Hypaphorine Attenuates Lipopolysaccharide-Induced Endothelial Inflammation via Regulation of TLR4 and PPAR-γ Dependent on PI3K/Akt/mTOR Signal Pathway

mTOR aggravated CD4+ T cell pyroptosis by regulating the PPARγ-Nrf2 pathway in sepsis

Sepsis is a systemic inflammatory response syndrome caused by a dysregulated host response to infection. CD4+T cell reduction is crucial to sepsis-induced immunosuppression. Pyroptosis, a programmed necrosis, is concerned with lymphocytopenia. Peroxisome proliferator-activated receptor gamma (PPARγ) regulated by upstream mTOR, exerts anti-pyroptosis effects. To investigate the potential effects of mTOR-PPARγ on sepsis-induced CD4+T cell depletion and the underlying mechanisms, we observed mTOR activation and pyroptosis with PPARγ-Nrf suppression through cecal ligation and puncture (CLP) sepsis mouse model. Further mechanism research used genetically modified mice with T cell-specific knockout mTOR or Tuberous Sclerosis Complex1 (TSC1). It revealed that mTOR mediated CD4 + T cell pyroptosis in septic mice by negatively regulating the PPARγ-Nrf2 signaling pathway. Taken together, mTOR-PPARγ-Nrf2 signaling mediated the CD4+ T cell pyroptosis in sepsis, contributing to CD4+T cell depletion and immunosuppression.

Unlocking new avenues for neuropsychiatric disease therapy: the emerging potential of Peroxisome proliferator-activated receptors as promising therapeutic targets

RATIONALE

Peroxisome proliferator-activated receptors (PPARs) are transcription factors that regulate various physiological processes such as inflammation, lipid metabolism, and glucose homeostasis. Recent studies suggest that targeting PPARs could be beneficial in treating neuropsychiatric disorders by modulating neuronal function and signaling pathways in the brain. PPAR-α, PPAR-δ, and PPAR-γ have been found to play important roles in cognitive function, neuroinflammation, and neuroprotection. Dysregulation of PPARs has been associated with neuropsychiatric disorders like bipolar disorder, schizophrenia, major depression disorder, and autism spectrum disorder. The limitations and side effects of current treatments have prompted research to target PPARs as a promising novel therapeutic strategy. Preclinical and clinical studies have shown the potential of PPAR agonists and antagonists to improve symptoms associated with these disorders.

OBJECTIVE

This review aims to provide an overview of the current understanding of PPARs in neuropsychiatric disorders, their potential as therapeutic targets, and the challenges and future directions for developing PPAR-based therapies.

METHODS

An extensive literature review of various search engines like PubMed, Medline, Bentham, Scopus, and EMBASE (Elsevier) databases was carried out with the keywords "PPAR, Neuropsychiatric disorders, Oxidative stress, Inflammation, Bipolar Disorder, Schizophrenia, Major depression disorder, Autism spectrum disorder, molecular pathway".

RESULT & CONCLUSION

Although PPARs present a hopeful direction for innovative therapeutic approaches in neuropsychiatric conditions, additional research is required to address obstacles and convert this potential into clinically viable and individualized treatments.

Exploring the mechanism of Liang Xue Wu Hua Tang in the treatment of rosacea via network pharmacology and molecular docking

Rosacea is a chronic and recurrent inflammatory skin disease affecting the center of the face that causes burning and itching sensations and changes in aesthetics. Liang Xue Wu Hua Tang (LXWHT) is a classic herbal formulation that is efficacious and has been widely used in the clinical treatment of rosacea; however, the pharmacological mechanisms remain unclear. The aim of the present study was to investigate the mechanism of action of LXWHT using network pharmacology and molecular docking. The Traditional Chinese Medicine System Pharmacology database was searched to identify the active ingredients and pharmacological targets of LXWHT, and the GeneCard, Disgenet, and Gene Expression Omnibus databases were applied to screen rosacea-related targets. Cytoscape software was used to visualize the protein-protein interaction network, and network topology analysis was used to identify core targets. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed for the core targets. Molecular docking simulations and visualization were performed using Maestro and PyMOL, respectively. A total of 43 active compounds and 28 potential targets for LXWHT treatment of rosacea were selected for analysis. The Gene Ontology/Kyoto Encyclopedia of Genes and Genomes results indicated that LXWHT may exert therapeutic effects on rosacea by intervening in immune pathways including tumor necrosis factor pathway, interleukin-17 pathways, and Toll-like receptor signaling pathways. Chemokine ligand 2, interferon-γ, interleukin-1ß, peroxisome proliferator-activated receptor-γ, and matrix metallopeptidase 9 may be the core therapeutic target. Quercetin, stigmasterol, kaempferol, beta-sitosterol, luteolin, beta-carotene, baicalein, acetin, and isorhamnetin were predicted to be the key active ingredients. LXWHT may exert therapeutic effects in the treatment of rosacea by modulating immunity and angiogenesis, laying the foundation for further research.

Bifidobacterium adolescentis-derived hypaphorine alleviates acetaminophen hepatotoxicity by promoting hepatic Cry1 expression

Acetaminophen (APAP)-induced liver injury (AILI) is a pressing public health concern. Although evidence suggests that Bifidobacterium adolescentis (B. adolescentis) can be used to treat liver disease, it is unclear if it can prevent AILI. In this report, we prove that B. adolescentis significantly attenuated AILI in mice, as demonstrated through biochemical analysis, histopathology, and enzyme-linked immunosorbent assays. Based on untargeted metabolomics and in vitro cultures, we found that B. adolescentis generates microbial metabolite hypaphorine. Functionally, hypaphorine inhibits the inflammatory response and hepatic oxidative stress to alleviate AILI in mice. Transcriptomic analysis indicates that Cry1 expression is increased in APAP-treated mice after hypaphorine treatment. Overexpression of Cry1 by its stabilizer KL001 effectively mitigates liver damage arising from oxidative stress in APAP-treated mice. Using the gene expression omnibus (GEO) database, we verified that Cry1 gene expression was also decreased in patients with APAP-induced acute liver failure. In conclusion, this study demonstrates that B. adolescentis inhibits APAP-induced liver injury by generating hypaphorine, which subsequently upregulates Cry1 to decrease inflammation and oxidative stress.

A review of the ethnopharmacology, phytochemistry, pharmacology, pharmacokinetics and toxicology of Abri Herba (Ji-Gu-Cao)

Abri Herba (AH, known as 'Ji-Gu-Cao' in China) has a long-term medicinal history of treating cholecystitis, acute and chronic hepatitis and non-alcoholic fatty liver (NAFL) in China or other Asian countries. This review aimed to provide a comprehensive analysis of AH in terms of ethnopharmacology, phytochemistry, pharmacology, pharmacokinetics and toxicology. The information involved in the study was collected from a variety of electronic resources, and >100 scientific studies have been used since 1962. Until now, 95 chemical compounds have been isolated and identified from AH and the seeds of Abrus cantoniensis Hance (ACH), including 47 terpenoids, 26 flavonoids and 4 alkaloids. The pharmacological activities of AH extracts and their pure compounds have been explored in the aspects of anti-hyperlipidaemia, hepatoprotection, anti-tumour, anti-viral, anti-bacterial, anti-inflammatory and analgesic, immunomodulation, antioxidant and others. The pharmacokinetics and excretion kinetics of AH in vivo and 15 traditional and clinical prescriptions containing AH have been sorted out, and the potential therapeutic mechanism and drug metabolism pattern were also summarised. The pods of ACH are toxic, with a median lethal dose (LD50) of 10.01 ± 2.90 g/kg (i.g.) in mice. Interestingly, the toxicity of ACH's pods and seeds decreased after boiling. However, the toxicity mechanism of pods of ACH is unclear, limiting its clinical application. Clinical trials in the future should be used to explore its safety. Meanwhile, as one of the relevant pharmacological activities, the effects and mechanism of AH on anti-hyperlipidaemia and hepatoprotection should be further studied, which is of great significance for understanding its mechanism of action in the treatment of NAFL disease and improving its clinical application.

C1q/Tumor Necrosis Factor-Related Protein-9 Enhances Macrophage Cholesterol Efflux and Improves Reverse Cholesterol Transport via AMPK Activation

Cholesterol efflux from foam cells in atherosclerotic plaques is crucial for reverse cholesterol transport (RCT), an important antiatherogenic event. ATP-binding cassette (ABC) transporters, ABCA1 and ABCG1, are key receptors in the cholesterol efflux pathway. C1q/tumor necrosis factor-related protein-9 (CTRP9) is a newly discovered adipokine and exhibits an atheroprotective activity. However, the role of CTRP9 in RCT still remains unknown. In this work, we investigated the effect of subcutaneous administration of CTRP9 protein on RCT and atherosclerotic lesion formation in ApoE-/- mice fed with a high-fat diet. CTRP9-dependent regulation of cholesterol efflux and ABC transporters in RAW 264.7 foam cells was determined. Our results showed that CTRP9 protein decreased atherosclerotic lesions, increased cholesterol efflux, and upregulated liver ABCA1 and ABCG1 expression in ApoE-/- mice. CTRP9 treatment dose-dependently increased mRNA and protein expression of ABCA1, ABCG1, and LXR-α in RAW 264.7 foam cells. Moreover, the expression and phosphorylation of AMPK was potentiated upon CTRP9 treatment. Notably, CTRP9-induced cholesterol efflux and upregulation of ABCA, ABCG1, and LXR-α were impaired when AMPK was knocked down. AMPK depletion restored cholesterol accumulation in CTRP9-treated RAW 264.7 cells. Taken together, subcutaneous injection is an effective novel delivery route for CTRP9 protein, and exogenous CTRP9 can facilitate cholesterol efflux and promote RCT in an animal model of atherosclerosis. The atheroprotective activity of CTRP9 is mediated through the activation of AMPK signaling.

