Vasopressin and oxytocin beyond the pituitary in the human brain

Vasopressin and oxytocin are primarily synthesized in the magnocellular supraoptic and paraventricular nuclei of the hypothalamus and transported to the posterior pituitary. In the human, an extensive accessory magnocellular neuroendocrine system is present with contact to the posterior pituitary and blood vessels in the hypothalamus itself. Vasopressin and oxytocin are involved in social and behavioral functions. However, only few neocortical areas are targeted by vasopressinergic and oxytocinergic nerve fibers, which mostly project to limbic areas in the forebrain, where also their receptors are located. Vasopressinergic/oxytocinergic perikarya in the forebrain project to the brain stem and spinal cord targeting nuclei and areas involved in autonomic functions. Parvocellular neurons containing vasopressin are located in the suprachiasmatic nucleus and synchronize the activity of the pacemaker in this nucleus. From the suprachiasmatic nucleus fibers project to the parvocellular part of the paraventricular nucleus, where preautonomic neurons project to the intermediolateral nucleus in the thoracic spinal cord, from where the superior cervical ganglion is reached whose noradrenergic fibers terminate in the pineal gland to stimulate melatonin secretion at night. The pineal gland is also innervated by vasopressin- and oxytocin-containing fibers reaching the gland via the "central innervation" in the pineal stalk, which might be involve in an annual regulation of melatonin secretion.

Identifying daily changes in circRNAs and circRNA-associated-ceRNA networks in the rat pineal gland

Circular RNAs (circRNAs) are a new class of covalently closed circular RNA molecules that are involved in many biological processes. However, information about circRNAs in the pineal gland, particularly that of rats, is limited. To establish resources for the study of the rat pineal gland, we performed transcriptome analysis of the pineal glands during the day and night. In this study, 1413 circRNAs and 1989 miRNAs were identified in the pineal gland of rats during the night and day using the Illumina platform. Forty differentially expressed circRNAs and 93 differentially expressed miRNAs were obtained, among which 20 circRNAs and 37 miRNAs were significantly upregulated during the day and 20 circRNAs and 56 miRNAs were significantly upregulated during the night. As circRNAs have been reported to work as miRNA sponges, we predicted 15940 interactions among 40 circRNAs, 93 miRNAs and 400 mRNAs with differential diurnal expression using miRanda and TargetScan to build a ceRNA regulatory network in the rat pineal gland. The diurnal expression profile of circRNAs in the rat pineal gland may provide additional information about the role of circRNAs in regulating changes in melatonin circadian rhythms. The analyzed data reported in this study will be an important resource for future studies to elucidate the altered physiology of circRNAs in diurnal rhythms.

Smaller pineal gland is associated with rapid eye movement sleep behavior disorder in Alzheimer's disease

BACKGROUND

To investigate the association between pineal gland volume and symptoms of rapid eye movement (REM) sleep behavior disorder (RBD) in Alzheimer's disease (AD) patients without any feature of dementia with Lewy bodies.

METHODS

We enrolled 296 community-dwelling probable AD patients who did not meet the diagnostic criteria for possible or probable dementia with Lewy bodies. Among them, 93 were amyloid beta (Aβ) positive on ¹⁸F-florbetaben amyloid brain positron emission tomography. We measured RBD symptoms using the REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ) and defined probable RBD (pRBD) as the RBDSQ of 5 or higher. We manually segmented pineal gland on 3T structural T1-weighted brain magnetic resonance imaging.

RESULTS

The participants with pRBD had smaller pineal parenchyma volume (VPP) than those without pRBD (p <  0.001). The smaller the VPP, the more severe the RBD symptoms (p <  0.001). VPP was inversely associated with risk of prevalent pRBD (odds ratio = 0.909, 95% confidence interval [CI] = 0.878-0.942, p <  0.001). Area under the receiver operator characteristic curve for pRBD of VPP was 0.80 (95% CI = 0.750-0.844, p <  0.0001). These results were not changed when we analyzed the 93 participants with Aβ-positive AD separately.

CONCLUSIONS

In AD patients, reduced pineal gland volume may be associated with RBD.

24 hour patterning in gene expression of pineal neurosteroid biosynthesis in young chickens (Gallus gallus domesticus L.)

The pineal gland, one of the three equivalent avian biological clock structures, is also the site of intensive neurosteroid synthesis (7α-hydroxypregnenolone and allopregnanolone). Pineal neurosteroid biosynthesis involves six enzymes: cytochrome P450 side-chain cleavage - Cyp11a1 encoded, cytochrome P450_7α - Cyp7b1, 3β-hydroxysteroid dehydrogenase - Hsd3b2, 5α-reductase - Srd5a1, 3α-hydroxysteroid dehydrogenase - Akr1d1, and 5β-reductase - Srd5a3. Regulation of neurosteroid biosynthesis is not fully understood; although it is known that the E4BP4 transcription factor induces activation of biosynthetic cholesterol genes, which are the targets for SREBP (element-binding protein transcription factor). SREBP principal activity in the pineal gland is suppression and inhibition of the Period2 canonical clock gene, suggesting our hypothesis that genes encoding enzymes involved in neurosteroidogenesis are under circadian clock control and are the Clock Control Genes (CCGs). Therefore, through investigation of daily changes in Cyp11a1, Cyp7b1, Hsd3b2, Akr1d1, Srd5a1, and Srd5a3, pineal genes were tested in vivo and in vitro, in cultured pinealocytes. Experiments were carried out on pineal glands taken from 16-day-old chickens in vivo or using in vitro cultures of pinealocytes collected from 16-day-old animals. Both the birds in the in vivo experiments and the pinealocytes were kept under controlled light conditions (LD 12:12) or in constant darkness (DD). Subsequently, materials were prepared for RT-qPCR analysis. Results revealed that three of the six tested genes: Cyp11a1, Cyp7b1, and Srd5a3 demonstrated significant 24-hour variation in in vivo and in vitro. Findings of this study confirm that these genes could be under clock control and satisfy many of the requirements to be identified as CCGs.

Developmental stage-specific A-to-I editing pattern in the postnatal pineal gland of pigs (Sus scrofa)

Background

RNA editing is a widespread post-transcriptional modification mechanism in mammalian genomes. Although many editing sites have been identified in domestic pigs (Sus scrofa), little is known about the characteristics and dynamic regulation of RNA editing in the pineal gland (PG), a small neuroendocrine gland that synthesizes and secretes melatonin, which is primarily responsible to modulate sleep patterns.

Results

This study analyzed the expression of adenosine-to-inosine (A-to-I) editing regulators and profiled the first dynamic A-to-I RNA editome during postnatal PG development. The results identified ADAR1 as the most abundantly expressed ADAR enzyme, which was down-regulated during postnatal PG development. Furthermore, 47,284 high-confidence RNA editing sites were identified, the majority of which (93.6%) were of the canonical A-to-I editing type, followed by C-to-T editing. Analysis of its characteristics showed that the A-to-I editing sites mostly localized in SINE retrotransposons PRE-1/Pre0_SS. Moreover, a strong deficiency and preference for guanine nucleotides at positions of one base upstream or downstream were found, respectively. The overall editing level at the puberty stage was higher than at both infancy and adulthood stages. Additionally, genome-wide RNA editing was found to exhibit a dynamic stage-specific fashion (postnatally). Genes that underwent developmental changes in RNA editing were associated with catabolic processes as well as protein localization and transport functions, implying that RNA editing might be responsible for the molecular machineries of the postnatal developing PG. Remarkably, RNA editing in 3'-UTRs might regulate gene expression by influencing miRNA binding during PG development.

