regulating the TLR-2/MyD88/MAPKs signaling pathways. Collectively, our data suggest that HMH could be developed as a potential natural agent to control E. faecalis-mediated biofilm formation and inflammation.

MyD88: At the heart of inflammatory signaling and cardiovascular disease

Cardiovascular disease is a leading cause of death worldwide and is associated with systemic inflammation. In depth study of the cell-specific signaling mechanisms mediating the inflammatory response is vital to improving anti-inflammatory therapies that reduce mortality and morbidity. Cellular damage in the cardiovascular system results in the release of damage associated molecular patterns (DAMPs), also known as "alarmins," which activate myeloid cells through the adaptor protein myeloid differentiation primary response 88 (MyD88). MyD88 is broadly expressed in most cell types of the immune and cardiovascular systems, and its role often differs in a cardiovascular disease context and cell specific manner. Herein we review what is known about MyD88 in the setting of a variety of cardiovascular diseases, discussing cell specific functions and the relative contributions of MyD88-dependent vs. independent alarmin triggered inflammatory signaling. The widespread involvement of these pathways in cardiovascular disease, and their largely unexplored complexity, sets the stage for future in depth mechanistic studies that may place MyD88 in both immune and non-immune cell types as an attractive target for therapeutic intervention in cardiovascular disease.

Nanoantioxidants: Pioneer Types, Advantages, Limitations, and Future Insights

Free radicals are generated as byproducts of normal metabolic processes as well as due to exposure to several environmental pollutants. They are highly reactive species, causing cellular damage and are associated with a plethora of oxidative stress-related diseases and disorders. Antioxidants can control autoxidation by interfering with free radical propagation or inhibiting free radical formation, reducing oxidative stress, improving immune function, and increasing health longevity. Antioxidant functionalized metal nanoparticles, transition metal oxides, and nanocomposites have been identified as potent nanoantioxidants. They can be formulated in monometallic, bimetallic, and multi-metallic combinations via chemical and green synthesis techniques. The intrinsic antioxidant properties of nanomaterials are dependent on their tunable configuration, physico-chemical properties, crystallinity, surface charge, particle size, surface-to-volume ratio, and surface coating. Nanoantioxidants have several advantages over conventional antioxidants, involving increased bioavailability, controlled release, and targeted delivery to the site of action. This review emphasizes the most pioneering types of nanoantioxidants such as nanoceria, silica nanoparticles, polydopamine nanoparticles, and nanocomposite-, polysaccharide-, and protein-based nanoantioxidants. This review overviews the antioxidant potential of biologically synthesized nanomaterials, which have emerged as significant alternatives due to their biocompatibility and high stability. The promising nanoencapsulation nanosystems such as solid lipid nanoparticles, nanostructured lipid carriers, and liposome nanoparticles are highlighted. The advantages, limitations, and future insights of nanoantioxidant applications are discussed.

The Potential Role of Polyphenols in Oxidative Stress and Inflammation Induced by Gut Microbiota in Alzheimer's Disease

Gut microbiota (GM) play a role in the metabolic health, gut eubiosis, nutrition, and physiology of humans. They are also involved in the regulation of inflammation, oxidative stress, immune responses, central and peripheral neurotransmission. Aging and unhealthy dietary patterns, along with oxidative and inflammatory responses due to gut dysbiosis, can lead to the pathogenesis of neurodegenerative diseases, especially Alzheimer's disease (AD). Although the exact mechanism between AD and GM dysbiosis is still unknown, recent studies claim that secretions from the gut can enhance hallmarks of AD by disturbing the intestinal permeability and blood-brain barrier via the microbiota-gut-brain axis. Dietary polyphenols are the secondary metabolites of plants that possess anti-oxidative and anti-inflammatory properties and can ameliorate gut dysbiosis by enhancing the abundance of beneficial bacteria. Thus, modulation of gut by polyphenols can prevent and treat AD and other neurodegenerative diseases. This review summarizes the role of oxidative stress, inflammation, and GM in AD. Further, it provides an overview on the ability of polyphenols to modulate gut dysbiosis, oxidative stress, and inflammation against AD.

Inhibition of CDK9 attenuates atherosclerosis by inhibiting inflammation and phenotypic switching of vascular smooth muscle cells

Background: Recent studies have demonstrated a key role of vascular smooth muscle cell (VSMC) dysfunction in atherosclerosis. Cyclin-dependent kinases 9 (CDK9), a potential biomarker of atherosclerosis, was significantly increased in coronary artery disease patient serum and played an important role in inflammatory diseases. This study was to explore the pharmacological role of CDK9 inhibition in attenuating atherosclerosis.

