Prenatal expression of interleukin 1beta and interleukin 6 in the rat pituitary gland

Serum Interleukin-1 Levels Are Associated with Intracranial Aneurysm Instability

Serum interleukin-1 (IL-1) are possibly indicative of the inflammation in the intracranial aneurysm (IA) wall. This study aimed to investigate whether IL-1 could discriminate the unstable IAs (ruptured intracranial aneurysms (RIAs) and symptomatic unruptured intracranial aneurysms (UIAs)) from stable, asymptomatic UIAs. IA tissues and blood samples from 35 RIA patients and 35 UIA patients were collected between January 2017 and June 2020 as the derivation cohort. Blood samples from 211 patients with UIAs were collected between January 2021 and June 2022 as the validation cohort (including 63 symptomatic UIAs). Blood samples from 35 non-cerebral-edema meningioma patients (non-inflammatory control) and 19 patients with unknown-cause subarachnoid hemorrhage (hemorrhagic control) were also collected. IL-1β and IL-1.ra (IL-1 receptor antagonist) were measured in serum and IA tissues, and the IL-1 ratio was calculated as log10 (IL-1.ra/IL-1β). Based on the derivation cohort, multivariate logistic analysis showed that IL-1β (odds ratio, 1.48, P = 0.001) and IL-1.ra (odds ratio, 0.74, P = 0.005) were associated with RIAs. The IL-1 ratio showed an excellent diagnostic accuracy for RIAs (c-statistic, 0.91). Histological analysis confirmed the significant correlation of IL-1 between serum and aneurysm tissues. IL-1 ratio could discriminate UIAs from non-inflammatory controls (c-statistic, 0.84), and RIAs from hemorrhagic controls (c-statistic, 0.95). Based on the validation cohort, the combination of IL-1 ratio and PHASES score had better diagnostic accuracy for symptomatic UIAs than PHASES score alone (c-statistic, 0.88 vs 0.80, P < 0.001). Serum IL-1 levels correlate with aneurysm tissue IL-1 levels and unstable aneurysm status, and could serve as a potential biomarker for IA instability.

Serum interleukin-1 is a new biomarker to predict the risk of rebleeding of ruptured intracranial aneurysm after admission

Interleukin-1 (IL-1) could induce inflammation of the aneurysm wall, which might be related to intracranial aneurysm rupture. The aim of this study was to investigate whether IL-1 could serve as a biomarker to predict the risk of rebleeding after admission. Data between January 2018 and September 2020 were collected from patients with ruptured intracranial aneurysms (RIAs) and were retrospectively reviewed. The serum IL-1β and IL-1ra levels were detected using a panel, and IL-1 ratio was calculated as the log10 (IL-1ra/IL-1β). The predictive accuracy of IL-1 compared with previous clinical morphology (CM) model and other risk factors were evaluated by the c-statistic. Five hundred thirty-eight patients were finally included in the study, with 86 rebleeding RIAs. The multivariate Cox analysis confirmed aspect ratio (AR) > 1.6 (hazard ratio (HR), 4.89 [95%CI, 2.76-8.64], P < 0.001), size ratio (SR) > 3.0 (HR, 2.40 [95%CI, 1.34-4.29], P = 0.003), higher serum IL-1β (HR, 1.88 [95%CI, 1.27-2.78], P = 0.002), and lower serum IL-1ra (HR, 0.67 [95%CI, 0.56-0.79], P < 0.001) as the independent risk factors for rebleeding after admission. According to the c-statistics, the IL-1 ratio had the highest predictive accuracy (0.82), followed by IL-1ra and IL-1β (0.80), AR > 1.6 (0.79), IL-1ra (0.78), IL-1β (0.74), and SR > 3.0 (0.56), respectively. Subgroup analysis based on AR and SR presented similar results. The model combining IL-1 ratio and CM model showed higher predictive accuracy for the rebleeding after admission (c-statistic, 0.90). Serum IL-1, especially IL-1 ratio, could serve as a biomarker to predict the risk of rebleeding after admission.

