NIR Light-Activated and RGD-Conjugated Ultrasmall Fe/PPy Nanopolymers for Enhanced Tumor Photothermal Ferrotherapy and MR Imaging.

Iron-based nanomaterials have shown great promise for tumor ferrotherapy in recent years. However, nanoparticle-induced ferroptosis has low therapeutic efficacy owing to unsatisfactory Fenton reaction activity in a typical tumor microenvironment. In this study, NIR light-activated Fe/PPy-RGD nanopolymers were developed to combine photothermal therapy and ferrotherapy and achieve enhanced antitumor activity. Importantly, Fe/PPy-RGD exhibited excellent therapeutic performance under NIR light activation both in vitro and in vivo. Under irradiation with NIR light, the heat generated by Fe/PPy-RGD not only induced a therapeutic photothermal effect but also enhanced the release of iron ions and the Fenton reaction by inducing ferroptosis. Additionally, by virtue of RGD conjugation and its ultrasmall size, Fe/PPy-RGD could effectively accumulate at tumor sites in living mice after systemic administration and could be monitored via MR imaging. Hence, this study provides a promising approach for integrating ferrotherapy with photothermal therapy to achieve enhanced tumor treatment.

Xanthatin induces glioma cell apoptosis and inhibits tumor growth via activating endoplasmic reticulum stress-dependent CHOP pathway.

Xanthatin is a natural sesquiterpene lactone purified from Xanthium strumarium L., which has shown prominent antitumor activity against a variety of cancer cells. In the current study, we investigated the effect of xanthatin on the growth of glioma cells in vitro and in vivo, and elucidated the underlying mechanisms. In both rat glioma C6 and human glioma U251 cell lines, xanthatin (1-15 µM) dose-dependently inhibited cell viability without apparent effect on the cell cycle. Furthermore, xanthatin treatment dose-dependently induced glioma cell apoptosis. In nude mice bearing C6 glioma tumor xenografts, administration of xanthatin (10, 20, 40 mg·kg-1·d-1, ip, for 2 weeks) dose-dependently inhibited the tumor growth, but did not affect the body weight. More importantly, xanthatin treatment markedly increased the expression levels of the endoplasmic reticulum (ER) stress-related markers in both the glioma cell lines as well as in C6 xenografts, including glucose-regulated protein 78, C/EBP-homologous protein (CHOP), activating factor 4, activating transcription factor 6, spliced X-box binding protein-1, phosphorylated protein kinase R-like endoplasmic reticulum kinase, and phosphorylated eukaryotic initiation factor 2a. Pretreatment of C6 glioma cells with the ER stress inhibitor 4-phenylbutyric acid (4-PBA, 7 mM) or knockdown of CHOP using small interfering RNA significantly attenuated xanthatin-induced cell apoptosis and increase of proapoptotic caspase-3. These results demonstrate that xanthatin induces glioma cell apoptosis and inhibits tumor growth via activating the ER stress-related unfolded protein response pathway involving CHOP induction. Xanthatin may serve as a promising agent in the treatment of human glioma.

The antitumour growth and antiangiogenesis effects of xanthatin in murine glioma dynamically evaluated by dynamic contrast-enhanced magnetic resonance imaging.

To investigate the suppressive effects of xanthatin on glioma growth in a nude mouse xenograft model and rat orthotopic implantation model using magnetic resonance imaging (MRI) to dynamically monitor the antitumour growth and antiangiogenesis effects of xanthatin. The nude mouse xenograft tumour model and rat orthotopic implantation model were established to observe the antitumour effects of xanthatin in vivo. In the rat orthotopic implanted tumour model, MRI scanning was used to dynamically monitor the antitumour growth effect and evaluate the antiangiogenesis effect of xanthatin. We found that xanthatin at a dose of 0.4 mg/10 g dramatically decreased the growth of xenograft tumours in nude mice. The antiangiogenesis effect of xanthatin C6 glioma was evaluated by dynamic contrast-enhanced (DCE) MRI via comparison of the volume transfer constant (Ktrans ) value, a parameter that reflects vessel permeability. We found that xanthatin at the doses of 8 and 16 mg/kg significantly decreased the Ktrans value, which suggests that xanthatin has antiangiogenesis effects. These data demonstrate the suppressive effects of xanthatin on C6 glioma occur via antiangiogenesis. Meanwhile, this study also provides evidence for the application of quantitative parameters of DCE-MRI for dynamically evaluating the growth and angiogenesis of intracranial tumours and for experimental and clinical research.

1α,25-Dihydroxyvitamin D3 up-regulates IL-34 expression in SH-SY5Y neural cells.