Methods: A small-molecule CDK9 inhibitor, LDC000067, was utilized to treat the high fat diet (HFD)-fed ApoE^-/- mice and human VSMCs.

Results: The results showed that inflammation and phenotypic switching of VSMCs were observed in HFD-induced atherosclerosis in ApoE^-/- mice, which were accompanied with increased CDK9 in the serum and atherosclerotic lesions where it colocalized with VSMCs. LDC000067 treatment significantly suppressed HFD-induced inflammation, proliferation and phenotypic switching of VSMCs, resulting in reduced atherosclerosis in the ApoE^-/- mice, while had no effect on plasma lipids. Further in vitro studies confirmed that LDC000067 and siRNA-mediated CDK9 knockdown reversed ox-LDL-induced inflammation and phenotypic switching of VSMCs from a contractile phenotype to a synthetic phenotype via inhibiting NF-κB signaling pathway in human VSMCs.

Conclusion: These results indicate that inhibition of CDK9 may be a novel therapeutic target for the prevention of atherosclerosis.

The roles of strawberry and honey phytochemicals on human health: A possible clue on the molecular mechanisms involved in the prevention of oxidative stress and inflammation

BACKGROUND

Oxidative stress and inflammation contribute to the etiopathogenesis of several human chronic diseases, such as cancer, diabetes, cardiovascular diseases and metabolic syndrome. Besides classic stimuli, such as reactive oxidant species, endotoxins (i.e., bacteria lipopolysaccharide), cytokines or carcinogens, oxidative stress and inflammation can be triggered by a poor diet and an excess of body fat and energy intake. Strawberry and honey are common rich sources of nutrients and bioactive compounds, widely studied for their roles exerted in health maintenance and disease prevention.

PURPOSE

This review aims to summarize and update the effects of strawberry and honey against oxidative stress and inflammation, with emphasis on metabolism and on the main molecular mechanisms involved in these effects.

METHODS

A wide range of literature, published in the last 10 years, elucidating the effects of strawberry and honey in preventing oxidative stress and inflammation both in vitro (whole matrix and digested fractions) and in vivo was collected from online electronic databases (PubMed, Scopus and Web of Science) and reviewed.

RESULTS

Strawberry and honey polyphenols may potentially prevent the chronic diseases related to oxidative stress and inflammation. Several in vitro and in vivo studies reported the effects of these foods in suppressing the oxidative stress, by decreasing ROS production and oxidative biomarkers, restoring the antioxidant enzyme activities, ameliorating the mitochondrial antioxidant status and functionality, among others, and the inflammatory process, by modulating the mediators of acute and chronic inflammation essential for the onset of several human diseases. These beneficial properties are mediated in part through their ability to target multiple signaling pathways, such as p38 MAPK, AMPK, PI3K/Akt, NF-κB and Nrf2.

CONCLUSIONS

Available scientific literature show that strawberry and honey may be effective in preventing oxidative stress and inflammation. The deep evaluation of the factors that affect their metabolism as well as the assessment of the main molecular mechanisms involved are of extreme importance for the possible therapeutic and preventive benefit against the most common human diseases. However, published literature is still scarce so that deeper studies should be performed in order to evaluate the bioavailability of these food matrices and their effects after digestion.

Flavonoids from sea buckthorn: A review on phytochemistry, pharmacokinetics and role in metabolic diseases

Sea buckthorn (Hippophae rhamnoides L., SBT) is being used as a folk medicine for their diverse medicinal properties. Flavonoids are generally considered as the main bioactive and characteristic ingredients in SBT. This review was conducted using a comprehensive literature search on the chemical components, quality control, pharmacokinetics of flavonoids from SBT (FSBT). Particularly, we highlighted the therapeutic potential in metabolic diseases and clinical applications of FSBT. More than 95 flavonoids have been identified from SBT. Although the oral bioavailability of FSBT was relatively low, FSBT displays significant effect on the regulation of metabolism to ameliorate metabolic disorders and their complications. There is a heightened need to explore the bioactive compounds in SBT and mechanism(s) of action of FSBT in order to fully understand the pathways of their activities. PRACTICAL APPLICATIONS: For years, due to the increasing emergence of metabolic syndrome and diverse functions of FSBT in regulating metabolism, they can be efficiently utilized for human health and have an urgent need to become a hotspot for research. This review will broaden the understanding of FSBT, providing some directions for further development and expanding the therapeutic applications of FSBT.

