Paeonol inhibits melanoma growth by targeting PD1 through upregulation of miR-139-5p.

The abnormal immune response mediated by malignant melanoma is related to PD1. Paeonol has pharmacological antitumor activity. Previous studies have indicated that paeonol induces tumor cell apoptosis, but its underlying mechanism in tumor immunity remains unknown. In this study, malignant melanoma was established in normal and thymectomized mice to determine the important role of the thymus in the antitumor effects of paeonol. Paeonol-treated thymocytes were cocultured with melanoma cell spheres to further evaluate the regulatory role of thymocytes in tumor immune dysfunction. Studies have shown that PD1 may be targeted by miR-139-5p. Our results revealed that tumor-induced thymic atrophy was significantly accompanied by high PD1 expression and low miR-139-5p expression. Interestingly, paeonol significantly reversed thymic atrophy and largely protected thymocytes against low PD1 expression and high miR-139-5p expression. Dual-luciferase assays indicated that miR-139-5p interacted with the 3' untranslated region (3'-UTR) of PD1. These results showed that paeonol alleviates PD1-mediated antitumor immunity by reducing miR-139-5p expression and demonstrated a novel mechanism for melanoma immunotherapy.

Microglial Metabolic Reprogramming: Emerging Insights and Therapeutic Strategies in Neurodegenerative Diseases.

Microglia, the resident immune cells of the central nervous system, play a critical role in maintaining brain homeostasis. However, in neurodegenerative conditions, microglial cells undergo metabolic reprogramming in response to pathological stimuli, including Aß plaques, Tau tangles, and α-synuclein aggregates. This metabolic shift is characterized by a transition from oxidative phosphorylation (OXPHOS) to glycolysis, increased glucose uptake, enhanced production of lactate, lipids, and succinate, and upregulation of glycolytic enzymes. These metabolic adaptations result in altered microglial functions, such as amplified inflammatory responses and diminished phagocytic capacity, which exacerbate neurodegeneration. This review highlights recent advances in understanding the molecular mechanisms underlying microglial metabolic reprogramming in neurodegenerative diseases and discusses potential therapeutic strategies targeting microglial metabolism to mitigate neuroinflammation and promote brain health. Microglial Metabolic Reprogramming in Neurodegenerative Diseases This graphical abstract illustrates the metabolic shift in microglial cells in response to pathological stimuli and highlights potential therapeutic strategies targeting microglial metabolism for improved brain health.

Paeonol attenuates inflammation by confining HMGB1 to the nucleus.

Inflammation is a biological process that exists in a large number of diseases. If the magnitude or duration of inflammation becomes uncontrolled, inflammation may cause pathological damage to the host. HMGB1 and NF-κB have been shown to play pivotal roles in inflammation-related diseases. New drugs aimed at inhibiting HMGB1 expression have become a key research focus. In the present study, we showed that paeonol (Pae), the main active component of Paeonia suffruticosa, decreases the expression of inflammatory cytokines and inhibits the translocation of HMGB1 induced by lipopolysaccharide (LPS). By constructing HMGB1-overexpressing (HMGB1+ ) and HMGB1-mutant (HMGB1m ) RAW264.7 cells, we found that the nuclear HMGB1 could induce an LPS-tolerant state in RAW264.7 cells and that paeonol had no influence on the expression of inflammatory cytokines in HMGB1m RAW264.7 cells. In addition, the anti-inflammatory property of paeonol was lost in HMGB1 conditional knockout mice, indicating that HMGB1 is a target of paeonol and a mediator through which paeonol exerts its anti-inflammatory function. Additionally, we also found that HMGB1 and P50 competitively bound with P65, thus inactivating the NF-κB pathway. Our research confirmed the anti-inflammation property of paeonol and suggests that inhibiting the translocation of HMGB1 could be a new strategy for treating inflammation.

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.

Decoding sTREM2: its impact on Alzheimer's disease - a comprehensive review of mechanisms and implications.

Soluble Triggering Receptor Expressed on Myeloid Cells 2 (sTREM2) plays a crucial role in the pathogenesis of Alzheimer's disease (AD). This review comprehensively examines sTREM2's involvement in AD, focusing on its regulatory functions in microglial responses, neuroinflammation, and interactions with key pathological processes. We discuss the dynamic changes in sTREM2 levels in cerebrospinal fluid and plasma throughout AD progression, highlighting its potential as a therapeutic target. Furthermore, we explore the impact of genetic variants on sTREM2 expression and its interplay with other AD risk genes. The evidence presented in this review suggests that modulating sTREM2 activity could influence AD trajectory, making it a promising avenue for future research and drug development. By providing a holistic understanding of sTREM2's multifaceted role in AD, this review aims to guide future studies and inspire novel therapeutic strategies.

