Targeting Therapeutic Windows for Rheumatoid Arthritis Prevention.

Rheumatoid arthritis (RA) is a worldwide public health problem. Interventions to delay or prevent the onset of RA have attracted much attention in recent years, and researchers are now exploring various prevention strategies. At present, there is still no unified consensus for RA prevention, but targeting therapeutic windows and implementing interventions for at-risk individuals are extremely important. Due to the limited number of clinical trials on pharmacologic interventions, further studies are needed to explore and establish optimal intervention regimens and effective measures to prevent progression to RA. In this review, we introduce the RA disease process and risk factors, and present research on the use of both Western and Chinese medicine from clinical perspectives regarding RA prevention. Furthermore, we describe several complete and ongoing clinical studies on the use of Chinese herbal formulae for the prevention of RA.

In silico analysis of serum miRNA profiles in seronegative and seropositive rheumatoid arthritis patients by small RNA sequencing.

Rheumatoid arthritis (RA) is a refractory autoimmune disease, affecting about 1% of the world's population. RA is divided into seronegative RA and seropositive RA. However, biomarkers for discriminating between seronegative and seropositive RA have not been reported. In this study, we profiled serum miRNAs in seronegative RA patients (N-RA), seropositive RA patients (P-RA) and healthy controls (HC) by small RNA sequencing. Results indicated that compared with HC group, there were one up-regulated and four downregulated miRNAs in N-RA group (fold change ≥ 2 and P value < 0.05); compared with P-RA group, there were two up-regulated and four downregulated miRNAs in N-RA group; compared with HC group, there were three up-regulated and four downregulated miRNAs in P-RA group. Among them, the level of hsa-miR-362-5p in N-RA group was up-regulated compared with that in HC group and P-RA group, and the level of hsa-miR-6855-5p and hsa-miR-187-3p in P-RA group was upregulated compared with that in N-RA group and HC group. Validation by qPCR confirmed that serum hsa-miR-362-5p level was elevated in N-RA group. Subsequently, by analyzing the target genes using RNAhybrid, PITA, Miranda and TargetScan and functions of differential miRNAs utilizing Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), we found that the target genes and molecular pathways regulated by miRNAs in seronegative RA and seropositive RA were roughly the same, and miRNAs in these two diseases may participate in the occurrence and development of diseases by regulating the immune system. In conclusion, this study revealed the profiles of serum miRNAs in seronegative and seropositive RA patients for the first time, providing potential biomarkers and targets for the diagnosis and treatment of seronegative and seropositive RA.

Deciphering the mechanism of PSORI-CM02 in suppressing keratinocyte proliferation through the mTOR/HK2/glycolysis axis.

Hyperplasia of epidermal keratinocytes that depend on glycolysis is a new hallmark of psoriasis pathogenesis. Our previous studies demonstrated that PSORI-CM02 could halt the pathological progression of psoriasis by targeting inflammatory response and angiogenesis, but its effect(s) and mechanism(s) on proliferating keratinocytes remained unclear. In this study, we aim to identify components of PSORI-CM02 that are absorbed into the blood and to determine the effect(s) of PSORI-CM02 on keratinocyte proliferation and its molecular mechanism(s). We used the immortalized human epidermal keratinocyte cell line, HaCaT, as an in vitro model of proliferating keratinocytes and the imiquimod-induced psoriasis mouse (IMQ) as an in vivo model. Metabolite profiles of vehicle pharmaceutic serum (VPS), PSORI-CM02 pharmaceutic serum (PPS), and water extraction (PWE) were compared, and 23 components of PSORI-CM02 were identified that were absorbed into the blood of mice. Both PPS and PWE inhibited the proliferation of HaCaT cells and consequently reduced the expression of the proliferation marker ki67. Additionally, PPS and PWE reduced phosphorylation levels of mTOR pathway kinases. Seahorse experiments demonstrated that PPS significantly inhibited glycolysis, glycolytic capacity, and mitochondrial respiration, thus reducing ATP production in HaCaT cells. Upon treatments of PPS or PWE, hexokinase 2 (HK2) expression was significantly decreased, as observed from the set of glycolytic genes we screened. Finally, in the IMQ model, we observed that treatment with PSORI-CM02 or BPTES, an inhibitor of mTOR signaling, reduced hyperproliferation of epidermal keratinocytes, inhibited the expression of p-S6 and reduced the number of proliferating cell nuclear antigen (PCNA)-positive cells in lesioned skin. Taken together, we demonstrate that PSORI-CM02 has an anti-proliferative effect on psoriatic keratinocytes, at least in part, by inhibiting the mTOR/HK2/glycolysis axis.

