Mitogen-activated protein kinases are involved in cucurbitacin D-induced antitumor effects on adult T-cell leukemia cells.

Adult T cell leukemia (ATL) is an aggressive and malignant blood disease. We previously reported that steroid-structured cucurbitacin D (CuD) induces apoptosis in ATL cells. In this study, we investigated the effects of mitogen-activated protein kinase (MAPK) signaling inhibitors on CuD-induced cell death in peripheral blood lymphocytes (PBLs) isolated from ATL/acute lymphoblastic leukemia (ALL) patients and two human leukemia cell lines (MT-1 and MT-4). PBLs were isolated from an ATL/ALL patient as well as from a healthy donor. Cell surface markers were examined using flow cytometry. Serum cytokine levels were estimated using LEGENDplex or analyzed at the Center for Clinical and Translational Research of Kyushu University Hospital. Cell proliferation was assessed using the Cell Titer-Glo luminescent cell viability assay. Protein expression was determined by western blotting. PBLs from patients highly expressed CD4 and CD5. Serum from the patient contained high levels of interleukin (IL)-8, IL-10, IL-18, and interferon-γ compared to the healthy donor. CuD-induced cell death was enhanced by the mitogen-activated protein kinase kinase (MEK)1/2 inhibitor U0126. However, a c-Jun N-terminal kinase (JNK) inhibitor prevented CuD-induced cell death. Immunoblot analyses revealed that CuD reduced the phosphorylation of extracellular signal-regulated kinase (ERK), p38, and JNK, and co-treatment with CuD and U0126 did not affect the phosphorylation of ERK. MEK1/2 and p38 inhibitors enhanced CuD-induced cell death, and U0126 enhanced the CuD-induced de-phosphorylation of ERK in MT-1 and MT-4 cells. We conclude that CuD reduces ERK activation, resulting in enhanced antitumor effects on leukemic cells.

Nuclear factor of activated T cells as a marker of in vivo low-dose dibenzo[a,h]anthracene exposure.

We previously demonstrated that particulate matter ≤2.5 µm (PM2.5) suppresses the immune response in the spleen in vivo. Although PM2.5 includes the polycyclic aromatic hydrocarbon (PAH) such as dibenzo[a,h]anthracene (DBA), it is unclear whether PAH has a direct effect on the responses of splenocytes. In our study, the concentration of DBA used was approximately 0.8 µm, which is much lower than concentrations used in other toxicological studies of DBA. Although exposure to high concentrations of DBA is implicated in carcinogenesis, the effects of low doses of DBA on immune cells in vivo remain unclear. Here, we investigated the effects of low DBA doses on mouse splenocytes in vivo. Mice were administered dimethyl sulfoxide or DBA (0.4 or 0.8 µm) intratracheally. Twenty-four hours after treatment, the mice were killed and their splenocytes were collected. DBA treatment enhanced mitogen-induced cell proliferation and cytokine production in the mouse splenocytes. Furthermore, DBA enhanced splenic CD4+ and CD8+ cell proliferation and cytokine production. The nuclear factor of activated T cells (NFAT) was activated in CD4+ cells. DBA also activated nuclear factor-kappa B and CCAAT enhancer-binding protein pathways in CD11b+ cells. DBA-enhanced splenocyte activation was Toll-like receptor 2-, 4-, 9- and MyD88-independent. These results suggest that NFAT represents a promising marker for evaluation of the effects of DBA on T cells and T-cell-dependent antibody responses.

ERK is involved in the differentiation and function of dimethyl sulfoxide-induced HL-60 neutrophil-like cells, which mimic inflammatory neutrophils.