Conclusions

This study profiles the first comprehensive developmental RNA editome in the pig PG, which contributes to the understanding of the importance of post-transcriptionally mediated regulation during mammalian postnatal PG development. Moreover, this study widely extends RNA editome resources in mammals.

Fluoride-Free Diet Stimulates Pineal Growth in Aged Male Rats

The pineal gland is a naturally calcifying endocrine organ which secretes the sleep-promoting hormone melatonin. Age-related changes of the pineal have been observed, including decreased pinealocyte numbers, increased calcification, and a reduction in melatonin production. Since fluoride is attracted to calcium within the pineal gland, this study sought to examine the effects of a fluoride-free diet on the morphology of the pineal gland of aged male rats (26 months old). All animals had previously been raised on standard fluoridated food and drinking water. These control animals were compared to other animals that were placed on a fluoride-free diet ("fluoride flush") for 4 or 8 weeks. At 4 weeks, pineal glands from fluoride-free animals showed a 96% increase in supporting cell numbers and at 8 weeks a 73% increase in the number of pinealocytes compared to control animals. In contrast, the number of pinealocytes and supporting cells in animals given an initial 4-week fluoride flush followed by a return to fluoridated drinking water (1.2 ppm NaF) for 4 weeks were not different from control animals. Our findings therefore demonstrate that a fluoride-free diet encouraged pinealocyte proliferation and pineal gland growth in aged animals and fluoride treatment inhibited gland growth. These findings suggest that dietary fluoride may be detrimental to the pineal gland.

Circadian disruption, melatonin rhythm perturbations and their contributions to chaotic physiology

The aim of this report is to summarize the data documenting the vital nature of well-regulated cellular and organismal circadian rhythms, which are also reflected in a stable melatonin cycle, in supporting optimal health. Cellular fluctuations in physiology exist in most cells of multicellular organisms with their stability relying on the prevailing light:dark cycle, since it regulates, via specialized intrinsically-photoreceptive retinal ganglion cells (ipRGC) and the retinohypothalamic tract, the master circadian oscillator, i.e., the suprachiasmatic nuclei (SCN). The output message of the SCN, as determined by the light:dark cycle, is transferred to peripheral oscillators, so-called slave cellular oscillators, directly via the autonomic nervous system with its limited distribution. and indirectly via the pineal-derived circulating melatonin rhythm, which contacts every cell. Via its regulatory effects on the neuroendocrine system, particularly the hypothalamo-pituitary-adrenal axis, the SCN also has a major influence on the adrenal glucocorticoid rhythm which impacts neurological diseases and psychological behaviors. Moreover, the SCN regulates the circadian production and secretion of melatonin. When the central circadian oscillator is disturbed, such as by light at night, it passes misinformation to all organs in the body. When this occurs the physiology of cells becomes altered and normal cellular functions are compromised. This physiological upheaval is a precursor to pathologies. The deterioration of the SCN/pineal network is often a normal consequence of aging and its related diseases, but in today's societies where manufactured light is becoming progressively more common worldwide, the associated pathologies may also be occurring at an earlier age.

Adult Pineal Region Atypical Teratoid Rhabdoid Tumor: A Case for Aggressive Surgical and Chemoradiation Management with Comprehensive Literature Review

BACKGROUND

Atypical teratoid rhabdoid tumor (ATRT) is a rare, highly malignant central nervous system neoplasm classified as an embryonal grade IV neoplasm by the World Health Organization. ATRT generally occurs in children younger than 3 years, with 85 pathologically confirmed cases reported in adults. It is most commonly supratentorial, with only 9 confirmed adult cases localized to the pineal region.

CASE DESCRIPTION

The case is described of a 29-year-old man with a history of chronic migraines and a previously negative computed tomography scan of the head presenting with worsening headaches and new-onset diplopia with upward gaze palsy. Computed tomography and magnetic resonance imaging showed a hemorrhagic pineal mass with extension into the right thalamus. After resection, the immunohistochemical staining and cytogenetic profile proved consistent with ATRT, making it the ninth reported case of pineal ATRT in an adult, which was treated aggressively with good outcome.

CONCLUSIONS

Adult ATRT is rare, especially in the pineal region, with only 9 cases reported. Because of the aggressiveness, ATRT must be considered in the differential diagnosis of pineal region lesions because early diagnosis and aggressive treatment are key to prolonged survival.

The role of a lncRNA (TCONS_00044595) in regulating pineal CLOCK expression after neonatal hypoxia-ischemia brain injury

A common, yet often neglectable, feature of neonatal hypoxic-ischemic brain damage (HIBD) is circadian rhythm disorders resulted from pineal gland dysfunction. Our previous work demonstrated that miRNAs play an important role in regulating key circadian genes in the pineal gland post HIBD [5,21]. In current study, we sought out to extend our investigation by profiling expression changes of pineal long non-coding RNAs (lncRNAs) upon neonatal HIBD using RNA-Seq. After validating lncRNA changes, we showed that one lncRNA: TCONS_00044595 is highly enriched in the pineal gland and exhibits a circadian expression pattern. Next, we performed bioinformatic analysis to predict the lncRNA-miRNA regulatory network and identified 168 miRNAs that potentially targetlncRNA TCONS_00044595. We further validated the bona fide interaction between one candidate miRNA: miR-182, a known factor to regulate pineal Clock expression, and lncRNA TCONS_00044595. Finally, we showed that suppression of lncRNA TCONS_00044595 alleviated the CLOCK activation both in the cultured pinealocytes under OGD conditions and in the pineal gland post HIBD in vivo. Our study thus shed light into novel mechanisms of pathophysiology of pineal dysfunction post neonatal HIBD.

Papillary Tumor of the Pineal Region: Systematic Review and Analysis of Prognostic Factors

BACKGROUND

Clinical outcomes and biological behavior of papillary tumors of the pineal region (PTPR) are still under investigation. The best therapeutic strategy has not been defined.

OBJECTIVE

To perform a comprehensive patient-level analysis of all PTPR cases and identify their clinical features, treatment options, and prognostic factors.

METHODS

A search of the medical databases for case series and reports on PTPRs from January 2003 to June 2017 was performed. Data addressing PTPR's clinical presentation, imaging, treatment, and histological features were. Variables associated with the primary outcome of 36-mo survival were identified through Cox regression models.