Novel Therapies for ANCA-associated Vasculitis: Apilimod Ameliorated Endothelial Cells Injury through TLR4/NF-κB Pathway and NLRP3 Inflammasome

BACKGROUND

Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is a rapidly progressive form of glomerulonephritis for which effective therapeutic drugs are currently lacking, and its underlying mechanism remains unclear.

AIMS

This study aimed to investigate new treatment options for AAV through a combination of bioinformatics analysis and cell molecular experiments.

METHODS

The research utilized integrated bioinformatics analysis to identify genes with differential expression, conduct enrichment analysis, and pinpoint hub genes associated with AAV. Potential therapeutic compounds for AAV were identified using Connectivity Map and molecular docking techniques. In vitro experiments were then carried out to examine the impact and mechanism of apilimod on endothelial cell injury induced by MPO-ANCA-positive IgG.

RESULTS

The findings revealed a set of 374 common genes from differentially expressed genes and key modules of WGCNA, which were notably enriched in immune and inflammatory response processes. A proteinprotein interaction network was established, leading to the identification of 10 hub genes, including TYROBP, PTPRC, ITGAM, KIF20A, CD86, CCL20, GAD1, LILRB2, CD8A, and COL5A2. Analysis from Connectivity Map and molecular docking suggested that apilimod could serve as a potential therapeutic cytokine inhibitor for ANCA-GN based on the hub genes. In vitro experiments demonstrated that apilimod could mitigate tight junction disruption, endothelial cell permeability, LDH release, and endothelial activation induced by MPO-ANCA-positive IgG. Additionally, apilimod treatment led to a significant reduction in the expression of proteins involved in the TLR4/NF-κB and NLRP3 inflammasome-mediated pyroptosis pathways.

CONCLUSION

This study sheds light on the potential pathogenesis of AAV and highlights the protective role of apilimod in mitigating MPO-ANCA-IgG-induced vascular endothelial cell injury by modulating the TLR4/ NF-kB and NLRP3 inflammasome-mediated pyroptosis pathway. These findings suggest that apilimod may hold promise as a treatment for AAV and warrant further investigation.

Bilobalide attenuates lipopolysaccharide‑induced HepG2 cell injury by inhibiting TLR4‑NF‑κB signaling via the PI3K/Akt pathway

Inflammation is involved in the pathological process underlying a number of liver diseases. Bilobalide (BB) is a natural compound from Ginkgo biloba leaves that was recently demonstrated to exert hepatoprotective effects by inhibiting oxidative stress in the liver cancer cell line HepG2. The anti-inflammatory activity of BB has been reported in recent studies. The major objective of the present study was to investigate whether BB could attenuate inflammation-associated cell damage. HepG2 cells were cultured with lipopolysaccharide (LPS) and BB, and cell damage was evaluated by measuring cell viability using MTT assay. The activity of the NF-κB signaling pathway was assessed by measuring the levels of IκBα, NF-κB p65, phosphorylated (p)-IκBα, p-p65, p65 DNA-binding activity and inflammatory cytokines IL-1β, IL-6 and TNF-α. A toll-like receptor (TLR)4 inhibitor (CLI-095) was used to detect the involvement of TLR4 in cell injury caused by LPS. In addition, the PI3K/Akt inhibitor LY294002 was applied to explore the involvement of the PI3K/Akt axis in mediating the effects of BB. The results demonstrated that LPS induced HepG2 cell injury. LPS also elevated the levels of p-IκBα, p-p65, p65 DNA-binding activity and inflammatory cytokines. However, CLI-095 significantly attenuated the LPS-induced cell damage and inhibited the activation of NF-κB signaling. BB also dose-dependently attenuated the LPS-induced cell damage, activation of NF-κB signaling and TLR4 overexpression. Furthermore, it was observed that LY294002 diminished the cytoprotective effects of BB on cell injury, TLR4 expression and NF-κB activation. These findings indicated that BB could attenuate LPS-induced inflammatory injury to HepG2 cells by regulating TLR4-NF-κB signaling.

Hepatoprotective effects of Niudali (Callerya speciosa) root aqueous extracts against tetrachloromethane-induced acute liver injury and inflammation

Niudali (Callerya speciosa) is commonly grown in southeastern regions of China and consumed as a food ingredient. Although Niudali root extracts showed various biological activities, the hepatoprotective effects of Niudali root phytochemicals are not fully studied. Herein, we prepared two Niudali root aqueous extracts, namely, c and Niudali polysaccharides-enriched extract (NPE), and identified an alkaloid, (hypaphorine) in NEW. The hepatoprotective effects of NWE, NPE, and hypaphorine were evaluated in an acute liver injury model induced by carbon tetrachloride (CCl4) in mice. Pathohistological examination and blood chemistry assays showed that treatment of NWE, NPE, and hypaphorine alleviated CCl4-induced liver damage by lowering the liver injury score (by 75.51%, 80.01%, and 41.22%) and serum aspartate and alanine transaminases level (by 63.24%, 85.22%, and 49.74% and by 78.73%, 80.08%, and 81.70%), respectively. NWE, NPE, and hypaphorine also reduced CCl4-induced hepatic oxidative stresses in the liver tissue by decreasing the levels of malondialdehyde (by 40.00%, 51.25%, and 28.75%) and reactive oxygen species (by 30.22%, 36.14%, and 33.54%) while increasing the levels of antioxidant enzymes including superoxide dismutase (by 21.36%, 21.64%, and 8.90%), catalase (by 22.13%, 33.33%, and 5.39%), and glutathione (by 84.87%, 90.65%, and 80.53%), respectively. Mechanistic assays showed that NWE, NPE, and hypaphorine alleviated liver damage by mediating inflammatory biomarkers (e.g., pro-inflammatory cytokines) via the signaling pathways of mitogen-activated protein kinases and nuclear factor-κB. Findings from our study extend the understanding of Niudali's hepatoprotective effects, which is useful for its development as a dietary intervention for liver inflammation.

PPARγ in Atherosclerotic Endothelial Dysfunction: Regulatory Compounds and PTMs

The formation of atherosclerotic plaques is one of the main sources of cardiovascular disease. In addition to known risk factors such as dyslipidemia, diabetes, obesity, and hypertension, endothelial dysfunction has been shown to play a key role in the formation and progression of atherosclerosis. Peroxisome proliferator-activated receptor-gamma (PPARγ), a transcription factor belonging to the steroid superfamily, is expressed in the aorta and plays a critical role in protecting endothelial function. It thereby serves as a target for treating both diabetes and atherosclerosis. Although many studies have examined endothelial cell disorders in atherosclerosis, the role of PPARγ in endothelial dysfunction is still not well understood. In this review, we summarize the possible mechanisms of action behind PPARγ regulatory compounds and post-translational modifications (PTMs) of PPARγ in the control of endothelial function. We also explore the potential use of endothelial PPARγ-targeted agents in the prevention and treatment of atherosclerosis.

Research Progress and Molecular Mechanisms of Endothelial Cells Inflammation in Vascular-Related Diseases

Endothelial cells (ECs) are widely distributed inside the vascular network, forming a vital barrier between the bloodstream and the walls of blood vessels. These versatile cells serve myriad functions, including the regulation of vascular tension and the management of hemostasis and thrombosis. Inflammation constitutes a cascade of biological responses incited by biological, chemical, or physical stimuli. While inflammation is inherently a protective mechanism, dysregulated inflammation can precipitate a host of vascular pathologies. ECs play a critical role in the genesis and progression of vascular inflammation, which has been implicated in the etiology of numerous vascular disorders, such as atherosclerosis, cardiovascular diseases, respiratory diseases, diabetes mellitus, and sepsis. Upon activation, ECs secrete potent inflammatory mediators that elicit both innate and adaptive immune reactions, culminating in inflammation. To date, no comprehensive and nuanced account of the research progress concerning ECs and inflammation in vascular-related maladies exists. Consequently, this review endeavors to synthesize the contributions of ECs to inflammatory processes, delineate the molecular signaling pathways involved in regulation, and categorize and consolidate the various models and treatment strategies for vascular-related diseases. It is our aspiration that this review furnishes cogent experimental evidence supporting the established link between endothelial inflammation and vascular-related pathologies, offers a theoretical foundation for clinical investigations, and imparts valuable insights for the development of therapeutic agents targeting these diseases.