Reports show that particulate matter (PM) is related to respiratory and cardiovascular diseases. We previously reported the biological effects of PM in vivo and the endocytosis of PM by primary neutrophils from mice. Cell lines can be used to elucidate the mechanism underlying immune responses in detail; however, information is limited regarding the functions of neutrophils after PM exposure. Here, we investigated the immune response of primary neutrophils and dimethyl sulfoxide (DMSO)- and all-trans retinoic acid (ATRA)-differentiated HL-60 (neutrophil-like) cells to PM. We showed that endocytosis by ATRA-HL cells was enhanced compared to that by DMSO-HL cells and that endocytosis in both cells was inhibited by dynamin inhibitors. A MEK inhibitor, but not p38 or JNK inhibitors, inhibited endocytosis. The MEK inhibitor also inhibited the differentiation of ATRA-HL cells to neutrophils. We identified that endocytosis of PM by neutrophils activated the MAPK ERK and p38 pathways. DMSO-HL and ATRA-HL cells both produced TNF-α and IL-8 after lipopolysaccharide (LPS) or PM treatment, whereas non-differentiated HL-60 cells did not. MCP-1 production was enhanced in DMSO-HL cells after LPS or PM treatment, whereas it was high in ATRA-HL cells. Reactive oxygen species (ROS) production was enhanced after PM treatment to DMSO-HL cells. Further, extracellular extracts promoted endocytosis. The MEK inhibitor also reduced the production of TNF-α, IL-8, and MCP-1. Taken together, ERK activation is key for both differentiation and endocytosis, and DMSO-HL cells at day 6 can serve as a model of inflammatory neutrophils, such as bronchus neutrophils, and a good tool to analyze the molecular events involved in immune responses to PM.

Th2 signals are not essential for the anti-arthritic effects of Trichinella spiralis in mice.

AIMS: Many parasitic helminths are known to alter host immune responses and consequently affect the progression of autoimmune and allergic diseases. The parasitic nematode Trichinella sp has been reported to suppress several experimental diseases in rodents, including experimental autoimmune encephalomyelitis, type 1 diabetes, colitis, airway inflammation and autoimmune arthritis. We tried to clarify requirement of Th2 cytokines in the anti-arthritic effects of Trichinella spiralis (Ts) against collagen-induced arthritis (CIA). METHODS AND RESULTS: We infected Ts and then induced CIA in STAT6KO DBA/1 mice, comparing the disease progression with that in wild-type (WT) DBA/1 mice, Ts significantly mitigated arthritis in WT mice, in addition to the impairment of anti-type II collagen (IIC) IgG production in a subclass-independent manner. The genetic absence of STAT6 in the mice did not abrogate the anti-arthritic effects of Ts. Alteration of splenic cytokines was not related to the anti-arthritic effects of the parasite. Moreover, lack of IL-10 did not abrogate the anti-arthritic effects of Ts. CONCLUSION: Our results suggest that the anti-arthritic effects of Ts do not require host Th2 signals.

Particulate Matter, Asian Sand Dust Delays Cyclophosphamide-induced Type 1 Diabetes in NOD Mice.

Although it is known that desert dust exacerbates allergic diseases, how it affects the onset of autoimmune diseases is unclear. No epidemiological investigations or animal experiments have been conducted so far to elucidate the effects of desert dust on autoimmune diseases. Here, we focused on particulate matter, such Asian sand dust (ASD) that has been known to cause adverse health effects in East Asian countries, and conducted animal experiments to examine how ASD influences type 1 diabetes (T1D), an autoimmune disease. An ASD suspension was intratracheally administered into NOD mice, which spontaneously develop T1D, for 4 times at 2-week intervals. Subsequently, the incidence of cyclophosphamide (CY)-induced diabetes was examined, which was then quantified using adoptive splenocyte-transfer assays. Kaplan-Meier curves of the cumulative T1D incidence were compared using the log-rank test, and unpaired two-tailed t tests were used for comparing the other data. We observed that ASD administration delayed T1D, and adoptive splenocytes derived from ASD-administered donor NOD mice also delayed the onset of T1D in recipient NOD mice. We further found that ASD increases concanavalin A-induced IFN-γ production and decreases regulatory T cells. Consequently, ASD suppresses the onset of T1D, activates spleen cells, and affects T-cell differentiation.

Endocytosis of particulate matter induces cytokine production by neutrophil via Toll-like receptor 4.