Gold Nanomaterial Engineering for Macrophage-Mediated Inflammation and Tumor Treatment

Macrophages play an important role in the body's immune defense process. Phenotype imbalance between M1 and M2 macrophages induced by inflammation-related disorders and tumor can also be reversibly converted to treat these diseases. As exogenous substances, a large part of gold-based nanomaterials interact with macrophages once they enter the body, which provides gold nanomaterials a huge advantage to act as imaging contrasts, active substance carriers, and therapeutic agents for macrophage modulation. By cutting off macrophage recruitment, inhibiting macrophage activities, and modulating M1/M2 polarization, gold nanomaterial engineering exerts therapeutic effects on inflammation-related diseases at target sites. In this review, biological functions of macrophages in inflammation-related diseases are introduced, the effect of physicochemical factors of gold nanomaterials including size, shape, and surface chemistry is focused on the interaction between macrophages and gold nanomaterials, and the applications of gold nanomaterials are elaborated for tracking and treating these diseases by macrophages. The rational and smart engineering of gold nanomaterials allows a promising platform for macrophage-mediated inflammation and tumor imaging and treatment.

Immunological mechanisms underlying sterile inflammation in the pathogenesis of atherosclerosis: potential sites for intervention

Introduction: Innate and adaptive immunity play a critical role in the underlying pathological mechanisms of atherosclerosis and potential target sites of sterile inflammation open opportunities to develop novel therapeutics. In response to oxidized LDL in the intimal layer, T cell subsets are recruited and activated at the site of atheroma to upregulate pro-atherogenic cytokines which exacerbate plaque formation instability.Areas covered: A systematic search of PubMed and the Web of Science was performed between January 2001- September 2020 and relevant articles in sterile inflammation and atherosclerosis were critically reviewed. The original information was collected on the interconnection between danger associated molecular patterns (DAMPs) as the mediators of sterile inflammation and the receptor complex of CD36-TLR4-TLR6 that primes and activates inflammasomes in the pathophysiology of atherosclerosis. Mediators of sterile inflammation are identified to target therapeutic strategies in the management of atherosclerosis.Expert opinion: Sterile inflammation via NLRP3 inflammasome is perpetuated by the activation of IL-1β and IL-18 and induction of pyroptosis resulting in the release of additional inflammatory cytokines and DAMPs. Challenges with current inhibitors of the NLRP3 inflammasome lie in the specificity, stability, and efficacy in targeting the NLRP3 inflammasome constituents without ameliorating upstream or downstream responses necessary for survival.

Targeted treatment of alcoholic liver disease based on inflammatory signalling pathways

Targeted therapy is an emerging treatment strategy for alcoholic liver disease (ALD). Inflammation plays an important role in the occurrence and development of ALD, and is a key choice for its targeted treatment, and anti-inflammatory treatment has been considered beneficial for liver disease. Surprisingly, immune checkpoint inhibitors have become important therapeutic agents for hepatocellular carcinoma (HCC). Moreover, studies have shown that the combination of inflammatory molecule inhibitors and immune checkpoint inhibitors can exert better effects than either alone in mouse models of HCC. This review discusses the mechanism of hepatic ethanol metabolism and the conditions under which inflammation occurs. In addition, we focus on the potential molecular targets in inflammatory signalling pathways and summarize the potential targeted inhibitors and immune checkpoint inhibitors, providing a theoretical basis for the targeted treatment of ALD and the development of new combination therapy strategies for HCC.

Compound LM9, a novel MyD88 inhibitor, efficiently mitigates inflammatory responses and fibrosis in obesity-induced cardiomyopathy

