Probes for INS

Neuronal circuits involving the central amygdala (CeA) are gaining prominence as important centers for regulation of metabolic functions. As a part of the subcortical food motivation circuitry, CeA is associated with food motivation and hunger. We have previously shown that interleukin-6 (IL-6) can act as a downstream mediator of the metabolic effects of glucagon-like peptide-1 receptor (GLP-1R) stimulation in the brain, but the sites of these effects are largely unknown. We here used the newly generated and validated RedIL6 reporter mouse strain to investigate the presence of IL-6 in the CeA, as well as possible interactions between IL-6 and GLP-1 in this nucleus. IL-6 was present in the CeA, mostly in cells in the medial and lateral parts of this structure, and a majority of IL-6-containing cells also co-expressed GLP-1R. Triple staining showed GLP-1 containing fibers co-staining with synaptophysin close to or overlapping with IL-6 containing cells. GLP-1R stimulation enhanced IL-6 mRNA levels. IL-6 receptor-alpha was found to a large part in neuronal CeA cells. Using electrophysiology, we determined that cells with neuronal properties in the CeA could be rapidly stimulated by IL-6 administration in vitro. Moreover, microinjections of IL-6 into the CeA could slightly reduce food intake in vivo in overnight fasted rats. In conclusion, IL-6 containing cells in the CeA express GLP-1R, are close to GLP-1-containing synapses, and get increased IL-6 mRNA in response to GLP-1R agonist treatment. IL-6, in turn, exerts biological effects in the CeA, possibly via IL-6 receptor-alpha present in this nucleus.

Abstract

Inflammatory cytokines, like tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6), are elevated in ovarian cancer. Differences in cytokine expression by histologic subytpe or ovarian cancer risk factors can provide useful insight into ovarian cancer risk and etiology. We used ribonucleic acid (RNA) in-situ hybridization to assess TNF-α and IL-6 expression on tissue microarray slides from 78 epithelial ovarian carcinomas (51 serous, 12 endometrioid, 7 clear cell, 2 mucinous, 6 other) from a population-based case control study. Cytokine expression was scored semi-quantitatively and odds ratios (OR) and 95% confidence intervals (CI) were calculated using polytomous logistic regression. TNF-α was expressed in 46% of the tumors while sparse IL-6 expression was seen only 18% of the tumors. For both markers, expression was most common in high grade serous carcinomas followed by endometrioid carcinomas. Parity was associated with a reduced risk of TNF-α positive (OR = 0.3, 95% CI: 0.1-0.7 for 3 or more children versus none) but not TNF-α negative tumors (p-heterogeneity = 0.02). In contrast, current smoking was associated with a nearly three fold increase in risk of TNF-α negative (OR = 2.8, 95% CI: 1.2, 6.6) but not TNF-α positive tumors (p-heterogeneity = 0.06). Our data suggests that TNF-α expression in ovarian carcinoma varies by histologic subtype and provides some support for the role of inflammation in ovarian carcinogenesis. The novel associations detected in our study need to be validated in a larger cohort of patients in future studies.

The ventrolateral periaqueductal gray (vlPAG) constitutes a major descending pain modulatory system and is a crucial site for opioid-induced analgesia. A number of previous studies have demonstrated that glutamate and GABA play critical opposing roles in nociceptive processing in the vlPAG. It has been suggested that glutamatergic neurotransmission exerts antinociceptive effects, whereas GABAergic neurotransmission exert pro-nociceptive effects on pain transmission, through descending pathways. The inability to exclusively manipulate subpopulations of neurons in the PAG has prevented direct testing of this hypothesis. Here we demonstrate the different contributions of genetically-defined glutamatergic and GABAergic vlPAG neurons in nociceptive processing by employing cell type-specific chemogenetic approaches in mice. Global chemogenetic manipulation of vlPAG neuronal activity suggests that vlPAG neural circuits exert tonic suppression of nociception, consistent with previous pharmacological and electrophysiological studies. However, selective modulation of GABAergic or glutamatergic neurons demonstrates an inverse regulation of nociceptive behaviors by these cell populations. Selective chemogenetic activation of glutamatergic neurons, or inhibition of GABAergic neurons, in vlPAG suppresses nociception. In contrast, inhibition of glutamatergic neurons, or activation of GABAergic neurons, in vlPAG facilitates nociception. Our findings provide direct experimental support for a model in which excitatory and inhibitory neurons in the PAG bidirectionally modulate nociception.