Particulate matter (PM) with a median diameter <2.5 µm, is associated with respiratory and cardiovascular diseases. We previously reported the biological effects of PM in vivo, and although neutrophils play an important role in initiating inflammation, few reports have focused on the relationship between PM inhalation and immune responses. Here, we investigated the effect of PM particle size on neutrophils, including their endocytosis activity and reactive oxygen species (ROS) production. Flow cytometry analysis indicated that 1 µm particles are readily endocytosed by neutrophils and that endocytosis is reduced at 4 °C. Inhibitors of the pleckstrin homology domain of dynamin repressed this process; however, GTPase and clathrin inhibitors did not affect endocytosis. Endocytosis by neutrophils in Toll-like receptor 4 (TLR4)- and MyD88-knockout mice was reduced compared with that in wild-type mice, indicating that TLR4 and MyD88 are important for the process. Neutrophil-mediated endocytosis caused oxidative stress, and N-acetylcysteine enhanced endocytosis. Expression levels of the oxidative stress markers, heme oxygenase-1 and p62 protein, were increased in an endocytosis-dependent manner. Phagocytosed neutrophils produced IL-6 and TNFα, whose production was decreased by dynamin inhibitors. We observed that infiltrated CD11b-positive cells in bronchoalveolar lavage fluid endocytose PMs. Overall, these results indicate that endocytosis and ROS production via TLR4 are important for the initiation of immune responses by neutrophils.

Lipopolysaccharide levels adherent to PM2.5 play an important role in particulate matter induced-immunosuppressive effects in mouse splenocytes.

Epidemiological studies show that exposure to ambient particulate matter (PM) is associated with serious adverse health effects, including, but not limited to, those on the respiratory system. In the present study, we investigated the splenic response in mice administered PM of ≤ 2.5 µ m diameter (PM2.5). Male BALB/c mice (7 or 8 weeks old) were intratracheally administered PM2.5 (0.1 mg) four times, at 2 week intervals, and dissected 24 h after the final administration. The effect of six types of PM2.5, collected in Shenyang or Beijing (China) and Kitakyushu (Japan), on splenocytes was examined. Our results revealed a strong correlation between the levels of lipopolysaccharide (LPS), but not that of ß-glucan and polycyclic aromatic hydrocarbons, attached to PM2.5 and the effect of PM2.5 on cell activity. PM2.5 with a low amount of LPS (PM2.5LL) reduced splenocyte mitogen-induced proliferation and cytokine production compared with that in control mice. The suppressive effects of PM2.5LL on proliferation and interleukin-2 production in splenocytes were rescued by the antioxidant N-acetylcysteine. Expression of heme oxygenase-1 was elevated after PM2.5LL administration, particularly in CD11b +  cells, while no elevation was observed in CD4+ , CD8+ or B220+ cells. Further, dissociation of the nuclear factor erythroid 2-related factor 2 from Kelch-like ECH-associating protein 1 was observed in splenocytes of PM2.5LL-administered mice. These data suggest that LPS attached to PM2.5 modulates the splenocyte immune responses to PM2.5.

Dual genetic absence of STAT6 and IL-10 does not abrogate anti-hyperglycemic effects of Schistosoma mansoni in streptozotocin-treated diabetic mice.

Schistosoma mansoni (Sm) is known to exert protective effects against various allergic and autoimmune disorders. It has been reported that this parasite protects NOD mice from spontaneous type 1 diabetes (T1D) and ameliorates streptozotocin (STZ)-induced T1D in wild-type mice. Here, we tried to clarify the anti-diabetic mechanisms of Sm in the latter model. Sm infection partially prevented the degradation of pancreatic islets and hyperglycemia in multiple low-dose (MLD) STZ-treated mice. Neither Treg cell depletion nor genetic absences of IL-10 and/or STAT6 abrogated the anti-hyperglycemic effects of Sm. Among M2 macrophage markers, Arg-1 and Ym1, but not Retnla, remained up-regulated in the pancreatic lymph nodes and in the spleens of STAT6/IL-10 double deficient (DKO) mice. Collectively, it is suggested that Sm exerts anti-diabetic effects on this experimental T1D model via Treg/IL-4/IL-13/IL-10-independent mechanisms. Augmented expressions of Arg-1 and Ym1 in the lymphoid organs adjacent to pancreas may be relevant to the anti-diabetic effects of Sm.

Relationship between triterpenoid anticancer drug resistance, autophagy, and caspase-1 in adult T-cell leukemia.