Single-Cell Analysis in Blood Reveals Distinct Immune Cell Profiles in Gouty Arthritis.

Gout is a chronic disease caused by monosodium urate crystal deposition. Previous studies have focused on the resident macrophage, infiltrating monocyte, and neutrophil responses to monosodium urate crystal, yet the mechanisms of the potential involvement of other immune cells remain largely unknown. In this study, we enrolled seven gout patients and five age-matched healthy individuals and applied single-cell mass cytometry to study the distribution of immune cell subsets in peripheral blood. To our knowledge, our study reveals the immune cell profiles of gout at different stages for the first time. We identified many immune cell subsets that are dysregulated in gout and promote gouty inflammation, especially those highly expressing CCR4 and OX40 (TNFR superfamily member 4), including CCR4+OX40+ monocytes, CCR4+OX40+CD56high NK cells, CCR4+OX40+CD4+ NK T cells, and CCR4+CD38+CD4+ naïve T cells. Notably, the plasma levels of CCL17 and CCL22, measured by ELISA, increased in the acute phase of gout and declined in the interval. We also found a clue that Th2-type immune responses may participate in gout pathology. Moreover, the subset of granzyme B+ (GZMB+) CD38+ NK cells is positively correlated with serum urea acid level, and another two γδT subsets, GZMB+CD161+ γδT cells and GZMB+CCR5+ γδT cells, are negatively correlated with erythrocyte sedimentation rate. In sum, gouty arthritis is not a disease simply mediated by macrophages; multiple types of immune cell may be involved in the pathogenesis of the disease. Future research needs to shift attention to other immune cell subsets, such as NK cells and T cells, which will facilitate the identification of novel therapeutic targets.

Chinese Herbal Formula Huayu-Qiangshen-Tongbi Decoction Attenuates Rheumatoid Arthritis through Upregulating miR-125b to Suppress NF-κB-Induced Inflammation by Targeting CK2.

The Huayu-Qiangshen-Tongbi (HQT) decoction, a Chinese medical formula, has been identified to show a potent therapeutic effect on rheumatoid arthritis (RA). However, the specific molecular mechanism of HQT in RA has not been well studied. In the present study, LPS-treated human rheumatoid fibroblast-like synoviocyte (FLS) MH7A cells and collagen-induced arthritis (CIA) mice were utilized as in vitro and in vivo models. Our results demonstrated that HQT could efficiently inhibit RA-induced inflammation by reducing the production of cytokines including tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1ß), and interleukin-6 (IL-6). Moreover, HQT significantly upregulated the expression of miR-125b. Besides, analysis of bioinformatics suggested casein kinase 2 (CK2) was a potential target of miR-125b. Luciferase reporter assay was performed and revealed that miR-125b suppressed CK2 expression in MH7A cells. Furthermore, miR-125b inhibited LPS-induced NF-kappa-B (NF-κB) activation, which is a downstream target of CK2. In addition, the NF-κB inhibitor ammonium pyrrolidinedithiocarbamate (PDTC) and NF-kappa-B inhibitor alpha (IkB-α) enhanced the inhibitory effect of miR-125b on the expression of TNF-α, IL-1ß, and IL-6. Taken together, our study revealed that HQT could attenuate RA through upregulating miR-125b to suppress NF-κB-induced inflammation by targeting CK2. The findings of this study should facilitate investigating the mechanism of HQT on RA and discovering novel therapeutic targets for RA.