Vitamin D supplementation is regarded as a novel approach to treat Alzheimer's disease, but the underlying mechanism remains elusive. The cytokine IL-34 provides strong neuroprotective and survival signals in brain injury and neurodegeneration and could be an immunological mediator for the vitamin D-induced protection. The aim of this study was to investigate whether human IL-34 is up-regulated in neuronal cells by the hormonally active form of vitamin D, 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3]. We found that IL-34 was detectable in a variety of cell lines and its expression was strongly induced in SH-SY5Y neural cells in a dose- and time-dependent manner by 1α,25(OH)2D3 through the vitamin D receptor (VDR). Furthermore, we identified the core promoter of IL-34 gene and a VDR binding site (CGCCCT) that was required for 1α,25(OH)2D3-induced IL-34 expression. These findings suggest that the induction of IL-34 expression by 1α,25(OH)2D3 may constitute a mechanism that explains the protective function of vitamin D in Alzheimer's disease.

Mesencephalic astrocyte-derived neurotrophic factor is involved in inflammation by negatively regulating the NF-κB pathway.

Inflammation can cause endoplasmic reticulum (ER) stress and therefore activates the unfolded protein response (UPR). ER stress and the consequent UPR have the potential to activate NF-κB. However, the factors mediating the crosstalk between ER stress and the NF-κB pathway remain unclear. Here, we determined that ER stress inducible protein Mesencephalic Astrocyte-derived Neurotrophic Factor (MANF) was up-regulated in autoimmune diseases and inflammatory disease models. Inflammation caused MANF to relocalize to the nuclei. MANF interacted with the DNA binding domain of p65 through its C-terminal SAP-like domain in the nuclei under the condition of inflammation or ER stress. MANF consequently inhibited p65-mediated transcriptional activation by interfering with the binding of p65 to its target genes promoters. Consistently, MANF suppressed the expressions of NF-κB-dependent target genes and the proliferation of inflammatory synoviocytes. These findings suggest that MANF may be a negative regulator of inflammation and mediate the crosstalk between the NF-κB pathway and ER stress.

Anti-tumor effects of paeonol in a HepA-hepatoma bearing mouse model via induction of tumor cell apoptosis and stimulation of IL-2 and TNF-alpha production.

Paeonol, a phenolic component from the root bark of Paeonia moutan, is traditionally used as a Chinese herbal medicine to activate the blood flow and remove blood stasis. Evidence shows that paeonol have anti-tumor, anti-inflammatory, and analgesic effects; however, the underlying mechanisms remain unknown. In this study, we investigated the molecular mechanisms by which paeonol exerts the anti-tumor effects by using a murine model of hepatoma established by in vivo injection of mouse HepA-hepatoma cells. Treatment of mice with 100, 200, or 400 mg/kg/day of paeonol significantly inhibited the growth of the HepA tumor in mice, induced HepA cell apoptosis as demonstrated by light microscopy and electron microscopy analyses, decreased the expression of Bcl-2 and increased the expression of Bax in HepA tumor tissues in a dose-related manner. Administration of paeonol in vivo also elevated serum levels of IL-2 and TNF-alpha in tumor-bearing mice. Moreover, splenocytes and macrophages isolated from paeonol-treated HepA tumor-bearing mice produced higher levels of IL-2 and TNF-alpha in response to concanavalin A and lipopolysaccharide stimulation, respectively, compared to these isolated from non-treated HepA tumor-bearing mice. In vitro treatment with paeonol was able to directly stimulate IL-2 and TNF-alpha production in splenocytes and macrophages from tumor-bearing mice, respectively. In conclusion, paeonol has the anti-tumor effect against hepatoma cells, which are likely mediated via induction of tumor cell apoptosis and stimulation of IL-2 and TNF-alpha production. Paeonol could be a promising drug to treat hepatocellular carcinoma.

Melatonin-selenium nanoparticles inhibit oxidative stress and protect against hepatic injury induced by Bacillus Calmette-Guérin/lipopolysaccharide in mice.

Melatonin-selenium nanoparticles (MT-Se), a novel complex, were synthesized by preparing selenium nanoparticles in melatonin medium. The present investigation was designed to determine the protective effects of MT-Se against Bacillus Calmette-Guérin (BCG)/lipopolysaccharide (LPS)-induced hepatic injury in mice. In BCG/LPS-induced hepatic injury model, MT-Se administered (i.g.) at doses of 5, 10, or 20 mg/kg to BCG/LPS-treated mice for 10 days, significantly reduced the increase in plasma aminotransferase, reduced the severe extent of hepatic cell damage and the immigration of inflammatory cells. The MT-Se particles also attenuated the increase in the content of thiobarbituric acid-reactive substances and enhanced the decrease in reduced activities of superoxide dismutase and glutathione peroxidase (GPx). However, treatment with MT-Se suppressed the increase in nitric oxide levels both in plasma and liver tissue. Furthermore, supplementation with MT-Se at the dose of 10 mg/kg (composed of 9.9 mg/kg melatonin and 0.1 mg/kg selenium) had great capability to protect against hepatocellular damage than a similar dose of melatonin (10 mg/kg) or selenium (0.1 mg/kg) alone. This effect may relate to its higher antioxidant efficacy in decreasing lipid peroxidation and increasing GPx activity. These results suggest that the mode of MT-Se hepatic protective action is, at least in part, related to its antioxidant properties.

