Blockade of the T cell immunoglobulin and mucin domain protein 3 pathway exacerbates sepsis-induced immune deviation and immunosuppression

Sepsis is a life-threatening condition, but the pathophysiological basis and biomarkers for the monitoring of sepsis and as targets for therapy remain to be determined. We have shown previously that T cell immunoglobulin and mucin domain protein 3 (Tim-3), a negative immune regulator, is involved in the physiopathology of sepsis, but the underlying mechanisms remain unclear. In the present study, we showed that Tim-3 signalling modulated the response patterns of both macrophages and T helper cells in sepsis. Blockade of the Tim-3 pathway exacerbated sepsis-induced proinflammatory macrophage responses and lymphocyte apoptosis during the early phase of sepsis, and enhanced the shift to anti-inflammatory responses for both macrophages and T helper cells during the late phase of sepsis. Tim-3 signalling was found to regulate CD80 and CD86 expression on macrophages both in vivo and in vitro. Co-culture of T cells with Tim-3 knock-down macrophages led to a biased T helper type 2 (Th2) response, partially explaining how Tim-3 signalling shapes inflammation patterns in vivo. Further studies on this pathway might shed new light on the pathogenesis of sepsis and suggest new approaches for intervention.

Abstract B48: Preclinical development of meta-[211At] astatobenzylguanidine ([211At] MABG) targeted radiotherapy for neuroblastoma

Background: Neuroblastoma (NB) is a radiosensitive malignancy accounting for 10% of childhood cancer mortality. NB cells frequently express the norepinephrine transporter (NET) providing a specific mechanism for uptake of NET-ligands. Meta-[131I]iodobenzylguanidine ([131I]MIBG) is a NET-ligand radiotherapeutic that shows single-agent response rates in refractory NB of 40-50%. However, due to the long path lengths of 131 I beta (β)-emission, and low biological effectiveness compared to alpha (α)-emitting radionuclides, [131I]MIBG is generally not curative, perhaps due to non-targeting of isolated circulating tumor cells. Here we report our efforts to optimize NET-targeted radiotherapy by developing relevant preclinical models of refractory NB for α-particle therapeutic [211At] MABG therapy.

Methods: We first determined NET (SLC6A2) mRNA and protein expression in 35 human NB cell lines using quantitative RT-PCR and western blotting. We then chose 5 lines with absent to intermediate levels of native NET expression (NB1691, SKNSH, IMR5, NLF and SKNBE2) for dual forced overexpression of human NET and luciferase cDNAs. We used [125I]MIBG for cell-based uptake assays in all isogenic pairs and biodistribution experiments in athymic mice bearing three separate NET-transduced xenografts (N=5 per cell line). These cell lines were also treated with [131I]MIBG and/or external beam radiation (XRT) followed by multi-log cytotoxicity assays. Therapeutic trials of [131I]MIBG (25 mCi/kg) in NB1691 subcutaneous xenograft and metastatic mouse models were also conducted. In parallel, [211At] MABG was synthesized by: (i) cyclotron-production of 211 At via 209 Bi(α,2n)211At reaction (ii) distillation of 211 At from the target, and (iii) solid phase no-carrier-added synthesis of [211At] MABG by radioastato-destannylation. [211At] MABG uptake studies were performed in isogenic NB cell lines.

Results: Unlike primary human NBs, NET expression was low in the majority of 35 cell-lines studied (median normalized expression value = 0.145; range 0.000-1.005), but all transduced lines showed significant overexpression (0.860-1.107) comparable to human primary tumors. Transduced lines showed 4-10 fold higher uptake of [125I]MIBG than non-transduced isogenic parental cell lines in vitro, and demonstrated significant tumor-specific uptake and retention in vivo with tumor-muscle ratios ranging from 13.80 to 29.48. In vitro cytotoxicity experiments using [131I]MIBG showed NET-expressing cell lines to be more susceptible to treatment compared to non-NET expressing pairs (IC50 of 2.937nCi vs. 15.99 nCi). Treatment of mice bearing NB1691-NET xenografts with [131I]MIBG showed tumor growth delay (p=0.0065), but no significant impact on survival, likely due to de novo radioresistance (1200 cGy of XRT had no impact on NB1691 proliferation; IMR-05 showed 97% decreased cell viability). Lastly, we successfully synthesized [211At] MABG, with radiochemical yields of ∼20% and showed NET specific uptake of [211At] MABG into 1691 NET transfected cells.