Sustained Drug Treatment Alters the Gut Microbiota in Rheumatoid Arthritis.

Several studies have investigated the causative role of the microbiome in the development of rheumatoid arthritis (RA), but changes in the gut microbiome in RA patients during drug treatment have been less well studied. Here, we tracked the longitudinal changes in gut bacteria in 22 RA patients who were randomized into two groups and treated with Huayu-Qiangshen-Tongbi formula (HQT) plus methotrexate (MTX) or leflunomide (LEF) plus MTX. There were differences in the gut microbiome between untreated (at baseline) RA patients and healthy controls, with 37 species being more abundant in the RA patients and 21 species (including Clostridium celatum) being less abundant. Regarding the functional analysis, vitamin K2 biosynthesis was associated with RA-enriched bacteria. Additionally, in RA patients, alterations in gut microbial species appeared to be associated with RA-related clinical indicators through changing various gut microbiome functional pathways. The clinical efficacy of the two treatments was further observed to be similar, but the response trends of RA-related clinical indices in the two treatment groups differed. For example, HQT treatment affected the erythrocyte sedimentation rate (ESR), while LEF treatment affected the C-reactive protein (CRP) level. Further, 11 species and 9 metabolic pathways significantly changed over time in the HQT group (including C. celatum, which increased), while only 4 species and 2 metabolic pathways significantly changed over time in the LEF group. In summary, we studied the alterations in the gut microbiome of RA patients being treated with HQT or LEF. The results provide useful information on the role of the gut microbiota in the pathogenesis of RA, and they also provide potentially effective directions for developing new RA treatments.

Anti-inflammatory and Pro-apoptotic Effects of 18beta-Glycyrrhetinic Acid In Vitro and In Vivo Models of Rheumatoid Arthritis.

18ß-Glycyrrhetinic acid (18ß-GA), an active component from Glycyrrhiza glabra L. root (licorice), has been demonstrated to be able to protect against inflammatory response and reduce methotrexate (MTX)-derived toxicity. This study was therefore designed to test the therapeutic possibility of 18ß-GA on rheumatoid arthritis (RA) and to explore the underlying mechanism. LPS or TNF-α-induced inflammatory cell models and collagen-induced arthritis (CIA) animal models were applied in this study. Real-time quantitative PCR (RT-qPCR) was used to measure the mRNA levels of various cytokines and FOXO family members. The protein levels of molecules in the MAPK/NF-κB signaling pathway were analyzed using western blot. The cell proliferation assay and colony-forming assay were used to test the influence of 18ß-GA on cell viability. The cell apoptosis assay and cell cycle assay were performed to detect the effect of 18ß-GA on cell proliferative capacity by using flow cytometry. Hematoxylin and eosin (H&E) staining was performed to evaluate pathological changes after drug administration. The enzyme-linked immunosorbent assay (ELISA) was carried out for the detection of cytokines in serum. In vitro, we found that 18ß-GA decreased the mRNA levels of IL-1ß, IL-6, and COX-2 by inhibiting the MAPK/NF-κB signaling pathway in MH7A and RAW264.7 cell lines. Moreover, 18ß-GA was able to suppress cell viability, trigger cell apoptosis, and G1 phase cell cycle arrest in our in vitro studies. 18ß-GA dramatically enhanced the mRNA level of FOXO3 in both TNF-α- and LPS-induced inflammation models in vitro. Interestingly, after analyzing GEO datasets, we found that the FOXO3 gene was significantly decreased in the RA synovial tissue as compared to healthy donors in multiple microarray studies. In vivo, 18ß-GA exhibited a promising therapeutic effect in a collagen-induced arthritis mouse model by alleviating joint pathological changes and declining serum levels of TNF-α, IL-1ß, and IL-6. Finally, we observed that 18ß-GA administration could mitigate liver damage caused by collagen or MTX. Collectively, the current study demonstrates for the first time that 18ß-GA can inhibit inflammation and proliferation of synovial cells, and the underlying mechanism may be associated with its inhibition of MAPK/NF-κB signaling and promotion of FOXO3 signaling. Therefore, 18ß-GA is expected to be a new drug candidate for RA therapy.

