Myeloid-derived Suppressor Cells Activate Liver Natural Killer Cells in a Murine Model in Uveal Melanoma.

OBJECTIVE: Elevated myeloid-derived suppressor cells (MDSCs) in many malignancies are associated with the increased risk for metastases and poor prognosis. Therefore, a mouse model of intraocular melanoma was established to explore how MDSCs influence liver metastases. METHODS: In this study, murine B16LS melanoma cells were transplanted into the posterior compartment (PC) of the eye of C57BL/6 mice. Leucocytes from the liver of naive mice and mice bearing melanoma liver metastasis were isolated using isotonic Percoll centrifugation, examined by flow cytometry for their expression of Gr1, CD11b, F4/80, RAE-1, and Mult-1, and further isolated for MDSCs and natural killer (NK) cells. The effects of MDSCs on NK cells were tested by coculturing and assessing the ability of NK cells to produce interferon-gamma (IFN-γ) by ELISA and NK cell cytotoxicity by 3H-thymidine incorporation assay. The impact of IFN-γ on liver metastases was examined via selectively depleting IFN-γ in vivo. RESULTS: The results showed that mice with liver metastases had increased levels of CD11b+Gr1+F4/80+ as well as CD11b+Gr1+F4/80- MDSCs. MDSCs significantly enhanced the generation of IFN-γ together with the cytotoxicity of the NK cells. Furthermore, these effects were cell-cell contact-dependent. Although IFN-γ was not of a toxic nature to the melanoma cells, it profoundly inhibited B16LS cell proliferation. Depleting IFN-γ in vivo led to increased liver metastases. CONCLUSION: All these findings first revealed that MDSCs accumulated in liver metastasis of intraocular melanoma could activate the NK cells to produce an effective anti-tumor immune response. Thus, the MDSCs' performance in different tumor models would need more investigation to boost current immunotherapy modalities.

[Effects of ginsenoside-Rg2 on mechanical allodynia, heat hyperalgeia, depressive state of rats with chronic sciatic nerve constriction injury].

OBJECTIVE: To investigate the effects of ginsenoside-Rg2 on mechanical allodynia, heat hyperalgeia, depressive state of rats with chronic sciatic nerve constriction injury. METHODS: Fifty SD rats were randomly divided into 5 groups: blank control group (Normal, normal + saline),sham operation group (Sham, sham operation + saline),chronic constriction injury of the sciatic nerve group (CCI, CCI + saline),ginsenoside-Rg2 low dose group (CCI + Rg2 5 mg/kg), and ginsenoside-Rg2 high dose group (CCI + Rg2 10 mg/kg).After the CCI model was established,drug were injected into the abdominal cavity through the syringe once a day,for 14 consecutive days.The mechanical shrinkage foot reflex threshold (MWT) and thermal withdrawal latency(TWL) were determined at 1 d before the operation and at 1,3,5,7,10 and 14 d after the operation.Light-dark transition test, forced swimming test were determined at 1 d before the operation and at 14 d after the operation. RESULTS: Compared with the sham group, the MWL and TWL of the CCI rats were decreased significantly (P＜0.01), time in the light compartment and number of transition were decreased (P＜0.01), the immobility time in FST was also prolonged significantly (P＜0.01). At 14 days after CCI operation, the MWL and TWL of the ginsenoside-Rg2 groups were increased significantly (P＜0.01), time in the light compartment and number of transition were also shortened significantly (P＜0.01), the immobility time in FST was also shortened significantly (P＜0.01). CONCLUSION: Intraperitoneal injection of ginsenoside-Rg2 can inhibit the mechanical and thermal pain sensitivity of CCI rats,and can relieve depressive state.

[The relationship between acute inflammatory cytokines, nerve function defect, daily living ability and PSD].