P-Selectin mediates targeting of a self-assembling phototherapeutic nanovehicle enclosing dipyridamole for managing thromboses

Thrombotic vascular disorders, specifically thromboembolisms, have a significant detrimental effect on public health. Despite the numerous thrombolytic and antithrombotic drugs available, their efficacy in penetrating thrombus formations is limited, and they carry a high risk of promoting bleeding. Consequently, the current medication dosage protocols are inadequate for preventing thrombus formation, and higher doses are necessary to achieve sufficient prevention. By integrating phototherapy with antithrombotic therapy, this study addresses difficulties related to thrombus-targeted drug delivery. We developed self-assembling nanoparticles (NPs) through the optimization of a co-assembly engineering process. These NPs, called DIP-FU-PPy NPs, consist of polypyrrole (PPy), dipyridamole (DIP), and P-selectin-targeted fucoidan (FU) and are designed to be delivered directly to thrombi. DIP-FU-PPy NPs are proposed to offer various potentials, encompassing drug-loading capability, targeted accumulation in thrombus sites, near-infrared (NIR) photothermal-enhanced thrombus management with therapeutic efficacy, and prevention of rethrombosis. As predicted, DIP-FU-PPy NPs prevented thrombus recurrence and emitted visible fluorescence signals during thrombus clot penetration with no adverse effects. Our co-delivery nano-platform is a simple and versatile solution for NIR-phototherapeutic multimodal thrombus control.

The causal effects of genetically determined human blood metabolites on the risk of atrial fibrillation

Background

Blood metabolites have been found related to atrial fibrillation (AF), but the causal role is still unclear. Mendel randomization (MR) can give information about the causality between blood metabolites and AF.

Methods

Two-sample MR analysis was used to evaluate the causality between 486 blood metabolites and AF. Firstly, the genome-wide association study (GWAS) data for AF (from Nielsen et al.) was analyzed and some metabolites were identified. Then another GWAS data for AF (from Roselli et al.) was repeatedly analyzed to verify the results. Inverse variance weighted method was mainly used to determine the causality, and MR-egger, Weighted Median, and MR-PRESSO models were used as supplements of MR. Cochran's Q test was used to assess heterogeneity. And MR-Egger intercept and MR-PRESSO global test were performed to measure pleiotropy.

Results

The study used Bonferroni's corrected P value (P < 1.03 × 10-4) as the significance threshold. After MR analysis and replication analysis, we found two overlapped metabolites. Among which tryptophan betaine was the most significant causal metabolite in both AF GWAS data (from Nielsen et al.) (odds ratio (OR) = 0.83, 95% confidence interval (CI) = 0.76-0.90, P = 9.37 × 10-6) and AF GWAS data (from Roselli et al.) (OR = 0.82, 95% CI = 0.76-0.88, P = 2.00 × 10-7), while uridine was nominally significant metabolites in both AF GWAS data (from Nielsen et al.) (OR = 0.58, 95% CI = 0.40-0.84, P = 0.004) and AF GWAS data (from Roselli et al.) (OR = 0.56, 95% CI = 0.35-0.88, P = 0.01). And the results of sensitivity analysis showed that none of them had obvious heterogeneity or pleiotropy.

Conclusion

The study identified several blood metabolites that were causally related to AF, which may provide new perspectives on the pathogenesis of AF.

Metabolomic Profiles Associated With Blood Pressure Reduction in Response to the DASH and DASH-Sodium Dietary Interventions

BACKGROUND

The DASH (Dietary Approaches to Stop Hypertension) diets reduced blood pressure (BP) in the DASH and DASH-Sodium trials, but the underlying mechanisms are unclear. We identified metabolites associated with systolic BP or diastolic BP (DBP) changes induced by dietary interventions (DASH versus control arms) in 2 randomized controlled feeding studies-the DASH and DASH-Sodium trials.

METHODS

Metabolomic profiling was conducted in serum and urine samples collected at the end of diet interventions: DASH (n=219) and DASH-Sodium (n=395). Using multivariable linear regression models, associations were examined between metabolites and change in systolic BP and DBP. Tested for interactions between diet interventions and metabolites were the following comparisons: (1) DASH versus control diets in the DASH trial (serum), (2) DASH high-sodium versus control high-sodium diets in the DASH-Sodium trial (urine), and (3) DASH low-sodium versus control high-sodium diets in the DASH-Sodium trial (urine).

RESULTS

Sixty-five significant interactions were identified (DASH trial [serum], 12; DASH high sodium [urine], 35; DASH low sodium [urine], 18) between metabolites and systolic BP or DBP. In the DASH trial, serum tryptophan betaine was associated with reductions in DBP in participants consuming the DASH diets but not control diets (P interaction, 0.023). In the DASH-Sodium trial, urine levels of N-methylglutamate and proline derivatives (eg, stachydrine, 3-hydroxystachydrine, N-methylproline, and N-methylhydroxyproline) were associated with reductions in systolic BP or DBP in participants consuming the DASH diets but not control diets (P interaction, <0.05 for all tests).

CONCLUSIONS

We identified metabolites that were associated with BP lowering in response to dietary interventions.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov/ct2/show/NCT03403166; Unique identifier: NCT03403166 (DASH trial). URL: https://www.

CLINICALTRIALS

gov/ct2/show/NCT00000608; Unique identifier: NCT00000608 (DASH-Sodium trial).

Analogs of 6-Bromohypaphorine with Increased Agonist Potency for α7 Nicotinic Receptor as Anti-Inflammatory Analgesic Agents

Hypaphorines, tryptophan derivatives, have anti-inflammatory activity, but their mechanism of action was largely unknown. Marine alkaloid L-6-bromohypaphorine with EC₅₀ of 80 μM acts as an agonist of α7 nicotinic acetylcholine receptor (nAChR) involved in anti-inflammatory regulation. We designed the 6-substituted hypaphorine analogs with increased potency using virtual screening of their binding to the α7 nAChR molecular model. Fourteen designed analogs were synthesized and tested in vitro by calcium fluorescence assay on the α7 nAChR expressed in neuro 2a cells, methoxy ester of D-6-iodohypaphorine (6ID) showing the highest potency (EC₅₀ 610 nM), being almost inactive toward α9α10 nAChR. The macrophages cytometry revealed an anti-inflammatory activity, decreasing the expression of TLR4 and increasing CD86, similarly to the action of PNU282987, a selective α7 nAChR agonist. 6ID administration in doses 0.1 and 0.5 mg/kg decreased carrageenan-induced allodynia and hyperalgesia in rodents, in accord with its anti-inflammatory action. Methoxy ester of D-6-nitrohypaphorine demonstrated anti-oedemic and analgesic effects in arthritis rat model at i.p. doses 0.05-0.26 mg/kg. Tested compounds showed excellent tolerability with no acute in vivo toxicity in dosages up to 100 mg/kg i.p. Thus, combining molecular modelling and natural product-inspired drug design improved the desired activity of the chosen nAChR ligand.

PPARs and the Kynurenine Pathway in Melanoma-Potential Biological Interactions

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors involved in various physiological and pathological processes within the skin. PPARs regulate several processes in one of the most aggressive skin cancers, melanoma, including proliferation, cell cycle, metabolic homeostasis, cell death, and metastasis. In this review, we focused not only on the biological activity of PPAR isoforms in melanoma initiation, progression, and metastasis but also on potential biological interactions between the PPAR signaling and the kynurenine pathways. The kynurenine pathway is a major pathway of tryptophan metabolism leading to nicotinamide adenine dinucleotide (NAD+) production. Importantly, various tryptophan metabolites exert biological activity toward cancer cells, including melanoma. Previous studies confirmed the functional relationship between PPAR and the kynurenine pathway in skeletal muscles. Despite the fact this interaction has not been reported in melanoma to date, some bioinformatics data and biological activity of PPAR ligands and tryptophan metabolites may suggest a potential involvement of these metabolic and signaling pathways in melanoma initiation, progression, and metastasis. Importantly, the possible relationship between the PPAR signaling pathway and the kynurenine pathway may relate not only to the direct biological effect on melanoma cells but also to the tumor microenvironment and the immune system.

An ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry identification and characterization of the active constituents from Abrus mollis Hance

Abrus mollis Hance is a traditional Chinese medicine that is widely used to treat acute and chronic hepatitis, steatosis, and fibrosis. Its therapeutic qualities of it have long been acknowledged, although the active ingredients responsible for its efficacy and the mechanisms of its action are unknown. In this study, the chemical constituents absorbed into the blood from Abrus mollis Hance were assessed by using liquid chromatography-quadrupole-time-of-flight mass spectrometry and the data was analyzed with the UNIFI screening platform. The results obtained were compared to existing chromatographic-mass spectrometry information, including retention times and molecular weights as well as known reference compounds. 41 chemical constituents were found in Abrus mollis Hance, and these included 16 flavonoids, 13 triterpenoids, five organic acids, and two alkaloids. Experimentally it was found that Abrus mollis Hance had a therapeutic benefit when treating α-naphthalene isothiocyanate-induced acute liver injury in rats. In addition, 11 blood prototypical constituents, including six flavonoids, three triterpenoids, and two alkaloids, were found in serum samples following intragastric administration of Abrus mollis Hance extracts to rats. This novel study can be used for the quality control and pharmacodynamic assessment of Abrus mollis Hance in order to assess its efficacy in the therapeutic treatment of patients.

