Brazilein inhibits epithelial-mesenchymal transition (EMT) and programmed death ligand 1 (PD-L1) expression in breast cancer cells

Triple-negative breast cancer (TNBC) exhibits high levels of Epithelial-mesenchymal transition (EMT) and Programmed death ligand 1 (PD-L1) expression, which promotes immune escape and metastasis. Brazilein is a natural compound extracted from Caesalpinia sappan L., and has been demonstrated to be an anti-inflammatory anti- proliferative and apoptosis-inducer in various cancer cells. Here, we investigated the effect of brazilein on EMT and PD-L1 expression in breast cancer cells and its related molecular mechanisms using MCF-7 and MDA-MB-231 cells as a model. Since the AKT, NF-κB, and GSK3β/β-catenin signaling were reported to be important mechanisms in immune escape and metastasis, the effect of brazilein on these signaling pathways were also found out in our study. Firstly, brazilein was treated on breast cancer cells at various concentrations to study cell viability, apoptosis, and apoptosis proteins. Then, breast cancer cells were treated with non-toxic concentrations of brazilein to study its influence on EMT and expression of PD-L1 protein using MTT, flow cytometry, western blot, and wound healing analysis, respectively. We found that brazilein exerts an anti-cancer effect by reducing cell viability via induction of apoptosis, while it also downregulated EMT and PD-L1 through suppression of phosphorylation of AKT, NF-κB, and GSK3β/β-catenin. Moreover, the migration ability was diminished by inhibiting the activation of MMP-9 and MMP-2. Taken together, brazilein might delay cancer progression through inhibition of EMT, PD-L1, and metastasis suggesting it might be a potential therapeutic option in breast cancer patients having a high level of EMT and PD-L1.

Sulfation of sialic acid is ubiquitous and essential for vertebrate development

Glycosylation of proteins and lipids occurs in vertebrates, usually terminating with sialylation, which regulates the physicochemical and biological properties of these glycoconjugates. Although less commonly known, sialic acid residues also undergo various modifications, such as acetylation, methylation, and sulfation. However, except for acetylation, the enzymes or functions of the other modification processes are unknown. To the best of our knowledge, this study is the first to demonstrate the ubiquitous occurrence of sulfated sialic acids and two genes encoding the sialate: O-sulfotransferases 1 and 2 in vertebrates. These two enzymes showed about 50% amino acid sequence identity, and appeared to be complementary to each other in acceptor substrate preferences. Gene targeting experiments showed that the deficiency of these genes was lethal for medaka fish during young fry development and accompanied by different phenotypes. Thus, the sulfation of sialic acids is essential for the vertebrate development.

Sesamin protects against neurotoxicity via inhibition of microglial activation under high glucose circumstances through modulating p38 and JNK signaling pathways

Diabetes mellitus (DM), one of the principal causes of morbidity and mortality worldwide, is implicated in the progression of age-related neurodegenerative diseases (NDDs), in which microglial activation is a crucial mediator. Sesamin, a kind of phytochemical, shows inhibitory effects on microglial activation. The present study studied whether sesamin protects against neurotoxicity triggered by high glucose-induced microglial activation. We firstly demonstrated that high doses of glucose, which mimics hyperglycemia in DM, did induce the activation of murine BV2 microglial cells, increasing inflammatory responses such as the production of ROS or inflammatory mediators like IL-1β, TNF-⍺, and nitric oxide, through activation of p38 and JNK signaling pathways. Next, conditioned medium (CM) collected from high glucose-activated BV2 cell culture was used to show aggravated neurotoxicity in differentiated PC12 cells, indicating that high glucose-activated microglia could induce neurotoxicity. Interestingly, pretreatment of BV2 cells with sesamin diminished high glucose-induced microglia activation and inflammatory responses. Moreover, neurotoxicity in PC12 cells was found to be decreased in the group treated with CM from the sesamin-pretreated BV2 cell culture, suggesting sesamin inhibited microglial activation, thereby protecting neurons from activated microglia-mediated neurotoxicity. Thus, sesamin might be a potential compound to use in the prevention of diabetic-induced NDDs.

