Blocking NF-kappaB activation may be an effective strategy in the fever therapy

Lipopolysaccharide (LPS) stimulates peripheral mononuclear cells (PBMC) to synthesize or release pyrogenic cytokines, including interleukin-1beta (IL-1beta), IL-6, and tumor necrosis factor-alpha (TNF-alpha). Nuclear factor-kappa B (NF-kappaB) influences inflammatory responses through the regulation of genes encoding cytokines. In the present study, experiments were carried out to determine whether an inhibition of NF-kappaB mechanisms causes an inhibition of pyrogenic cytokine synthesis or release from PBMC and results in antipyresis. Intravenous administration of the supernatant fluids obtained from the human PBMC incubated with LPS caused feverlike hyperthermia in rabbits. The febrile responses were in parallel with the levels of IL-1beta, IL-6, and TNF-alpha in supernatant fluids. Both the fever and the increased levels of these cytokines in supernatant fluids were decreased by incubating LPS-PBMC with NF-kappaB inhibitors, including pyrrolidine dithiocarbamate, sodium pyrithione, N-acetyl-cysteine, and curcumin. Moreover, an intravenous administration of LPS (0.5-2 microg/kg) produced dose-dependent fever in the rabbits. The fevers were in parallel with the levels of IL-1beta, IL-6, and TNF-alpha in rabbit serum. A pretreatment of rabbits with an intravenous injection of pyrrolidine dithiocarbamate, sodium pryithione, N-acetyl-cysteine, or curcumin 1 h before the intravenous administration of LPS significantly attenuated the LPS-induced fever and/or increased levels of these cytokines in the serum of rabbits. Furthermore, pretreatment with an intravenous dose of anti-IL-1beta, anti-IL-6, or anti-TNF-alpha monoclonal antibody significantly attenuated the fever induced by the intravenous injection of LPS in rabbits. The antipyretic effects exerted by anti-L-1beta monoclonal antibody were greater than those exerted by anti-L-6 or anti-NF-alpha monoclonal antibody. The data indicate that NF-kappaB activation correlates with an LPS-induced synthesis or a release of cytokines (in particular, IL-1beta) from PBMC and triggers fever. Blocking NF-kappaB mechanisms in the PBMC with NF-kappaB inhibitors may be an effective strategy in the fever therapy.     

Characteristics of well-differentiated thyroid cancer associated with multinodular goiter

BACKGROUND: The likelihood of thyroid cancer is similar in patients with one or more nodules, but tumor characteristics of thyroid cancer in glands with multinodular goiter are unclear. MATERIALS AND METHODS: This study consisted of 100 consecutive patients (ages 15-81 years; 84 women), who underwent thyroidectomy for papillary or follicular thyroid carcinoma between 2005 and 2006. Patient demographics, diagnostic tests, operations, and pathological findings were reviewed. RESULTS: In a univariate analysis, cancer diagnosed within multinodular goiter was different from solitary cancer nodule in age of diagnosis (48 vs 40 years, p = 0.002), tumor size (1.42 vs 2.20 cm, p = 0.024), and the presence of cervical lymph node metastases (p = 0.035). There was no difference in gender, extrathyroidal invasion, multifocality, and types of operation. Only age (odds ratio, 1.056) and tumor size (odds ratio, 0.730) revealed independent correlation in multivariate analysis. CONCLUSION: Thyroid cancer in glands with multiple nodules is associated with older age at diagnosis and smaller tumor size.     

Suppressive effects of levobupivacaine on endotoxin-induced microglial activation

Background

We sought to elucidate the effects of levobupivacaine on modulating endotoxin-induced upregulation of inflammatory mediators and activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs) signaling pathways in activated microglia.

Materials and methods

Confluent murine microglia (BV-2) were treated with endotoxin (lipopolysaccharide, 50 ng/mL) or endotoxin plus levobupivacaine (5, 25, or 50 μM) and denoted as the LPS, LPS + L(5), LPS + L(25), and LPS + L(50) groups, respectively. Levobupivacaine was administered immediately after endotoxin. Control groups were run simultaneously.