Preparation and characterization of vaccarin, hypaphorine and chitosan nanoparticles and their promoting effects on chronic wounds healing

Chronic wounds have become an important factor hindering human health, affecting tens of millions of people worldwide, especially diabetic wounds. Based on the antibacterial properties of chitosan, the angiogenesis promoting effect of vaccarin (VAC) and the anti-inflammatory effect of hypaphorine (HYP), nanoparticles with high bioavailability were prepared. VAC, HYP and chitosan nanoparticles (VAC + HYP-NPS) were used to the treatment of chronic wounds. Transmission electron microscopy (TEM) images showed the nanoparticles were spherical. ZetaPALS showed the potential of nanoparticles were -12.8 ± 5.53 mV and the size were 166.8 ± 29.95 nm. Methyl thiazolyl tetrazolium (MTT) assay showed that VAC + HYP-NPS had no toxicity and the biocompatibility was satisfactory. In the treatment of chronic wounds in diabetic rats, VAC + HYP-NPS significantly promoted the re-epithelialization of chronic wounds and accelerated the healing of chronic wounds. In the process of chronic wounds healing, VAC + HYP-NPS played the antibacterial effect of chitosan, the angiogenic effect of VAC and the anti-inflammatory effect of HYP, and finally promoted the chronic wounds healing. Overall, the developed VAC + HYP-NPS have potential application in chronic wounds healing. In view of the complexity of the causes of chronic wounds, multi-target drug administration may be an effective way to treat chronic wounds.

The synergistic ameliorative activity of peroxisome proliferator-activated receptor-alpha and gamma agonists, fenofibrate and pioglitazone, on hippocampal neurodegeneration in a rat model of insulin resistance

Insulin resistance (IR) is a risk factor for metabolic disorders and neurodegeneration. Peroxisome proliferator-activated receptor (PPAR) agonists have been proven to mitigate the neuronal pathology associated with IR. However, the synergetic efficacy of these agonists is yet to be fully described. Hence, we aimed to investigate the efficacy of PPARα/γ agonists (fenofibrate and pioglitazone) on a high-fat diet (HFD) and streptozotocin (STZ)-induced hippocampal neurodegeneration. Male Wistar rats (200 ± 25 mg/body weight [BW]) were divided into five groups. The experimental groups were fed on an HFD for 12 weeks coupled with 5 days of an STZ injection (30 mg/kg/BW, i.p) to induce IR. Fenofibrate (FEN; 100 mg/kg/BW, orally), pioglitazone (PIO; 20 mg/kg/BW, orally), and their combination were administered for 2 weeks postinduction. Behavioral tests were conducted, and blood was collected to determine insulin sensitivity after treatment. Animals were killed for assessment of oxidative stress, cellular morphology characterization, and astrocytic evaluation. HFD/STZ-induced IR increased malondialdehyde (MDA) levels and decreased glutathione (GSH) levels. Evidence of cellular alterations and overexpression of astrocytic protein was observed in the hippocampus. By contrast, monotherapy of FEN and PIO increased the GSH level (p < 0.05), decreased the MDA level (p < 0.05), and improved cellular morphology and astrocytic expression. Furthermore, the combined treatment led to improved therapeutic activities compared to monotherapies. In conclusion, FEN and PIO exerted a therapeutic synergistic effect on HFD/STZ-induced IR in the hippocampus.

Peroxisome Proliferator-Activated Receptor Activation in Precision-Cut Bovine Liver Slices Reveals Novel Putative PPAR Targets in Periparturient Dairy Cows

Metabolic challenges experienced by dairy cows during the transition between pregnancy and lactation (also known as peripartum), are of considerable interest from a nutrigenomic perspective. The mobilization of large amounts of non-esterified fatty acids (NEFA) leads to an increase in NEFA uptake in the liver, the excess of which can cause hepatic accumulation of lipids and ultimately fatty liver. Interestingly, peripartum NEFA activate the Peroxisome Proliferator-activated Receptor (PPAR), a transcriptional regulator with known nutrigenomic properties. The study of PPAR activation in the liver of periparturient dairy cows is thus crucial; however, current in vitro models of the bovine liver are inadequate, and the isolation of primary hepatocytes is time consuming, resource intensive, and prone to errors, with the resulting cells losing characteristic phenotypical traits within hours. The objective of the current study was to evaluate the use of precision-cut liver slices (PCLS) from liver biopsies as a model for PPAR activation in periparturient dairy cows. Three primiparous Jersey cows were enrolled in the experiment, and PCLS from each were prepared prepartum (−8.0 ± 3.6 DIM) and postpartum (+7.7± 1.2 DIM) and treated independently with a variety of PPAR agonists and antagonists: the PPARα agonist WY-14643 and antagonist GW-6471; the PPARδ agonist GW-50156 and antagonist GSK-3787; and the PPARγ agonist rosiglitazone and antagonist GW-9662. Gene expression was assayed through RT-qPCR and RNAseq, and intracellular triacylglycerol (TAG) concentration was measured. PCLS obtained from postpartum cows and treated with a PPARγ agonist displayed upregulation of ACADVL and LIPC while those treated with PPARδ agonist had increased expression of LIPC, PPARD, and PDK4. In PCLS from prepartum cows, transcription of LIPC was increased by all PPAR agonists and NEFA. TAG concentration tended to be larger in tissue slices treated with PPARδ agonist compared to CTR. Use of PPAR isotype-specific antagonists in PCLS cultivated in autologous blood serum failed to decrease expression of PPAR targets, except for PDK4, which was confirmed to be a PPARδ target. Transcriptome sequencing revealed considerable differences in response to PPAR agonists at a false discovery rate-adjusted p-value of 0.2, with the most notable effects exerted by the PPARδ and PPARγ agonists. Differentially expressed genes were mainly related to pathways involved with lipid metabolism and the immune response. Among differentially expressed genes, a subset of 91 genes were identified as novel putative PPAR targets in the bovine liver, by cross-referencing our results with a publicly available dataset of predicted PPAR target genes, and supplementing our findings with prior literature. Our results provide important insights on the use of PCLS as a model for assaying PPAR activation in the periparturient dairy cow.

β‑aminoisobutyric acid ameliorates hypertensive vascular remodeling via activating the AMPK/SIRT1 pathway in VSMCs

Excessive proliferation and migration of vascular smooth muscle cells (VSMCs) play a fundamental role in the pathogenesis of hypertension-related vascular remodeling. β-aminoisobutyric acid (BAIBA) is a nonprotein β-amino acid with multiple pharmacological actions. Recently, BAIBA has been shown to attenuate salt‑sensitive hypertension, but the role of BAIBA in hypertension-related vascular remodeling has yet to be fully clarified. This study examined the potential roles and underlying mechanisms of BAIBA in VSMC proliferation and migration induced by hypertension. Primary VSMCs were cultured from the aortas of Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Our results showed that BAIBA pretreatment obviously alleviated the phenotypic transformation, proliferation, and migration of SHR-derived VSMCs. Exogenous BAIBA significantly inhibited the release of inflammatory cytokines by diminishing phosphorylation and nuclear translocation of p65 NFκB, retarding IκBα phosphorylation and degradation, as well as erasing STAT3 phosphorylation in VSMCs. Supplementation of BAIBA triggered Nrf2 dissociation from Keap1 and inhibited oxidative stress in VSMCs from SHR. Mechanistically, activation of the AMPK/sirtuin 1 (SIRT1) axis was required for BAIBA to cube hypertension-induced VSMC proliferation, migration, oxidative damage and inflammatory response. Most importantly, exogenous BAIBA alleviated hypertension, ameliorated vascular remodeling and fibrosis, abated vascular oxidative burst and inflammation in SHR, an effect that was abolished by deficiency of AMPKα1 and SIRT1. BAIBA might serve as a novel therapeutic agent to prevent vascular remodeling in the context of hypertension.

Metabolomic Profile of Different Dietary Patterns and Their Association with Frailty Index in Community-Dwelling Older Men and Women

Diet quality has been associated with slower rates of aging; however, the mechanisms underlying the role of a healthy diet in aging are not fully understood. To address this question, we aimed to identify plasma metabolomic biomarkers of dietary patterns and explored whether these metabolites mediate the relationship between diet and healthy aging, as assessed by the frailty index (FI) in 806 participants of the Baltimore Longitudinal Study of Aging. Adherence to different dietary patterns was evaluated using the Mediterranean diet score (MDS), Mediterranean-DASH Diet Intervention for Neurodegenerative Delay (MIND) score, and Alternate Healthy Eating Index-2010 (AHEI). Associations between diet, FI, and metabolites were assessed using linear regression models. Higher adherence to these dietary patterns was associated with lower FI. We found 236, 218, and 278 metabolites associated with the MDS, MIND, and AHEI, respectively, with 127 common metabolites, which included lipids, tri/di-glycerides, lyso/phosphatidylcholine, amino acids, bile acids, ceramides, cholesterol esters, fatty acids and acylcarnitines, indoles, and sphingomyelins. Metabolomic signatures of diet explained 28%, 37%, and 38% of the variance of the MDS, MIND, and AHEI, respectively. Signatures of MIND and AHEI mediated 55% and 61% of the association between each dietary pattern with FI, while the mediating effect of MDS signature was not statistically significant. The high number of metabolites associated with the different dietary patterns supports the notion of common mechanisms that underly the relationship between diet and frailty. The identification of multiple metabolite classes suggests that the effect of diet is complex and not mediated by any specific biomarkers. Furthermore, these metabolites may serve as biomarkers for poor diet quality to identify individuals for targeted dietary interventions.