Targeting Human Osteoarthritic Chondrocytes with Ligand Directed Bacteriophage-Based Particles

Osteoarthritis (OA) is a degenerative joint disease characterized by progressive deterioration and loss of articular cartilage. There is currently no treatment to reverse the onset of OA. Thus, we developed a targeted delivery strategy to transfer genes into primary human chondrocytes as a proof-of-concept study. We displayed a chondrocyte-affinity peptide (CAP) on the pIII minor coat protein of the M13 filamentous bacteriophage (phage)-based particle carrying a mammalian transgene cassette under cytomegalovirus CMV promoter and inverted terminal repeats (ITRs) cis elements of adeno-associated virus serotype 2 (AAV-2). Primary human articular chondrocytes (HACs) were used as an in vitro model, and the selectivity and binding properties of the CAP ligand in relation to the pathogenic conditions of HACs were characterized. We found that the CAP ligand is highly selective toward pathogenic HACs. Furthermore, the stability, cytotoxicity, and gene delivery efficacy of the CAP-displaying phage (CAP.Phage) were evaluated. We found that the phage particle is stable under a wide range of temperatures and pH values, while showing no cytotoxicity to HACs. Importantly, the CAP.Phage particle, carrying a secreted luciferase (Lucia) reporter gene, efficiently and selectively delivered transgene expression to HACs. In summary, it was found that the CAP ligand preferably binds to pathogenic chondrocytes, and the CAP.Phage particle successfully targets and delivers transgene to HACs.

Atorvastatin Attenuates Programmed Death Ligand-1 (PD-L1) Induction in Human Hepatocellular Carcinoma Cells

Liver cancer is the sixth most common cancer worldwide with high morbidity and mortality. Programmed death ligand 1 (PD-L1) is a major ligand of programmed death 1 receptor (PD1), and PD1/PD-L1 checkpoint acts as a negative regulator of the immune system. Cancers evade the host’s immune defense via PD-L1 expression. This study aimed to investigate the effects of tumor-related cytokines, interferon gamma (IFNγ), and tumor necrosis factor alpha (TNFα) on PD-L1 expression in human hepatocellular carcinoma cells, HepG2. Furthermore, as atorvastatin, a cholesterol-lowering agent, is documented for its immunomodulatory properties, its effect on PD-L1 expression was investigated. In this study, through real-time RT-PCR, Western blot, and immunocytochemistry methods, PD-L1 expression in both mRNA and protein levels was found to be synergistically upregulated in HepG2 by a combination of IFNγ and TNFα, and STAT1 activation was mainly responsible for that synergistic effect. Next, atorvastatin can inhibit the induction of PD-L1 by either IFNγ alone or IFNγ/TNFα combination treatment in HepG2 cells. In conclusion, in HepG2 cells, expression of PD-L1 was augmented by cytokines in the tumor microenvironment, and the effect of atorvastatin on tumor immune response through inhibition of PD-L1 induction should be taken into consideration in cancer patients who have been prescribed atorvastatin.

Bacteriophage-mediated therapy of chondrosarcoma by selective delivery of the tumor necrosis factor alpha (TNFα) gene

Chondrosarcoma is a cartilage-forming bone tumor, well known for intrinsic resistance to chemotherapy and radiotherapy. We have designed a targeted chondrosarcoma gene therapy using a bacteriophage (phage) particle to deliver therapeutic genes. Phage has no tropism for mammalian cells, allowing engineered phage to be targeted to specific cell surface receptors in cancer. We modified the phage capsid to display the RGD4C ligand on the pIII minor coat proteins to specifically bind to αvβ3 or αvβ5 integrin receptors. The endosomal escape peptide, H5WYG, was also displayed on recombinant pVIII major coat proteins to enhance gene delivery. Finally, a human tumor necrosis factor alpha (TNFα) therapeutic transgene expression cassette was incorporated into the phage genome. First, we found that human chondrosarcoma cells (SW1353) have high expression of αvβ3, αvβ5 integrin receptors, and both TNFα receptors. Targeted particle encoding a luciferase reporter gene efficiently and selectively mediated gene delivery to these cells. When SW1353 cells were treated with the targeted particle encoding a TNFα transgene, significant cell killing was evident and was associated with high expression of TNFα and apoptosis-related genes. In vivo, mice with established human chondrosarcoma showed suppression of tumors upon repetitive intravenous administrations of the targeted phage. These data show that our phage-based particle is a promising, selective, and efficient tool for targeted chondrosarcoma therapy.

