ABSTRACT
Many compounds of ginsenosides show anti-inflammatory properties. However, their anti-inflammatory effects in intervertebral chondrocytes in the presence of inflammatory factors have never been shown. Increased levels of pro-inflammatory cytokines are generally associated with the degradation and death of chondrocytes; therefore, finding an effective and nontoxic substance that attenuates the inflammation is worthwhile. In this study, chondrocytes were isolated from the nucleus pulposus tissues, and the cells were treated with ginsenoside compounds and IL-1ß, alone and in combination. Cell viability and death rate were assessed by CCK-8 and flow cytometry methods, respectively. PCR, western blot, and immunoprecipitation assays were performed to determine the mRNA and protein expression, and the interactions between proteins, respectively. Monomeric component of ginsenoside Rd had no toxicity at the tested range of concentrations. Furthermore, Rd suppressed the inflammatory response of chondrocytes to interleukin (IL)-1ß by suppressing the increase in IL-1ß, tumor necrosis factor (TNF)-α, IL-6, COX-2, and inducible nitric oxide synthase (iNOS) expression, and retarding IL-1ß-induced degradation of chondrocytes by improving cell proliferation characteristics and expression of aggrecan and COL2A1. These protective effects of Rd were associated with ubiquitination of IL-1 receptor accessory protein (IL1RAP), blocking the stimulation of IL-1ß to NF-κB. Bioinformatics analysis showed that NEDD4, CBL, CBLB, CBLC, and ITCH most likely target IL1RAP. Rd increased intracellular ITCH level and the amount of ITCH attaching to IL1RAP. Thus, IL1RAP ubiquitination promoted by Rd is likely to occur by up-regulation of ITCH. In summary, Rd inhibited IL-1ß-induced inflammation and degradation of intervertebral disc chondrocytes by increasing IL1RAP ubiquitination.
Subject(s)
Chondrocytes/drug effects , Ginsenosides/pharmacology , Interleukin-1 Receptor Accessory Protein/metabolism , Interleukin-1beta/drug effects , Intervertebral Disc Degeneration/metabolism , Adult , Aged , Aggrecans/metabolism , Cell Survival/drug effects , Chondrocytes/cytology , Chondrocytes/metabolism , Cyclooxygenase 2/metabolism , Dinoprostone/metabolism , Female , Ginsenosides/metabolism , Humans , Inflammation/metabolism , Interleukin-1beta/metabolism , Low Back Pain/metabolism , Male , Middle Aged , Nitric Oxide Synthase/metabolism , Nucleus Pulposus/cytology , Nucleus Pulposus/drug effects , Nucleus Pulposus/metabolism , Tumor Necrosis Factor-alpha/metabolism , UbiquitinationABSTRACT
Many compounds of ginsenosides show anti-inflammatory properties. However, their anti-inflammatory effects in intervertebral chondrocytes in the presence of inflammatory factors have never been shown. Increased levels of pro-inflammatory cytokines are generally associated with the degradation and death of chondrocytes; therefore, finding an effective and nontoxic substance that attenuates the inflammation is worthwhile. In this study, chondrocytes were isolated from the nucleus pulposus tissues, and the cells were treated with ginsenoside compounds and IL-1β, alone and in combination. Cell viability and death rate were assessed by CCK-8 and flow cytometry methods, respectively. PCR, western blot, and immunoprecipitation assays were performed to determine the mRNA and protein expression, and the interactions between proteins, respectively. Monomeric component of ginsenoside Rd had no toxicity at the tested range of concentrations. Furthermore, Rd suppressed the inflammatory response of chondrocytes to interleukin (IL)-1β by suppressing the increase in IL-1β, tumor necrosis factor (TNF)-α, IL-6, COX-2, and inducible nitric oxide synthase (iNOS) expression, and retarding IL-1β-induced degradation of chondrocytes by improving cell proliferation characteristics and expression of aggrecan and COL2A1. These protective effects of Rd were associated with ubiquitination of IL-1 receptor accessory protein (IL1RAP), blocking the stimulation of IL-1β to NF-κB. Bioinformatics analysis showed that NEDD4, CBL, CBLB, CBLC, and ITCH most likely target IL1RAP. Rd increased intracellular ITCH level and the amount of ITCH attaching to IL1RAP. Thus, IL1RAP ubiquitination promoted by Rd is likely to occur by up-regulation of ITCH. In summary, Rd inhibited IL-1β-induced inflammation and degradation of intervertebral disc chondrocytes by increasing IL1RAP ubiquitination.
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Chondrocytes/drug effects , Ginsenosides/pharmacology , Interleukin-1beta/drug effects , Interleukin-1 Receptor Accessory Protein/metabolism , Intervertebral Disc Degeneration/metabolism , Dinoprostone/metabolism , Cell Survival/drug effects , Tumor Necrosis Factor-alpha/metabolism , Low Back Pain/metabolism , Nitric Oxide Synthase/metabolism , Chondrocytes/cytology , Chondrocytes/metabolism , Ginsenosides/metabolism , Cyclooxygenase 2/metabolism , Aggrecans/metabolism , Interleukin-1beta/metabolism , Ubiquitination , Nucleus Pulposus/cytology , Nucleus Pulposus/drug effects , Nucleus Pulposus/metabolism , Inflammation/metabolismABSTRACT
There is an ongoing need to develop strategic combinations of therapeutic agents to prevent type 1 diabetes (T1D) or to preserve islet ß-cell mass in new-onset disease. Although clinical trials using candidate therapeutics are commonly based on preclinical studies, concern is growing regarding the reproducibility as well as the potential clinical translation of reported results using animal models of human disorders. In response, the National Institutes of Health Immune Tolerance Network and JDRF established a multicenter consortium of academic institutions designed to assess the efficacy and intergroup reproducibility of clinically applicable immunotherapies for reversing new-onset disease in the NOD mouse model of T1D. Predicated on prior studies, this consortium conducted coordinated, prospective studies, using joint standard operating procedures, fixed criteria for study entry, and common reagents, to optimize combined anti-CD3 treatment plus interleukin-1 (IL-1) blockade to reverse new-onset disease in NOD mice. We did not find that IL-1 blockade with anti-IL-1ß monoclonal antibody or IL-1trap provided additional benefit for reversing new-onset disease compared with anti-CD3 treatment alone. These results demonstrate the value of larger, multicenter preclinical studies for vetting and prioritizing therapeutics for future clinical use.