Significance Statement The PAG is a midbrain region critical for the modulation of pain. However, the roles played by the distinct cell types within the PAG in nociceptive processing are poorly understood. This work addresses the divergent roles of glutamatergic and GABAergic PAG neuronal subpopulations in nociceptive processing. We demonstrate that activation of glutamatergic neurons or inhibition of GABAergic neurons suppresses nociception. Whereas inhibition of glutamatergic neuronal activity or activation of GABAergic neuronal activity potentiates nociception. This report identifies distinct roles for these neuronal populations in modulating nociceptive processing.

Abstract

BACKGROUND & AIMS:

The present study aimed to elucidate the clinicopathological significance of IL-6 and IL-33 expression in intrahepatic cholangiocarcinomas (iCCAs) and perihilar cholangiocarcinomas (pCCAs).

METHODS:

IL-6 and IL-33 mRNA expression was examined in iCCAs (n=55) and pCCAs (n=32) using quantitative real-time PCR and a highly sensitive in situ hybridization protocol (RNAscope™ ), and expression values were correlated with clinicopathological features. According to a recently proposed classification scheme, iCCAs were separated into small- (n=33) and large-duct types (n=22).

RESULTS:

IL-6 and IL-33 expression levels were higher in large-duct iCCAs and pCCAs than in small-duct iCCAs, with a positive correlation between the values of these cytokines. In double in situ hybridization/immunostaining, IL-6 mRNA was expressed in actin-positive (myo)fibroblasts, while IL-33 was mainly produced by CD31-positive endothelial cells. Based on the average expression value as a cut-off point, cases were classified as IL-6high and IL-6low or IL-33high and IL-33low . In the combined cohort of large-duct iCCAs and pCCAs, IL-6high and IL-6low cholangiocarcinomas shared many features, while IL-33high cases had less aggressive characteristics than IL-33low cases as evidenced by lower tumour marker concentrations, smaller tumour sizes, less common vascular invasion, lower pT stages, and higher lymphocyte-to-monocyte ratios in blood. KRAS mutations were slightly less common in IL-33high cases than in IL-33low cancers (9% vs 29%; p=0.061). The strong expression of IL-33 in tissue appeared to be an independent favourable prognostic factor.

CONCLUSIONS:

IL-33high cholangiocarcinomas may represent a unique, less aggressive carcinogenetic process of the large bile ducts.

Amplifications at 9p24 have been identified in breast cancer and other malignancies, but the genes within this locus causally associated with oncogenicity or tumor progression remain unclear. Targeted next-generation sequencing of postchemotherapy triple-negative breast cancers (TNBCs) identified a group of 9p24-amplified tumors, which contained focal amplification of the Janus kinase 2 (JAK2) gene. These patients had markedly inferior recurrence-free and overall survival compared to patients with TNBC withoutJAK2amplification. Detection ofJAK2/9p24 amplifications was more common in chemotherapy-treated TNBCs than in untreated TNBCs or basal-like cancers, or in other breast cancer subtypes. Similar rates ofJAK2amplification were confirmed in patient-derived TNBC xenografts. In patients for whom longitudinal specimens were available,JAK2amplification was selected for during neoadjuvant chemotherapy and eventual metastatic spread, suggesting a role in tumorigenicity and chemoresistance, phenotypes often attributed to a cancer stem cell-like cell population. In TNBC cell lines withJAK2copy gains or amplification, specific inhibition of JAK2 signaling reduced mammosphere formation and cooperated with chemotherapy in reducing tumor growth in vivo. In these cells, inhibition of JAK1-signal transducer and activator of transcription 3 (STAT3) signaling had little effect or, in some cases, counteracted JAK2-specific inhibition. Collectively, these results suggest that JAK2-specific inhibitors are more efficacious than dual JAK1/2 inhibitors against JAK2-amplified TNBCs. Furthermore,JAK2amplification is a potential biomarker for JAK2 dependence, which, in turn, can be used to select patients for clinical trials with JAK2 inhibitors.