Inhibition of programmed death ligand 1 (PD-L1) expression in breast cancer cells by sesamin

Programmed death ligand 1 (PD-L1) is overexpressed in some metastatic breast cancer subtypes, specifically triple-negative breast cancer (TNBC). This feature can assist in the eradication of anti-tumor immunity, thereby enhancing the survival of the tumor. This study aims to explore how sesamin affects PD-L1 expression in breast cancer cells and its related molecular mechanisms. We found high levels of expression of PD-L1 in both mRNA and protein levels in the TNBC cell line, MDA-MB231, but not in the luminal type-breast cancer cell line, MCF-7. We then demonstrated the tumor suppressive effect of sesamin, which induced the inhibition of cell proliferation in MDA-MB231 cells. Additionally, sesamin triggered PD-L1 downregulation (both mRNA and protein) through the inhibition of AKT, NF-κB and JAK/Stat signaling in MDA-MB231 cells. Moreover, the migration ability of MDA-MB231 cells was effectively diminished by sesamin via inhibition of the activation of MMP-9 and MMP-2. In summary, this study demonstrated that sesamin suppresses MDA-MB231 breast cancer cells' proliferation and migration; and decreases the expression of PD-L1 via the downregulation of AKT, NF-κB, and JAK/Stat signaling. Therefore, sesamin may be an effective alternative and novel therapeutic option for immunotherapy in breast cancer cells with high PD-L1 expression.

Protocatechuic acid inhibits inflammatory responses in LPS-activated BV2 microglia via regulating SIRT1/NF-κB pathway contributed to the suppression of microglial activation-induced PC12 cell apoptosis

SIRT1 exhibits inhibitory effects on microglial activation-induced neurodegeneration. Regulating SIRT1 may become a novel approach for curing neurodegenerative diseases. Protocatechuic acid (PA), a phenolic acid, has anti-neuroinflammatory effects. The effect of PA on SIRT1 in activated microglia remains unknown. Here, we examined whether PA has anti-inflammatory effects against microglial activation-induced neuronal cell death via regulating SIRT1 in microglia. We found that PA inhibited the release of inflammatory mediators in LPS-activated BV2 microglia via the SIRT1/NF-κB pathway and thereby attenuated microglial activation-induced PC12 cell apoptosis. This suggests that SIRT1 mediates the anti-neuroinflammatory effects of PA to ameliorate microglial activation-induced neuron death.

Inhibitory Effect of Hesperidin on the Expression of Programmed Death Ligand (PD-L1) in Breast Cancer

Programmed death ligand 1 (PD-L1) is overexpressed in the most aggressive breast cancer subtype, triple-negative breast cancer (TNBC), assisting the eradication of antitumor immunity, and thereby enhancing the survival of the tumor. This study explored how hesperidin affects PD-L1 expression, and thereby cancer progression in breast cancer cells. We found that MDA-MB231, the triple-negative breast adenocarcinoma cancer cell line, (high aggressiveness) has higher expression, in both mRNA and protein, of PD-L1 than that of the other breast cancer cell line, MCF-7 (low aggressiveness). Hesperidin inhibited cell proliferation in MDA-MB231 cells. Additionally, high expression of PD-L1 (both mRNA and protein) in aggressive cancer cells was strongly inhibited by hesperidin through inhibition of Akt and NF-κB signaling. Moreover, hesperidin treatment, by inhibiting activation of matrix metalloproteinases such as MMP-9 and MMP-2, suppressed the metastatic phenotype and cell migration in the PD-L1 high-expressing MDA-MB231 cells. In summary, hesperidin inhibits breast cancer cell growth through the inhibition of the expression of PD-L1 via downregulation of Akt and NF-κB signaling in TNBC. Moreover, hesperidin significantly suppresses cell migration of MDA-MB231 cells. Our findings reveal fresh insights into the anticancer effects of hesperidin which might have potential clinical implications.

