Triptolide exhibits anti-inflammatory, anti-catabolic as well as anabolic effects and suppresses TLR expression and MAPK activity in IL-1β treated human intervertebral disc cells

Application of network pharmacology and dock of molecules on the exploration of the mechanism of frankincense-myrrh for lumbar intervertebral disc degeneration: A review

To investigate the efficacy of Frankincense-Myrrh in lumbar Intervertebral degenerative diseases (LIDD). The active components of frankincense-myrrh was retrieved with a unique system pharmacology platform for Traditional Chinese Medicine Systems Pharmacology (TCMSP). The LIDD-related target genes were screened with DisGeNET and Genecards databases. Then, STRING & Cytoscape were used for analyzing the Protein-Protein Interaction network. DAVID was used for analyzing Gene Ontology (GO) & Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. Finally, molecules of AutoDockVina and Pymol were used for docking the molecules for verifying active ingredients and key targets' binding force. The 105 LIDD-related targets identified in Ruxiang (RX)-Moyao (MY) involve 53 active ingredients. In addition, topological analysis was conducted for identifying the 12 key targets. According to the analysis results of GO & KEGG, RX-MY is significant for treating LIDD through participating in many pathways and biological processes, such as signaling pathways of inflammatory response reactive process, MAP kinase activity, TNF, and MAPK, etc. According to the dock results, the active components oxo-tirucalic, acid, isofouquierone, (7S, 8R, 9S, 10R, 13S, 14S,17Z)-17-ethylidene-7-hydroxy-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15-decahydrocyclopenta [a] phenanthrene-3,16-dion in RX-MY binds actively. The basic pharmacological action and RX-MY-related mechanism in the treatment of LIDD was revealed in this study for the first time. It is predicted that the results may provide a treatment plan for RX-MY with replacement of NSAIDs and warrant investigation of new therapeutic alternatives for LIDD. However, these predictions should be validated by relevant pharmacological trials.

Human 3D nucleus pulposus microtissue model to evaluate the potential of pre-conditioned nasal chondrocytes for the repair of degenerated intervertebral disc

Introduction: An in vitro model that appropriately recapitulates the degenerative disc disease (DDD) microenvironment is needed to explore clinically relevant cell-based therapeutic strategies for early-stage degenerative disc disease. We developed an advanced 3D nucleus pulposus (NP) microtissues (µT) model generated with cells isolated from human degenerating NP tissue (Pfirrmann grade: 2-3), which were exposed to hypoxia, low glucose, acidity and low-grade inflammation. This model was then used to test the performance of nasal chondrocytes (NC) suspension or spheroids (NCS) after pre-conditioning with drugs known to exert anti-inflammatory or anabolic activities. Methods: NPµTs were formed by i) spheroids generated with NP cells (NPS) alone or in combination with ii) NCS or iii) NC suspension and cultured in healthy or degenerative disc disease condition. Anti-inflammatory and anabolic drugs (amiloride, celecoxib, metformin, IL-1Ra, GDF-5) were used for pre-conditioning of NC/NCS. The effects of pre-conditioning were tested in 2D, 3D, and degenerative NPµT model. Histological, biochemical, and gene expression analysis were performed to assess matrix content (glycosaminoglycans, type I and II collagen), production and release of inflammatory/catabolic factors (IL-6, IL-8, MMP-3, MMP-13) and cell viability (cleaved caspase 3). Results: The degenerative NPµT contained less glycosaminoglycans, collagens, and released higher levels of IL-8 compared to the healthy NPµT. In the degenerative NPµT, NCS performed superior compared to NC cell suspension but still showed lower viability. Among the different compounds tested, only IL-1Ra pre-conditioning inhibited the expression of inflammatory/catabolic mediators and promoted glycosaminoglycan accumulation in NC/NCS in DDD microenvironment. In degenerative NPµT model, preconditioning of NCS with IL-1Ra also provided superior anti-inflammatory/catabolic activity compared to non-preconditioned NCS. Conclusion: The degenerative NPµT model is suitable to study the responses of therapeutic cells to microenvironment mimicking early-stage degenerative disc disease. In particular, we showed that NC in spheroidal organization as compared to NC cell suspension exhibited superior regenerative performance and that IL-1Ra pre-conditioning of NCS could further improve their ability to counteract inflammation/catabolism and support new matrix production within harsh degenerative disc disease microenvironment. Studies in an orthotopic in vivo model are necessary to assess the clinical relevance of our findings in the context of IVD repair.

The Effects of Elgucare on Degenerated Intervertebral Disc-Induced Low Back Pain and Disc Regeneration: A Clinical Trial

INTRODUCTION

Chronic low back pain (LBP) has a wide range of causes. However, most cases are induced by degeneration of the lumbar intervertebral discs (IVDs), and the aching caused by local compression of the affected region has considerable impacts on quality of life. This clinical trial investigated the use of Elgucare, a Chinese herbal formula, as a food supplement to reduce the pain of patients with LBP induced by degeneration of the lumbar IVDs.

METHODS

The study assessed patient subjective quality of life, functional limitations caused by LBP, and variations in pain. The assessment was done through the visual analogue scale (VAS) and effects on lumbar IVD thickness, water content, and bone mineral density (BMD). These parameters were evaluated before and after the administration of Elgucare or a placebo, one of which was taken by each participant for a 12-month period.

RESULTS

Elgucare reduced the patients' mean VAS pain score by 2.25 points and improved their mean LBP-hampered mobility as assessed by the Roland-Morris Questionnaire by 5.17 points. The results of another questionnaire indicated that Elgucare slowed the LBP-induced deterioration of patients' quality of life, while objective assessment indices obtained through X-ray and magnetic resonance imaging showed that the height and water retention of their IVDs were increased. However, the BMD results showed no improvements.

CONCLUSIONS

Elgucare can increase the water retention and height of IVDs and reduce LBP, thereby enhancing quality of life. Therefore, Elgucare can potentially be used as a clinical supplement.