40 Hz Electroacupuncture relieves the memory dysfunction of 5xFAD mice by regulating neuronal electrical activity.

In this investigation, we probed the impacts of 40 Hz Electroacupuncture (EA) on the cognitive function and brain activity in 5xFAD mice. Three groups of mice were constituted: the Model group of 5xFAD mice, the Wild Type (WT) group of littermate controls, and the EA group of 5xFAD mice subjected to EA treatment. Behavioral tests were conducted to evaluate memory function and anxiety levels, while the presence of Aß plaques were detected via immunostaining, and neuronal activity was measured using multichannel recordings. Our results indicated that EA therapy enhanced memory function and anxiety-like behavior in 5xFAD mice, as well as diminishing the abundance and dimensions of Aß plaques in the hippocampus and mPFC regions. Notably, the suppression of astrocyte activation was observed, which was potentially associated with alterations in gamma oscillation. Furthermore, the synaptic transmission of neurons was amplified, suggesting a possible modulation in neural activity. These findings indicate that 40 Hz EA could influence cognitive performance and potentially affect neuronal activity in 5xFAD mice, while the direct connection between EA and neuronal electrical activity regulation requires further exploration. The potential frequency-specific effects of EA on protective mechanisms in the brain was not addressed in this study and thus presents a direction for future research.

Microglia in Alzheimer's disease: pathogenesis, mechanisms, and therapeutic potentials.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by protein aggregation in the brain. Recent studies have revealed the critical role of microglia in AD pathogenesis. This review provides a comprehensive summary of the current understanding of microglial involvement in AD, focusing on genetic determinants, phenotypic state, phagocytic capacity, neuroinflammatory response, and impact on synaptic plasticity and neuronal regulation. Furthermore, recent developments in drug discovery targeting microglia in AD are reviewed, highlighting potential avenues for therapeutic intervention. This review emphasizes the essential role of microglia in AD and provides insights into potential treatments.

Paeonol enhances macrophage phagocytic function by modulating lipid metabolism through the P53-TREM2 axis.

Introduction: The emerging concept of immunometabolism highlights the interplay between lipid metabolism and phagocytosis in macrophages. Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) has been identified as an essential modulator of both lipid metabolism and phagocytic function in macrophages. This study aims to investigate the roles of P53 and TREM2 in regulating macrophage lipid metabolism and phagocytosis and to evaluate the potential therapeutic effects of paeonol on these processes. Methods: CRISPR-Cas9 was utilized to generate P53 and TREM2 knockout RAW264.7 cell lines. The dual-luciferase reporter gene assay was performed to assess the interaction between P53 and the TREM2 promoter. A series of functional assays were conducted to evaluate the impact of P53 and TREM2 on macrophage lipid metabolism and phagocytic function. The effects of Paeonol on these processes were also examined. Results: Our findings revealed that paeonol induces the accumulation of P53 in the nucleus. P53 acts as a transcription factor that upregulates the expression of TREM2, promoting macrophage lipid metabolism, metabolic activity, and phagocytic capacity. Additionally, dual-luciferase reporter gene assays confirmed the interaction between P53 and the TREM2 promoter. Discussion: This study provides novel insights into the roles of P53 and TREM2 in regulating macrophage lipid metabolism and phagocytic function. Further research is warranted to explore the potential applications of Paeonol and to elucidate the molecular mechanisms underlying the observed effects.

Color Image Recovery Using Low-Rank Quaternion Matrix Completion Algorithm.

As a new color image representation tool, quaternion has achieved excellent results in color image processing problems. In this paper, we propose a novel low-rank quaternion matrix completion algorithm to recover missing data of a color image. Motivated by two kinds of low-rank approximation approaches (low-rank decomposition and nuclear norm minimization) in traditional matrix-based methods, we combine the two approaches in our quaternion matrix-based model. Furthermore, the nuclear norm of the quaternion matrix is replaced by the sum of the Frobenius norm of its two low-rank factor quaternion matrices. Based on the relationship between the quaternion matrix and its equivalent complex matrix, the problem eventually is converted from the quaternion number domain to the complex number domain. An alternating minimization method is applied to solve the model. Simulation results on color image recovery show the superior performance and efficiency of the proposed algorithm over some tensor-based and quaternion-based ones.

Quaternion Scalar and Vector Norm Decomposition: Quaternion PCA for Color Face Recognition.