Leukemia Inhibitory Factor Represses GnRH Gene Expression via cFOS during Inflammation in Male Mice

BACKGROUND

The mechanisms whereby neuroinflammation negatively affects neuronal function in the hypothalamus are not clear. Our previous study determined that obesity-mediated chronic inflammation elicits sex-specific impairment in reproductive function via reduction in spine density in gonadotropin-releasing hormone (GnRH) neurons. Neuroinflammation and subsequent decrease in GnRH neuron spine density was specific for male mice, while protection in females was independent of ovarian estrogens.

METHODS

To examine if neuroinflammation-induced cytokines can directly regulate GnRH gene expression, herein we examined signaling pathways and mechanisms in males in vivo and in GnRH-expressing cell line, GT1-7.

RESULTS

GnRH neurons express cytokine receptors, and chronic or acute neuroinflammation represses GnRH gene expression in vivo. Leukemia inhibitory factor (LIF) in particular represses GnRH expression in GT1-7 cells, while other cytokines do not. STAT3 and MAPK pathways are activated following LIF treatment, but only MAPK pathway, specifically p38α, is sufficient to repress the GnRH gene. LIF induces cFOS that represses the GnRH gene via the -1,793 site in the enhancer region. In vivo, following high-fat diet, cFOS is induced in GnRH neurons and neurons juxtaposed to the leaky blood brain barrier of the organum vasculosum of the lamina terminalis, but not in the neurons further away.

CONCLUSION

Our results indicate that the increase in LIF due to neuroinflammation induces cFOS and represses the GnRH gene. Therefore, in addition to synaptic changes in GnRH neurons, neuroinflammatory cytokines directly regulate gene expression and reproductive function, and the specificity for neuronal targets may stem from the proximity to the fenestrated capillaries.

Endothelial immunocytochemical expression of pituitary IL-1β and its relation to ACTH-positive cells is regulated by corticosterone in the male rat

Interleukin-1 beta (IL-1β) is a cytokine linking the neuroendocrine system and metabolic homeostasis. We have previously demonstrated the relevance of IL-1β for maintaining the pituitary ACTH-producing cells by immuno-blocking its effects in pituitary cultures. However, the morphological characteristics and the intimate relationship of the pituitary cells expressing IL-1β and ACTH remain unknown. For determining pituitary variations of immunoreactivity for IL-1β and its relation with ACTH-positive cells under stress situations, we performed an immunohistochemical analysis of the expression of IL-1β and ACTH in the pituitary gland of adult rats, in the absence or presence of corticosterone, by establishing different groups: untreated, sham-operated, and bilaterally adrenalectomized animals. In the rats subjected to surgery, the glucocorticoid was administered on the same day of the intervention and on the third day post-surgery. Interestingly, it was observed that IL-1β was located in the pituitary endothelial cells at the hypophyseal portal vessels, regardless of the treatment schedule. When comparing the pituitary immunoreactive surface to IL-1β expression without corticosterone, adrenalectomized animals displayed a significantly greater area than the sham-operated animals. Corticosterone significantly inhibited the effect of adrenalectomy depending on the time interval it was administered. By in situ hybridization, IL-1β mRNA expression was also correlated with immnunocytochemical expression of pituitary IL-1β. Our results demonstrate that IL-1β is a constitutive element in endothelial portal pituitary vessels and under stress experimental conditions IL-1β increases its expression and its relation with ACTH-positive cells, suggesting that IL-1β could participate in an autocrine-paracrine fashion thereby modulating the pituitary population of ACTH-positive cells.