RESULTS

The initial search yielded 1164 studies, of which 71 were included (60 case reports and 11 case series), containing 177 patients (mean age 33.0 ± 15.3 yr and 53.2% male). Intracranial hypertension and hydrocephalus prevailed as the clinical picture. Surgery was performed on 82.0% and gross total resection (GTR) was achieved on 71.4%. A total of 56.8% recurred after a median 29 mo (quartiles 10.5-45.5). The 36-mo survival rate was 83.5% (95% confidence interval [CI] 76.2-89.2%). Good functional outcomes (Glasgow Outcome Scale 4/5) were observed in 60.0%. The variables of interest were inconsistently reported and the multivariable analysis final sample was 133 patients. After adjustment for age, tumor size (each additional centimeter, hazard ratio [HR] 1.99, 95% CI 1.12-3.53, P = .019) and surgical treatment (HR 0.16, 95% CI 0.05-0.45, P = .001) were associated with 36-mo survival.

CONCLUSION

Tumor size and surgery are associated with improvement in 36-mo survival. We did not observe any significant benefits from GTR or adjuvant treatments.

Effects of melatonin on the in vitro growth of early antral follicles and maturation of ovine oocytes

This study aimed to evaluate the effect of melatonin on the in vitro culture and maturation of isolated sheep early antral follicles. Isolated early antral follicles were cultured for 12 d in α-minimum essential medium (MEM⁺) alone (control) or α-MEM⁺ added with fixed different concentrations (100, 500, or 1,000 pg/mL) or a sequential concentration of melatonin (MelSeq; day 6 = 100; day 12 = 500 pg/mL). The percentage of morphologically normal follicles was higher (P < 0.05) in 500 pg/mL melatonin than the other treatments at 6 d. Mel 500 also showed a higher rate of fully grown oocytes (P < 0.05) than other treatments. After in vitro culture, reactive oxygen species (ROS) levels in oocytes were similar between Mel 500 and MelSeq, with both being lower (P < 0.05) than other treatments. Oocytes cultured in both Mel 500 and Mel 1000 showed glutathione peroxidase levels similar (P > 0.05) to the control group and higher (P < 0.05) than other treatments. Mitochondrial activity was similar (P > 0.05) among control, Mel 500, and Mel 1000 treatments. Mel 500 treatment presented a higher percentage of germinal vesicle breakdown oocytes than the control group and similar percentages to the other treatments. Follicles cultured in melatonin followed by oocyte maturation with the addition of 500 pg/mL melatonin in maturation medium showed increased (P < 0.05) levels of mitochondrial activity compared to α-MEM⁺ alone. In conclusion, the concentration of 500 pg/mL of melatonin promotes development and decreases ROS levels of ovine oocytes from in vitro grown early antral follicles. Moreover, melatonin increases mitochondrial activity and promotes the acquisition of meiotic competence of these oocytes.

Revisiting the pineal gland: a review of calcification, masses, precocious puberty, and melatonin functions

Introduction: The pineal gland, an endocrine organ of the posterior cranial fossa famously involved in sleep and wakefulness, has continually been a topic of scientific advancement and curiosity. Methods: We review present an up-to-date review including the anatomy, embryology, and physiology of the pineal gland and its ability to secrete hormones including melatonin, pathophysiology of pineal gland tumors, cysts, and calcifications, their clinical presentation including their association with parkinsonism and precocious puberty, and various treatment approaches. Results: Exploring the biochemistry of melatonin, various calcification morphologies, and pineal tumors may uncover a wider role and the exhaustive case study consolidation allows clinicians to carefully review the literature and aid their treatment approaches. Conclusion: It is imperative that clinicians and diagnosticians are able to distinguish manifestations of an overlooked gland.

Functional heterogeneity in the pineal projection neurons of zebrafish

The zebrafish pineal organ is a photoreceptive structure containing two main neuronal populations (photoreceptors and projections neurons). Here we describe a subpopulation of projection neurons that expresses the melanopsin gene, opn4xa. This new pineal cell type, that displays characteristics of both projection neurons and photoreceptors, share a similar dependency for BMP and Notch signalling pathways with classical non-photosensitive projection neurons (PN). Functionally, however, whereas classical, opn4xa-negative PNs display an achromatic LIGHT OFF response, the novel cell type we describe exhibit a LIGHT ON character that is elicited by green and blue light. Taken together, our data suggest a previously unanticipated heterogeneity in the projection neuron population in the zebrafish pineal organ raising the question of the importance of these differences in pineal function.

Pineal Cyst Apoplexy: A Rare Complication of Common Entity

Pineal cysts (PCs) are often encountered as incidental findings in intracranial images. The vast majority of cysts are normally asymptomatic and clinically benign. Bleeding into the cysts, which leads to neurological symptoms and signs, is considered to be quite rare. The authors illustrate a newly identified complication of PC in a 56-year-old woman who characterized by headache of sudden onset and vomiting. MRI disclosed a small hemorrhagic PC without narrowing of the cerebral aqueduct. The patient was managed conservatively without any surgical interventions, and she remained symptom-free over a period of 15-year follow-up. The description of this case adds to the limited literature on the series in which nonsurgical treatments had a role in the care for patients with PC complicated by intracystic hemorrhage.

Circadian sleep/wake-associated cells show dipeptide repeat protein aggregates in C9orf72-related ALS and FTLD cases

Motor-, behavior- and/or cognition-related symptoms are key hallmarks in patients with amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) with TDP-43 pathology (FTLD-TDP), respectively. It has been reported that these patients also experience sleep disturbances, which might implicate a disturbed circadian rhythm of the sleep/wake cycle. It remains unknown, however, whether cells involved in the circadian sleep/wake cycle are affected by ALS- and FTLD-related neuropathological changes including phosphorylated TDP-43 (pTDP-43) aggregates and dipeptide repeat protein (DPR) inclusions resulting from the C9orf72 hexanucleotide repeat expansion. Immunohistochemistry for DPR and pTDP-43 pathology was performed in post-mortem hypothalamus and pineal gland tissue of patients with ALS and/or FTLD-TDP with and without the C9orf72 repeat expansion and healthy controls. Circadian sleep/wake-associated cells, including pinealocytes and hypothalamic neurons related to the suprachiasmatic nucleus (SCN), were microscopically assessed. We observed numerous DPR inclusions (poly(GA), poly(GP), poly(GR) and poly(PR)) in the pinealocytes and few poly(GA) inclusions in the SCN-related neurons in C9orf72-related ALS and/or FTLD-TDP cases. These circadian sleep/wake-associated cells, however, were devoid of pTDP-43 pathology both in C9orf72- and nonC9orf72-related ALS and/or FTLD-TDP cases. Our neuropathological findings show that pinealocytes and, to a lesser extent, SCN-related neurons are affected by DPR pathology. This may reflect an involvement of these cells in sleep/wake disturbances observed in ALS and/or FTLD-TDP patients.