The mechanism of Chinese herbal formula HQT in the treatment of rheumatoid arthritis is related to its regulation of lncRNA uc.477 and miR-19b.

Rheumatoid arthritis (RA) pathogenesis has been associated with dysregulation of long noncoding RNA (lncRNA) and microRNA (miRNA) expression in serum and in lesioned tissue. In this study, a microarray assay was performed to study the profile of lncRNAs in the serum of RA patients and healthy donors, and a set of novel lncRNAs associated with RA was identified. For the remainder of the study, focus is on the top hit, lncRNA uc.477. The upregulation of lncRNA uc.477 and downregulation of miR-19b were validated in the serum of RA patients compared to that of healthy donors, and similar results were further confirmed by quantitative real-time PCR analysis of a cell line: RA-derived human fibroblast-like synoviocytes (HFLS-RA). LncRNA uc.477 could interfere with the processing of pri-miR-19b to produce its mature form and thereby played a pro-inflammatory role. In addition, Huayu Qiangshen Tongbi formula (HQT), a traditional Chinese medicine (TCM), has been shown to exert a promising therapeutic effect on RA and to exhibit long-term safety in our previous clinical retrospective study. Importantly, HQT treatment normalized the levels of lncRNA uc.477 and miR-19b in HFLS-RA in vitro and in mouse models of collagen-induced arthritis. HQT treatment, knockdown of lncRNA uc.477, and overexpression of miR-19b resulted in a comparable inhibition of pro-inflammatory cytokine gene expression in HFLS-RA cells. Together, these data suggest that the therapeutic effects of HQT on RA are closely related to its modulation of lncRNA uc.477 and miR-19b.

Nuclear HMGB1 promotes the phagocytic ability of macrophages.

Phagocytosis is a basic immune response to the invasion of pathogens. High mobility group protein B1 (HMGB1) is a DNA chaperone that is associated with phagocytosis. However, its influence on phagocytosis is debated. In the present study, HMGB1-mutant, HMGB1-overexpressing and HMGB1-silenced RAW264.7 cells were constructed. In addition, HMGB1 conditional knockout mice were constructed to determine the influence of HMGB1 on phagocytosis. Lipopolysaccharide (LPS) was used to stimulate the translocation of HMGB1 from the nucleus to the cytoplasm. Zymosan particles were used to test the phagocytic function of the macrophages. Our results showed that the accumulation of HMGB1 in the nucleus enhances the phagocytic function of the macrophages. By interacting with P53, nuclear HMGB1 may remain in the nucleus and decrease the negative influence of P53 on the phosphorylation of focal adhesion kinase (FAK). The increase in phosphorylated FAK promotes the formation of pseudopods and enhances the phagocytic ability of macrophages.

Rhein attenuates lipopolysaccharide-primed inflammation through NF-κB inhibition in RAW264.7 cells: targeting the PPAR-γ signal pathway.