Conclusions: Development of targeted radiotherapy for neuroblastoma has been limited by the lack of preclinical models and alternative therapeutics. Our development of multiple isogenic pairs with varying NET expression, documentation of de novo radiation sensitivity, and the production of [211At] MABG, will allow for rapid assessment of targeted radiotherapeutic strategies (including combination approaches) to support clinical development of alpha-particle therapeutics in a childhood cancer.

Citation Format: V Batra, AM Chacko, M Gagliardi, C Hou, J L. Mikitsh, R H. Freifelder, A Kachur, B C. LeGeyt, A Schmitz, L Toto, G Vaidyanathan, M R. Zalutsky, K K. Matthay, W A. Weiss, W C. Gustafson, D Pryma, J M. Maris. Preclinical development of meta-[211At] astatobenzylguanidine ([211At] MABG) targeted radiotherapy for neuroblastoma. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr B48.

The effects and underlying mechanism of excessive iodide on excessive fluoride-induced thyroid cytotoxicity

In many regions, excessive fluoride and excessive iodide coexist in groundwater, which may lead to biphasic hazards to human thyroid. To explore fluoride-induced thyroid cytotoxicity and the mechanism underlying the effects of excessive iodide on fluoride-induced cytotoxicity, a thyroid cell line (Nthy-ori 3-1) was exposed to excessive fluoride and/or excessive iodide. Cell viability, lactate dehydrogenase (LDH) leakage, reactive oxygen species (ROS) formation, apoptosis, and the expression levels of inositol-requiring enzyme 1 (IRE1) pathway-related molecules were detected. Fluoride and/or iodide decreased cell viability and increased LDH leakage and apoptosis. ROS, the expression levels of glucose-regulated protein 78 (GRP78), IRE1, C/EBP homologous protein (CHOP), and spliced X-box-binding protein-1 (sXBP-1) were enhanced by fluoride or the combination of the two elements. Collectively, excessive fluoride and excessive iodide have detrimental influences on human thyroid cells. Furthermore, an antagonistic interaction between fluoride and excessive iodide exists, and cytotoxicity may be related to IRE1 pathway-induced apoptosis.

The role of the IRE1 pathway in excessive iodide- and/or fluoride-induced apoptosis in Nthy-ori 3-1 cells in vitro

Excessive iodide and fluoride coexist in the groundwater in many regions, causing a potential risk to the human thyroid. To investigate the mechanism of iodide- and fluoride-induced thyroid cytotoxicity, human thyroid follicular epithelial cells (Nthy-ori 3-1) were treated with different concentrations of potassium iodide (KI), with or without sodium fluoride (NaF). Cell morphology, viability, lactate dehydrogenase (LDH) leakage, apoptosis, and expression of inositol-requiring enzyme 1 (IRE1) pathway-related molecules were assessed. Results showed 50 mM of KI, 1 mM of NaF, and 50 mM of KI +1 mM of NaF changed cellular morphology, decreased viability, and increased LDH leakage and apoptosis. Elevated expression of binding protein (BiP), IRE1, and C/EBP homologous protein (CHOP) mRNA and protein, as well as spliced X-box-binding protein-1 (sXBP-1) mRNA, were observed in the 1 mM NaF and 50 mM KI +1 mM NaF groups. Collectively, excessive iodide and/or fluoride is cytotoxic to the human thyroid. Although these data do not manifest iodide could induce the IRE1 pathway, the cytotoxicity followed by exposure to fluoride alone or in combination with iodide may be related to IRE1 pathway-induced apoptosis. Furthermore, exposure to the combination of excessive iodide and fluoride may cause interactive effects on thyroid cytotoxicity.