OBJECTIVE: To investigate the correlation between poststroke depression (PSD) and serum levels of inflammatory cytokines, neurologic impairment, daily life ability in patients with acute cerebral infarction at different time. METHODS: Two hundreds and eighty patients who admitted to our hospital with a diagnosis of acute infarction excluded the patients mismatch conditions were evaluated by Hamilton depres-sion rating scale (HDRS) to diagnose PSD respectively at admission and 3 months after stroke. Serum inflammatory cytokines high-sensitivity C-reactive protein(hs-CRP), tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6) were determined. NIH stroke scale(NIHSS) and Barthel index for daily life ability were used to evaluate nerve functions. Then we analyzed the correlation between PSD and serum inflammatory cytokines, correlation between PSD and functional impairment and daily life ability at different time. Logistic regression was performed to ana-lyze the risk factors of PSD. RESULTS: The PSD incidence was higher in recovery stage than that in acute stage, but there was no difference. Serum inflammatory cytokines were higher in PSD group at admission than that in non-PSD group. The NIHSS score and Barthel index in PSD group were different from those in non-group at acute and recovery stage. The OR score was 1.765, 1.646, 1.817, 1.188 and 2.015 respec-tively to TNF-α, IL-6 and Barthel index in the acute phase and to NIHSS and Barthel index in recovery stage. CONCLUSIONS: The pathogenesis of PSD at different courses of stroke is not same. TNF-α, IL-6 and Barthel index are the independent risk factors of PSD in acute phase, so do NIHSS score and Barthel index in recovery period.

[The protective effects of sacral nerve electrostimulation on intestinal mucosal mechanical barrier in rats with spinal cord injury].

OBJECTIVE: To study the protective effects of sacral nerve root electrostimulation on intestinal mechanical barrier in rats with spinal cord injury (SCI). METHODS: Fifty six Wistar rats were divided into normal group, SCI control group and SCI group with sacral nerve root electrostimulation (8 rats in each subgroup at 24, 48, 72 h after spinal cord injury). The following experiments were performed respectively in rats from the 3 groups: bacteria culture from intestinal mesentery lymph nodes, liver, spleen, intestinal morphology observation and detection the protein expression level of ZO-1. RESULTS: The intestinal mucosa appeared different degree of damage in SCI control group; cell-cell connections between intestinal epithelial cells were destroyed; Endotoxin levels in blood and the number of bacterial translocation increased obviously. Sacral nerve stimulation was found toimprove the intestinal mucosal, reduce the endotoxin content in the blood to normal level and the decrease the incidences of bacterial translocation of the gut origin. The expression of tight junction protein ZO-1 of rat intestinal tissue had no statistical differences among the 3 groups. On the other hand, the distribution of tight junction protein ZO-1 appeared different degrees of scattered and irregular in the control group while that in the experimental group appeared different degree of improvement as determined by the immunohistochemistry of rat intestinal tissue. CONCLUSION: sacral nerve root electrostimulation can rehabilitate the peristalsis of denervated colon, promote defeacation and decrease bacterial amount, protection of the intestinal mechanical barrier between intestinal epithelial cells and tight junction, reducing the endotoxin content in the blood and suppressing bacterial translocation from the gut.

The effect of genetically modified Lactobacillus plantarum 590 on the gut health of Sprague-Dawley rats.

Lp was a generally recognized as safe microorganism. Lactobacillus plantarum 590 was obtained by inserting nisI gene into Lp genome to help it tolerate higher concentration nisin. As the unintended effects of the genetically modified microorganism (GMM) are the most important barriers to the progress of GMM, we have performed a useful exploration to establish a new in vivo evaluation model for GMM from the point of view of intestinal health. In this study, Sprague-Dawley rats were orally administered with Lp 590 and Lp for 4 weeks. Fecal samples were collected to determine the number of beneficial bacteria Bifidobacterium and harmful bacteria Clostridium perfringens. Denaturing gradient gel electrophoresis was used to detect the bacterial profiles of every group. Fecal enzyme activities and short-chain fatty acids as main metabolites were also examined. Real time PCR (RT-PCR) and immunohistochemistry were used to analyze two proteins (ZO-1 and occludin) and secretory immunoglobulin A to detect intestinal permeability and mucosal immunity, gut permeability and gut mucosal immunity were analyzed to see whether GM Lp 590 can induce changes of the gut health when compared with non-GM Lp group, andeventually we concluded that there is no significant difference between GM Lp 590-fed group and non-GM Lp-fed group. The conclusion of gut health test was comparable withthat from traditional subchronic test. Evaluation of intestinal health will be a new approach of assessing the safety of GMM.