Protective Effects of Abrus cantoniensis Hance on the Fatty Liver Hemorrhagic Syndrome in Laying Hens Based on Liver Metabolomics and Gut Microbiota

As a metabolic disease, fatty liver hemorrhagic syndrome (FLHS) has become a serious concern in laying hens worldwide. Abrus cantoniensis Hance (AC) is a commonly used plant in traditional medicine for liver disease treatment. Nevertheless, the effect and mechanism of the decoction of AC (ACD) on FLHS remain unclear. In this study, ultra-high performance liquid chromatography analysis was used to identify the main phytochemicals in ACD. FLHS model of laying hens was induced by a high-energy low-protein (HELP) diet, and ACD (0.5, 1, 2 g ACD/hen per day) was given to the hens in drinking water at the same time for 48 days. Biochemical blood indicators and histopathological analysis of the liver were detected and observed to evaluate the therapeutic effect of ACD. Moreover, the effects of ACD on liver metabolomics and gut microbiota in laying hens with FLHS were investigated. The results showed that four phytochemicals, including abrine, hypaphorine, vicenin-2, and schaftoside, were identified in ACD. ACD treatment ameliorated biochemical blood indicators in laying hens with FLHS by decreasing aspartate aminotransferase, alanine aminotransferase, triglycerides, low-density lipoprotein cholesterol, and total cholesterol, and increasing high-density lipoprotein cholesterol. In addition, lipid accumulation in the liver and pathological damages were relieved in ACD treatment groups. Moreover, distinct changes in liver metabolic profile after ACD treatment were observed, 17 endogenous liver metabolites mainly associated with the metabolism of arachidonic acid, histidine, tyrosine, and tryptophan were reversed by ACD. Gut microbiota analysis revealed that ACD treatment significantly increased bacterial richness (Chao 1, P < 0.05; Ace, P < 0.01), and upregulated the relative abundance of Bacteroidetes and downregulated Proteobacteria, improving the negative effects caused by HELP diet in laying hens. Taken together, ACD had a protective effect on FLHS by regulating blood lipids, reducing liver lipid accumulation, and improving the dysbiosis of liver metabolomics and gut microbiota.

An evaluation of maternal serum dynamic thiol-disulfide homeostasis and ischemia modified albumin changes in pregnant women with COVID-19

Objective:

It is thought that oxidative stress, free radicals, reactive oxygen species and reactive nitrogen species affect the pathophysiology of coronavirus disease-2019 (COVID-19). This study aimed to evaluate the oxidative status in pregnant patients with COVID-19 infection according to the changes seen in the levels of maternal serum thiol-disulfide and ischemia-modified albumin (IMA).

Materials and Methods:

A study group was formed of 40 pregnant women with confirmed COVID-19 infection (study group) and a control group of 40 healthy pregnant women with no risk factors determined. In this prospective, case-controlled study, analyses were made of the maternal serum native thiol, total thiol, disulfide, IMA, and disulfide/native thiol concentrations.

Results:

The maternal serum native thiol and total thiol concentrations in the study group were determined to be statistically significantly lower (p=0.007 and p=0.006, respectively), and the disulfide/native thiol ratio was higher but not to a level of statistical significance (p=0.473). There was no difference between the two groups regarding IMA levels (p=0.731).

Conclusion:

The thiol-disulfide balance was seen to shift in the oxidant direction in pregnancies with COVID-19, which might support the view that ischemic processes play a role in the etiopathogenesis of this novel disease.

Systematic Review of Potential Anticancerous Activities of Erythrina senegalensis DC (Fabaceae)

The objective of this study was to carry out a systematic review of the substances isolated from the African medicinal plant Erythrina senegalensis, focusing on compounds harboring activities against cancer models detailed in depth herein at both in vitro and in vivo preclinical levels. The review was conducted through Pubmed and Google Scholar. Nineteen out of the forty-two secondary metabolites isolated to date from E. senegalensis displayed interesting in vitro and/or in vivo antitumor activities. They belonged to alkaloid (Erysodine), triterpenes (Erythrodiol, maniladiol, oleanolic acid), prenylated isoflavonoids (senegalensin, erysenegalensein E, erysenegalensein M, alpinumisoflavone, derrone, warangalone), flavonoids (erythrisenegalone, senegalensein, lupinifolin, carpachromene) and pterocarpans (erybraedine A, erybraedine C, phaseollin). Among the isoflavonoids called "erysenegalensein", only erysenealenseins E and M have been tested for their anticancerous properties and turned out to be cytotoxic. Although the stem bark is the most frequently used part of the plant, all pterocarpans were isolated from roots and all alkaloids from seeds. The mechanisms of action of its metabolites include apoptosis, pyroptosis, autophagy and mitophagy via the modulation of cytoplasmic proteins, miRNA and enzymes involved in critical pathways deregulated in cancer. Alpinumisoflavone and oleanolic acid were studied in a broad spectrum of cancer models both in vitro and in preclinical models in vivo with promising results. Other metabolites, including carpachromen, phaseollin, erybraedin A, erysenegalensein M and maniladiol need to be further investigated, as they display potent in vitro effects.

Triggering Receptor Expressed on Myeloid Cells 2 Protects Dopaminergic Neurons by Promoting Autophagy in the Inflammatory Pathogenesis of Parkinson's Disease

Parkinson's disease is a neurodegenerative disorder with an inflammatory response as the core pathogenic mechanism. Previous human genetics findings support the view that the loss of TREM2 function will aggravate neurodegeneration, and TREM2 is one of the most highly expressed receptors in microglia. However, the role of TREM2 in the inflammatory mechanism of PD is not clear. In our study, it was found both in vivo and in vitro that the activation of microglia not only promoted the secretion of inflammatory factors but also decreased the level of TREM2 and inhibited the occurrence of autophagy. In contrast, an increase in the level of TREM2 decreased the expression of inflammatory factors and enhanced the level of autophagy through the p38 MAPK/mTOR pathway. Moreover, increased TREM2 expression significantly decreased the apoptosis of dopaminergic (DA) neurons and improved the motor ability of PD mice. In summary, TREM2 is an important link between the pathogenesis of PD and inflammation. Our study provides a new view for the mechanism of TREM2 in PD and reveals TREM2 as a potential therapeutic target for PD.

Preparation of W/O Hypaphorine-Chitosan Nanoparticles and Its Application on Promoting Chronic Wound Healing via Alleviating Inflammation Block

Chronic wound repair is a common complication in patients with diabetes mellitus, which causes a heavy burden on social medical resources and the economy. Hypaphorine (HYP) has good anti-inflammatory effect, and chitosan (CS) is used in the treatment of wounds because of its good antibacterial effect. The purpose of this research was to investigate the role and mechanism of HYP-nano-microspheres in the treatment of wounds for diabetic rats. The morphology of HYP-NPS was observed by transmission electron microscopy (TEM). RAW 264.7 macrophages were used to assess the bio-compatibility of HYP-NPS. A full-thickness dermal wound in a diabetic rat model was performed to evaluate the wound healing function of HYP-NPS. The results revealed that HYP-NPS nanoparticles were spherical with an average diameter of approximately 50 nm. The cell experiments hinted that HYP-NPS had the potential as a trauma material. The wound test in diabetic rats indicated that HYP-NPS fostered the healing of chronic wounds. The mechanism was through down-regulating the expression of pro-inflammatory cytokines IL-1β and TNF-α in the skin of the wound, and accelerating the transition of chronic wound from inflammation to tissue regeneration. These results indicate that HYP-NPS has a good application prospect in the treatment of chronic wounds.

Isobavachalcone ameliorates cognitive deficits, and Aβ and tau pathologies in triple-transgenic mice with Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that affects 50 million people worldwide. The current medicines have modest benefits in preventing or curing AD. Thus, it is urgent to discover drugs with the potential to change the progression of the disease. The primary clinical symptoms are memory loss and anxiety, while the critical pathological characteristics are Aβ plaques and hyperphosphorylated tau tangles. In this study, isobavachalcone (ISO), isolated from Psoralea corylifolia, was administered to 3×Tg-AD mice. It has been shown that this compound could significantly improve anxiety, memory and recognition deficits in the AD mice, attenuate the accumulation of Aβ oligomers, reduce the hyperphosphorylation of tau, and prevent the production of tau filaments. The metabolomic analysis implicates that the most probable pathways affected by ISO were bile secretion, tyrosine metabolism, and purine metabolism. In summary, ISO possesses the potential for further development as a drug candidate for AD.

