Immuno-regulatory effects of CKBM on the activities of mitogen-activated protein kinases and the release of cytokines in THP-1 monocytic cells

Calcium-sensing receptor in the T lymphocyte enhanced the apoptosis and cytokine secretion in sepsis

Calcium-sensing receptor (CaSR) is a member of the G protein-coupled receptor superfamily that existed in lymphocytes and promoted cytokine secretion. Lymphocytes are also involved in sepsis. However, the role of CaSR in lymphocytes in sepsis is unclear. In this study, we want to examine whether the CaSR in lymphocytes in sepsis is involved in the cytokine secretions and apoptosis and make clear the relationship between NF-κB and MAPK signal transduction pathways. We investigated the issues mentioned earlier using Western blotting, ELISA, and Flow Cytometry. The sepsis was remodeled by cecal ligation and puncture (CLP). We found that CaSR protein expression increased in the peripheral blood T lymphocytes in CLP rats. The calcimimetic R568 (NPS R568) promoted, whereas the calcilytic NPS 2143 attenuated, signaling pathways proteins P65 (subunit of NF-κB), ERK1/2, and JNK (one subgroup of MAPKs) phosphorylation. However, P-P38 and P-JAKs exhibit no significant changes. Furthermore, the production TNF-α and IL-4 was greater in CLP rats than in normal rats, and NPS R568 promoted secretion of these cytokines. Simultaneously, the apoptotic ratio of T cells in CLP increased, and NPS R 568 exacerbated the apoptosis degree. However, these effects could also be inhibited by U0126 or SP600125 (MAPKs pathway inhibitor) or Bay-11-7082 or (NF-κB pathway inhibitor). From these results, we can conclude that, in the sepsis, CaSR activation promoted T-cell apoptosis and the secretion of pro-inflammatory cytokine TNF-α and anti-inflammatory cytokines IL-4 probably through NF-κB and partial MAPK signal transduction pathways.

Schizandra arisanensis extract attenuates cytokine-mediated cytotoxicity in insulin-secreting cells

AIM: To explore the bioactivity of an ethanolic extract of Schizandra arisanensis (SA-Et) and isolated constituents against interleukin-1β and interferon-γ-mediated β cell death and abolition of insulin secretion.

METHODS: By employing BRIN-BD11 cells, the effects of SA-Et administration on cytokine-mediated cell death and abolition of insulin secretion were evaluated by a viability assay, cell cycle analysis, and insulin assay. The associated gene and protein expressions were also measured. In addition, the bioactivities of several peak compounds collected from the SA-Et were tested against cytokine-mediated β cell death.

RESULTS: Our results revealed that SA-Et dose-dependently ameliorated cytokine-mediated β cell death and apoptosis. Instead of suppressing inducible nitric oxide synthase/nitric oxide cascade or p38MAPK activity, suppression of stress-activated protein kinase/c-Jun NH2-terminal kinase activity appeared to be the target for SA-Et against the cytokine mix. In addition, SA-Et provided some insulinotropic effects which re-activated the abolished insulin exocytosis in cytokine-treated BRIN-BD11 cells. Finally, schiarisanrin A and B isolated from the SA-Et showed a dose-dependent protective effect against cytokine-mediated β cell death.

CONCLUSION: This is the first report on SA-Et ameliorating cytokine-mediated β cell death and dysfunction via anti-apoptotic and insulinotropic actions.

Expression of the calcium sensing receptor in human peripheral blood T lymphocyte and its contribution to cytokine secretion through MAPKs or NF-κB pathways