Kobayashi award: Discovery of cerebellar and pineal neurosteroids and their biological actions on the growth and survival of Purkinje cells during development (review)

The brain has traditionally been considered to be a target site of peripheral steroid hormones. On the other hand, extensive studies over the past thirty years have demonstrated that the brain is a site of biosynthesis of several steroids. Such steroids synthesized de novo from cholesterol in the brain are called neurosteroids. To investigate the biosynthesis and biological actions of neurosteroids in the brain, data on the regio- and temporal-specific synthesis of neurosteroids are needed. In the mid 1990s, the Purkinje cell, an important cerebellar neuron, was discovered as a major cell producing neurosteroids in the brain of vertebrates. It was the first demonstration of de novo neuronal biosynthesis of neurosteroids in the brain. Subsequently, neuronal biosynthesis of neurosteroids and biological actions of neurosteroids have become clear by the follow-up studies using the Purkinje cell as an excellent cellular model. Progesterone and estradiol, which are known as sex steroid hormones, are actively synthesized de novo from cholesterol in the Purkinje cell during development, when cerebellar neuronal circuit formation occurs. Importantly, progesterone and estradiol synthesized in the Purkinje cell promote dendritic growth, spinogenesis and synaptogenesis via their cognate nuclear receptors in the Purkinje cell. Neurotrophic factors may mediate these neurosteroid actions. Futhermore, allopregnanolone (3α,5α-tetrahydroprogesterone), a progesterone metabolite, is also synthesized in the cerebellum and acts on the survival of Purkinje cells. On the other hand, at the beginning of 2010s, the pineal gland, an endocrine organ located close to the cerebellum, was discovered as an important site of the biosynthesis of neurosteroids. Allopregnanolone, a major pineal neurosteroid, acts on the Purkinje cell for the survival of Purkinje cells by suppressing the expression of caspase-3, a crucial mediator of apoptosis. I as a recipient of Kobayashi Award from the Japan Society for Comparative Endocrinology in 2016 summarize the discovery of cerebellar and pineal neurosteroids and their biological actions on the growth and survival of Purkinje cells during development.

Pineal gland volumes are changed in patients with obsessive-compulsive personality disorder

OBJECTIVE

In the present study, taking into consideration our previous studies showing an association on the neuroanatomy of OCD and obsessive-compulsive personality disorders (OCPD), we also decided to examine pineal gland volumes in patients with obsessive-compulsive personality disorder and hypothesized that gland volumes would be found as altered in comparison with those of healthy subjects.

METHODS

Sixteen patients with OCPD and eighteen healthy control subjects underwent magnetic resonance imaging (MRI). We compared the volumes of pineal gland by using MRI between groups.

RESULTS

As compared to healthy control subjects, patients with OCPD had statistically significant smaller pineal gland volumes by using independent sample t test (87.34 ± 19.72 mm³ for patients with OCPD vs. 108.62 ± 22.56 mm³, with a statistically significantly difference of p < 0.01.When controlling for gender distribution, age and whole brain volumes in the General Linear Model, we saw that patients with OCPD had still statistically significant smaller pineal volumes compared to those of healthy control subjects.

CONCLUSION

Finally, the findings of the present study revealed that patients with OCPD had reduced pineal gland volumes compared to those of healthy control subjects, supporting the fact that OCPD might be included in the OCD spectrum disorders, since we have previously found same result in patients with OCPD.

Current understanding of pineal gland structure and function in headache

PURPOSE

The pineal gland plays an important role in biological rhythms, circadian and circannual variations, which are key aspects in several headache disorders.

OVERVIEW

Melatonin, the main pineal secreting hormone, has been extensively studied in primary and secondary headache disorders. Altered melatonin secretion occurs in many headache syndromes. Experimental data show pineal gland and melatonin both interfere in headache animal models, decreasing trigeminal activation. Melatonin has been shown to regulate CGRP and control its release.

DISCUSSION

Melatonin has been used successfully as a treatment for migraine, cluster headaches and other headaches. There is a rationale for including the pineal gland as a relevant brain structure in the mechanisms of headache pathophysiology, and melatonin as a treatment option in primary headache.

Pineal gland abnormality in major depressive disorder

Patients with major depressive disorder (MDD) often have circadian rhythm alteration and sleep disturbance. The pineal gland regulates the circadian rhythm and sleep by the secretion of melatonin neurohormone. However, the relationship between pineal abnormality and MDD remains elusive. 50 patients with MDD and 35 gender- and age-matched healthy controls underwent high-resolution structural MRI. Pineal parenchymal volume (PPV) was measured manually. Inter-group differences in prevalence of pineal cyst and PPV were examined. In addition, we investigated the correlations between PPV and symptom severity as well as sleep variables in the patient group. Compared to healthy controls, patients with MDD had a higher prevalence of pineal cyst. Moreover, patients had significantly decreased PPV relative to controls. However, no significant correlations were observed between PPV and symptom severity as well as sleep variables. Our findings suggest that pineal abnormality may play a critical role in depression.

Primary pineal tumors - Unraveling histological challenges and certain clinical myths

Background

Pineal gland tumors range from the well-differentiated "pineocytoma" [World Health Organization (WHO) grade I], which have a very good prognosis, to the aggressive and poorly differentiated "pineoblastoma" (WHO grade IV) with "pineal parenchymal tumor of intermediate differentiation" (PPTID; WHO grades II and III) occupying intermediary differentiation and prognosis. Papillary tumor of the pineal region (PTPR; WHO grades II and III) is a distinct entity with propensity for recurrence and spinal dissemination. However, the diagnostic criteria to differentiate these entities, especially between WHO grades II and III of both PPTID and PTPR, remain nebulous.

Objective

To evaluate the relative frequency of the individual entities and histomorphological (including the proliferation indices) features across the spectrum of pineal parenchymal tumors (PPTs) [including PTPRs] along their course.

Design

All cases of PPTs were retrieved, reviewed, and graded based on the histological criteria defined in the literature.

Results

PPTID, more commonly seen in young adults, was the most common subtype of PPT. This was followed by pineoblastoma which was more commonly seen in children. Clinical progression was seen in both grades II and III of PPTID; however, it was more commonly seen in cases with a MIB1 labeling index of >10%. PTPRs (both grades II and III) showed an aggressive histological transformation and also intraparenchymal metastasis.

Conclusion

PPTIDs are the most common adult primary PPTs and have the potential to progress and disseminate in both grades II and III. Both grades of PTPRs have a metastatic potential. These findings suggest the need for postoperative adjuvant therapy in both grades of PPTID and PTPR.

Pineal gland dysfunction in Alzheimer's disease: relationship with the immune-pineal axis, sleep disturbance, and neurogenesis

Alzheimer’s disease (AD) is a globally common neurodegenerative disease, which is accompanied by alterations to various lifestyle patterns, such as sleep disturbance. The pineal gland is the primary endocrine organ that secretes hormones, such as melatonin, and controls the circadian rhythms. The decrease in pineal gland volume and pineal calcification leads to the reduction of melatonin production. Melatonin has been reported to have multiple roles in the central nervous system (CNS), including improving neurogenesis and synaptic plasticity, suppressing neuroinflammation, enhancing memory function, and protecting against oxidative stress. Recently, reduced pineal gland volume and pineal calcification, accompanied by cognitive decline and sleep disturbances have been observed in AD patients. Here, I review current significant evidence of the contribution of pineal dysfunction in AD to the progress of AD neuropathology. I suggest new insights to understanding the relationship between AD pathogenesis and pineal gland function.