Hypaphorine exerts anti-inflammatory effects in sepsis induced acute lung injury via modulating DUSP1/p38/JNK pathway

Sepsis is a systemic inflammatory response syndrome attributed to infection, while sepsis-induced acute lung injury (ALI) has high morbidity and mortality. Here, we aimed to explore the specific mechanism of hypaphorine's anti-inflammatory effects in ALI. Lipopolysaccharide (LPS) was adopted to construct ALI model both in vivo and in vitro. BEAS-2B cell viability and apoptosis was testified by the MTT assay and flow cytometry. Reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) were performed to examine the expression of proinflammatory cytokines (IL-1β, IL-6, TNF-α, and IL-18), and Western blot was adopted to examine the expression of the apoptosis-related proteins (Bax, Bcl2, and Caspase3) and the DUSP1/p38/JNK signaling pathway. At the same time, lung injury score, lactate dehydrogenase (LDH) and myeloperoxidase (MPO) activity were monitored. The dry/wet weight method was used to examine lung edema, and the total protein content in BALF was determined to test pulmonary vascular permeability. As the data suggested, hypaphorine inhibited the LPS-mediated apoptosis of alveolar epithelial cells. What is more, hypaphorine attenuated the expression of inflammatory factors (IL-1β, IL-6, TNF-α, and IL-18) and inactivated the p38/JNK signaling pathway through upregulating DUSP1 in a dose-dependent manner. Meanwhile, DUSP1 knockdown weakened the anti-inflammatory effect of hypaphorine on LPS-mediated lung injury. Furthermore, hypaphorine also relieved LPS induced ALI in rats with anti-inflammatory effects. Taken together, hypaphorine prevented LPS-mediated ALI and proinflammatory response via inactivating the p38/JNK signaling pathway by upregulating DUSP1.

Inhibitory Effects of Isobavachalcone on Tau Protein Aggregation, Tau Phosphorylation, and Oligomeric Tau-Induced Apoptosis

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases without any effective medicine treatments. The neurofibrillary tangles containing hyperphosphorylated tau protein are one important pathological characteristic. Thus, one practicable strategy for AD drug design is to discover compounds that could inhibit tau protein aggregation and/or phosphorylation. In this study, isobavachalcone, a natural plant-derived compound, has been shown to inhibit tau protein aggregation and disaggregate tau fibrils in vitro by directly interacting with tau protein at amino acids I278, V309, etc. It is able to reduce tau phosphorylation at four disease-related sites in vivo by regulating the critical kinase and protein phosphatase, GSK3β and PP2A. The compound also exhibits protection against tau oligomers-induced apoptosis through the mitochondria and ER mediated apoptotic pathways. In summary, isobavachalcone is a promising candidate for further evaluation as a potential preventive and therapeutic medicine for AD.

The Effects of Pro-Inflammatory and Anti-Inflammatory Agents for the Suppression of Intimal Hyperplasia: An Evidence-Based Review

Anti-atherogenic therapy is crucial in halting the progression of inflammation-induced intimal hyperplasia. The aim of this concise review was to methodically assess the recent findings of the different approaches, mainly on the recruitment of chemokines and/or cytokine and its effects in combating the intimal hyperplasia caused by various risk factors. Pubmed and Scopus databases were searched, followed by article selection based on pre-set inclusion and exclusion criteria. The combination of keywords used were monocyte chemoattractant protein-1 OR MCP-1 OR TNF-alpha OR TNF-α AND hyperplasia OR intimal hyperplasia OR neointimal hyperplasia AND in vitro. These keywords combination was incorporated in the study and had successfully identified 77 articles, with 22 articles were acquired from Pubmed, whereas 55 articles were obtained from Scopus. However, after title screening, only twelve articles meet the requirements of defined inclusion criteria. We classified the data into 4 different approaches, i.e., utilisation of natural product, genetic manipulation and protein inhibition, targeted drugs in clinical setting, and chemokine and cytokines induction. Most of the articles are working on genetic manipulation targeted on specific pathway to inhibit the pro-inflammatory factors expression. We also found that the utilisation of chemokine- and cytokine-related treatments are emerging throughout the years. However, there is no study utilising the combination of approaches that might give a better outcome in combating intimal hyperplasia. Hopefully, this concise review will provide an insight regarding the usage of different novel approaches in halting the progression of intimal hyperplasia, which serves as a key factor for the development of atherosclerosis in cardiovascular disease.

Modulation of the Innate Immune Response by Targeting Toll-like Receptors: A Perspective on Their Agonists and Antagonists

Toll-like receptors (TLRs) are a class of proteins that recognize pathogen-associated molecular patterns (PAMPs) and damaged-associated molecular patterns (DAMPs), and they are involved in the regulation of innate immune system. These transmembrane receptors, localized at the cellular or endosomal membrane, trigger inflammatory processes through either myeloid differentiation primary response 88 (MyD88) or TIR-domain-containing adapter-inducing interferon-β (TRIF) signaling pathways. In the last decades, extensive research has been performed on TLR modulators and their therapeutic implication under several pathological conditions, spanning from infections to cancer, from metabolic disorders to neurodegeneration and autoimmune diseases. This Perspective will highlight the recent discoveries in this field, emphasizing the role of TLRs in different diseases and the therapeutic effect of their natural and synthetic modulators, and it will discuss insights for the future exploitation of TLR modulators in human health.

The Role of Toll-like Receptors in Atherothrombotic Cardiovascular Disease

Toll-like receptors (TLRs) are dominant components of the innate immune system. Activated by both pathogen-associated molecular patterns and damage-associated molecular patterns, TLRs underpin the pathology of numerous inflammation related diseases that include not only immune diseases, but also cardiovascular disease (CVD), diabetes, obesity, and cancers. Growing evidence has demonstrated that TLRs are involved in multiple cardiovascular pathophysiologies, such as atherosclerosis and hypertension. Specifically, a trial called the Canakinumab Anti-inflammatory Thrombosis Outcomes Study showed the use of an antibody that neutralizes interleukin-1β, reduces the recurrence of cardiovascular events, demonstrating inflammation as a therapeutic target and also the research value of targeting the TLR system in CVD. In this review, we provide an update of the interplay between TLR signaling, inflammatory mediators, and atherothrombosis, with an aim to identify new therapeutic targets for atherothrombotic CVD.

Dehydroabietic acid alleviates high fat diet-induced insulin resistance and hepatic steatosis through dual activation of PPAR-γ and PPAR-α

Dual-PPAR-α/γ agonist has the dual potentials to improve insulin resistance (IR) and hepatic steatosis associated with obesity. This study aimed to investigate whether dehydroabietic acid (DA), a naturally occurred compound, can bind to and activate both PPAR-γ and PPAR-α to ameliorate IR and hepatic steatosis in high-fat diet (HFD)-fed mice.. We found that DA formed stable hydrogen bonds with the ligand-binding domains of PPAR-γ and PPAR-α. DA treatment also promoted 3T3-L1 differentiation via PPAR-γ activation, and mitochondrial oxygen consumption in HL7702 cells via PPAR-α activation. In HFD-fed mice, DA treatment alleviated glucose intolerance and IR, and reduced hepatic steatosis, liver injury markers (ALT, AST), and lipid accumulation, and promoted mRNA expression of PPAR-γ and PPAR-α signaling elements involved in IR and lipid metabolism in vivo and in vitro, and inhibited mRNA expression of pro-inflammatory factors. Therefore, DA is a dual-PPAR-α/γ and PPAR-γ partial agonist, which can attenuate IR and hepatic steatosis induced by HFD-consumption in mice.

Cinnamaldehyde Inhibits Inflammation of Human Synoviocyte Cells Through Regulation of Jak/Stat Pathway and Ameliorates Collagen-Induced Arthritis in Rats

Cinnamaldehyde (Cin), a bioactive cinnamon essential oil from traditional Chinese medicine herb Cinnamomum cassia, has been reported to have multipharmacological activities including anti-inflammation. However, its role and molecular mechanism of anti-inflammatory activity in musculoskeletal tissues remains unclear. Here, we first investigated the effects and molecular mechanisms of Cin in human synoviocyte cells. Then in vivo therapeutic effect of Cin on collagen-induced arthritis (CIA) also studied. Cell Counting Kit ‎CCK-8 assay was performed to evaluate the cell cytotoxicity. Proinflammatory cytokine expression was evaluated using quantitative polymerase chain reaction and ELISA. Protein expression was measured by western blotting. The in vivo effect of Cin (75 mg/kg per day) was evaluated in rats with CIA by gavage administration. Disease progression was assessed by clinical scoring, radiographic, and histologic examinations. Cin significantly inhibited interleukin (IL)-1β-induced IL-6, IL-8, and tumor necrosis factor-α release from human synoviocyte cells. The molecular analysis revealed that Cin impaired IL-6-induced activation of Janus kinase 2 (JAK2), signal transducer and activator of transcription 1 (STAT1), and STAT3 signaling pathway by inhibiting the phosphorylation of JAK2, STAT1, and STAT3, without affecting NF-κB pathway. Cin reduced collagen-induced swollen paw volume of arthritic rats. The anti-inflammation effects of Cin were associated with decreased severity of arthritis, joint swelling, and reduced bone erosion and destruction. Furthermore, serum IL-6 level was decreased when Cin administered therapeutically to CIA rats. Cin suppresses IL-1β-induced inflammation in synoviocytes through the JAK/STAT pathway and alleviated collagen-induced arthritis in rats. These data indicated that Cin might be a potential traditional Chinese medicine-derived, disease-modifying, antirheumatic herbal drug. SIGNIFICANCE STATEMENT: In this study, we found that cinnamaldehyde (Cin) suppressed proinflammatory cytokines secretion in rheumatology arthritis synoviocyte cells by Janus kinase/signal transducer and activator of transcription pathway. The in vivo results showed that Cin ameliorated collagen-induced arthritis in rats. These findings indicate that Cin is a potential traditional Chinese medicine-derived, disease-modifying, antirheumatic herbal drug.