Influence of different urination methods on the urinary systems of patients with spinal cord injury

OBJECTIVE

This study evaluated the influence of different urination methods on the urinary systems of patients with spinal cord injury.

METHODS

Patients with spinal cord injury were grouped according to their usual voiding method: clean intermittent catheterization (CIC); Credé manoeuvre/reflex voiding; indwelling catheterization; normal voiding. Urinary tract infections (UTIs) were monitored and type B-ultra-sonography (B-USG) scans, renal function tests and urodynamic studies were performed in all patients over a 2-year period.

RESULTS

Compared with the normal voiding group (n = 14), incidence rates of UTIs were significantly different in the Credé manoeuvre/reflex voiding (n = 26) and indwelling catheterization (n = 12) groups but not in the CIC group (n = 15). All intervention groups had a significantly higher rate of positive findings on B-USG scan and a significantly increased residual urine volume, compared with the normal voiding group. In addition, residual urine volume was significantly lower in the CIC group compared with the Credé manoeuvre/reflex voiding and indwelling catheterization groups.

CONCLUSION

CIC was shown to be the optimal method for assisted bladder voiding after spinal cord injury.

Genetic manipulation of sex ratio for the large-scale breeding of YY super-male and XY all-male yellow catfish (Pelteobagrus fulvidraco (Richardson))

Yellow catfish has become one of the most important freshwater aquaculture species in China. The mono-sex male yellow catfish has important application value in aquaculture because the male grows generally faster than the sibling females under the same conditions. This study has screened YY super-male and YY physiological female yellow catfish by sex reversal, gynogenesis, and progeny testing, which can help to achieve the large-scale production of YY super-male and XY all-male. From 2008 to 2010, about 123,000 YY super-male were produced, and about 81 million XY all-male fry were produced with 100% male rate by random sampling. Therefore, these results indicate that YY super-male and YY physiological female yellow catfish can be viable and fertile. We conclude that the mono-sex breeding technique by YY super-male yellow catfish is stable and reliable, which has great potential for application in yellow catfish aquaculture.

Unilateral lesion of the nigrostriatal pathway decreases the response of GABA interneurons in the dorsal raphe nucleus to 5-HT(1A) receptor stimulation in the rat

This study examined the firing rate and pattern of electrophysiologically and chemically identified GABA interneurons in the dorsal raphe nucleus (DRN), and role of 5-HT(1A) receptor agonist 8-OH-DPAT and the medial prefrontal cortex (mPFC) in the firing activity in rats with 6-hydroxydopamine lesions of the substantia nigra pars compacta (SNc). The interneurons in rats with lesions of the SNc showed a more burst-firing, while having no change in the firing rate; the mPFC and combined mPFC and SNc lesions in rats decreased the firing rate of the interneurons and firing pattern shifted towards a more burst-firing compared to rats with sham lesions of the SNc, respectively. In rats with sham lesions of the SNc, administration of 8-OH-DPAT (1-243 μg/kg, i.v.) produced excitatory-inhibitory, excitatory and inhibitory effects in the firing rate of individual interneurons. However, when these effects were averaged over the group, 8-OH-DPAT had no significant effect on firing rate. In rats with lesions of the SNc, mPFC and the paired lesions, 8-OH-DPAT, at the same doses, inhibited all interneurons tested, respectively. Cumulative doses producing inhibition in rats with the paired lesions were higher than that of rats with lesions of the mPFC. In contrast to rats with sham lesions of the SNc, SNc lesion reduced expression of 5-HT(1A) receptor on parvalbumin positive neurons in the DRN, a subpopulation of GABA interneurons. Our results indicate that the SNc and mPFC regulate the firing activity of GABA interneurons in the DRN. Furthermore, response of likely GABA interneurons to systemic administration of 8-OH-DPAT is altered by lesion of the SNc and mPFC.