Results

The concentrations of inflammatory mediators, including macrophage inflammatory protein-2 (P = 0.023 and 0.016), tumor necrosis factor-α (P = 0.025 and 0.020), interleukin (IL)-1β (P = 0.018 and 0.014), IL-6 (P = 0.029 and 0.023), nitric oxide (P = 0.025 and 0.026), and prostaglandin E₂ (P = 0.028 and 0.016) of the LPS + L(25) and LPS + L(50) groups were significantly lower than those of the LPS group. The concentrations of macrophage inflammatory protein-2 (P = 0.035), IL-1β (P = 0.024), nitric oxide (P = 0.031), and prostaglandin E₂ (P = 0.036) but not tumor necrosis factor-α and interleukin-6 of the LPS + L(5) group were also significantly lower than those of the LPS group. These data revealed that effects of endotoxin on upregulating inflammatory mediators were inhibited by levobupivacaine. Moreover, effects of endotoxin on activating NF-κB, including inhibitor-κB degradation, NF-κB nuclear translocation, and NF-κB–DNA binding, were also inhibited by levobupivacaine. Similarly, effects of endotoxin on activating MAPKs, including extracellular signal–regulated kinase, c-jun N-terminal kinase, and p38 MAPK, were also significantly inhibited by levobupivacaine.

Conclusions

Levobupivacaine significantly inhibited endotoxin-induced upregulation of inflammatory mediators and activation of NF-κB and MAPKs signaling pathways in activated microglia.     

Overexpression of chitinase-3-like protein 1 is associated with structural recurrence in patients with differentiated thyroid cancer

We previously identified that the expression of chitinase-3-like protein 1 (CHI3L1) was upregulated during thyroid cancer progression. Here, we investigated the prognostic significance of CHI3L1 expression in thyroid neoplasms and examined the potential oncogenic roles. CHI3L1 immunochemical staining was performed on tissue microarrays of benign and malignant thyroid tumours. Compared with normal thyroid tissue and benign thyroid lesions that had low or no detectable CHI3L1 expression, CHI3L1 was overexpressed in both differentiated and undifferentiated thyroid cancer. High CHI3L1 expression was associated with extrathyroidal extension, lymph node metastasis, and shorter recurrence-free survival in differentiated thyroid cancer. The biological roles of CHI3L1 were further investigated by gain- and loss-of-function assays. CHI3L1 silencing suppressed clonogenicity, migration, invasion, anoikis resistance, and angiogenesis in thyroid cancer cells, although exogenous CHI3L1 treatment promoted these malignant phenotypes. Cysteine-rich angiogenic inducer 61 (CYR61) was identified as a downstream target of CHI3L1 by RNA-seq analysis. CYR61 silencing or treatment reversed the alterations induced by CHI3L1 modulation. Our results demonstrate that CHI3L1 is overexpressed in thyroid cancer and is associated with an increased risk of disease recurrence. Additionally, CYR61 may participate in CHI3L1-mediated tumour progression. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Regulation of leptin receptor expression in human papillary thyroid cancer cells

Epidemiological studies suggest an important link between obesity and thyroid cancer. The adipose tissue-derived polypeptide leptin acting via leptin receptor may modulate cell migration of thyroid cancer cells. Previously we have demonstrated that leptin receptor is overexpressed in papillary thyroid cancer and is associated with tumor aggressiveness. The present study was undertaken to explore the possible regulatory factors which would influence leptin receptor expression in papillary thyroid cancer cells. We found that DNA methyltransferase inhibitor (5-Aza-2′-deoxycytidine) and histone deacetylase inhibitor (trichostatin A) reduced leptin receptor expression. Conversely, insulin upregulated leptin receptor expression in a time- and dose-dependent manner. Hypoxia-mimicking agent (cobalt chloride) had no effect on leptin receptor expression. Taken together, our study provides evidence that epigenetic events and insulin stimulation take part in regulation of leptin receptor expression in papillary thyroid cancer cells.     