Activation of STAT3 is a key event in TLR4 signaling-mediated melanoma progression

Malignant melanoma is aggressive and has a high mortality rate. Toll-like receptor 4 (TLR4) has been linked to melanoma growth, angiogenesis and metastasis. However, signal transduction mediated by TLR4 for driving melanoma progression is not fully understood. Signal transducer and activator of transcription 3 (STAT3) has been identified as a major oncogene in melanoma progression. We found: that TLR4 expression positively correlates with activation/phosphorylation of STAT3 in human melanoma samples; that TLR4 ligands activate STAT3 through MYD88 and TRIF in melanoma cells; and that intratumoral activation of TLR4 increases STAT3 activation in the tumor and promotes tumor growth, angiogenesis, epithelial-mesenchymal transition (EMT) and the formation of an immunosuppressive tumor microenvironment in mice. Further, we found that the effects mediated by activating TLR4 are weakened by suppressing STAT3 function with a dominant negative STAT3 variant in melanoma. Collectively, our work identifies STAT3 activation as a key event in TLR4 signaling-mediated melanoma progression, shedding new light on the pathophysiology of melanoma.

Magnolol alleviates Alzheimer's disease-like pathology in transgenic C. elegans by promoting microglia phagocytosis and the degradation of beta-amyloid through activation of PPAR-γ

This study aims to investigate whether magnolol (MG), a natural neolignane compound, can prevent AD induced by beta-amyloid (Aβ) and the possible mechanisms involved. MG dose-dependently reduces Aβ deposition, toxicity and memory impairment caused by Aβ in transgenic C. elegans. More importantly, these effects are reversed by GW9662, a selective peroxisome proliferator-activated receptor-γ (PPAR-γ) antagonist. MG is more effective in enhancing PPAR-γ luciferase levels than honokiol (HK). Meanwhile, MG has the potential to bind with the ligand binding domain of PPAR-γ (PPAR-γ-LBD). As expected, MG inhibited the luciferase activity of NF-κB and its target genes of inflammatory cytokines, and this effect was blocked by GW9662. The luciferase activity of Nrf2-ARE expression can be activated by MG and decreased Aβ-induced reactive oxygen species (ROS). The target gene LXR of PPAR-γ is activated by MG, which upregulates ApoE and promotes microglia phagocytosis and the degradation of Aβ, and these effects were also reversed by GW9662. In summary, MG can attenuate Aβ-induced AD and the underlying mechanism is the reduction of inflammation and promotion of phagocytosis and degradation of Aβ, which is dependent on PPAR-γ.

Exploration of the Molecular Mechanism of FUZI (Aconiti Lateralis Radix Praeparata) in Allergic Rhinitis Treatment Based on Network Pharmacology

FUZI (Aconiti Lateralis Radix Praeparata) is a traditional Chinese medicine herb used extensively for nourishing yang (regarded as the positive, male universal force), which is critical in treatment of allergic rhinitis. In this paper, FUZI was explored based on network pharmacology. The active components of FUZI were screened out, its protein targets were assessed, and the protein interaction network map was built with the differential protein of allergic rhinitis, as an attempt to determine the critical targets of FUZI for treating allergic rhinitis. Subsequently, DAVID was employed to explore the biological function and pathway enrichment to determine the biological pathway of FUZI for treating allergic rhinitis.

As suggested by the results, FUZI is likely to affect the inhibition of inflammation and the regulation of immunity, probably reducing the incidence of allergic rhinitis, or alleviating nasal discomfort attributed to allergic inflammation. The targets and pathways of FUZI for treating allergic rhinitis assessed by network pharmacology provided a direction for our subsequent studies and may be a novel therapeutic target.

The ethanolic extract from Erythrina mulungu Benth. flowers attenuates allergic airway inflammation and hyperresponsiveness in a murine model of asthma

ETHNOPHARMACOLOGICAL RELEVANCE

Erythrina mulungu Benth. ("mulungu", Fabaceae) is a Brazilian native species with ethnopharmacological use for respiratory diseases. However, the effects of E. mulungu on the respiratory were never studied.

AIMS OF THE STUDY

To evaluate the effects of an ethanolic extract from flowers of E. mulungu in ovalbumin (OVA)-induced asthma in mice, and to study the mechanisms involved.

MATERIALS AND METHODS

OVA-sensitized mice were intraperitoneally (i.p.) treated with four doses (200, 400, 600, and 800 mg/kg) of the E. mulungu extract or dexamethasone (DEXA, 2 mg/kg) during seven consecutive days and simultaneously challenged with intranasal OVA. Bronchial hyperresponsiveness was evaluated in vivo, 24 h after the last OVA challenge. Bronchoalveolar lavage (BAL) was collected for counting the number of total and differential inflammatory cells. Blood was collected for measurement of anti-OVA IgE levels. Levels of cytokines interleukin (IL)- 4, IL-5, IL-10, IL-13, and interferon (INF)-γ were measured in pulmonary homogenate by ELISA. The recruitment of inflammatory cells to the lung tissue was determined using hematoxylin and eosin staining (H&E). The extract's chromatographic profile was evaluated by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS).

RESULTS

The treatment with E. mulungu extract significantly reduced bronchial hyperresponsiveness, significantly reduced the number of leukocytes, eosinophils, and lymphocytes in BAL, and significantly decreased the levels of IL-4 and IL-5, while increased levels of IL-13 and INF-γ. In addition, E. mulungu significantly decreased the cellular inflammatory infiltration in the lung tissue. Erysotrine, erysotrine-N-oxide, and hypaphorine were the major constituents identified in the extract.

CONCLUSION

Collectively, these results confirm the potential of E. mulungu for asthma treatment, through modulation of inflammatory response, supporting its ethnopharmacological use for respiratory diseases.

Carnosine Decreases PMA-Induced Oxidative Stress and Inflammation in Murine Macrophages

Carnosine is an endogenous dipeptide composed of β-alanine and L-histidine. This naturally occurring molecule is present at high concentrations in several mammalian excitable tissues such as muscles and brain, while it can be found at low concentrations in a few invertebrates. Carnosine has been shown to be involved in different cellular defense mechanisms including the inhibition of protein cross-linking, reactive oxygen and nitrogen species detoxification as well as the counteraction of inflammation. As a part of the immune response, macrophages are the primary cell type that is activated. These cells play a crucial role in many diseases associated with oxidative stress and inflammation, including atherosclerosis, diabetes, and neurodegenerative diseases. In the present study, carnosine was first tested for its ability to counteract oxidative stress. In our experimental model, represented by RAW 264.7 macrophages challenged with phorbol 12-myristate 13-acetate (PMA) and superoxide dismutase (SOD) inhibitors, carnosine was able to decrease the intracellular concentration of superoxide anions (O2-•) as well as the expression of Nox1 and Nox2 enzyme genes. This carnosine antioxidant activity was accompanied by the attenuation of the PMA-induced Akt phosphorylation, the down-regulation of TNF-α and IL-6 mRNAs, and the up-regulation of the expression of the anti-inflammatory mediators IL-4, IL-10, and TGF-β1. Additionally, when carnosine was used at the highest dose (20 mM), there was a generalized amelioration of the macrophage energy state, evaluated through the increase both in the total nucleoside triphosphate concentrations and the sum of the pool of intracellular nicotinic coenzymes. Finally, carnosine was able to decrease the oxidized (NADP+)/reduced (NADPH) ratio of nicotinamide adenine dinucleotide phosphate in a concentration dependent manner, indicating a strong inhibitory effect of this molecule towards the main source of reactive oxygen species in macrophages. Our data suggest a multimodal mechanism of action of carnosine underlying its beneficial effects on macrophage cells under oxidative stress and inflammation conditions.

The effect of fenofibrate, a PPARα activator on toll-like receptor-4 signal transduction in melanoma both in vitro and in vivo

BACKGROUND

The anti-cancer effect of peroxisome proliferator-activated receptor (PPAR) α ligands on growth and metastatic potential of melanoma cells has been shown previously. However, the mechanism underlying these effects remains to be elucidated. Here, we investigated the effects of fenofibrate (PPAR ligand) on Toll-like receptor-4 (TLR-4) signaling in mice melanoma.