Inflammation is a common inducer of numerous severe diseases such as sepsis. The NF-κB signaling pathway plays a key role in the inflammatory process. Its activation promotes the release of pro-inflammatory mediators like inducible nitric oxide synthase and tumor necrosis factor alpha. Peroxisome proliferator-activated receptor gamma (PPAR-γ) inactivates nuclear factor kappa B (NF-κB) and subsequently attenuates inflammation. Rhein, an agent isolated from rhubarb, has been known to have anti-inflammatory effects. However, its influence on PPAR-γ remains largely unknown. In this study, an inflammation model was constructed by stimulating RAW264.7 cells with lipopolysaccharide. Rhein was used as a therapeutic agent, while rosiglitazone (PPAR-γ activator) and GW9662 (PPAR-γ inhibitor) were used as disrupters for in depth studies. The results demonstrated that rhein inhibits NF-κB activation and inflammatory factor release. However, GW9662 significantly reduced this effect, indicating that PPAR-γ is a critical mediator in the rhein-mediated anti-inflammatory process. Additionally, positive modulation of PPAR-γ expression and activity by rosiglitazone correspondingly influenced the effects of rhein on inflammatory factors and NF-κB expression. We also found that rhein could enhance PPAR-γ, NF-κB, and histone deacetylase 3 (HDAC3) binding. These results indicate that rhein exerts its anti-inflammation function by regulating the PPAR-γ-NF-κB-HDAC3 axis.

Paeonol attenuates inflammation by targeting HMGB1 through upregulating miR-339-5p.

Sepsis is a life-threatening disease caused by infection. Inflammation is a key pathogenic process in sepsis. Paeonol, an active ingredient in moutan cortex (a Chinese herb), has many pharmacological activities, such as anti-inflammatory and antitumour actions. Previous studies have indicated that paeonol inhibits the expression of HMGB1 and the transcriptional activity of NF-κB. However, its underlying mechanism is still unknown. In this study, microarray assay and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) results confirmed that paeonol could significantly up-regulate the expression of miR-339-5p in RAW264.7 cells stimulated by LPS. Dual-luciferase assays indicated that miR-339-5p interacted with the 3' untranslated region (3'-UTR) of HMGB1. Western blot, immunofluorescence and enzyme-linked immunosorbent assay (ELISA) analyses indicated that miR-339-5p mimic and siHMGB1 both negatively regulated the expression and secretion of inflammatory cytokines (e.g., HMGB1, IL-1ß and TNF-α) in LPS-induced RAW264.7 cells. Studies have confirmed that IKK-ß is targeted by miR-339-5p, and we further found that paeonol could inhibit IKK-ß expression. Positive mutual feedback between HMGB1 and IKK-ß was observed when we silenced HMGB1 or IKK-ß. These results indicated that paeonol could attenuate the inflammation mediated by HMGB1 and IKK-ß by upregulating miR-339-5p expression. In addition, we constructed CLP model mice by cecal ligation and puncture. Paeonol was used to intervene to investigate its anti-inflammatory effect in vivo. The results showed that paeonol could improve the survival rate of sepsis mice and protect the kidney of sepsis mice.

Anti-Inflammatory Effects of Shenfu Injection against Acute Lung Injury through Inhibiting HMGB1-NF-κB Pathway in a Rat Model of Endotoxin Shock.

Shenfu injection (SFI), a Chinese herbal medicine with substances extracted from Ginseng Radix et Rhizoma Rubra and Aconiti Lateralis Radix Praeparata, is widely used as an anti-inflammatory reagent to treat endotoxin shock in China. However, the mechanism of SFI in endotoxin shock remains to be illuminated. High mobility group box 1 (HMGB1), a vital inflammatory factor in the late stage of endotoxin shock, may stimulate multiple signalling cascades, including κB (NF-κB), a nuclear transcription factor, as well as tumour necrosis factor (TNF)-α and interleukin (IL)-1ß, among others in the overexpression of downstream proinflammatory cytokines. An investigation into the effects of SFI on the inhibition of the HMGB1-NF-κB pathway revealed the contribution of SFI to acute lung injury (ALI) in a rat model of endotoxin shock. To assess the anti-inflammatory activity of SFI, 5 ml/kg, 10 ml/kg, or 15 ml/kg of SFI was administered to different groups of rats following an injection of LPS, and the mean arterial pressure (MAP) at 5 h and the survival rate at 72 h were measured. 24 h after LPS injection, we observed pathological changes in the lung tissue and measured the mRNA expression, production, translocation, and secretion of HMGB1, as well as the expression of the NF-κB signal pathway-related proteins inhibitor of NF-κB (IκB)-α, P50, and P65. We also evaluated the regulation of SFI on the secretion of inflammatory factors including interleukin-1 beta (IL-1ß) and TNF-α. SFI effectively prevented the drop in MAP, relieved lung tissue damage, and increased the survival rate in the endotoxin shock model in dose-dependent manner. SFI inhibited the transcription, expression, translocation, and secretion of HMGB1, increased the expression of toll-like receptor (TLR4), increased the production of IκB-α, and decreased the levels of P65, P50, and TNF-α in the lung tissue of endotoxin shock rats in a dose-dependent manner. Furthermore, SFI decreased the secretion of proinflammatory cytokines TNF-α and IL-1ß. In summary, SFI improves the survival rate of endotoxin shock, perhaps through inhibiting the HMGB1-NF-κB pathway and thus preventing cytokine storm.