Inhibition of toll-like receptor 4 protects against inflammation-induced mechanobiological alterations to intervertebral disc cells

Intervertebral disc (IVD) degeneration is associated with elevated levels of inflammatory cytokines implicated in disease aetiology and matrix degradation. Toll-like receptor-4 (TLR4) has been shown to participate in the inflammatory responses of the nucleus pulposus (NP) and its levels are upregulated in disc degeneration. Activation of TLR4 in NP cells leads to significant, persistent changes in cell biophysical properties, including hydraulic permeability and osmotically active water content, as well as alterations to the actin cytoskeleton. The study hypothesis was that inflammation-induced changes to cellular biomechanical properties and actin cytoskeleton of NP cells could be prevented by inhibiting TLR4 signalling. Isolated NP cells from bovine discs were treated with lipopolysaccharide (LPS), the best studied TLR4 agonist, with or without treatment with the TLR4 inhibitor TAK-242. Cellular volume regulation responses to step osmotic loading were measured and the transient volume-response was captured by time-lapse microscopy. Volume-responses were analysed using mixture theory framework to investigate hydraulic permeability and osmotically active intracellular water content. Hydraulic permeability and cell radius were significantly increased with LPS treatment and these changes were blocked in cells treated with TAK-242. LPS-induced remodelling of cortical actin and IL-6 upregulation were also mitigated by TAK-242 treatment. These findings indicated that TLR4 signalling participated in NP cell biophysical regulation and may be an important target for mitigating altered cell responses observed in IVD inflammation and degeneration.

Painful intervertebral disc degeneration and inflammation: from laboratory evidence to clinical interventions

Low back pain (LBP), as a leading cause of disability, is a common musculoskeletal disorder that results in major social and economic burdens. Recent research has identified inflammation and related signaling pathways as important factors in the onset and progression of disc degeneration, a significant contributor to LBP. Inflammatory mediators also play an indispensable role in discogenic LBP. The suppression of LBP is a primary goal of clinical practice but has not received enough attention in disc research studies. Here, an overview of the advances in inflammation-related pain in disc degeneration is provided, with a discussion on the role of inflammation in IVD degeneration and pain induction. Puncture models, mechanical models, and spontaneous models as the main animal models to study painful disc degeneration are discussed, and the underlying signaling pathways are summarized. Furthermore, potential drug candidates, either under laboratory investigation or undergoing clinical trials, to suppress discogenic LBP by eliminating inflammation are explored. We hope to attract more research interest to address inflammation and pain in IDD and contribute to promoting more translational research.

Mesenchymal stem cells-derived exosomes ameliorate nucleus pulposus cells apoptosis via delivering miR-142-3p: therapeutic potential for intervertebral disc degenerative diseases

Intervertebral disc degeneration (IDD) is the main cause of lower back pain (LBP), and puzzles massive individuals worldwide. Mesenchymal stem cells (MSCs) transplantation has been demonstrated to potentially ameliorate IDD progression, while the underlying mechanism has not been fully explained. Interleukin-1β (IL-1β) was used to induce nucleus pulposus cells (NPCs) injury. Bone marrow MSCs-derived exosomes were isolated using the super centrifugation method, and characterized using Transmission electron microscopy (TEM) and western blot. Cell viability was determined by MTT, while apoptosis was measured by Annexin-V staining using flow cytometry. miR-142-3fp and gene expressions were measured by real-time PCR. The protein expressions were determined by western blot. Herein, we found exosomes from bone marrow MSCs are circular vesicles, about 80 nm in diameter, and with robust expression of TSG101 and CD63, but without of Calnexin. MSCs exosomes alleviated NPCs apoptosis by reducing IL-1β-induced inflammatory cytokines secretion and MAPK signaling activation. Additionally, MSCs exosomes inhibited NPCs apoptosis and MAPK signaling by delivering miR-142-3p that targets mixed lineage kinase 3 (MLK3). Overexpression of MLK3 abolished the effects of MSCs exosomes on the inflammatory condition, cell apoptosis, and MAPK signaling activation in NPCs. The results confirmed that bone marrow MSCs-derived exosomes-packaged miR-142-3p alleviates NPCs injury through suppressing MAPK signaling by targeting MLK3. The work highlights the therapeutic effect of MSCs on IDD progression, and bone marrow MSCs exosomes might be apromising therapeutic strategy for IDD.

Lessons learned from intervertebral disc pathophysiology to guide rational design of sequential delivery systems for therapeutic biological factors

Intervertebral disc (IVD) degeneration has been associated with low back pain, which is a major musculoskeletal disorder and socio-economic problem that affects as many as 600 million patients worldwide. Here, we first review the current knowledge of IVD physiology and physiopathological processes in terms of homeostasis regulation and consecutive events that lead to tissue degeneration. Recent progress with IVD restoration by anti-catabolic or pro-anabolic approaches are then analyzed, as are the design of macro-, micro-, and nano-platforms to control the delivery of such therapeutic agents. Finally, we hypothesize that a sequential delivery strategy that i) firstly targets the inflammatory, pro-catabolic microenvironment with release of anti-inflammatory or anti-catabolic cytokines; ii) secondly increases cell density in the less hostile microenvironment by endogenous cell recruitment or exogenous cell injection, and finally iii) enhances cellular synthesis of extracellular matrix with release of pro-anabolic factors, would constitute an innovative yet challenging approach to IVD regeneration.

PG490-88, a derivative of triptolide, suppresses ischemia/reperfusion-induced lung damage by maintaining tight junction barriers and targeting multiple signaling pathways

Previous studies demonstrated that triptolide (PG490) has many anti-inflammatory and immunosuppressive effects. However, little is known about the effect of PG490-88 (a water-soluble derivative of triptolide) on ischemia/reperfusion (I/R)-induced acute lung injury. We assessed the effects of PG490-88 on I/R-induced acute lung injury in rats and on hypoxia/reoxygenation (H/R) in a line of murine epithelial cells. Isolated perfused rat lungs were subjected to 40 min of ischemia, followed by 60 min of reperfusion to induce I/R injury. Induction of I/R led to lung edema, elevated pulmonary arterial pressure, histological evidence of lung inflammation, oxidative stress, and increased levels of TNF-α and CINC-1 in bronchoalveolar lavage fluid. PG490-88 significantly suppressed all of these responses. Additionally, induction of I/R reduced the expression of claudin-4, occludin, and ZO-1, and increased apoptosis in lung tissue. PG490-88 also significantly suppressed these effects. I/R reduced the levels of IκB-α and MKP-1, and increased the levels of nuclear NF-κB and mitogen-activated protein kinase in lung tissue, and PG490-88 suppressed these effects. In vitro studies using mouse lung alveolar epithelial cells indicated that H/R increased the levels of phosphorylated p65 and MIP-2, but decreased the level of IκB-α. PG490-88 also suppressed these effects. In I/R damaged lungs, PG490-88 suppresses the inflammatory response, disruption of tight junction structure, and apoptosis. PG490-88 has the potential as a prophylactic agent to prevent I/R-induced lung injury.