METHODS

Mice melanoma cells (B16F10) were treated with fenofibrate or LPS or LPS + fenofibrate or pre-treated with CLI-095 (a TLR4 inhibitor), followed by fenofibrate. In in vivo model, C57BL/6 mice were subcutaneously injected with B16F10 cells (with/without LPS pre-treatment), and fenofibrate was administrated after development of palpable tumors. Cell proliferation, the expression level of Tlr4, Myd88, Nf-κb1 genes, TLR-4 protein expression, TNF-α levels, and tumor volume were measured.

RESULT

Our results indicated that fenofibrate significantly inhibited the Tlr-4, Myd-88, and Nf-kb1 mRNA expression and TNF-α concentration in B16F10 LPS-stimulated cells. In addition, blocking TLR-4 signaling increased the anti-inflammatory potential of fenofibrate. Also fenofibrate can reduce LPS-induced tumor volume, Tlr-4, Myd-88, Nf-kb1 mRNA, and TLR-4 protein expression in tumor tissue and also TNF-α level in tumor tissue lysate.

CONCLUSION

Our data indicate that fenofibrate may exert its anti-melanoma effects via interaction with TLR4-dependent signaling pathway (TLR-4/MyD-88/ NF-kB).

Galectin-3 deficiency protects lipopolysaccharide-induced chondrocytes injury via regulation of TLR4 and PPAR-γ-mediated NF-κB signaling pathway

The aim of the present study was to identify the functional role of galectin-3 (Gal-3) in lipopolysaccharide (LPS)-induced injury in ATDC5 cells and to explore the probable molecular mechanisms. Here, we identified that LPS is sufficient to enhance the expression of Gal-3 in ATDC5 cells. In addition, repression of Gal-3 obviously impeded LPS-stimulated inflammation damage as exemplified by a reduction in the release of inflammatory mediators interleukin (IL)-1β, IL-6, and tumor necrosis factor-α, as well as the production of nitric oxide and prostaglandin E2 (PGE2) concomitant with the downregulation of matrix metalloproteinases (MMP)-13 and MMP-3 expression in ATDC5 cells after LPS administration. Moreover, ablation of Gal-3 dramatically augmented cell ability and attenuated cell apoptosis accompanied by an increase in the expression of antiapoptotic protein Bcl-2 and a decrease in the expression of proapoptotic protein Bax and caspase-3 in ATDC5 cells subjected with LPS. Importantly, we observed that forced expression of TLR4 or blocked PPAR-γ with the antagonist GW9662 effectively abolished Gal-3 inhibition-mediated anti-inflammatory and antiapoptosis effects triggered by LPS. Mechanistically, depletion of Gal-3 prevents the NF-κB signaling pathway. Taken together, these findings indicated that the absence of Gal-3 exerted chondroprotective properties dependent on TLR4 and PPAR-γ-mediated NF-κB signaling, indicating that Gal-3 functions as a protector in the development and progression of osteoarthritis.

Death-associated protein kinase 3 deficiency alleviates vascular calcification via AMPK-mediated inhibition of endoplasmic reticulum stress

Vascular calcification (VC) is a critical feature of chronic kidney disease (CKD), diabetes, hypertension, and atherosclerosis. Death-associated protein kinase 3 (DAPK3) is involved in vascular remodeling in hypertension. However, it remains to be clarified whether DAPK3 controls vascular smooth muscle cell (VSMC) phenotypic transition into an osteogenic cell phenotype, which is an important process for VC. In vivo VC was induced in rats by vitamin D3 and nicotine. VSMCs were incubated with calcifying media containing β-glycerophosphate and Ca²⁺ to induce VC in vitro. Herein, we demonstrated increased expression of DAPK3 in the aortas of VC rats and VSMCs cultured in calcifying media. Knockdown of DAPK3 significantly inhibited calcifying media-induced VSMC mineralization and retarded the phenotypic transformation of VSMCs into osteogenic cells. Silencing of DAPK3 suppressed endoplasmic reticulum stress (ERS) related protein expressions, but upregulated the phosphorylation level of AMP-activated protein kinase (AMPK) in calcified VSMCs. Moreover, pretreatment with AMPK inhibitor Compound C abolished DAPK3 shRNA-mediated inhibition of ERS in VSMCs. In vivo, DAPK inhibitor significantly prevented calcium deposition in the aortas of VC rats. The present results revealed that DAPK3 modulated VSMC calcification through AMPK-mediated ERS signaling.

Crosstalk between Peroxisome Proliferator-Activated Receptors and Toll-Like Receptors: A Systematic Review

As one of the four major families of pattern recognition receptors (PRRs), toll like receptors (TLRs) are crucial and important components of the innate immune system. Peroxisome proliferatoractivated receptors (PPARs) with three isoforms are transcription factors classified as a subfamily of nuclear receptor proteins, and are of significant regulatory activity in cellular differentiation, development, metabolism, and tumorigenesis. It is well established that PPARs agonists display anti-inflammatory effects through inhibition of the nuclear factor-kappa B (NF-κB) pathway, a key regulator of immune and inflammatory responses, in a sense that TLRs signaling pathways are mainly toward activation of NF-κB. Through a systematic review of previous studies, we aimed to address and clarify the reciprocal interaction between TLRs and PPARs in hope to find alternative therapeutic approaches for inflammatory diseases. Among the available scientific database, 31 articles were selected for this review. A comprehensive review of this database confirms the presence of a cross-talk between PPARs and TLRs, indicating that not only PPARs stimulation may affect the expression level of TLRs via several mechanisms leading to modulating TLRs activities, but also TLRs have the potential to moderate the expression of PPARs. We, therefore, conclude that, as a key regulator of the innate immune system, the interaction between PPARs and TLRs is a potential therapeutic target in disease treatment.

MicroRNA-9-5p promotes angiogenesis but inhibits apoptosis and inflammation of high glucose-induced injury in human umbilical vascular endothelial cells by targeting CXCR4

High glucose (HG) has the potential to cause vascular endothelial cell injury, while microRNAs (miRNAs) play a key role in treating endothelial cell injury. CXC chemokine receptor-4 (CXCR4) is reported to be expressed in vascular endothelial cells. Hence, this study investigated role of miR-9-5p in the angiogenesis and apoptosis of HG-induced human umbilical vascular endothelial cells (HUVECs) injury. Dual luciferase reporter gene assay verified that miR-9-5p targeted CXCR4. RT-qPCR and western blot analysis revealed that miR-9-5p was down-regulated, meanwhile CXCR4 was up-regulated in the HG-induced HUVECs. HUVECs were cultured in 30 mmol/L HG in vitro, and then transfected with miR-9-5p mimic or CXCR4 siRNA to identify the effect of miR-9-5p on cell activity, angiogenesis, apoptosis, and inflammation of HG-induced HUVECs. The results suggested that overexpression of miR-9-5p or silencing of CXCR4 in HG-induced HUVECs increased cell proliferation and tubule length, while decreasing the apoptosis rate and the expression of inflammatory factors. Furthermore, miR-9-5p inhibited the phosphorylation of extracellular regulated protein kinases (ERK), protein kinase B (AKT), and Mammalian Target of Rapamycin (mTOR) proteins via downregulation of CXCR4. Therefore, overexpression of miR-9-5p suppressed the mitogen-activated protein kinase (MAPK)/ERK and the PI3K/AKT/mTOR pathway by inhibiting CXCR4, thereby reducing HG-induced injury in HUVECs.

Minimally modified low-density lipoprotein upregulates the ETB and α1 receptors in mouse mesenteric arteries in vivo by activating the PI3K/Akt pathway

OBJECTIVES

The current study aimed to explore whether minimally modified low-density lipoprotein (mmLDL) via tail vein injection upregulates the ET_B and α₁ receptors in mouse mesenteric arteries by activating the PI3K/Akt pathway.

METHODS

The contraction curves of the mesenteric arteries caused by sarafotoxin 6c (S6c, ET_B receptor agonist) and phenylephrine (PE, α₁ receptor agonist) were measured by a myograph system. Serum oxLDL was detected using enzyme-linked immunosorbent assays. The levels of the ET_B receptor, the α₁ receptor, PI3K, p-PI3K and p-Akt were detected using real-time polymerase chain reaction and Western blot analyses.

KEY FINDINGS

Minimally modified low-density lipoprotein noticeably enhanced the contraction effect curves of S6c and PE, with significantly increased E_max values (P < 0.01), compared to those of the control group. This treatment significantly increased the mRNA expression and protein levels of the ET_B and α₁ receptors and the protein levels of p-PI3K and p-Akt in the vessel wall (P < 0.01). LY294002 inhibited the effect of mmLDL.

CONCLUSIONS

An increase in mmLDL activated the PI3K/Akt pathway, which upregulated the expression of the ET_B and α₁ receptors and enhanced the ET_B and α_1- receptor-mediated contractile function.