Leptin alone and in combination with interleukin-1-beta induced cartilage degradation potentially inhibited by EPA and DHA

Osteoarthritis (OA) is the most common form of arthritis. Obesity has been believed to be an important risk factor for OA development and the progression of not only load-bearing joints, but low-load-bearing joints as well. Increased leptin has been the focus of a link between obesity and OA. In this study, the effects of pathological (100ng/ml) or supra-pathological (10μg/ml) concentrations of leptin alone or in combination with IL1β on cartilage metabolisms were studied in porcine cartilage explant. The involved mechanisms were examined in human articular chondrocytes (HACs). Moreover, the protective effect of omega-3 polyunsaturated acids, eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) was also investigated. Leptin (10μg/ml) alone or in combination with IL1β could induce cartilage destruction, although lower concentrations had no effect. Leptin activated NFκB, ERK, JNK and p38 in HACs, which led to the induction of MMP3, MMP13 and ADAMTS4 secretions. The combined effect could further induce those enzymes through the additive effect on activation of NFκB and JNK. Interestingly, both EPA and DHA could inhibit cartilage damage induced by leptin plus IL1β by reducing the activation of NFκB and JNK, which led to the decrease of ADAMTS4 secretion. Altogether, only a supra-pathological concentration of leptin alone or in combination with IL1β could induce cartilage destruction, whereas a pathological one could not. This effect could be inhibited by EPA and DHA. To gain greater understanding of the link between leptin and OA, the effect of different levels of leptin on several states of OA cartilage requires further investigation.

Effects of sesamin on primary human synovial fibroblasts and SW982 cell line induced by tumor necrosis factor-alpha as a synovitis-like model

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune disease that causes chronic synovitis, cartilage degradation and bone deformities. Synovitis is the term for inflammation of the synovial membrane, an early stage of RA. The pathogenesis of the disease occurs through cytokine induction. The major cytokine that increases the severity of RA is TNF-α. Thus, inhibition of the TNF-α cascade is an effective way to diminish the progression of the disease. We are interested in investigating the difference between primary human synovial fibroblast (hSF) cells and SW982 as synovitis models induced by TNF-α and in monitoring their responses to sesamin as an anti-inflammatory phytochemical.

METHOD

The designed experiments were performed in hSF cells or the SW982 cell line treated with 10 ng/ml TNF-α with or without 0.25, 0.5 or 1 μM sesamin. Subsequently, pro-inflammatory cytokine genes and proteins were measured in parallel with a study of associated signalling transduction involved in inflammatory processes, including NF-κB and MAPK pathways.

RESULTS

The results demonstrated that although hSF and SW982 cells responded to TNF-α induction in the same fashion, they reacted at different levels. TNF-α could induce IL-6, IL-8 and IL-1β in both cell types, but the levels in SW982 cells were much higher than in hSF cells. This characteristic was due to the different induction of MAPKs in each cell type. Both cell types reacted to sesamin in almost the same fashion. However, hSF cells were more sensitive to sesamin than SW982 cells in terms of the anti-RA effect.

CONCLUSIONS

The responses of TNF-α-induced hSF and SW982 were different at the signal transduction level. However, the two cell types showed almost the same reaction to sesamin treatment in terms of the end point of the response.

Ex vivo model exhibits protective effects of sesamin against destruction of cartilage induced with a combination of tumor necrosis factor-alpha and oncostatin M

Background

Rheumatoid arthritis (RA) is an autoimmune disease associated with chronic inflammatory arthritis. TNF-α and OSM are pro-inflammatory cytokines that play a key role in RA progression. Thus, reducing the effects of both cytokines is practical in order to relieve the progression of the disease. This current study is interested in sesamin, an active compound in sesame seeds. Sesamin has been shown to be a chondroprotective agent in osteoarthritis models. Here, we have evaluated a porcine cartilage explant as a cartilage degradation model related to RA induced by TNF-α and/or OSM in order to investigate the effects of sesamin on TNF-α and OSM in the cartilage degradation model.

Methods

A porcine cartilage explant was induced with a combination of TNF-α and OSM (test group) or IL-1β and OSM (control group) followed by a co-treatment of sesamin over a long-term period (35 days). After which, the tested explants were analyzed for indications of both the remaining and the degradation aspects using glycosaminoglycan and collagen as an indicator.