The Differential Effects of Leukocyte-Containing and Pure Platelet-Rich Plasma on Nucleus Pulposus-Derived Mesenchymal Stem Cells: Implications for the Clinical Treatment of Intervertebral Disc Degeneration

Background

Platelet-rich plasma (PRP) is a promising strategy for intervertebral disc degeneration. However, the potential harmful effects of leukocytes in PRP on nucleus pulposus-derived mesenchymal stem cells (NPMSCs) have seldom been studied. This study aimed at comparatively evaluating effects of pure platelet-rich plasma (P-PRP) and leukocyte-containing platelet-rich plasma (L-PRP) on rabbit NPMSCs in vitro.

Methods

NPMSCs isolated from rabbit NP tissues were treated with L-PRP or P-PRP in vitro, and then cell proliferation and expression of stem cell markers, proinflammatory cytokines (TNF-α, IL-1β), production of ECM (extracellular matrix-related protein), and NF-κB p65 protein were validated by CCK-8 assay, real-time polymerase chain reaction, enzyme-linked immunosorbent assay, immunofluorescence, and western blot respectively.

Results

NPMSCs differentiate into nucleus pulposus-like cells after treatment of PRPs (P-PRP and L-PRP), and NPMSCs exhibited maximum proliferation at a 10% PRP dose. L-PRP had observably higher concentration of leukocytes, TNF-α, and IL-1β than P-PRP. Furthermore, compared to P-PRP, L-PRP induced the differentiated NPMSCs to upregulate the expression of TNF-α and IL-1β, enhanced activation of the NF-κB pathway, increased the expression of MMP-1 and MMP-13, and produced less ECM in differentiated NPMSCs.

Conclusions

Both P-PRP and L-PRP can induce the proliferation and NP-differentiation of NPMSCs. Compared to L-PRP, P-PRP can avoid the activation of the NF-κB pathway, thus reducing the inflammatory and catabolic responses.

Photobiomodulation of extracellular matrix enzymes in human nucleus pulposus cells as a potential treatment for intervertebral disk degeneration

Intervertebral disc (IVD) degeneration is associated with imbalances between catabolic and anabolic responses, regulated by extracellular matrix (ECM)-modifying enzymes such as matrix metalloproteinases (MMPs) and their endogenous tissue inhibitors of metalloproteinases (TIMPs). Potential contributing factors, such as interleukin (IL)-1β and tumor necrosis factor (TNF)-α, derived from infiltrated, activated macrophages within IVD tissues, can trigger abnormal production of ECM-modifying enzymes and progression of IVD degeneration. Novel therapies for regulating ECM-modifying enzymes can prevent or ameliorate IVD degeneration. Photobiomodulation (PBM), known to regulate wound repair, exhibits regenerative potential by modulating biological molecules. This study examined the effects of PBM, administered at various wavelengths (630, 525, and 465 nm) and energy densities (16, 32, and 64 J/cm²), on the production of ECM-modifying enzymes in replicated degenerative IVD. Our results showed that PBM selectively inhibited the production of ECM-modifying enzymes in a dose- and wavelength-dependent manner, suggesting that it could be a novel tool for treating symptomatic IVD degeneration.

Strategies for Annulus Fibrosus Regeneration: From Biological Therapies to Tissue Engineering

Intervertebral disc (IVD) is an avascular tissue which contributes to the weight bearing, motion, and flexibility of spine. However, IVD is susceptible to damage and even failure due to injury, pathology, and aging. Annulus fibrosus (AF), the structural and functional integrity of which is critically essential to confine nucleus pulpous (NP) and maintain physiological intradiscal pressure under mechanical loading, plays a critical role in the biomechanical properties of IVD. AF degeneration commonly results in substantial deterioration of IVD. During this process, the biomechanical properties of AF and the balance between anabolism and catabolism in IVD are progressively disrupted, leading to chronic back pain, and even disability of individuals. Therefore, repairing and regenerating AF are effective treatments to degeneration-associated pains. However, they remain highly challenging due to the complexity of natural AF tissue in the aspects of cell phenotype, biochemical composition, microstructure, and mechanical properties. Tissue engineering (TE), by combining biological science and materials engineering, shed lights on AF regeneration. In this article, we review recent advances in the pro-anabolic approaches in the form of cell delivery, bioactive factors delivery, gene therapy, and TE strategies for achieving AF regeneration.

A selective inhibition of c-Fos/activator protein-1 as a potential therapeutic target for intervertebral disc degeneration and associated pain

Intervertebral disc (IVD) degeneration is a major cause of low back pain. The transcription factor c-Fos/Activator Protein-1 (AP-1) controls the expression of inflammatory cytokines and matrix metalloproteinases (MMPs) that contribute to the pathogenesis IVD degeneration. We investigated the effects of inhibition of c-Fos/AP-1 on IVD degeneration and associated pain. A selective inhibitor, T-5224, significantly suppressed the interleukin-1β-induced up-regulation of Mmp-3, Mmp-13 and Adamts-5 transcription in human nucleus pulposus cells and in a mouse explant culture model of IVD degeneration. We used a tail disc percutaneous needle puncture method to further assess the effects of oral administration of T-5224 on IVD degeneration. Analysis of disc height, T2-magnetic resonance imaging (MRI) findings, and histology revealed that IVD degeneration was significantly mitigated by T-5224. Further, oral administration of T-5224 ameliorated pain as indicated by the extended tail-flick latency in response to heat stimulation of rats with needle-puncture-induced IVD degeneration. These findings suggest that the inhibition of c-Fos/AP-1 prevents disc degeneration and its associated pain and that T-5224 may serve as a drug for the prevention of IVD degeneration.