The calcium-sensing receptor (CaSR) has been reported to play an important role in many tissues and organs. However, studies about the expression and function of CaSR in T lymphocytes are still not very lucid. In this study, we investigated the above-mentioned issues using RT-PCR, immunofluorescence staining, Western blotting, and the ELISA techniques. We found that the CaSR protein was expressed, and mainly located in the membrane in the normal human peripheral blood T lymphocytes. GdCl(3) (an agonist of CaSR) increased the dose-dependency of the CaSR expression, which was abolished by NPS2390 (an inhibitor of CaSR). GdCl(3) and Ca(2+) increased the phosphorylation of extracellular signal-regulated kinase (ERK)1/2 (one subgroup of MAPKs) and P65 (subunit of NF-κB),but, they had no significant effects on the JNK and P38 subgroups of MAPKs. Meantime, GdCl(3) and Ca(2+) stimulated both the IL-6 and TNF-β releases and their mRNA expressions. However, these effects of GdCl(3) and Ca(2+) were inhibited by NPS2390, U0126 (MAPKs pathway inhibitor) or Bay-11-7082 (NF-κB pathway inhibitor). These results suggested that CaSR was functionally expressed in the T cells, and the activated CaSR contributed to the cytokine secretion through the partial MAPK and NF-κB pathways.

Identification of bioactive constituents of Ziziphus jujube fruit extracts exerting antiproliferative and apoptotic effects in human breast cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Ziziphus extracts have been used in Traditional Chinese Medicine for the treatment of cancer.

AIM OF THE STUDY

In the present study we have investigated the effects of Ziziphus jujube extracts (ZEs) on breast cancer.

MATERIALS AND METHODS

We evaluated the effects of increasing concentrations of ZEs on ERα positive MCF-7 and ERα negative SKBR3 breast cancer cell proliferation using MTT assays. Apoptosis was analyzed by evaluating the involvement of some pro-apoptotic proteins, including Bax, Bad, Bid and PARP cleavage by immunoblotting analysis. Moreover, the effects of ZEs treatment on apoptosis were tested by both DNA fragmentation and terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) staining. By using chromatographic techniques, we identified the constituents of the effective extracts.

RESULTS

ZE1, ZE2, and ZE4 exerted significant antiproliferative effects on estrogen receptor alpha (ERα) positive MCF-7 (IC(50) values of 14.42, 7.64, 1.69μg/mL) and ERα negative SKBR3 (IC(50) values of 14.06, 6.21, 3.70μg/mL) human breast cancer cells. Remarkably, ZEs did not affect cell viability of both normal human fibroblasts BJ1-hTERT and nonmalignant breast epithelial MCF-10A cells. Treatment with ZEs induced cell death by apoptosis in both malignant breast cells. We found that the most effective extracts ZE2 and ZE4 shared a number of triterpenic acids, already known for their anticancer activities.

CONCLUSIONS

Our data provide a rational base for the use of Ziziphus extracts in the treatment of breast cancer in Traditional Chinese Medicine.

Alterations to the protein profile of bladder carcinoma cell lines induced by plant extract MINA-05 in vitro

Bladder cancer (BLCa) is a severe urological cancer of both men and women that commonly recurs and once invasive, is difficult to treat. MINA-05 (CK Life Sciences Int'l, Hong Kong) is a derivative of complex botanical extracts, shown to reduce cellular proliferation of bladder and prostate carcinomas. We tested the effects of MINA-05 against human BLCa cell sublines, B8, B8-RSP-GCK, B8-RSP-LN and C3, from a transitional cell carcinoma, grade IV, to determine the molecular targets of treatment by observing the cellular protein profile. Cells were acclimatised for 48 h then treated for 72 h with concentrations of MINA-05 reflecting 1/2 IC(50), IC(50) and 2 x IC(50) (n = 3) or with vehicle, (0.5% DMSO). Dose-dependant changes in protein abundance were detected and characterised using 2-dimensional electrophoresis and MS. We identified 10 proteins that underwent changes in abundance, pI and/or molecular mass in response to treatment. MINA-05 was shown to influence proteins across numerous functional classes including cytoskeletal proteins, energy metabolism proteins, protein degradation proteins and tumour suppressors, suggesting a global impact on these cell lines. This study implies that the ability of MINA-05 to retard cellular proliferation is attributed to its ability to alter cell cycling, metabolism, protein degradation and the cancer cell environment.