Pineal Region Gliomas: A Single-Center Experience with 25 Cases

BACKGROUND

Pineal region glioma is a rare systematically reported tumor in the literatures, and little is known about its behavior, development, and best treatment strategies because of its complex anatomical relationship and rarity.

OBJECTIVE

We reviewed the outcomes of patients with pineal region gliomas in West China hospital in the past 5 years and searched the literature to add more information. As a result, key factors related to prognosis are identified.

METHODS

Twenty-five patients with pineal region gliomas were selected and information was collected about detailed medical history, imaging data, treatment methods, pathologic results, and latest neurosurgical radiologic progress during follow-up.

RESULTS

Pilocytic astrocytomas (20%) and glioblastomas (24%) were the most common pathologic subtypes. Twenty-three patients underwent open surgery, 3 Gamma Knife radiosurgery, and 4 whole-brain radiation therapy. Chemotherapy was applied to 3 patients. Low-grade gliomas tended to have a better prognosis than did high-grade. Karnofsky Performance Status at admission (≤60) was intimately associated with prognosis for low-grade gliomas. As for high-grade gliomas, patients whose age at admission was ≤30 years had a better prognosis than did older patients (＞30 years). However, whatever the grade, there was no overall survival difference as to gender, gross total resection versus not gross total resection, preoperative maximal tumor diameter (≤4 vs. ＞4 cm), and time since first symptoms (≤30 vs. ＞30 days), and radiation therapy versus no radiation therapy.

CONCLUSIONS

Open surgery is the first-line strategy for pineal region gliomas with tolerable mortality and disability rate. Radiosurgery and chemotherapy can be applied as adjuvant or alternative methods when surgery is contraindicated.

Pineal gland and schizophrenia: A systematic review and meta-analysis

Melatonin (MLT), the main hormone of the pineal gland (PG), is assumed to support initiation and maintenance of sleep, and a stable sleep-wake cycle, exerting antioxidative and neuroprotective actions. Evidence demonstrates that sleep and circadian rhythm abnormalities are very common in schizophrenia patients. Some imaging studies suggest structural abnormalities of the PG in these patients as well. We aimed to critically appraise the literature on PG imaging and melatonin secretion in schizophrenia patients, in comparison to matched healthy controls, and to review placebo-controlled trials of add-on exogenous MLT treatment in schizophrenia patients. In this systematic review, twenty-nine studies were included. Meta-analytical evaluation of data was possible only for MLT secretion finding that midnight plasma levels were significantly reduced in individuals with schizophrenia as compared to healthy controls (Hedge`s g = 1.32, p < 0.01). Imaging studies demonstrated greater prevalence of enlarged calcifications (>1 cm) of the PG (2 out of 2 computed tomography studies) and smaller PG volume (2 out of 3 magnetic resonance studies) compared with healthy controls. Anatomic and functional abnormalities of the PG were not associated with duration of illness or with treatment factors, maybe suggesting them to be primary characteristics of the disease and genetically based. Add-on MLT treatment leads to a modest improvement of objective and subjective sleep quality, of metabolic adverse effects of antipsychotics, and of tardive dyskinesia symptoms in schizophrenia patients. It remains to be established whether MLT treatment in prodromal phases of the disease could prevent neurostructural abnormalities.

Circadian circuits in humans: White matter microstructure predicts daytime sleepiness

The suprachiasmatic nucleus of the hypothalamus is the chief circadian pacemaker in the brain, and is entrained to day-night cycles by visual afferents from melanopsin containing retinal ganglion cells via the inferior accessory optic tract. Tracer studies have demonstrated efferents from the suprachiasmatic nucleus projecting to the paraventricular nucleus of the hypothalamus, which in turn project to first-order sympathetic neurons in the intermedio-lateral grey of the spinal cord. Sympathetic projections to the pineal gland trigger the secretion of the sleep inducing hormone melatonin. The current study reports the first demonstration of potential sympathopetal hypothalamic projections involved in circadian regulation in humans with in vivo virtual white matter dissections using probabilistic diffusion tensor imaging (DTI) tractography. Additionally, our data shows a correlation between individual differences in white matter microstructure (measured with fractional anisotropy) and increased daytime sleepiness [measured with the Epworth Sleepiness Scale (ESS, Johns, 1991)]. Sympathopetal connections with the hypothalamus were virtually dissected using designated masks on the optic chiasm, which served as an anatomical landmark for retinal fibres projecting to the suprachiasmatic nucleus, and a waypoint mask on the lateral medulla, where hypothalamic projections to the sympathetic nervous system traverse in humans. Sympathopetal projections were demonstrated in each hemisphere in twenty-six subjects. The tract passed through the suprachiasmatic nucleus of the hypothalamus and its trajectory corresponds to the dorsal longitudinal fasciculus traversing the periaqueductal region and the lateral medulla. White matter microstructure (FA) in the left hemisphere correlated with high scores on the ESS, suggesting an association between circadian pathway white matter microstructure, and increased daytime sleepiness.

Reduced pineal gland volume across the stages of schizophrenia

A few magnetic resonance imaging (MRI) studies reported reduced pineal gland volume in chronic schizophrenia (Sz), implicating the involvement of melatonin in the pathophysiology of the illness. However, it is not known whether this abnormality, if present, exists at the early illness stages and/or develops progressively over the course of the illness. This MRI study examined pineal gland volume in 64 patients with first-episode schizophrenia (FESz), 40 patients with chronic Sz, 22 individuals with at-risk mental state (ARMS), and 84 healthy controls. Longitudinal changes in pineal volume (mean inter-scan interval = 2.5 ± 0.7 years) were also examined in a subsample of 23 FESz, 16 chronic Sz, and 21 healthy subjects. In the cross-sectional comparison, the ARMS, FESz, and chronic Sz groups had significantly smaller pineal volume to the same degree as compared with healthy controls. A longitudinal comparison demonstrated that pineal volume did not change over time in any group. There was no association between pineal volume and clinical variables (e.g., symptom severity, medication) in the ARMS and Sz groups. The results suggest that a smaller pineal gland may be a static vulnerability marker of Sz, which probably reflects an early neurodevelopmental abnormality.