Stimulatory effect of stevioside on peripheral mu opioid receptors in animals

Stevioside is a dietary supplement widely used as a sweetener to prevent hyperglycemic disorders. However, the action mechanisms of this substance for glucose homeostasis remain obscure. In the present study, a dose-related plasma glucose reduction was observed in Wistar rats receiving intraperitoneally injections of stevioside. Similar to the regulation of glucose metabolism by the activation of mu opioid receptors, this action of stevioside was reversed by naloxonazine under the blockade of mu opioid receptors. We also found that stevioside increased glycogen synthesis in isolated hepatocytes, which was concentration-dependently blocked by naloxonazine. Stevioside did not modify the plasma beta-endorphin levels in Wistar rats but it directly increased the phosphorylation of mu opioid receptors in Chinese hamster ovary cells transfected with mu opioid receptors. Unlike morphine, chronic administration of stevioside did not induce the withdrawal signs in mice. Furthermore, stevioside by intraperitoneal injections did not influence the feeding behaviors of rats. By contrast, intracerebroventricular injections of stevioside increased the rats’ food intake, which was also inhibited by pretreatment with naloxonazine. These results showed that it is difficult for stevioside to enter the brain. Stevioside has the ability to activate peripheral mu opioid receptors for lowering plasma glucose and to increase glycogen synthesis in liver. Thus, the stimulation of peripheral mu opioid receptors is responsible for the action of stevioside in the regulation of glucose homeostasis.     

A novel role of andrographolide,an NF-kappa B inhibitor,on inhibition of platelet activation: the pivotal mechanisms of endothelial nitric oxide synthase/cyclic GMP

Andrographolide is a novel NF-κB inhibitor from the leaves of Andrographis paniculata. Platelet activation is relevant to a variety of thrombotic diseases. However, no data are available concerning the effects of andrographolide in platelet activation. The aim of this study was to examine the mechanisms of andrographolide in preventing platelet activation. Andrographolide (25–75 μΜ) exhibited a more potent activity of inhibiting platelet aggregation stimulated by collagen. Andrographolide inhibited collagen-stimulated platelet activation accompanied by relative Ca²⁺ mobilization; thromboxane A₂ formation; and phospholipase C (PLC)γ2, protein kinase C (PKC), mitogen-activated protein kinase (MAPK), and Akt phosphorylation. Andrographolide markedly increased cyclic GMP, but not cyclic AMP levels. Andrographolide also stimulated endothelial nitric oxide synthase (eNOS) expression, NO release, and vasodilator-stimulated phosphoprotein (VASP) phosphorylation. ODQ, an inhibitor of guanylate cyclase, markedly reversed the andrographolide-mediated inhibitory effects on platelet aggregation, p38 MAPK and Akt phosphorylation, and the andrographolide-mediated stimulatory effect on VASP phosphorylation. Furthermore, a PI3 kinase inhibitor (LY294002) but not a PKC inhibitor (Ro318220) significantly diminished p38 MAPK phosphorylation; nevertheless, a p38 MAPK inhibitor (SB203580) and LY294002 diminished PKC activity stimulated by collagen. Andrographolide also reduced collagen-triggered hydroxyl radical (OH^⋅) formation. In vivo studies revealed that andrographolide (22 and 55 μg/kg) is effective in reducing the mortality of ADP-induced acute pulmonary thromboembolism and significantly prolonged platelet plug formation in mice. This study demonstrates for the first time that andrographolide possesses a novel role of antiplatelet activity, which may involve the activation of the eNOS-NO/cyclic GMP pathway, resulting in the inhibition of the PI3 kinase/Akt-p38 MAPK and PLCγ2–PKC cascades, thereby leading to inhibition of platelet aggregation.