Emerging Targets in Pituitary Adenomas: Role of the CXCL12/CXCR4-R7 System

Chemokines are chemotactic regulators of immune surveillance in physiological and pathological conditions such as inflammation, infection, and cancer. Several chemokines and cognate receptors are constitutively expressed in the central nervous system, not only in glial and endothelial cells but also in neurons, controlling neurogenesis, neurite outgrowth, and axonal guidance during development. In particular, the chemokine CXCL12 and its receptors, CXCR4 and CXCR7, form a functional network that controls plasticity in different brain areas, influencing neurotransmission, neuromodulation, and cell migration, and the dysregulation of this chemokinergic axis is involved in several neurodegenerative, neuroinflammatory, and malignant diseases. CXCR4 primarily mediates the transduction of proliferative signals, while CXCR7 seems to be mainly responsible for scavenging CXCL12. Importantly, the multiple intracellular signalling generated by CXCL12 interaction with its receptors influences hypothalamic modulation of neuroendocrine functions, although a direct modulation of pituitary functioning via autocrine/paracrine mechanisms was also reported. Both CXCL12 and CXCR4 are constitutively overexpressed in pituitary adenomas and their signalling induces cell survival and proliferation, as well as hormonal hypersecretion. In this review we focus on the physiological and pathological functions of immune-related cyto- and chemokines, mainly focusing on the CXCL12/CXCR4-7 axis, and their role in pituitary tumorigenesis. Accordingly, we discuss the potential targeting of CXCR4 as novel pharmacological approach for pituitary adenomas.

Ontogeny and the effects of in utero brain ischemia on interleukin-1β and interleukin-6 protein expression in ovine cerebral cortex and white matter

Interleukin (IL)-1β and IL-6 have been implicated in brain development, injury progression, and fetal/maternal immune interactions. We examined IL-1β and IL-6 protein expression in cerebral cortex (CC) and white matter (WM) from non-ischemic ovine fetuses at 87-90, 122-127, and 135-137 days of gestation, pregnant ewes at 87-90 and 135-137 days of gestation, and fetuses exposed to 48 or 72h of reperfusion after ischemia. Protein expression was determined by Western immunoblot. In non-ischemic CC, IL-1β was higher (P<0.05) in adult sheep and fetuses at 135-137 than 87-90 and 122-127 days, and IL-6 higher at 122-127 than 87-90 days, and in adults than fetuses at 87-90, 122-127, and 135-137 days of gestation. In non-ischemic fetal WM, IL-6 was higher at 135-137 than 87-90 days, but IL-1β did not differ. In CC, IL-1β was higher in ewes at 135-137 than 87-90 days and IL-6 at 135-137 days and in non-pregnant adults than ewes at 87-90 days of gestation. In WM, IL-1β was higher in ewes at 135-137 than 87-90 days of gestation, but IL-6 did not differ. Forty-eight and 72h after ischemia, CC IL-1β was higher than in non-ischemic fetuses. Seventy-two hours after ischemia, IL-1β and IL-6 were higher in WM than CC. In conclusion, IL-1β and IL-6 exhibit developmental regulation in fetal brain, change during gestation in brains of pregnant ewes, show regional differences in normal brains of fetuses and ewes, demonstrate differential responses after ischemia in CC and WM, and IL-1β but not IL-6 increases after ischemia in CC.

Molecular cloning and characterization of interleukin-1β in half-smooth tongue sole Cynoglossus semilaevis

As a member of the interleukin (IL)-1 family, IL-1β is a prototypical proinflammatory cytokine, which plays a crucial role in immune responses. Herein, we reported the full length cDNA of IL-1β in half-smooth tongue sole (Cynoglossus semilaevis). The csIL-1β cDNA contained a 130 bp 5' UTR, a 417 bp 3' UTR and a 741 bp coding sequence (CDS) that translated into a polypeptide of 246 amino acids. The protein sequence included a typical IL-1 family signature and lacked an interleukin-converting enzyme (ICE) cut site. RT-PCR analysis indicated a broad expression of csIL-1β, especially in immune-related organs. After injection with inactive Vibrio anguillarum, the expression of csIL-1β was induced in the head kidney and spleen and reached the highest level at 8 h post injection. Higher expression of csIL-1β was observed at gastrula stage, eye-bud stage and hatching stage and lower level of csIL-1β mRNA was detected at metamorphic stage. The expression of csIL-1β during development suggested IL-1β might be involved not only in immunity but also development. Taken together, the present study indicated that csIL-1β played an important role in immune responses and development like its mammalian counterparts, although species-specific features were present.