How to Monitor the Neuroimmune Biological Response in Patients Affected by Immune Alteration-Related Systemic Diseases

The clinical management of patients affected by systemic diseases, including cancer and autoimmune diseases, is generally founded on the evaluation of the only markers related to the single disease rather than the biological immuno-inflammatory response of patients, despite the fundamental role of cytokine network in the pathogenesis of cancer and autoimmunity is well known. Cancer progression has appeared to be associated with a progressive decline in the blood levels of the main antitumor cytokines, including IL-2 and IL-12, in association with an increase in those of inflammatory cytokines, including IL-6, TNF-alpha, and IL-1-beta, and immunosuppressive cytokines, namely TGF-beta and IL-10. On the other hand, the severity of the autoimmune diseases has been proven to be greater in the presence of high blood levels of IL-17, TNF-alpha, IL-6, IL-1-beta, IFN-gamma, and IL-18, in association with low levels of TGF-beta and IL-10. However, because of excessive cost and complexity of analyzing the data regarding the secretion of the single cytokines, the relation between lymphocyte-induced immune activation and monocyte-macrophage-mediated immunosuppression has been recently proven to be expressed by the simple lymphocyte-to-monocyte ratio (LMR). The evidence of low LMR values has appeared to correlate with a poor prognosis in cancer and with a disease control in the autoimmune diseases. Moreover, since the in vivo immunoinflammatory response is physiologically under a neuroendocrine modulation, for the evaluation of patient biological response it would be necessary to investigate the function of at least the two main neuroendocrine structures involved in the neuroendocrine modulation of the immune responses, consisting of the hypothalamic-pituitary-adrenal axis and the pineal gland, since the lack of physiological circadian rhythm of cortisol and pineal hormone melatonin has appeared to be associated with a worse prognosis in the human systemic diseases.

Signaling within the pineal gland: A parallelism with the central nervous system

The pineal gland (PG) derives from the neural tube, like the rest of the central nervous system (CNS). The PG is specialized in synthesizing and secreting melatonin in a circadian fashion. The nocturnal elevation of melatonin is a highly conserved feature among species which proves its importance in nature. Here, we review a limited set of intrinsic and extrinsic regulatory elements that have been shown or proposed to influence the PG's melatonin production, as well as pineal ontogeny and homeostasis. Intrinsic regulators include the transcription factors CREB, Pax6 and NeuroD1. In addition, microglia within the PG participate as extrinsic regulators of these functions. We further discuss how these same elements work in other parts of the CNS, and note similarities and differences to their roles in the PG. Since the PG is a relatively well-defined and highly specialized organ within the CNS, we suggest that applying this comparative approach to additional PG regulators may be a useful tool for understanding complex areas of the brain, as well as the influence of the PG in both health and disease, including circadian functions and disorders.

Pinealectomy alters IFN-γ and IL-10 levels in primary thymocyte culture of rats

Melatonin, produced mainly by the pineal gland, has an immunomodulatory role. However, the effects of the pineal gland and/or melatonin on thymus cytokine levels such as interferon-gamma (IFN-γ), interleukin (IL)-4, and IL-10 are not well known. Twenty-one male Wistar rats (220-250 gr) were randomly divided into three groups (n=7): intact control, sham, and pinealectomy. Primary thymocyte cultures were prepared from each group and dispensed into well plates as Control, DMSO (or vehicle), Sham-pinealectomy, Pinealectomy, Pinealectomy+10µM melatonin, and Pinealectomy+100µM melatonin. IFN-γ, IL-4, and IL-10 concentrations were measured in the thymocytes (as nonstimulated and Concanavalin A-stimulated) after 24 h. IFN-γ levels significantly increased and IL-10 levels significantly decreased in both media prepared from pinealectomized rats. There was no significant difference between the groups in terms of IL-4. In the pinealectomy+10µM melatonin group, IFN-γ and IL-10 levels did not differ from the pinealectomy group. However, the dose of 100µM melatonin caused a decrease in levels of IFN-γ in both thymocyte media and an increase in the concentration of IL-10 in Concanavalin A-stimulated thymocytes. In conclusion, pineal gland and/or melatonin affect IFN-γ and IL-10 levels in the thymus gland.

Melatonin promotes reduction in TNF levels and improves the lipid profile and insulin sensitivity in pinealectomized rats with periodontal disease

AIM

This study aimed to investigate the effects of melatonin (ME) on insulin resistance (IR) and signaling (IS), proinflammatory cytokine levels, and lipid profiles in pinealectomyzed (PNX) rats with periodontal disease (PD).

MAIN METHODS

One hundred and forty-four rats (age = 40 days) were distributed into 8 groups: 1) control (CN); 2) PD only; 3) PNX only; 4) PNX and PD (PNXPD); 5) CN treated with ME (CNM); 6) PD treated with ME (PDM); 7) PNX treated with ME(PNXM); 8) PNX and PD treated with ME(PNXPDM). The PNX groups were subjected to pinealectomy at 40 and at 60 days of age. The animals were then subjected to PD induction in the mandibular first molars. After PD induction, the ME replacement therapy (MERT-5 mg/kg body weight) was performed using water for 28 days. After this period, the plasma concentration of glucose, insulin, TNF, IL-6, triglycerides, total cholesterol, HDL-cholesterol, LDL-cholesterol, and VLDL-cholesterol and the HOMA-IR index were determined. Akt serine phosphorylation status in the white adipose tissue, gastrocnemius muscle, and rat liver were also evaluated.

KEY FINDINGS

PD, PNX, and PNXPD groups showed an increase in IR with elevated plasma levels of insulin and TNF compared to CN group. PNX and PNXPD groups presented alteration in lipid profile compared to CN group. MERT improved all of the analyzed parameters. No difference was observed in the IS among different groups.

SIGNIFICANCE

The results suggest that MERT efficiently prevents IR, improves lipid profile, and increases plasma levels of insulin and TNF in PD and PNX rats.

Interstitial Cells in the Pineal Gland of Pregnant and Nonpregnant Viscachas (Lagostomus maximus maximus): A Morphometric and Biochemical Study

The pineal gland of mammals undergoes morphological and biochemical changes throughout the gestation period. In viscachas, a seasonal breeding rodent, pregnancy lasts approximately 154 days and 3 stages can be defined, i.e., early, mid, and late pregnancy. The purpose of this study is to analyze morphometric variations in the expression of S-100 protein, glial fibrillary acidic protein (GFAP), and vimentin in the interstitial cells (IC) in pregnant and nonpregnant viscachas by immunohistochemistry (IHC). We also aim to evaluate a probable relation between glandular activity and pregnancy. The immunopositive percentage area (%IA) for the studied proteins and the number of immunoreactive cells against the S-100 protein with a visible nucleus (nº IC-S-100) were analyzed. Estradiol and progesterone serum levels were also determined by RIA. Variations in the expression of the S-100 protein and GFAP, as well as changes in the nº IC-S-100 related to serum hormone levels, were found between pregnant and nonpregnant viscachas. Viscachas in mid pregnancy exhibited the highest values of %IA for the analyzed proteins, followed by females in late and early pregnancy, while the nonpregnant ones showed the lowest values for all of the groups studied. Likewise, the nº IC-S-100 also varied following the same pattern. Thus, these variations seem to indicate a direct relationship between glandular activity and gonadal hormone levels. On these grounds, we may conclude that IC undergo changes in relation to ovarian hormone levels and participate in the regulation of glandular activity during pregnancy. However, further research is necessary to elucidate this relationship.