Downregulation of ERBB3 decreases the proliferation, migration and invasion of cervical cancer cells though the interaction with MTK-1.

Cervical cancer is a common malignancy in females. Diagnosis and treatment of cervical cancer remains a challenge due to difficulties in the presence of tumor metastasis. Increased expression level of Erb-b2 receptor tyrosine kinase 3 (ERBB3) has previously been demonstrated to be associated with the occurrence of cervical cancer; however, the functionality of ERBB3 in the development of cervical cancer remains incompletely understood. In the present study, the expression level of ERBB3 in patients with cervical squamous cell carcinoma and cervical adenocarcinoma was detected by reverse transcription quantitative polymerase chain reaction. The effects of ERBB3 small interfering RNA silencing on cell proliferation, migration and invasion were explored, and the interaction between ERBB3 and mitogen-activated protein kinase kinase kinase 4 (MTK-1) was also investigated. It was identified that the downregulation of ERBB3 significantly decreased the proliferative, migratory and invasive abilities of cervical cancer cells. In addition, the expression level of MTK-1 was also significantly decreased following MTK-1 siRNA silencing. Therefore, we hypothesize that the downregulation of ERBB3 may decrease the proliferative, migratory and invasive abilities of cervical cancer cells by inhibiting the expression of MTK-1.

Paeonol attenuates acute lung injury by inhibiting HMGB1 in lipopolysaccharide-induced shock rats.

High-mobility group box 1 (HMGB1) is a highly conserved DNA-binding nuclear protein that facilitates gene transcription and the DNA repair response. However, HMGB1 may be released by necrotic cells as well as activated monocytes and macrophages following stimulation with lipopolysaccharide (LPS), interleukin-1ß (IL-1ß), or tumor necrosis factor-α (TNF-α). Extracellular HMGB1 plays a critical role in the pathogenesis of acute lung injury (ALI) through activating the nuclear transcription factor κB (NF-κB) P65 pathway, thus, it may be a promising therapeutic target in shock-induced ALI. Paeonol (Pae) is the main active component of Paeonia suffruticosa, which has been used to inhibit the inflammatory response in traditional Chinese medicine. We have proven that Pae inhibits the expression, relocation and secretion of HMGB1 in vitro. However, the role of Pae in the HMGB1-NF-κB pathway remains unknown. We herein investigated the role of Pae in LPS-induced ALI rats. In this study, LPS induced a marked decrease in the mean arterial pressure (MAP) and survival rate (only 25% after 72 h), and induced severe pathological changes in the lung tissue of rats, which was accompanied by elevated expression of HMGB1 and its downstream protein NF-κB P65. Treatment with Pae significantly improved the survival rate (>60%) and MAP, and attenuated the pathological damage to the lung tissue in ALI rats. Western blotting revealed that Pae also inhibited the total expression of HMGB1, NF-κB P65 and TNF-α in the lung tissue of ALI rats. Moreover, Pae increased the expression of HMGB1 in the nucleus, inhibited the production of HMGB1 in the cytoplasm, and decreased the expression of P65 both in the nucleus and cytoplasm of lung tissue cells in LPS-induced ALI rats. The results were in agreement with those observed in the in vitro experiment. These findings indicate that Pae may be a potential treatment for ALI through its repression of the HMGB1-NF-κB P65 signaling pathway.