Inflammatory Processes Associated with Canine Intervertebral Disc Herniation

Intervertebral disc herniation (IVDH) is an important pathology in humans and also in dogs. While the molecular disease mechanisms are well investigated in humans, little is known about the inflammatory mediators in naturally occurring canine IVDH. The objective of this study was to investigate whether the involved proinflammatory cytokines in human IVDH are also key cytokines in canine IVDH and thus to elucidate the suitability of the dog as a model for human trials. 59 samples from 25 dogs with surgically confirmed thoracolumbar IVDH were collected and classified in three subgroups: herniated (H), affected non-herniated (NH) disc, and adjacent non-affected (NA) disc. Discs from 11 healthy dogs acted as controls (C). Samples were analyzed for IL-1, IL-6, IL-8, and TNF-α expression (qPCR/ELISA) as well as cell infiltration and activation of the MAP kinase pathways (immunohistochemistry). Gene and protein expression of all key cytokines could be detected in IVDH affected dogs. Canine IVDH was significantly associated with a higher gene expression of IL-6 (H > C, NH > C) and TNF-α (H > C, NH > C, NA > C) and a significant down-regulation of IL-1β (H < C). Dogs with spontaneous pain had significantly higher IL-6 mRNA compared to those with pain arising only upon palpation. An inter-donor comparison (H and HN relative to NA) revealed a significant increase of IL-6 gene expression (H > NA, NH > NA). IL-8 (H > C, NA > C) and TNF-α (NH > C) protein levels were significantly increased in diseased dogs while inversely, IL-6 protein levels were significantly higher in patients with better clinical outcome. Aside from resident IVD cells, mostly monocytes and macrophages were found in extruded material, with concomitant activation of extracellular signal-regulated kinase p38 in the majority of samples. Dogs with spontaneous IVDH might provide a useful model for human disc diseases. Although the expression of key cytokines found in human IVDH was also demonstrated in canine tissue, the inflammatory mechanisms accompanying canine IVDH diverges partially from humans, which will require further investigations in the future. In dogs, IL-6 seems to play an important pathological role and may represent a new potential therapeutic target for canine patients.

Triptolide suppresses paraquat induced idiopathic pulmonary fibrosis by inhibiting TGFB1-dependent epithelial mesenchymal transition

Idiopathic pulmonary fibrosis (IPF) and tumor are highly similar to abnormal cell proliferation that damages the body. This malignant cell evolution in a stressful environment closely resembles that of epithelial-mesenchymal transition (EMT). As a popular EMT-inducing factor, TGFβ plays an important role in the progression of multiple diseases. However, the drugs that target TGFB1 are limited. In this study, we found that triptolide (TPL), a Chinese medicine extract, exerts an anti-lung fibrosis effect by inhibiting the EMT of lung epithelial cells. In addition, triptolide directly binds to TGFβ and subsequently increase E-cadherin expression and decrease vimentin expression. In in vivo studies, TPL improves the survival state and inhibits lung fibrosis in mice. In summary, this study revealed the potential therapeutic effect of paraquat induced TPL in lung fibrosis by regulating TGFβ-dependent EMT progression.

Triptolide exerts protective effects against fibrosis following ileocolonic anastomosis by mechanisms involving the miR-16-1/HSP70 pathway in IL-10-deficient mice

Surgeries, particularly ileocecal resection (ICR), are often required in the treatment of Crohn's disease (CD). However, recurrences are common for patients who undergo ICR, and anastomotic fibrosis is the main cause of re-operation. The present study aimed to investigate the therapeutic effects of triptolide (TPL) in ameliorating fibrosis following ileocolonic anastomosis. A model of IL-10^−/− mice undergoing ICR was used to study post surgical inflammation and fibrosis of anastomosis. For this purpsose, interleukin (IL)-10^−/− mice were randomly divided into 3 groups as follows: the control group, the saline-treated group subjected to ICR (ST-ICR) and the TPL-treated group subjected to ICR (TT-ICR). Wild-type (WT) mice of matching ages were assigned to the WT group. The effects of TPL treatment on ileocolonic anastomosis were determined by histopathological evaluation, western blot analysis and ELISA. The analysis of the effects of TPL treatment on microRNA-16-1 (miR-16-1) and heat shock protein 70 (HSP70) expression was carried out by RT-qPCR and western blot analysis. Compared with the control group, significantly higher inflammation scores following anastomosis were observed in the ST-ICR group (P<0.05), although reversion was observed in the TT-ICR group, which was consistent with changes in the area of CD₄⁺ cell infiltration. The elevated fibrosis scores and the overexpression of procollagen I and III in the ST-ICR group were all inhibited by TPL. With an increase in the severity of inflammation and fibrosis, the levels of IL-6, tumor necrosis factor-α (TNF-α) and transforming growth factor-β1 (TGF-β1) increased; however, a significant decrease in these levels was observed following treatment with TPL (P<0.05). The results of RT-qPCR revealed that the upregulated miR-16-1 levels in the ST-ICR group were significantly reduced by TPL. HSP70, which can be inhibited by miR-16-1, ameliorates anastomotic inflammation and fibrosis. Thus, the present study demonstrates that TPL exerts a protective effect against fibrosis following anastomosis in CD. The miR-16-1/HSP70 signaling pathway, which can be regulated by TPL, may thus represent a novel therapeutic option in CD that deserves further investigation.

Surgical anatomy, radiological features, and molecular biology of the lumbar intervertebral discs

The intervertebral disc (IVD) is a joint unique in structure and functions. Lying between adjacent vertebrae, it provides both the primary support and the elasticity required for the spine to move stably. Various aspects of the IVD have long been studied by researchers seeking a better understanding of its dynamics, aging, and subsequent disorders. In this article, we review the surgical anatomy, imaging modalities, and molecular biology of the lumbar IVD. Clin. Anat. 30:251-266, 2017. © 2017 Wiley Periodicals, Inc.

17beta-estradiol Attenuates TNF-α-Induced Premature Senescence of Nucleus Pulposus Cells through Regulating the ROS/NF-κB Pathway

Background: Accelerated cellular senescence within the nucleus pulposus (NP) region is a common feature of disc degeneration. Our previous work indicated that TNF-α promoted NP cell senescence. Although the intervertebral disc has been reported to be an estrogen-sensitive tissue, it is unclear whether estrogen can inhibit premature senescence of NP cells.

Objective: To investigate whether 17beta-estradiol (E₂) can attenuate TNF-α-induced premature senescence of NP cells and the potential mechanism behind this regulatory process.

Methods: Isolated NP cells and intact intervertebral discs from healthy rats were cultured with or without TNF-α, E₂ or their combination. The pan estrogen receptor (ER) antagonist ICI 182780 was used to investigate the role of ER. Direct and indirect indicators including cell proliferation, SA-β-Gal activity, telomerase activity, cell cycle, and the expression of matrix macromolecules (aggrecan and collagen II) and senescence markers (p16 and p53) were used to evaluate the premature senescence of NP cells. Additionally, intracellular reactive oxygen species (ROS) and NF-κB/p65 activity were also detected in the NP cell cultures.

Results: In the NP cell cultures, E₂ significantly increased cell proliferation potency, telomerase activity and the expression of matrix macromolecules but attenuated SA-β-Gal activity, senescence marker (p53 and p16) expression and G1 cycle arrest in TNF-α-treated NP cells. Furthermore, E₂ inhibited ROS generation and phospho-NF-κB/p65 expression in the TNF-α-treated NP cells. However, the ER antagonist ICI 182780 abolished the effects of E₂ on TNF-α-treated NP cells. In the disc organ cultures, E₂ also significantly increased matrix synthesis, whereas it decreased senescence marker (p53 and p16) expression, which could be abolished by the ER antagonist ICI 182780.