Results

The combination of TNF-α and OSM promoted cartilage degradation more than either TNF-α or OSM alone and was comparable with the combination of IL-1β and OSM. Sesamin could be offering protection against cartilage degradation by reducing GAGs and collagen turnover in the generated model.

Conclusions

Sesamin might be a promising agent as an alternative treatment for RA patients. Furthermore, the generated model revealed itself to be an impressive test model for the analysis of phytochemical substances against the cartilage degradation model for RA. The model could be used to test for the prevention of cartilage degradation in other biological agents induced with TNF-α and OSM as well.

Comparison of growth factor adsorbed scaffold and conventional scaffold with growth factor supplemented media for primary human articular chondrocyte 3D culture

Background

Cartilage tissue engineering offers new strategies in repairing damaged cartilage. Scaffolds have been used for the in vitro and in vivo procedures for this application, which demonstrates the compatible biological and physical properties that mimic natural tissues. Several types of scaffolds were used and had different effects on cell functions. The study was designed to develop a functional gelatin scaffold by adsorption of hyaluronan (HA) and the transforming growth factor β3 (TGF-β3) in a commercially available gelatin scaffold.

Results

The biological properties of human articular chondrocytes were investigated during a 21-day cultivation embedded in either HA + TGF-β3 adsorbed scaffolds or the conventional supplemented method. The rising of proliferation of chondrocytes embedded in adsorbed scaffolds was observed at day 17 and 21 of cultivation (1.27 and 1.28 fold, respectively). The chondrogenic gene expression of the chondrocytes embedded in HA + TGF-β3 adsorbed scaffolds significantly increased: SOX-9 (1.65 fold), ACAN (7.65 fold) and COL2A1 (1.83 fold). Remarkably, over the 21 days of cultivation, HA + TGF-β3 adsorbed scaffolds promoted the extracellular matrix molecules production with higher accumulation of HA (1.2 fold), collagen (1.42 fold) and uronic acid (1.41 fold). Moreover, the cell population and extracellular matrix production, which were examined by a histological analysis and a scanning electron microscope, were correlated with the biochemical analysis.

Conclusion

A small amount of HA and TGF-β3 initially adsorbed in the scaffolds (70 μg and 10 ng, respectively) was consumed over the 21-day cultivation. The HA + TGF-β3 adsorbed gelatin scaffold is effective and more suitable than the conventional supplemented method for the in vitro assessment of human chondrocyte 3D culture.

Chondroprotective and anti-inflammatory effects of sesamin

Osteoarthritis (OA) is a major disability of elderly people. Sesamin is the main compound in Sesamun indicum Linn., and it has an anti-inflammatory effect by specifically inhibiting Δ5-desaturase in polyunsaturated fatty acid biosynthesis. The chondroprotective effects of sesamin were thus studied in a porcine cartilage explant induced with interleukin-1beta (IL-1β) and in a papain-induced osteoarthritis rat model. With the porcine cartilage explant, IL-1β induced release of sulfated-glycosaminoglycan (s-GAG) and hydroxyproline release, and this induction was significantly inhibited by sesamin. This ability to inhibit these processes might be due to its ability to decrease expression of MMP-1, -3 and -13, which can degrade both PGs and type II collagen, both at the mRNA and protein levels. Interestingly, activation of MMP-3 might also be inhibited by sesamin. Moreover, in human articular chondrocytes (HACs), some pathways of IL-1β signal transduction were inhibited by sesamin: p38 and JNK. In the papain-induced OA rat model, sesamin treatment reversed the following pathological changes in OA cartilage: reduced disorganization of chondrocytes in cartilage, increased cartilage thickness, and decreased type II collagen and PGs loss. Sesamin alone might increase formation of type II collagen and PGs in the cartilage tissue of control rats. These results demonstrate that sesamin efficiently suppressed the pathological processes in an OA model. Thus, sesamin could be a potential therapeutic strategy for treatment of OA.