Paeonol Reduces the Nucleocytoplasmic Transportation of HMGB1 by Upregulating HDAC3 in LPS-Induced RAW264.7 Cells.

Extracellular high mobility group box 1 (HMGB1) is a lethal pro-inflammatory mediator in endotoxin shock. Hyperacetylation of HMGB1, regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs), changes its subcellular localization and secretion to the extracellular matrix. Paeonol (2'-hydroxy-4'-methoxyacetophenone), one of the main active components of Paeonia suffruticosa, exerts anti-inflammatory effects. Our previous study demonstrated that Paeonol inhibited the relocation and secretion of HMGB1 in lipopolysaccharide (LPS)-activated RAW264.7 cells. However, it is still unclear whether Paeonol can regulate HATs/HDACs, which are responsible for the translocation of HMGB1 from nucleus to cytoplasm. To answer this question, P300 (a transcriptional coactivator with HATs) and HDAC3 were investigated using RT-qPCR and western blotting. The results showed that HMGB1 translocated from the nucleus to the cytoplasm, accompanied by upregulation of P300 and downregulation of HDAC3 in LPS-induced RAW264.7 cells. Paeonol, however, reversed the expression of P300 and HDAC3 significantly, suggesting that Paeonol may be involved in the acetylation of HMGB1 by regulating P300/HDAC3. Then, the effect of HDAC3 on the nucleocytoplasmic transportation of HMGB1 by HDAC3-SiRNA was evaluated. The results demonstrated that the inhibition of HDAC3 resulted in the nucleocytoplasmic translocation of HMGB1, with or without LPS stimulation. Moreover, Paeonol had no effect on the translocation of HMGB1 following ablation of HDAC3. These findings support the hypothesis that Paeonol can inhibit the translocation and secretion of HMGB1 in LPS-induced RAW264.7 cells by upregulating the expression of HDAC3. Paeonol may therefore be a valuable candidate as an HMGB1-targeting drug for inflammatory diseases via upregulation of HDAC3.

Chrysophanol demonstrates anti-inflammatory properties in LPS-primed RAW 264.7 macrophages through activating PPAR-γ.

Sepsis is a life-threatening disease. Inflammation is a major concomitant symptom of sepsis Chrysophanol, an anthraquinone derivative isolated from the rhizomes of rheumpalmatum, has been reported to have a protective effect against lipopolysaccharide(LPS)-induced inflammation. However, the underlying molecular mechanisms are not well understood. The aim of this study was to explore the effect and mechanism of chrysophanol on lipopolysaccharide (LPS)-induced anti-inflammatory effect of RAW264.7 cells and its involved potential mechanism. The mRNA and protein expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and inducible nitric oxide synthase (iNOS), nuclear factor kappa B (NF-κB) and PPAR-γ were measured by qRT-PCR and western blotting, the production of TNF-α, IL-1ß was evaluated by ELISA. Then, the phosphorylation of NF-κB p65 was also detected by western blotting. And NF-κB p65 promoter activity was analyzed by the Dual-Luciferase reporter assay system as well. Meanwhile, PPAR-γ inhibitor GW9662 was performed to knockdown PPAR-γ expression in cells. Our data revealed that LPS induced the up-regulation of TNF-α, IL-1ß, iNOS and NF-κB p65, the down-regulation of PPAR-γ were substantially suppressed by chrysophanol in RAW264.7 cells. Furthermore, our data also figured out that these effects of chrysophanol were largely abrogated by PPAR-γ inhibitor GW9662. Taken together, our results indicated that LPS-induced inflammation was potently compromised by chrysophanol very likely through the PPAR-γ-dependent inactivation of NF-κB in RAW264.7 cells.