Conclusion: The interaction between E₂ and ER can attenuate TNF-α-induced premature senescence of rat NP cells through interfering with the ROS/NF-κB pathway.

An Inflammatory Nucleus Pulposus Tissue Culture Model to Test Molecular Regenerative Therapies: Validation with Epigallocatechin 3-Gallate

Organ cultures are practical tools to investigate regenerative strategies for the intervertebral disc. However, most existing organ culture systems induce severe tissue degradation with only limited representation of the in vivo processes. The objective of this study was to develop a space- and cost-efficient tissue culture model, which represents degenerative processes of the nucleus pulposus (NP). Intact bovine NPs were cultured in a previously developed system using Dyneema jackets. Degenerative changes in the NP tissue were induced either by the direct injection of chondroitinase ABC (1-20 U/mL) or by the diffusion of interleukin-1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) (both 100 ng/mL) from the culture media. Extracellular matrix composition (collagens, proteoglycans, water, and DNA) and the expression of inflammatory and catabolic genes were analyzed. The anti-inflammatory and anti-catabolic compound epigallocatechin 3-gallate (EGCG, 10 µM) was employed to assess the relevance of the degenerative NP model. Although a single injection of chondroitinase ABC reduced the proteoglycan content in the NPs, it did not activate cellular responses. On the other hand, IL-1β and TNF-α significantly increased the mRNA expression of inflammatory mediators IL-6, IL-8, inducible nitric oxide synthase (iNOS), prostaglandin-endoperoxide synthase 2 (PTGS2) and matrix metalloproteinases (MMP1, MMP3, and MMP13). The cytokine-induced gene expression in the NPs was ameliorated with EGCG. This study provides a proof of concept that inflammatory NP cultures, with appropriate containment, can be useful for the discovery and evaluation of molecular therapeutic strategies against early degenerative disc disease.

Immunosuppressive, anti-inflammatory and anti-cancer properties of triptolide: A mini review

OBJECTIVE

Triptolide, the active component of Tripterygium wilfordii Hook F has been used to treat autoimmune and inflammatory conditions for over two hundred years in traditional Chinese medicine. However, the processes through which triptolide exerts immunosuppression and anti-inflammation are not understood well. In this review, we discuss the autoimmune disorders and inflammatory conditions that are currently treated with triptolide. Triptolide also possesses anti-tumorigenic effects. We discuss the toxicity of various triptolide derivatives and offer suggestions to improve its safety. This study also examines the clinical trials that have investigated the efficacy of triptolide. Our aim is to examine the mechanisms that are responsible for the immunosuppressive, anti-inflammatory, and anti-cancer effects of triptolide.

MATERIALS AND METHODS

The present review provides a comprehensive summary of the literature with respect to the immunosuppressive, anti-inflammatory, and anti-cancer properties of triptolide.

RESULTS

Triptolide possesses immunosuppressive, anti-inflammatory, and anti-cancer effects.

CONCLUSION

Triptolide can be used alone or in combination with existing therapeutic modalities as novel treatments for autoimmune disorders, cancers, and for immunosuppression.

Piperine mediates LPS induced inflammatory and catabolic effects in rat intervertebral disc

Piperine is an exact of the active phenolic component from Black pepper. It has been reported to have many biological activities including anti-oxidant, anti-inflammatory and anti-tumor effects. Intervertebral disc degeneration (IDD) is a degenerative disease closely relate to inflammation of nucleus pulposus (NP) cells. This study aimed to assess the anti-inflammatory and anti-catabolic effects of piperine in rat intervertebral disc using in vitro and ex vivo analyzes. We demonstrated that piperine could inhibit LPS induced expression and production of inflammatory factors and catabolic proteases in NP cells culture model. It significantly inhibited multiple inflammatory factors and oxidative stress-associated genes (IL-1β, TNF-α, IL-6, iNOS), MMPs (MMP-3, MMP-13), ADAMTS (ADAMTS-4, ADAMTS-5) mRNA expression and NO production in a concentration-dependent manner. Moreover, piperine could reverse the LPS-induced inhibition of gene expression of aggrecan and collagen-II. Histologic and dimethylmethylene blue analysis indicated piperine could also against LPS induced proteoglycan (PG) depletion in a rat intervertebral disc culture model. Western blot results showed that piperine inhibited the LPS-mediated phosphorylation of JNK and activation of NF-κB. Finally, our results demonstrated the ability of piperine to antagonize LPS-mediated inflammation of NP cells and suppression of PG in rat intervertebral disc, suggesting a potential agent for treatment of IDD in future.

Neuroprotective effects of DAHP and Triptolide in focal cerebral ischemia via apoptosis inhibition and PI3K/Akt/mTOR pathway activation

Triptolide (TP), one of the major active components of the traditional Chinese herb Tripterygium wilfordii Hook F, and 2, 4-diamino-6-hydroxypyrimidine (DAHP), an inhibitor of tetrahydrobiopterin (BH4) synthesis, have been reported to have potent anti-inflammatory and immunosuppressive properties. However, the protective effects of TP and DAHP on cerebral ischemia have not been reported yet. In this study, we investigated the neuroprotective effects of TP and DAHP in a middle cerebral artery occlusion (MCAO) rat model. Furthermore, we examined whether the neuroprotective effects of TP and DAHP were associated with the inhibition of apoptosis through suppressing BH4 and inducible NOS (iNOS) synthesis or the activation of the phosphoinositide-3-kinase/serine-threonine kinase Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway. Our results showed that pretreatments with TP (0.2 mg/kg) and DAHP (0.5 g/kg) significantly reduced ischemic lesion volume, water content, and neuronal cell death compared with the vehicle MCAO rats. In addition, compared with the MCAO group, TP, and DAHP pretreatment groups significantly reduced astrocyte numbers, caspase-3, cleaved caspase-3, and NF-κB up-regulation, while increased Bcl-2 expression. Moreover, protein expressions of PI3K, Akt, and mTOR increased, while extracellular signal-regulated protein kinases 1 and 2 (ERK1 and ERK2) phosphorylation decreased in both the TP-treated rats and DAHP-treated rats. These results demonstrate that TP and DAHP can decrease cell apoptosis in focal cerebral ischemia rat brains and that the mechanism may be related to the activation of the PI3K/Akt/mTOR pathway and inactivation of the ERK1/2 pathway. Thus our hypothesis was reached PI3K/Akt/mTOR and ERK1/2 pathways may provide distinct cellular targets for a new generation of therapeutic agents for the treatment of stroke, and TP and DAHP may be potential neuroprotective agents for cerebral ischemia/reperfusion injury.