CKBM stimulates MAPKs but inhibits LPS-induced IFN-gamma in lymphocytes

CKBM is an herbal formula composed of five Chinese medicinal herbs (Panax ginseng, Schisandra chinensis, Fructus crataegi, Ziziphus jujuba and Glycine max) supplemented with processed Saccharomyces cerevisiae. It has been demonstrated that CKBM is capable of triggering the release of IL-6 and TNFalpha from human peripheral blood mononuclear cells. In this report, T-lymphocytic Sup-T1 cells and B-lymphocytic Ramos cells were utilized as cellular models to investigate how CKBM regulates intracellular signaling as well as the production of cytokines. CKBM stimulated the three major subgroups of mitogen-activated protein kinase (i.e. ERK, JNK and p38) in Sup-T1 cells, but only triggered the activation of ERK and p38 in Ramos cells. The induction of mitogen-activated protein kinases (MAPK) activations varied with the duration of treatment, as well as with the dosage of CKBM. In terms of cytokine production, treatment of CKBM alone did not trigger the release of IL-1beta and IFNgamma, but it suppressed the LPS-induced IFNgamma production from both Sup-T1 cells and Ramos cells. In view of the therapeutic effects of traditional Chinese medicines in inflammatory and autoimmune disorders, the results suggest that CKBM may exhibit its immuno-modulatory effects by regulating intracellular signaling as well as cytokine production in different lymphocytic cell types.

Protocatechuic acid induces cell death in HepG2 hepatocellular carcinoma cells through a c-Jun N-terminal kinase-dependent mechanism

Protocatechuic acid (PCA), chlorogenic acid (CA) and luteolin (LT) are plant phenols found in Chinese medicinal herbs such as Lonicera japonica. Cytotoxicity assays showed that PCA, CA and LT (at 100 micromol/L) effectively killed the HepG2 hepatocellular carcinoma cells. Among these three naturally occurring compounds, only PCA was capable of stimulating the c-Jun N-terminal kinase (JNK) and p38 subgroups of the mitogen-activated protein kinase (MAPK) family. Coincidently, PCA-induced cell death was rescued by specific inhibitors for JNK and p38, while the cytotoxicities of CA and LT were partially eliminated by the antioxidant effect of N-acetyl-L-cysteine (NAC). Further investigation demonstrated that the aqueous extract of Lonicera japonica also triggered HepG2 cell death in a JNK-dependent manner, but the amount of PCA alone in this herbal extract was insufficient to contribute the subsequent cytotoxic effect. Collectively, our results suggest that PCA is a naturally occurring compound capable of inducing JNK-dependent hepatocellular carcinoma cell death.

Monocyte-Mediated Rotenone Neurotoxicity towards Human Neuroblastoma SH-SY5Y: Role of Mitogen-Activated Protein Kinases

Increasing evidence has suggested an important role for rotenone in the pathogenesis of Parkinson's disease (PD). In this report, sequential linking of two culture systems, monocytic THP-1 cell line and SH-SY5Y neuroblastoma, was utilized. The supernatant from rotenone-stimulated THP-1 cells was used as the incubating medium for the second culture which adopted cells of the SH-SY5Y neuroblastoma. At 6.25-50 nM, concentrations that were nontoxic to SH-SY5Y directly, rotenone induced dose-dependent cell death on SH-SY5Y through stimulating monocyte THP-1 within a period of 48 h. Cytotoxicity was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Hoechst 33258 staining revealed that the treatment of SH-SY5Y with rotenone-stimulated THP-1 supernatant resulted in condensed nuclei and a decrease in cell size. Apoptotic rate measured by flow cytometric analysis indicated that at 25 and 50 nM, the percentage of apoptotic SH-SY5Y cells accumulated to 31.5% and 37.0% respectively. We further investigated whether rotenone (50 nM) activated mitogen-activated protein kinase (MAPK) cascades, and found it had effect on p38 MAPK and ERK in THP-1 cells, but not JNK. Pretreatment of THP-1 cells with the MAPK kinase inhibitor, PD98059, inhibited THP-1 cell-mediated rotenone neurotoxicity towards SH-SY5Y, whereas the p38 MEK inhibitor, SB203580, had no effect. These results suggested that activation of microglia intracellular signaling pathway may also involve in microglia-enhanced rotenone neurotoxicity.