Mechanisms of cardiomyopathy caused by obesity/hyperlipidemia are complicated. Obesity is usually associated with chronic low-grade inflammation and may lead to the onset and progression of myocardial fibrosis and remodeling. TLR4/MyD88 signaling pathway, as a key regulator of inflammation, plays an important role in the pathogenesis of obesity-induced cardiomyopathy. We previously demonstrated that LM9, a novel MyD88 inhibitor, attenuated inflammatory responses and fibrosis in obesity-induced cardiomyopathy by inhibiting the formation of TLR4/MyD88 complex. In this study, we investigated the protective effects of LM9 on obesity-induced cardiomyopathy in vitro and in vivo. We showed that LM9 (5, 10 μM) significantly attenuates palmitic acid (PA)-induced inflammation in mouse peritoneal macrophages, evidenced by decreased expression of proinflammatory genes including TNF-α, IL-6, IL-1β, and ICAM-1. In cardiac-derived H9C2 cells, LM9 treatment suppressed PA-induced inflammation, lipid accumulation, and fibrotic responses. In addition, LM9 treatment also inhibited PA-activated TLR4/MyD88/NF-κB signaling pathway. We further revealed in HEK293 cells that LM9 treatment blocked the TLR4/MyD88 binding and MyD88 homodimer formation. In HFD-fed mice, administration of LM9 (5, 10 mg/kg, ig, every other days for 8 weeks) dose-dependently alleviated inflammation and fibrosis in heart tissues and decreased serum lipid concentration. In conclusion, this study demonstrates that MyD88 inhibitor LM9 exerts protective effects against obesity-induced cardiomyopathy, suggesting LM9 to be a promising therapeutic candidate drug for the obesity-related cardiac complications.

Macrophage-derived myeloid differentiation protein 2 plays an essential role in ox-LDL-induced inflammation and atherosclerosis

Background

Atherosclerosis is a chronic inflammatory disease. Although Toll-like receptor 4 (TLR4) has been involved in inflammatory atherosclerosis, the exact mechanisms by which oxidized-low-density lipoproteins (ox-LDL) activates TLR4 and elicits inflammatory genesis are not fully known. Myeloid differentiation factor 2 (MD2) is an extracellular molecule indispensable for lipopolysaccharide recognition of TLR4.

Method

Apoe^−/−Md2^−/− mice and pharmacological inhibitor of MD2 were used in this study. We also reconstituted Apoe^−/− mice with either Apoe^−/− or Apoe^−/−Md2^−/− marrow-derived cells. Mechanistic studies were performed in primary macrophages, HEK-293T cells, and cell-free system.

Finding

MD2 levels are elevated in atherosclerotic lesion macrophages, and MD2 deficiency or pharmacological inhibition in mice reduces the inflammation and stunts the development of atherosclerotic lesions in Apoe^−/− mice fed with high-fat diet. Transfer of marrow-derived cells from Apoe-Md2 double knockout mice to Apoe knockout mice confirmed the critical role of bone marrow-derived MD2 in inflammatory factor induction and atherosclerosis development. Mechanistically, we show that MD2 does not alter ox-LDL uptake by macrophages but is required for TLR4 activation and inflammation via directly binding to ox-LDL, which triggers MD2/TLR4 complex formation and TLR4-MyD88-NFκB pro-inflammatory cascade.

Interpretation

We provide a mechanistic basis of ox-LDL-induced macrophage inflammation, illustrate the role of macrophage-derived MD2 in atherosclerosis, and support the therapeutic potential of MD2 targeting in atherosclerosis-driven cardiovascular diseases.

Funding

This work was supported by the National Key Research Project of China (2017YFA0506000), National Natural Science Foundation of China (21961142009, 81930108, 81670244, and 81700402), and Natural Science Foundation of Zhejiang Province (LY19H020004).

AZD4547 Attenuates Lipopolysaccharide-Induced Acute Kidney Injury by Inhibiting Inflammation: The Role of FGFR1 in Renal Tubular Epithelial Cells

Introduction

Inflammation plays an important role in the pathogenesis of acute kidney injury (AKI). Fibroblast growth factor receptor 1 (FGFR1) signaling is implicated in kidney pathology. AZD4547 is a small molecule inhibitor of FGFR1.

Materials and Methods

Here, we investigated whether AZD4547 could mitigate inflammatory responses in AKI. C57BL/6 mice were injected with lipopolysaccharide (LPS) to induce AKI. FGFR1 was blocked using AZD4547 or CRISPR/Cas9 genome editing. After immunofluorescent double-staining of kidney tissues showing that P-FGFR1 was localized to renal tubular epithelial cells, a tubular epithelial cell line (NRK-52E) was used for in vitro analysis.

Results

AZD4547 significantly reduced renal inflammation, cell apoptosis, and kidney dysfunction in AKI mice. In vitro, treatment of NRK-52E cells with AZD4547 attenuated LPS-induced inflammatory responses and was associated with downregulated P-FGFR1 levels. These findings were further confirmed in NRK-52E cells by knocking down the expression of FGFR1.

Conclusion

Our findings provide direct evidence that FGFR1 mediates LPS-induced inflammation leading to renal dysfunction. We also show that AZD4547 is a potential therapeutic agent to reduce inflammatory responses in AKI. Both FGFR1 and AZD4547 may interesting therapeutic options to combat AKI.