Current trends in biologics delivery to restore intervertebral disc anabolism

Low back pain is generally attributed to intervertebral disc (IVD) degeneration. This is a multifactorial disease induced by genetic and environmental factors and that progresses with aging. Disc degeneration is characterized by a limited ability of IVD cells to produce functional matrix while producing abnormal amounts of matrix-degrading enzymes. The prolonged imbalance between anabolism and catabolism in degenerative discs alters their composition and hydration. In turn, this results in increased angiogenesis and the loss of the disc's ability to maintain its aneural condition. Inflammation in the IVD, in particular the presence of pro-inflammatory cytokines, was found to favor innervation and also sensitization of the nociceptive pathways, thereby exacerbating degenerative symptoms. In this review, we discuss anti-inflammatory approaches to encounter disc catabolism, potential treatments to lower discogenic pain and pro-anabolic approaches in the form of protein delivery, gene therapy and cell delivery, to trigger regeneration in the IVD.

Autophagy upregulation and apoptosis downregulation in DAHP and triptolide treated cerebral ischemia

It has previously been demonstrated that ischemic stroke activates autophagy pathways; however, the mechanism remains unclear. The aim of this study is to further investigate the role that autophagy plays in cerebral ischemia. 2, 4-diamino-6-hydroxy-pyrimidine (DAHP), for its nitric oxide synthase (NOS) inhibiting neuroprotective effect, and triptolide (TP), for its anti-inflammatory property, were selected to administer pre middle cerebral artery occlusion (MCAO). The drugs were administered 12 hours prior to MCAO. Both magnetic resonance imaging (MRI) and 2, 3, 5-triphenyltetrazolium chloride (TTC) staining showed that the drugs reduce the area of infarction. Immunoblotting analysis revealed increases in Beclin-1 and myeloid cell leukelia-1(Mcl-1) in treated rats. This could be a contributing factor to the reduction in autophagy induced damage. Immunochemistry and western blot showed that mTOR expression in treated rats was marginally different 24 h after injury, and this could also be significant in the mechanism. Furthermore, terminal deoxynucleotidyl transferase- (TdT-) mediated dUTP nick end labeling (TUNEL) staining proved that the drugs are effective in reducing apoptosis. The upregulation of Beclin-1 and Mcl-1 and downregulation of Bcl-2, caspase-3, and the Bcl-2/Beclin-1 ratio infer that the neuroprotective effect of DAHP and TP act via the mediation of autophagy and apoptosis pathways.

Triptolide: progress on research in pharmacodynamics and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Tripterygium wilfordii Hook. f. (Tripterygium wilfordii), also known as Huangteng and gelsemium elegan, is a traditional Chinese medicine that has been marketed in China as Tripterygium wilfordii glycoside tablets. Triptolide (TP), an active component in Tripterygium wilfordii extracts, has been used to treat various diseases, including lupus, cancer, rheumatoid arthritis and nephritic syndrome. This review summarizes recent developments in the research on the pharmacodynamics, pharmacokinetics, pharmacy and toxicology of TP, with a focus on its novel mechanism of reducing toxicity. This review provides insight for future studies on traditional Chinese medicine, a field that is both historically and currently important.

MATERIALS AND METHODS

We included studies published primarily within the last five years that were available in online academic databases (e.g., PubMed, Google Scholar, CNKI, SciFinder and Web of Science).

RESULTS

TP has a long history of use in China because it displays multiple pharmacological activities, including anti-rheumatism, anti-inflammatory, anti-tumor and neuroprotective properties. It has been widely used for the treatment of various diseases, such as rheumatoid arthritis, nephritic syndrome, lupus, Behcet׳s disease and central nervous system diseases. Recently, numerous breakthroughs have been made in our understanding of the pharmacological efficacy of TP. Although TP has been marketed as a traditional Chinese medicine, its multi-organ toxicity prevents it from being widely used in clinical practice.

CONCLUSIONS

Triptolide, a biologically active natural product extracted from the root of Tripterygium wilfordii, has shown promising pharmacological effects, particularly as an anti-tumor agent. Currently, in anti-cancer research, more effort should be devoted to investigating effective anti-tumor targets and confirming the anti-tumor spectrum and clinical indications of novel anti-tumor pro-drugs. To apply TP appropriately, with high efficacy and low toxicity, the safety and non-toxic dose range for specific target organs and diseases should be determined, the altered pathways and mechanisms of exposure need to be clarified, and an early warning system for toxicity needs to be established. With further in-depth study of the efficacy and toxicity of TP, we believe that TP will become a promising multi-use drug with improved clinical efficacy and safety in the future.

Leptin induces terminal differentiation of rat annulus fibrosus cells via activation of MAPK signaling

Both leptin and its receptor are expressed in rat annulus fibrosus (AF) cells. However, little is known about their role and mechanism during disc degeneration. The mitogen activating protein kinase (MAPK) pathway which mediates leptin-induced terminal differentiation of rat AF cells was analyzed using PCR, Western-blot and immunocytochemistry. It was found that leptin-induced AF cells terminal differentiation, which may be attributed to upregulated p38 and ERK1/2 phosphorylation, however, JNK phosphorylation was not observed. Specific inhibitors of p38 or ERK1/2, but not JNK, could inhibit the stimulative activity of leptin on collagen X and MMP-13 protein levels. This study, for the first time, shows that the MAPK pathway, especially p38 and ERK1/2 signaling, plays a distinct role in leptin-induced AF cells terminal differentiation.