We previously reported that the inflammasome inhibitor cucurbitacin D (CuD) induces apoptosis in human leukemia cell lines. Here, we investigated the effects of CuD and a B-cell lymphoma extra-large (Bcl-xL) inhibitor on autophagy in peripheral blood lymphocytes (PBL) isolated from adult T-cell leukemia (ATL) patients. CuD induced PBL cell death in patients but not in healthy donors. This effect was not significantly inhibited by treatment with rapamycin or 3-methyladenine (3-MA). The Bcl-xL inhibitor Z36 induced death in primary cells from ATL patients including that induced by CuD treatment, effects that were partly inhibited by 3-MA. Similarly, cell death induced by the steroid prednisolone was enhanced in the presence of Z36. A western blot analysis revealed that Z36 also promoted CuD-induced poly(ADP ribose) polymerase cleavage. Interestingly, the effects of CuD and Z36 were attenuated in primary ATL patient cells obtained upon recurrence after umbilical cord blood transplantation, as compared to those obtained before chemotherapy. Furthermore, cells from this patient expressed a high level of caspase-1, and treatment with caspase-1 inhibitor-enhanced CuD-induced cell death. Taken together, these results suggest that rescue from resistance to steroid drugs can enhance chemotherapy, and that caspase-1 is a good marker for drug resistance in ATL patients.

Autophagy is associated with cucurbitacin D-induced apoptosis in human T cell leukemia cells.

We previously reported that the inflammasome inhibitor cucurbitacin D (CuD) induces apoptosis in human leukemia cell lines. In the present study, we investigated the effects of co-treatment with an additional Bcl-xL inhibitor, Z36. Treatment with Z36 induced cell death in leukemia cell lines, with MT-4 cells exhibiting the lowest sensitivity to Z36. Co-treatment of cells with Z36 and CuD resulted in a greater degree of cell death for Hut78 and Jurkat cells than treatment with CuD alone. In contrast, co-treatment of MT-4 cells with Z36 and CuD had a suppressive effect on cell death. The autophagy inhibitor 3-methyladenine (3-MA) suppressed the growth of leukemia cell lines HuT78, Jurkat, MT-1, and MT-4. CuD-induced cell death was enhanced by 3-MA in Jurkat cells, but inhibited in MT-4 cells. Western blotting results revealed cleavage of poly(ADP ribose) polymerase (PARP), supporting CuD-induced cell death; 3-MA enhanced CuD-Z36-induced PARP cleavage. Taken together, our results indicate that autophagy negatively regulates chemical-induced cell death of leukemia cells, and that controlling autophagy could be beneficial in the development of more effective chemotherapies against leukemia.

A rare case of paragonimiasis miyazakii with lung involvement diagnosed 7 years after infection: A case report and literature review.

We report a rare case of pulmonary paragonimiasis caused by Paragonimus miyazakii that showed pulmonary manifestations and a long-term clinical course after infection. A 45-year-old Japanese male developed cough and dyspnea in 2004 and was diagnosed with eosinophilic pneumonia. He had been treated with low-dose oral corticosteroid for 7 years. He recalled that he had consumed a large amount of raw freshwater crab (Geothelphusa dehaani) several weeks before he had been admitted for the first time, and that had been the only occasion when he had eaten this meat. The patient was referred to our hospital due to persistent hemoptysis, and his chest computed tomography scan showed pulmonary nodules and cavities, and his serum total IgE level was elevated. Bronchoscopy was performed, and ova were detected in the bronchoalveolar lavage fluid. The morphological examination of the ova and immunoserological examination yielded typical findings of P. miyazakii. Treatment with praziquantel improved his chest radiographic findings and a decrease of serum total IgE, as well as the values of immunoserological examination for P. miyazakii. The clinical course of this patient indicated that he had been infected with P. miyazakii for 7 years at least, which is unusual for paragonimiasis miyazakii.

Reciprocal effects of Schistosoma mansoni infection on spontaneous autoimmune arthritis in IL-1 receptor antagonist-deficient mice.

Schistosome infections have been shown to prevent inflammation in induced-type arthritis models. However, its effects on spontaneous arthritis remain unknown. We here investigated the effects of Schistosoma mansoni (Sm) infection on spontaneous autoimmune arthritis in IL-1 receptor antagonist (IL-1Ra)-deficient mice. Sm infection partially reduced the severity of arthritis in male IL-1Ra-deficient mice. The splenic responses of IL-17 and TNF-α were reduced, while those of IL-4 and IL-10 were enhanced by the infection. However, Sm infection increased IgG rheumatoid factor and anti-dsDNA IgG serum levels. These results suggest that Sm infection has both ameliorating and exacerbating effects on autoimmunity in IL-1Ra-deficient mice.