Identification of insulin-regulated aminopeptidase (IRAP) in the rat pineal gland and the modulation of melatonin synthesis by angiotensin IV

A local renin-angiotensin system (RAS) has been postulated in the pineal gland. In addition to angiotensin II (Ang II), other active metabolites have been described. In this study, we aimed to investigate a role for Ang IV in melatonin synthesis and the presence of its proposed (IRAP)/AT₄ receptor (insulin-regulated aminopeptidase) in the pineal gland. The effect of Ang IV on melatonin synthesis was investigated in vitro using isolated pinealocytes. IRAP protein expression and activity were evaluated by Western blot and fluorimetry using Leu-4Me-β-naphthylamide as a substrate. Melatonin was analyzed by HPLC, calcium content by confocal microscopy and cAMP by immunoassay. Ang IV significantly augmented the NE-induced melatonin synthesis to a similar degree as that achieved by Ang II. This Ang IV effect in pinealocytes appears to be mediated by an increase in the intracellular calcium content but not by cAMP. The (IRAP)/AT₄ expression and activity were identified in the pineal gland, which were significantly higher in membrane fractions than in soluble fractions. Ang IV significantly reduced IRAP activity in the pineal membrane fractions. The main findings of the present study are as follows: (1) Ang IV potentiates NE-stimulated melatonin production in pinealocytes, (2) the (IRAP)/AT₄ receptor is present in the rat pineal gland, and (3) Ang IV inhibits IRAP activity and increases pinealocytes [Ca²⁺]_i. We conclude that Ang IV is an important component of RAS and modulates melatonin synthesis in the rat pineal gland.

Stimulation role of epinephrine in transcription of the melatonin synthesis key enzyme AANAT in the pineal gland of broilers

Melatonin is a crucial neurohormone synthesized in the pineal gland that influences the physiology of animals. The molecular mechanism of norepinephrine control of the synthesis of melatonin is well documented; however, few reports have described the effects of epinephrine on the synthesis of melatonin. In this study, the effect of epinephrine on melatonin synthesis was investigated by adding different concentrations of epinephrine or norepinephrine to broiler pineal glands cultured in vitro. In addition, we investigated how epinephrine regulates the synthesis of melatonin and the transcription of the key melatonin synthesis enzyme AANAT. We determined the abundance of melatonin, norepinephrine, and epinephrine in broiler serum and the mRNA expression levels of key enzymes under different light conditions. The minimum concentrations of epinephrine and norepinephrine required to recover the melatonin synthesis rhythm in pineal cells were 10^-13 and 10^-11 mol/L, respectively. Under various light durations, epinephrine reached maximum levels two hours earlier than melatonin. These results demonstrate for the first time that epinephrine can increase the synthesis of melatonin by increasing the transcription of AANAT.

7α-Hydroxypregnenolone regulating locomotor behavior identified in the brain and pineal gland across vertebrates

The brain synthesizes steroids de novo from cholesterol, which are called neurosteroids. Based on extensive studies on neurosteroids over the past thirty years, it is now accepted that neurosteroidogenesis in the brain is a conserved property across vertebrates. However, the formation of bioactive neurosteroids in the brain is still incompletely elucidated in vertebrates. In fact, we recently identified 7α-hydroxypregnenolone (7α-OH PREG) as a novel bioactive neurosteroid stimulating locomotor behavior in the brain of several vertebrates. The follow-up studies have demonstrated that the stimulatory action of brain 7α-OH PREG on locomotor behavior is mediated by the dopaminergic system across vertebrates. More recently, we have further demonstrated that the pineal gland, an endocrine organ located close to the brain, is a major site of the formation of bioactive neurosteroids. In addition to the brain, the pineal gland actively produces 7α-OH PREG de novo from cholesterol as a major pineal neurosteroid that acts on the brain to control locomotor rhythms. This review summarizes the identification, biosynthesis and mode of action of brain and pineal 7α-OH PREG, a new bioactive neurosteroid regulating locomotor behavior, across vertebrates.

The pineal gland of the shrew (Blarina brevicauda and Blarina carolinensis): a light and electron microscopic study of pinealocytes

The pineal gland structure and ultrastructure in the Northern (Blarina brevicauda) and Southern short-tailed shrew (Blarina carolinensis) are described by light and electron microscopy. Results observed were similar to other mammals of Insectivora described previously, specifically, the hedgehog (Erinaceus europaeus) and the Old World mole (Talpa europea). Two different types of pinealocytes were noticed by electron microscopy, in addition to relatively few glial cells. Granular vesicles were not noticed in abundance. The granular endoplasmic reticulum was observed and studded with vesicles. The golgi apparatus was well developed and appeared often. Synaptic ribbons were observed in several different formations consisting of ribbons and/or rods. The ciliary derivative, the rudimentary photoreceptor structures found in the pinealocytes of population I, was noticed in a 9 + 0 tubular pattern. Within these semifossorial shrews, the relationship between specific intracellular organelles and their function was discussed.

Pineal region glioblastomas display features of diffuse midline and non-midline gliomas

INTRODUCTION

Pineal region glioblastomas (GBM) are very rare, with approximately 46 cases described in the literature. The epidemiology, pathogenesis, and treatment of these lesions are poorly characterized.

METHODS

We identified all cases of pineal region GBM treated surgically at our institution between 1990 and 2017. Demographic and clinical follow-up data were extracted from the medical records for all cases. Pathology was reviewed and classified according to 2016 World Health Organization (WHO) criteria. Specific attention was given to the frequency of histone H3 K27M mutations in these midline gliomas.

RESULTS

Eight patients (seven men, one woman) with pineal region GBM, WHO grade IV, were identified. The most common presenting symptoms were headache (75%), vision changes (75%), and gait imbalance/ataxia (50%). Median age at diagnosis was 48.5 years (range 36-74 years). Radical subtotal resection, via a supracerebellar infratentorial approach, was achieved in 75% of patients. Review of the surgical pathology revealed seven primary GBMs (including one giant cell GBM) and one pineal region GBM that developed three years after resection of a pineal parenchymal tumor of intermediate differentiation. No cases demonstrated evidence of IDH-1 R132H mutation (N = 6) or 1p/19q co-deletion (N = 3). One case tested positive for the histone H3 K27M-mutation. Targeted exome sequencing of 467 cancer-related genes revealed nonsense mutations in ATRX and NF1. Adjuvant radiation and chemotherapy was employed in 87.5% and 75.0% of patients, respectively. Median overall survival (OS) was 15 months (range 2-24 months) from GBM diagnosis.

CONCLUSIONS

This study expands the clinical and pathologic spectrum of pineal region GBM, and provides the first report of the genetic landscape of these tumors.

Pineal volume and evening melatonin in young people with affective disorders

Affective disorders in young people have been associated with disruptions in circadian rhythms, including abnormalities in secretion of the pineal hormone melatonin. Previous research reports relationships between pineal gland volumes, melatonin secretion, and sleep-wake cycles, but the relationship between these factors has not been explored in affective disorders. This study aimed to characterize these factors and explore associations with mood symptoms and functioning in a sample of young people with affective disorders. Pineal volume from magnetic resonance imaging and melatonin assay from evening dim-light saliva collection were evaluated in 50 individuals (15-30 years old; 72 % female) with bipolar, depressive, or anxiety disorders. Actigraphy monitoring was also conducted for approximately two weeks to derive sleep-wake measures. Pineal volume was associated with melatonin secretion across the evening, replicating previous findings in psychiatrically healthy individuals. Pineal volume was smaller in participants in which melatonin onset was not detected. Timing of melatonin secretion was related to sleep timing, but amount of melatonin and pineal volume were not related to any sleep-wake measures. A shorter phase angle between onset of melatonin secretion and sleep onset was associated with longer total sleep time. Lower melatonin levels were associated with poorer social and occupational functioning. Although pineal volume is not directly related to sleep disturbances or symptoms, melatonin may influence both sleep-wake cycles and functioning in the early stages of affective disorder. Causal links remain to be established, however, treatments that target circadian rhythms may be useful in improving functioning in young people with affective disorders.