This paper proposes a decomposition called quaternion scalar and vector norm decomposition (QSVND) for approximation problems in color image processing. Different from traditional quaternion norm approximations that are always the single objective models (SOM), QSVND is adopted to transform the SOM into the bi-objective model (BOM). Furthermore, regularization is used to solve the BOM problem as a common scalarization method, which converts the BOM into a more reasonable SOM. This can handle over-fitting or under-fitting problems neglected in this kind of research for quaternion representation (QR) in color image processing. That is how to treat redundancy caused by the extra scalar part when the vector part of a quaternion is used to represent a color pixel. We apply QSVND to quaternion principal component analysis (QPCA) for color face recognition (FR), which can deal with the phenomenon of under-fitting of vector part norm approximation. Comparisons with the competing approaches on AR, FERET, FEI, and KDEF&AKDEF databases consistently show the superiority of the proposed approach for color FR.

Tanshinone IIA sodium sulfonate attenuates inflammation by upregulating circ-Sirt1 and inhibiting the entry of NF-κB into the nucleus.

Inflammation is a biological process that exists in a large number of diseases. NF-κB has been proven to play a pivotal role in the development of inflammation. New drugs aimed at inhibiting the expression of NF-κB have gained attention from researchers. Sirt1 has an anti-inflammatory function, and the circRNA encoded by the Sirt1 gene may also play roles in the anti-inflammatory reaction of Sirt1. In the present study, LPS-treated RAW264.7 cells were used as an inflammatory cell model, and tanshinone IIA sodium sulfonate (TSS) was used as a therapeutic drug. We found that TSS downregulated LPS-induced TNF-α and IL-1ß expression nearly threefold. LPS reduced Circ-sirt1 mRNA expression by one-third, while TSS started this phenomenon. In addition, overexpression/knockdown of Circ-sirt1 neutralized the function of TSS by regulating the translocation of NF-κB. Thus, we proved that TSS has an anti-inflammatory function by upregulating circ-Sirt1 and subsequently inhibiting the translocation of NF-κB. An in vivo experiment was also performed to confirm the protective function of TSS on inflammation. These results indicated that TSS is a potential treatment for inflammation.

Protective effect of plastrum testudinis extract on dopaminergic neurons in a Parkinson's disease model through DNMT1 nuclear translocation and SNCA's methylation.

The pathological characteristics of Parkinson's disease (PD) include dopaminergic neuron damage, specifically disorders caused by dopamine synthesis, in vivo. Plastrum testudinis extract (PTE) and its bioactive ingredient ethyl stearate (PubChem CID: 8122) were reported to be correlated with tyrosine hydroxylase (TH), which is a biomarker of dopaminergic neurons. This suggests that PTE and its small-molecule active ingredient ethyl stearate have potential for development as a therapeutic drug for PD. In this study, we treated 6-hydroxydopamine (6-OHDA)-induced model rats and PC12 cells with PTE. The mechanism of action of PTE and ethyl stearate was investigated by western blotting, bisulfite sequencing PCR (BSP), real-time PCR, immunofluorescence and siRNA transfection. PTE effectively upregulated the TH expression and downregulated the alpha-synuclein expression in both the substantia nigra and the striatum of the midbrain in a PD model rat. The PC12 cell model showed that both PTE and its active monomer ethyl stearate significantly promoted TH expression and blocked alpha-synuclein, agreeing with the in vivo results. BSP showed that PTE and ethyl stearate increased the methylation level of the Snca intron 1 region. These findings suggest that some of the protective effects of PTE on dopaminergic neurons are mediated by ethyl stearate. The mechanism of ethyl stearate may involve disrupting the abnormal aggregation of DNA (cytosine-5)-methyltransferase 1 (DNMT1) with alpha-synuclein by releasing DNMT1, upregulating Snca intron 1 CpG island methylation, and ultimately, reducing the expression of alpha-synuclein.

Paeonol promotes the phagocytic ability of macrophages through confining HMGB1 to the nucleus.

Phagocytosis is a basic immune response to the pathogens invading. Immunosuppression may occur in diseases like sepsis and cancer, and cause a low phagocytic ability of phagocytes. High mobility group protein B1 (HMGB1) is a DNA chaperone which is closely related to the phagocytosis. Nonetheless, its influence on phagocytosis is still controversial. We found that paeonol could inhibit the translocation of HMGB1 from the nucleus to the cytoplasm, it may have an impact on phagocytosis. In the present study, we performed in vivo and in vitro experiments to investigate the influence of paeonol on phagocytosis. Zymosan was used to test the phagocytic function of macrophages. Our results showed that paeonol promotes the phagocytosis of macrophages through confining HMGB1 to the nucleus. Through interacting with P53, the nuclear HMGB1 keep it in the nucleus and decrease the negative influence of P53 on the phosphorylation of Focal Adhesion Kinase (FAK). The increasing of phosphorylated FAK promotes the formation of pseudopod and enhances the phagocytic ability of macrophages.

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.

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.

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.

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.