Melatonin-selenium nanoparticles protects liver against immunological injury induced by bacillus Calmette-Guerin and lipopolysaccharide.

AIM: Melatonin-selenium nanoparticle (MT-Se), a novel complex, was synthesized by preparing selenium nanoparticles in a melatonin medium. The present investigation was designed to determine the protective effects of MT-Se against immunological liver injury in mice induced by bacillus Calmette-Guerin (BCG)/lipopolysaccharide (LPS). METHODS: The model of immunological liver injury in mice was prepared. The levels of alanine aminotransferase, aspartate amino-transferase, nitric oxide (NO) in serum, malondialdehyde content, superoxide dismutase (SOD), and glutathione peroxidase (GSH-px) activities in a liver homogenate were assayed by spectrophotometry. The content of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) were determined by ELISA. The splenocyte proliferation was assayed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) dye reduction. Meanwhile, a hepatic pathological examination was observed. RESULTS: In the BCG/LPS-induced hepatic injury model, MT-Se administered at doses of 5, 10, or 20 mg/kg to the BCG/LPS-treated mice for 10 d significantly reduced the increase in serum aminotransferase, reduced the severe extent of hepatic cell damage and the immigration of inflammatory cells. It also attenuated the increase in the content of thiobarbituric acid-reactive substances and enhanced the decrease in activities of SOD and GSH-px. In contrast, the treatment with MT-Se suppressed the increase in NO level in both the serum and liver tissue. Furthermore, MT-Se significantly lowered an increase in TNF-alpha and IL-1beta levels in the liver and inhibited the production of TNF- alpha and IL-1beta by peritoneal macrophages. A downregulation effect of MT-Se on splenocyte proliferation was also observed. CONCLUSION: MT-Se showed a hepatic protective action on immunological liver injury in mice.

Glucosides of Chaenomeles speciosa remit rat adjuvant arthritis by inhibiting synoviocyte activities.

AIM: To investigate the effects of Glucosides of Chaenomeles speciosa (GCS) on rat adjuvant arthritis (AA) and to clarify the role of synoviocytes in this process. METHODS: Complete Freund's adjuvant was used to induce AA in rats. Secondary paw swelling of AA rats was measured with MK-550 volume meter. The pain response and polyarthritis index were scored. Synoviocytes were separated by incubation of collagenase and trypsin, and morphological changes of synoviocytes were observed by transmission electron microscope. Interleukin-1 (IL-1) production was measured by thymocyte proliferation assay. Tumor necrosis factor (TNFalpha) and prostaglandin E2 (PGE2) production were determined by radioimmunoassay. RESULTS: There were significant secondary inflammatory reactions in AA rats. The morphology of synoviocytes from AA rats was changed, companying the elevation of the level of IL-1,TNFalpha, and PGE2 produced by synoviocytes from AA rats. GCS (60 and 120 mg/kg, ig, 8 d) suppressed secondary inflammatory paw swelling, pain response, and polyarthritis index. It also improved ultrastructural changes of synoviocytes and inhibited IL-1,TNFalpha, and PGE2 production in AA rats. The inhibitory effect of GCS 120 mg/kg was more evident than that of Actarit 60 mg/kg. CONCLUSION: GCS reduced the secondary inflammatory in AA rats, which is associated with prevention of ultrastructural changes of synoviocytes and inhibition of secretion of proimflammatory cytokines.

Effects and mechanisms of melatonin on immune responses in mice of different months.

AIM: To study the effects and mechanisms of melatonin (MT) on immune responses in mice of different months. METHODS: Thymocyte proliferation and IL-2 activity were assayed by 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) and activated mouse splenocyte proliferation methods, respectively; cAMP and methionine-enkephalin (met-Enk) level was determined by competitive protein binding assay and radioimmunoassay, respectively. RESULTS: The function of lymphocytes, obtained from BALB/c mice aged 6 and 11 months were decreased, which was restored by melatonin at the dose of 5 mg/kg or 30 mg/kg. In vitro, proliferation of lymphocytes in 11-month-old mice was decreased and cAMP level was increased. Melatonin (0.1 nmol/L or 1 micromol/L) had negative regulation to this. Forskolin (10 micromol/L) enhanced the cAMP level of lymphocytes in 2- and 11-month-old mice (P<0.01), which was antagonized partially by melatonin and this effect of melatonin was also abolished by pertussis toxin (1 mg/L) completely. Melatonin (1 micromol/L and 0.1 nmol/L) increased the content of met-Enk of lymphocytes in 2- and 11-month-old mice, respectively (P<0.01), which was blocked by nifedipine (1 micromol/L). CONCLUSION: Melatonin exerted an effect on immune responses in mice of different months, which might be mediated by G protein-AC-cAMP signal transduction pathway and regulation of met-Enk level.