[Hydrogen peroxide induces high mobility group box 1 release in human bronchial epithelial cells]

OBJECTIVE

To investigate the effect of hydrogen dioxide (H(2)O(2)) on the release and translocation of high mobility group box 1 release (HMGB1) from normal human bronchiolar epithelial cells (HBE).

METHODS

MTT assay was used to assess the viability of HBE135-E6E7 cells exposed to different concentrations of H(2)O(2). The expression and location of HMGB1 in the cytoplasm, nuclei and culture medium of the exposed cells were determined using Western blotting and immunofluorescence assay.

RESULTS

Exposure to 125 µmmol/L H(2)O(2) did not obviously affect the cell viability. At the concentration of 250 µmmol/L, H(2)O(2) significantly decreased the cell viability (P<0.05), but significant cell death occurred only after exposure to 400 µmmol/L H(2)O(2) (P=0.000). Compared with the control cells, the cells exposed to 12.5, 125 and 250 µmmol/L H(2)O(2) for 24 h showed significantly increased levels of HMGB1 in the culture medium (P<0.05), and exposure to 125 µmmol/L H(2)O(2) for 12 and 24 h also caused significantly increased HMGB1 level (P<0.05). Exposure to 125 µmmol/L H(2)O(2) for 24 h significantly increased HMGB1 expression in the cytoplasm but decreased its expression in the nucleus. HMGB1 translocation from the nuclei to the cytoplasm and to the plasmalemma occurred after 125 µmmol/L H(2)O(2) exposure for 12 h and 24 h, respectively.

CONCLUSION

H(2)O(2) can induce HMGB1 translocation and release in human bronchial epithelial cells, suggesting the involvement of HMGB1 in airway oxidative stress in chronic inflammatory diseases such as asthma and COPD.

Moderate accuracy of peripheral eosinophil count for predicting eosinophilic phenotype in steroid-naïve non-atopic adult asthmatics

BACKGROUND AND AIM

Eosinophilic phenotype, sputum eosinophil count ≥3%, of asthma is a valuable clinical parameter. However, measurement of sputum inflammatory cells is time-consuming and requires specialized personnel. A simpler surrogate, such as peripheral eosinophil count, would be beneficial. The aim of this study was to assess the value of peripheral eosinophil count for predicting the eosinophilic phenotype of adult asthmatics.

MATERIALS AND METHODS

This retrospective study was conducted in 192 adult asthmatics. Sputum and venous blood were collected at the same visit and analyzed for cell differential. Receiver-operating characteristic (ROC) curve analysis was used to assess the relationship between eosinophilic phenotype and peripheral eosinophil count.

RESULTS

Peripheral eosinophil count, derived from the ROC curve, of more than 210 cells/mm(3) yielded 67.7% sensitivity and 66.2% specificity [area under the curve (AUC)=0.698, p=0.0001] for identifying the eosinophilic phenotype in the total patients. Multiple regression analysis revealed that steroid treatment and atopy significantly influenced the peripheral eosinophil count. Within the steroid-naïve subgroup, a peripheral eosinophil count of >190 cells/mm(3) yielded 76.3% sensitivity and 67.4% specificity (AUC=0.730, p<0.0001) for identifying eosinophilic phenotype, while in the steroid treated subgroup, the AUC was 0.554 (p=0.4985). Within the steroid-naïve non-atopic subgroup, a peripheral eosinophil count of >190 cells/mm(3) yielded 73.1% sensitivity and 79.3% specificity (AUC=0.809, p=0.0001) for identifying the eosinophilic phenotype, while in the steroid-naïve atopic subgroup, the AUC was 0.588 (p=0.2723).

CONCLUSION

Peripheral eosinophil count is able to identify the presence of eosinophilic phenotype in steroid-naïve non-atopic adult asthmatics with moderate accuracy.