Asian sand dust causes subacute peripheral immune modification with NF-κB activation.

Asian sand dust (ASD), a type of particulate matter found in Asia, migrates to East Asia. The increased airborne spread of ASD has led to concerns regarding possible adverse health effects. Our group previously reported that ASD induces lung inflammation in mice, but it is still unclear whether ASD affects lymphoid organs. In this study, we investigated the effect of ASD on splenocytes in a mouse model of ASD exposure. ICR mice were intratracheally administered a single dose of normal saline (control) or ASD and were subsequently sacrificed 1 or 3 days later. TNF-α production in bronchoalveolar lavage fluids was higher at day 1, but not at day 3, after ASD administration. The enzyme-linked immunosorbent assay results showed that ASD administration increased mitogen-induced IL-2, TNF-α, and IL-6 production in splenocytes. Additionally, cell viability assay showed enhanced splenocyte proliferation at day 3, but not at day 1, after ASD administration. The electrophoretic mobility shift assay results demonstrated that nuclear factor κB (NF-κB) was activated in splenocytes on day 3, but not on day 1. In particular, NF-κB activation was detected in CD4(+) and CD11b(+) cells on day 3. These results suggest that ASD induces subacute inflammatory responses with NF-κB activation in the spleen, in contrast to acute inflammation in the lungs.

IL-6-accelerated calcification by induction of ROR2 in human adipose tissue-derived mesenchymal stem cells is STAT3 dependent.

OBJECTIVE: The mechanisms of ectopic calcification in inflammatory diseases are poorly understood. We investigated the effects of inflammatory cytokines on the mechanisms of calcification in human adipose tissue-derived mesenchymal stem cells (hADSCs). METHODS: The effects of inflammatory cytokines were evaluated using hADSCs cultured in osteoblast induction medium. mRNA expression was measured by real-time PCR and protein levels were measured by western blotting. Cell mineralization was evaluated by Alizarin Red S staining. RESULTS: In hADSCs, administration of IL-6/soluble IL-6 receptor (sIL-6R), TNF or IL-1ß accelerated calcification through enhanced expression of an osteoblast differentiation marker, runt-related transcription factor 2 (RUNX2). IL-6/sIL-6R had the greatest effect. The transcription of mRNA for receptor tyrosine kinase-like orphan receptor 2 (ROR2), involved in the non-canonical wingless-type (WNT) MMTV integration site pathway, was increased, while ß-catenin expression, an essential factor in the canonical WNT signalling pathway for osteoblast differentiation, did not change. Suppression of signal transducer and activator of transcription 3 (STAT3), but not STAT1, by small interfering RNA (siRNA) exerted a strong inhibitory effect on RUNX2 and ROR2 expression, and inhibited accelerated calcification. CONCLUSION: IL-6/sIL-6R stimulation accelerated the ROR2/WNT5A pathway in hADSCs in a STAT3-dependent manner, resulting in augmented calcification. These results suggest that the mechanisms of ectopic calcification accelerated by IL-6 in hADSCs may be involved in chronic inflammatory tissues and that IL-6 inhibitors may be beneficial in the treatment of ectopic calcification in inflammatory diseases.

Cucurbitacin D is a new inflammasome activator in macrophages.

We previously reported that cucurbitacin D isolated from Trichosanthes kirilowii has anti-tumor roles to leukemia cells. However, the effect of cucurbitacin D on immune cells is not fully understood although there is no toxic activity to normal cells. In this study, immunomodulating activities of cucurbitacin D were investigated in macrophages. Cucurbitacin D could increase LPS-induced interleukin (IL)-1ß production in culture supernatant of THP-1 cells, peritoneal exudate cells (PECs), bone marrow derived macrophages (BMDMs), and RAW264 cells. At the transcriptional level, cucurbitacin D enhanced LPS-induced IL-1ß mRNA expression through activation of ERK1/2 mitogen-activated protein kinases (MAPKs). At the posttranscriptional level, the activation of caspase-1 induced by cucurbitacin D has also been demonstrated following treatment with a caspase-1 inhibitor and siRNA. Importantly, cucurbitacin D has further been shown to induce inflammasome activation independent of ERK1/2 activation. Western blotting showed interaction of NOD-like receptor family, pyrin domain containing 3 (NALP3) and apoptosis-associated speck-like protein containing a caspase-activating and recruitment domain (ASC), suggesting activation of the inflammasome and a possible reason for activation of caspase-1. Taken together, these results suggest that cucurbitacin D could initiate immunomodulating activity in macrophages to lead to inflammasome activation as well as enhancement of LPS signaling.