Tumor necrosis factor-α- and interleukin-1β-dependent matrix metalloproteinase-3 expression in nucleus pulposus cells requires cooperative signaling via syndecan 4 and mitogen-activated protein kinase-NF-κB axis: implications in inflammatory disc disease

Matrix metalloproteinase-3 (MMP-3) plays an important role in intervertebral disc degeneration, a ubiquitous condition closely linked to low back pain and disability. Elevated expression of syndecan 4, a cell surface heparan sulfate proteoglycan, actively controls disc matrix catabolism. However, the relationship between MMP-3 expression and syndecan 4 in the context of inflammatory disc disease has not been clearly defined. We investigated the mechanisms by which cytokines control MMP-3 expression in rat and human nucleus pulposus cells. Cytokine treatment increased MMP-3 expression and promoter activity. Stable silencing of syndecan 4 blocked cytokine-mediated MMP-3 expression; more important, syndecan 4 did not mediate its effects through NF-κB or mitogen-activated protein kinase (MAPK) pathways. However, treatment with MAPK and NF-κB inhibitors resulted in partial blocking of the inductive effect of cytokines on MMP-3 expression. Loss-of-function studies confirmed that NF-κB, p38α/β2/γ/δ, and extracellular signal-regulated kinase (ERK) 2, but not ERK1, contributed to cytokine-dependent induction of MMP3 promoter activity. Similarly, inhibitor treatments, lentiviral short hairpin-p65, and short hairpin-IκB kinase β significantly decreased cytokine-dependent up-regulation in MMP-3 expression. Finally, we show that transforming growth factor-β can block the up-regulation of MMP-3 induced by tumor necrosis factor (TNF)-α by counteracting the NF-κB pathway and syndecan 4 expression. Taken together, our results suggest that cooperative signaling through syndecan 4 and the TNF receptor 1-MAPK-NF-κB axis is required for TNF-α-dependent expression of MMP-3 in nucleus pulposus cells. Controlling these pathways may slow the progression of intervertebral disc degeneration and matrix catabolism.

Expression and regulation of toll-like receptors (TLRs) in human intervertebral disc cells

PURPOSE

Although inflammatory processes play an essential role in painful intervertebral disc (IVD) degeneration, the underlying regulatory mechanisms are not well understood. This study was designed to investigate the expression, regulation and importance of specific toll-like receptors (TLRs)--which have been shown to play an essential role e.g. in osteoarthritis--during degenerative disc disease.

METHODS

The expression of TLRs in human IVDs was measured in isolated cells as well as in normal or degenerated IVD tissue. The role of IL-1β or TNF-α in regulating TLRs (expression/activation) as well as in regulating activity of down-stream pathways (NF-κB) and expression of inflammation-related genes (IL-6, IL-8, HSP60, HSP70, HMGB1) was analyzed.

RESULTS

Expression of TLR1/2/3/4/5/6/9/10 was detected in isolated human IVD cells, with TLR1/2/4/6 being dependent on the degree of IVD degeneration. Stimulation with IL-1β or TNF-α moderately increased TLR1/TLR4 mRNA expression (TNF-α only), and strongly increased TLR2 mRNA expression (IL-1β/TNF-α), with the latter being confirmed on the protein level. Stimulation with IL-1β, TNF-α or Pam3CSK4 (a TLR2-ligand) stimulated IL-6 and IL-8, which was inhibited by a TLR2 neutralizing antibody for Pam3CSK4; IL-1β and TNF-α caused NF-κB activation. HSP60, HSP70 and HMGB1 did not increase IL-6 or IL-8 and were not regulated by IL-1β/TNF-α.

CONCLUSION

We provide evidence that several TLRs are expressed in human IVD cells, with TLR2 possibly playing the most crucial role. As TLRs mediate catabolic and inflammatory processes, increased levels of TLRs may lead to aggravated disc degeneration, chronic inflammation and pain development. Especially with the identification of more endogenous TLR ligands, targeting these receptors may hold therapeutic promise.

Triptolide ameliorates lipopolysaccharide-induced acute lung injury in rats

Background

Acute lung injury (ALI) is a serious clinical syndrome with a high rate of mortality. In this study, the effects of triptolide on lipopolysaccharide (LPS)-induced ALI in rats were investigated.

Methods

Sixty-five male Sprague Dawley rats(approved by ethics committee of the First Affiliated Hospital of Soochow University) were randomly divided into five groups. The control group was injected with 2.5 mL saline/kg body weight via the tail vein and intraperitoneally with 1% dimethyl sulfoxide (DMSO) (n = 5). The L group was administered with 0.2% LPS dissolved in saline (5 mg/kg) to induce ALI via the tail vein (n = 15). The TP1, TP2, and TP3 groups were treated as rats in the L group and then intraperitoneally injected with 25, 50, and 100 μg triptolide/kg body weight, respectively (15 rats per group). Blood samples from the left heart artery were taken for blood gas analysis at 1 hour before injection and at 1, 3, 6, and 12 hours after saline and DMSO administration in the control group, LPS injection in the L group, and triptolide injection in the TP1, TP2, and TP3 groups. Lung wet-to-dry weight (W/D) ratio, diffuse alveolar damage (DAD) score, TNF-α levels, and mRNA and protein expression of toll-like receptor 4 (TLR4) were analyzed.

Results

Compared with the control group, the arterial partial pressure of oxygen (PaO₂) declined (P <0.05), the W/D ratio and DAD score increased (P <0.05), and TNF-α levels in serum and bronchoalveolar lavage fluid (BALF) and mRNA and protein expression of TLR4 were significantly increased in the L group (P <0.05). Compared with the L group, PaO₂ significantly increased in the TP2 and TP3 groups (P <0.05), while the W/D ratio and DAD score were significantly decreased in the TP2 and TP3 groups (P <0.05). TNF-α levels and mRNA and protein expression of TLR4 were significantly decreased in the TP2 and TP3 groups compared with the L group (P <0.05).

Conclusions

Triptolide can ameliorate LPS-induced ALI by reducing the release of the inflammatory mediator TNF-α and inhibiting TLR4 expression.

Role of cytokines in intervertebral disc degeneration: pain and disc content

Degeneration of the intervertebral discs (IVDs) is a major contributor to back, neck and radicular pain. IVD degeneration is characterized by increases in levels of the proinflammatory cytokines TNF, IL-1α, IL-1β, IL-6 and IL-17 secreted by the IVD cells; these cytokines promote extracellular matrix degradation, chemokine production and changes in IVD cell phenotype. The resulting imbalance in catabolic and anabolic responses leads to the degeneration of IVD tissues, as well as disc herniation and radicular pain. The release of chemokines from degenerating discs promotes the infiltration and activation of immune cells, further amplifying the inflammatory cascade. Leukocyte migration into the IVD is accompanied by the appearance of microvasculature tissue and nerve fibres. Furthermore, neurogenic factors, generated by both disc and immune cells, induce expression of pain-associated cation channels in the dorsal root ganglion. Depolarization of these ion channels is likely to promote discogenic and radicular pain, and reinforce the cytokine-mediated degenerative cascade. Taken together, an enhanced understanding of the contribution of cytokines and immune cells to these catabolic, angiogenic and nociceptive processes could provide new targets for the treatment of symptomatic disc disease. In this Review, the role of key inflammatory cytokines during each of the individual phases of degenerative disc disease, as well as the outcomes of major clinical studies aimed at blocking cytokine function, are discussed.