In vivo effect of 5-HT₇ receptor agonist on pyramidal neurons in medial frontal cortex of normal and 6-hydroxydopamine-lesioned rats: an electrophysiological study

The 5-hydroxytryptamine (5-HT)-7 receptor began to be cloned and pharmacologically characterized close to 20 years ago. It couples positively via G-proteins to adenylyl cyclase and activation of this receptor increases neuronal excitability, and several studies have shown that degeneration of the nigrostriatal pathway leads to an impairment of 5-HT system. Here we reported that systemic and local administration of 5-HT₇ receptor agonist AS 19 produced excitation, inhibition and no change in the firing rate of pyramidal neurons in medial prefrontal cortex (mPFC) of normal and 6-hydroxydopamine-lesioned rats. In normal rats, the mean response of the pyramidal neurons to AS 19 by systemic and local administration in mPFC was excitatory. The inhibitory effect by systemic administration of AS 19 was reversed by GABA(A) receptor antagonist picrotoxinin. Systemic administration of picrotoxinin excited all the neurons examined in normal rats, and after treatment with picrotoxinin, the local administration of AS 19 further increased the firing rate of the neurons. In the lesioned rats, systemic administration of AS 19, at the same doses, also increased the mean firing rate of the pyramidal neurons. However, cumulative dose producing excitation in the lesioned rats was higher than that of normal rats. Systemic administration of AS 19 produced inhibitory effect in the lesioned rats, which was partially reversed by picrotoxinin. The local administration of AS 19, at the same dose, did not change the firing rate of the neurons in the lesioned rats. Systemic administration of picrotoxinin and the local administration of AS 19 did not affect the firing rate of the neurons in the lesioned rats. These results indicate that activity of mPFC pyramidal neurons is regulated through activation of 5-HT₇ receptor by direct or indirect action, and degeneration of the nigrostriatal pathway leads to decreased response of these neurons to AS 19, suggesting dysfunction and/or down-regulation of 5-HT₇ receptor on the pyramidal neurons and GABA interneurons in the lesioned rats.

Unilateral lesion of the nigrostriatal pathway decreases the response of fast-spiking interneurons in the medial prefrontal cortex to 5-HT1A receptor agonist and expression of the receptor in parvalbumin-positive neurons in the rat

5-Hydroxytryptamine(1A) (5-HT(1A)) receptors are expressed in the prefrontal cortical interneurons. Among these interneurons, calcium-binding protein parvalbumin (PV)-positive fast spiking (FS) interneurons play an important role in regulatory function of the prefrontal cortex. In the present study, the response of medial prefrontal cortex (mPFC) FS interneurons to the selective 5-HT(1A) receptor agonist 8-OH-DPAT and change in expression of 5-HT(1A) receptor on PV-positive neurons were examined in rats with 6-hydroxydopamine (6-OHDA) lesions of the substantia nigra pars compacta (SNc) by using extracellular recording and double-labeling immunofluorescence histochemistry. Systemic administration of 8-OH-DPAT (1-243 μg/kg, i.v.) dose-dependently inhibited the mean firing rate of the FS interneurons in sham-operated and the lesioned rats, respectively. The cumulative doses producing inhibition in the lesioned rats (243 μg/kg) was significantly higher than that of sham-operated rats (27 μg/kg). Furthermore, the local application of 8-OH-DPAT (0.01 μg) in the mPFC inhibited the FS interneurons in sham-operated rats, while having no effect on firing rate of the FS interneurons in the lesioned rats. In contrast to sham-operated rats, the lesion of the SNc in rats did not cause the change of PV-positive neurons in the prelimbic prefrontal cortex, a subregion of the mPFC, whereas the lesion of the SNc markedly reduced in percentage of PV-positive neurons expressing 5-HT(1A) receptors. Our results indicate that degeneration of the nigrostriatal pathway results in the decreased response of FS interneurons in the mPFC to 5-HT(1A) receptor stimulation, which attributes to down-regulation of 5-HT(1A) receptor expression in these interneurons.