Alpinia galanga extracts downregulate interleukin-1β-induced matrix metalloproteinases expression in human synovial fibroblasts

Alpinia galanga has been used as alternative medicine for anti-rheumatic activities. However, the precise action of the extract on arthritic diseases is not yet fully understood. In this study, we investigated the effects of A. galanga extracts on the expression of genes involved in catabolic activities in an interleukin-1β (IL-1β)-induced human synovial fibroblast as an inflammatory model. Confluent primary human synovial fibroblasts were treated for 24 h with A. galanga hexane extracts in the presence of recombinant human IL-1β. MMPs in the culture medium were monitored by gelatin zymography. Total RNA was isolated from the cell lysate and analyzed via semi-quantitative RT-PCR. After treatment with A. galanga extracts, MMP-2 activity in the culture medium was significantly reduced. In addition, MMP-1, MMP-3, MMP-13, and Cox-2 expression were downregulated. These data suggest that the decrease of gene expression and production of MMPs in synovial fibroblasts against inflammatory stimuli could be due to the effects of the A. galanga extracts. Therefore, A. galanga extracts might be a promising therapeutic agent for arthritis.

Comparison of glucose derivatives effects on cartilage degradation

BACKGROUND

Glucosamine (GlcN) is a well-recognized candidate for treatment of osteoarthritis. However, it is currently used in derivative forms, such as glucosamine-hydrochloride (GlcN-HCl) or glucosamine sulfate (GlcN-S). However, the molecular mode of action remains unclear. In this study, we compared the effects of Glucose (Glc), Glucuronic acid (GlcA), Glucosamine hydrochloride (GlcN-HCl) and Glucosamine sulfate (GlcN-S) on cartilage degradation.

METHODS

Porcine cartilage explants were co-cultured with recombinant human IL-1beta and each tested substance for 3 days. HA, s-GAG and MMP-2 releases to media were measured using ELISA, dye-binding assay and gelatin zymography, respectively. Similar studies were performed in a human articular chondrocytes (HAC) monolayer culture, where cells were co-treated with IL-1beta and each reagent for 24 hours. Subsequently, cells were harvested and gene expression measured using RT-PCR. All experiments were carried out in triplicate. Student's t-tests were used for statistical analysis.

RESULTS

In cartilage explants treated with IL-1beta, GlcN-S had the highest chondroprotective activity of all four chemicals as shown by the inhibition of HA, s-GAG and MMP-2 released from cartilage. The anabolic (aggrecan core protein; AGG, SOX9) and catabolic (MMP-3, -13) genes in HACs treated with IL-1beta and with/without chemicals were studied using RT-PCR. It was found that, GlcN-HCl and GlcN-S could reduce the expression of both MMP-3 and -13 genes. The IL-1beta induced-MMP-13 gene expression was decreased maximally by GlcN-S, while the reduction of induced-MMP-3 gene expression was greatest with GlcN-HCl. Glc and GlcA reversed the effect of IL-1beta on the expression of AGG and SOX9, but other substances had no effect.

CONCLUSION

This study shows that glucosamine derivatives can alter anabolic and catabolic processes in HACs induced by IL-1beta. GlcN-S and GluN-HCl decreased induced MMP-3 and -13 expressions, while Glc and GlcA increased reduced-AGG and SOX9 expression. The chondroprotective study using porcine cartilage explant showed that GlcN-S had the strongest effect.

The effects of p-hydroxycinnamaldehyde from Alpinia galanga extracts on human chondrocytes

Osteoarthritis (OA) is the most common form of arthritis and affects millions of people worldwide. Patients have traditionally been treated with non-steroidal anti-inflammatory drugs (NSAIDs), but these are associated with significant side effects. Purification of the acetone extract of Alpinia galanga afforded p-hydroxycinnamaldehyde, as identified by nuclear magnetic resonance and mass spectrometry analyses. By exploiting the cartilage explant culture, p-hydroxycinnamaldehyde suppressed loss of uronic acid, resulting in release of hyaluronan (HA), sulfated glycosaminoglycans (s-GAGs) and matrix metalloproteinases (MMPs). p-Hydroxycinnamaldehyde and interleukin-1beta (IL-1beta), when incubated in primary human chondrocytes, also reduced release of HA, s-GAG and MMP-2. The results demonstrated: (a) that expression levels of the catabolic genes MMP-3 and MMP-13 were suppressed and (b) mRNA expression levels of anabolic genes of collagen II, SOX9 and aggrecan were increased. This study shows that p-hydroxycinnaldehyde from A. galanga Linn. is a potential therapeutic agent for treatment of OA.