Heligmosomoides polygyrus infection reduces severity of type 1 diabetes induced by multiple low-dose streptozotocin in mice via STAT6- and IL-10-independent mechanisms.

Some parasitic helminths are known to protect their hosts from allergic and autoimmune disorders. Here, we tested the effects of a gastrointestinal nematode, Heligmosomoides polygyrus (Hp), on streptozotocin (STZ)-induced type 1 diabetes (T1D) in mice. Hp infection significantly suppressed hyperglycemia induced by multiple low-dose administration of STZ, but did not affect hyperglycemia induced by single high-dose administration of STZ. In the multiple low dose model, Hp infection prevented a decrease in pancreatic islet size. The augmentation of TNF-α and IL-1ß expression in the pancreas was abrogated by Hp infection. The genetic absence of IL-10 or STAT6 did not abrogate the anti-hyperglycemic effect of Hp. Hp has a suppressive effect on immune mechanism-mediated experimental T1D via Th2 polarization-independent mechanisms.

Use of cell-free circulating schistosome DNA in serum, urine, semen, and saliva to monitor a case of refractory imported schistosomiasis hematobia.

This case of imported refractory schistosomiasis has highlighted the usefulness of cell-free parasite DNA as a diagnostic marker to assess active schistosome infection. In contrast to the rapid disappearance of ova in urine, parasite DNA remained persistent in several other specimen types even after the fourth treatment with praziquantel. This result was consistent with the presence of morphologically intact ova in bladder biopsy samples and with the corresponding symptoms.

Neurolytic celiac plexus block reduces occurrence and duration of terminal delirium in patients with pancreatic cancer.

PURPOSE: WHO's three step ladder sometimes cannot provide adequate pain relief for pancreatic cancer. Some patients develop terminal delirium (TD). The aim of this study was to test if the addition of a celiac plexus block (CPB) to pharmacotherapy could reduce the incidence of TD. METHODS: Pancreatic cancer patients under the care of our palliative-care team were investigated with regard to the duration and occurrence of TD, pain scores [numerical rating score (NRS)] and daily opioid dose. Between August 2007 to September 2008, 17 patients received only pharmacotherapy (control group). Then, we modified our guideline for analgesia, performing CPB 7 days after the first intervention of our team. Between October 2008 to September 2009, 19 patients received CPB. RESULTS: The opioid doses in CPB group were significantly lower both at 10 days after the first intervention (3 days after CPB) (27 ± 11 vs. 66 ± 82 mg; p = 0.029) and 2 days before death (37 ± 25 vs. 124 ± 117 mg; p = 0.009). NRS in the CPB group were significantly lower both at 10 days after the first intervention (0 [0-2] vs. 3 [2-5], p < 0.0001) and 2 days before death (1 [0-2] vs. 3 [1-4.5], p = 0.018). The occurrence and duration of TD in CPB group were both reduced (42 vs. 94 %, p = 0.019; and 1.8 ± 2.9 vs. 10.4 ± 7.5 days, p = 0.0003). CONCLUSION: The duration and occurrence of TD and the pain severity were significantly less in pancreatic cancer patients who underwent neurolytic CPB.

Schistosome: its benefit and harm in patients suffering from concomitant diseases.

Schistosomiasis is an important tropical disease affecting approximately 200 million people worldwide. Because of its chronicity and robust immunomodulatory activity, the effects of schistosomes on other diseases, such as allergies, autoimmunity, and infectious diseases, have been studied extensively in both epidemiological and experimental settings. In this paper, we summarize the beneficial and harmful effects of schistosomes. The importance of controlling schistosomiasis is also discussed.