Metabolite profiling and identification of triptolide in rats

The purpose of the current study was to investigate the metabolite profile of [(3)H]triptolide in rats. The separation and characterisation techniques used to identify the major metabolites were high-performance liquid chromatography-online radiodetector, ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry, and nuclear magnetic resonance. In all, 33 major metabolites were detected. The major components found in the rat plasma included the parent drug and its monohydroxy- and dihydroxy-metabolites. Reference standards for the monohydroxy-metabolites were obtained either by the incubation of the parent drug with rat liver microsomes or by microbial transformation with Cunninghamella blakesleana. The metabolites' structures were identified as 17-hydroxytriptolide, 16-hydroxytriptolide, tripdiolide, and 15-hydroxytriptolide. The major metabolites found in male rat urine included the monohydroxy-, dihydroxy-, and trihydroxy-metabolites. The major metabolites in female rat urine were the monohydroxy- and dihydroxy-metabolites, as well as sulphates of the monohydroxy-metabolites. A glutathione adduct, multiple hydroxy-metabolites, and a number of unidentified metabolites were detected in the bile and faeces of male rats. Sulphates of monohydroxy-metabolites were detected in the bile and faeces of female rats.

Inflammatory mediators in intervertebral disk degeneration and discogenic pain

Although degeneration of the intervertebral disk has historically been described as a misbalance between anabolic and catabolic factors, the role of inflammatory mediators has long been neglected. However, past research clearly indicates that inflammatory mediators such as interleukin (IL)-1β, IL-6, IL-8 and tumor necrosis factor-α are expressed at higher levels in "diseased" intervertebral disks. Both disk cells as well as invading macrophages can be the source of the detected cytokines. Importantly, occurrence of inflammatory mediators in the disk can worsen the progress of degeneration by inducing the expression of matrix degrading enzymes as well as by inhibiting extracellular matrix synthesis. In addition, inflammatory mediators play a crucial role in pain development during intervertebral disk herniation (i.e., sciatica) and disk degeneration (i.e., discogenic pain). This review provides information on the most relevant inflammatory mediators during different types of disk diseases and explains how these factors can induce disk degeneration and the development of discogenic and sciatic/radiculopathic pain.

Regulation of cytokine and chemokine expression by the ribotoxic stress response elicited by Shiga toxin type 1 in human macrophage-like THP-1 cells

Shiga toxins (Stxs) are cytotoxins produced by the enteric pathogens Shigella dysenteriae serotype 1 and Shiga toxin-producing Escherichia coli (STEC). Stxs bind to a membrane glycolipid receptor, enter cells, and undergo retrograde transport to ultimately reach the cytosol, where the toxins exert their protein synthesis-inhibitory activity by depurination of a single adenine residue from the 28S rRNA component of eukaryotic ribosomes. The depurination reaction activates the ribotoxic stress response, leading to signaling via the mitogen-activated protein kinase (MAPK) pathways (Jun N-terminal protein kinase [JNK], p38, and extracellular signal-regulated kinase [ERK]) in human epithelial, endothelial, and myeloid cells. We previously showed that treatment of human macrophage-like THP-1 cells with Stxs resulted in increased cytokine and chemokine expression. In the present study, we show that individual inactivation of ERK, JNK, and p38 MAPKs using pharmacological inhibitors in the presence of Stx1 resulted in differential regulation of the cytokines tumor necrosis factor alpha and interleukin-1β (IL-1β) and chemokines IL-8, growth-regulated protein-β, macrophage inflammatory protein-1α (MIP-1α), and MIP-1β. THP-1 cells exposed to Stx1 upregulate the expression of select dual-specificity phosphatases (DUSPs), enzymes that dephosphorylate and inactivate MAPKs in mammalian cells. In this study, we confirmed DUSP1 protein production by THP-1 cells treated with Stx1. DUSP1 inhibition by triptolide showed that ERK and p38 phosphorylation is regulated by DUSP1, while JNK phosphorylation is not. Inhibition of p38 MAPK signaling blocked the ability of Stx1 to induce DUSP1 mRNA expression, suggesting that an autoregulatory signaling loop may be activated by Stxs. Thus, Stxs appear to be capable of eliciting signals which both activate and deactivate signaling for increased cytokine/chemokine production in human macrophage-like cells.

TLR2 signaling subpathways regulate TLR9 signaling for the effective induction of IL-12 upon stimulation by heat-killed Brucella abortus

Brucella abortus is a Gram-negative intracellular bacterium that induces MyD88-dependent IL-12 production in dentritic cells (DCs) and a subsequent protective Th1 immune response. Previous studies have shown that the Toll-like receptor 2 (TLR2) is required for tumor-necrosis factor (TNF) production, whereas TLR9 is responsible for IL-12 induction in DCs after exposure to heat-killed Brucella abortus (HKBA). TLR2 is located on the cell surface and is required for optimal microorganism-induced phagocytosis by innate immune cells; thus, phagocytosis is an indispensable preliminary step for bacterial genomic DNA recognition by TLR9 in late-endosomal compartments. Here, we hypothesized that TLR2-triggered signals after HKBA stimulation might cross-regulate TLR9 signaling through the indirect modulation of the phagocytic function of DCs or the direct modulation of cytokine gene expression. Our results indicate that HKBA phagocytosis was TLR2-dependent and an essential step for IL-12p40 induction. In addition, HKBA exposure triggered the TLR2-mediated activation of both p38 and extracellular signal-regulated kinase 1/2 (ERK1/2). Interestingly, although p38 was required for HKBA phagocytosis and phagosome maturation, ERK1/2 did not affect these processes but negatively regulated IL-12 production. Although p38 inhibitors tempered both TNF and IL-12 responses to HKBA, pre-treatment with an ERK1/2 inhibitor significantly increased IL-12p40 and abrogated TNF production in HKBA-stimulated DCs. Further experiments showed that the signaling events that mediated ERK1/2 activation after TLR2 triggering also required HKBA-induced Ras activation. Furthermore, Ras-guanine nucleotide-releasing protein 1 (RasGRP1) mediated the TLR2-induced ERK1/2 activation and inhibition of IL-12p40 production. Taken together, our results demonstrated that HKBA-mediated TLR2-triggering activates both the p38 and ERK1/2 signaling subpathways, which divergently regulate TLR9 activation at several levels to induce an appropriate protective IL-12 response.