Melatonin restrains angiogenic factors in triple-negative breast cancer by targeting miR-152-3p: In vivo and in vitro studies

AIMS

Breast cancer represents the second most prevalent tumor-related cause of death among women. Although studies have already been published regarding the association between breast tumors and miRNAs, this field remains unclear. MicroRNAs (miRNAs) are defined as non-coding RNA molecules, and are known to be involved in cell pathways through the regulation of gene expression. Melatonin can regulate miRNAs and genes related with angiogenesis. This hormone is produced naturally by the pineal gland and presents several antitumor effects. The aim of this study was to understand the action of melatonin in the regulation of miRNA-152-3p in vivo and in vitro.

MAIN METHODS

In order to standardize the melatonin treatment in the MDA-MB-468 cells, we carried out the cell viability assay at different concentrations. PCR Array plates were used to identify the differentiated expression of miRNAs after the treatment with melatonin. The relative quantification of the target gene expression (IGF-IR, HIF-1α and VEGF) was performed by real-time PCR. For the tumor development, MDA-MB-468 cells were implanted in female BALB/c mice, and treated or not treated with melatonin. Moreover, the quantification of the target genes protein expression was performed by immunocytochemistry and immunohistochemistry.

KEY FINDINGS

Relative quantification shows that the melatonin treatment increases the gene expression of miR-152-3p and the target genes, and decreased protein levels of the genes both in vitro and in vivo.

SIGNIFICANCE

Our results confirm the action of melatonin on the miR-152-3p regulation known to be involved in the progression of breast cancer.

Unilateral paraneoplastic optic disc edema and retinal periphlebitis in pineal germinoma

Purpose

To describe a unilateral ocular paraneoplastic syndrome in pineal germinoma.

Observations

A 24-year-old male presented with diplopia, excessive thirst, and frequent urination. Cranial MRI showed a mass in pineal gland. Dorsal midbrain syndrome signs were present. Examination showed optic disc edema and segmental retinal periphlebitis in right and normal fundus in left eye. Rheumatologic work-up was negative. Brain biopsy confirmed pineal germinoma. Retinal findings were attributed to paraneoplastic syndrome. Resolution of optic disc edema and retinal periphlebitis occurred following chemotherapy and focal irradiation.

Conclusions

and importance: To date there are two published case reports on bilateral optic disc edema and retinal periphlebitis occurring as a paraneoplastic syndrome in pineal germinoma. This is the first report on a patient with pineal germinoma who had unilateral paraneoplastic involvement characterized by optic disc edema and retinal periphlebitis and who showed complete resolution of ocular disease after treatment of underlying tumor.

Retrospective Analysis of the Clinical Characteristics, Therapeutic Aspects, and Prognostic Factors of 18 Cases of Childhood Pineoblastoma

BACKGROUND

Pineoblastoma is a rare malignant tumor of the pineal gland, which is more common in children.

METHODS

We retrospectively reviewed 18 cases of pineoblastoma in children (10 girls), including general, clinical, and therapeutic information, and factors affecting prognosis.

RESULTS

The median age of the children was 51.7 months (range, 19-156 months). Presenting symptoms included vomiting (64.70%), headache (47.06%), weak or unsteady walking (35.29%), and nausea (29.41%). Rarer symptoms (1 patient each) included limb rigidity, inability to speak, double vision, fever, and Parinaud syndrome. Five and 13 children, respectively, underwent subtotal and gross total resection; 5 and 13 children received adjuvant craniospinal irradiation therapy and chemotherapy. Two children received both craniospinal irradiation and chemotherapy. The 5-year overall survival of the patients was 27.8% (5/18). The survival rate of children older than 4 years (66.7%) was significantly higher than that of younger children (8.3%). The 5-year overall survival rate of boys (50.7%) was higher than that of girls (10.0%); that of children who underwent gross total resection (30.8%) was higher than that of children who underwent subtotal resection (20.0%); and that of children treated with adjuvant craniospinal irradiation (50.7%) was higher than that of those not given craniospinal irradiation (10.0%). However, in each of these 3 comparisons the differences were not significant.

CONCLUSION

Pineoblastoma is rare but often fatal, especially in children younger than 4 years. Survival rates tend to be higher in boys, children undergoing gross total resection (rather than subtotal), and those given craniospinal irradiation.

Morphologic variations in the pineal gland of the albino rat after a chronic alcoholisation process

We studied the effect of alcohol on the pineal gland of 48 male Wistar rats. Animals were divided into control and experimental groups. The experimental group underwent a previous progressive alcoholisation period with ethanol diluted in water at a concentration of 40%. Animals were sacrificed at 3, 6, 9 and 12 months, and the ultrastructure, karyometric indices, and number of synaptic bodies in the pineal gland were analysed. The results showed progressive morphologic alterations in the ethanol-treated animals, which culminated in fatty degeneration of the pineal parenchyma after 6 months. The karyometric indices decreased in both the central and peripheral areas compared with the control group. Moreover, the seasonal rhythmicity observed in the controls disappeared in the experimental groups, whose number of different populations of synaptic bodies (synaptic ribbons and synaptic spherules) considerably lowered with inversion of their normal seasonal rhythm. These results support that chronic alcoholisation leads to fatty degeneration of the pineal parenchyma, and a considerable alteration in nuclear functional rhythms and synaptic bodies.

Surgical Resection of Pineal Epidermoid Cyst Contributed to Relieving Schizophrenia Symptoms

BACKGROUND

The pineal gland has been demonstrated to be involved in the development of mood and psychotic disorders. However, few studies have looked at the relationship between pineal region tumors and psychiatric disorders. Intracranial epidermoid cysts usually arise in the cerebellopontine angle area and are extremely rare in the pineal region. The case of pineal epidermoid cyst presenting as schizophrenia has never been reported before.

CASE PRESENTATION

We described the case of a 23-year-old man who presented to the hospital with symptoms suggestive of schizophrenia. During work-up, he was found to have a pineal lesion on brain magnetic resonance imaging. Total resection of the tumor was subsequently performed, and pathology confirmed an epidermoid cyst. One month after surgery, the patient's psychotic symptoms significantly improved free of drug and fully returned to work 3 months postoperatively.

CONCLUSIONS

This case highlights the importance of including mass lesions of the pineal region in the differential diagnosis of psychotic disorders. It also provides further support that the pineal region may play a role in the pathophysiology of psychiatric diseases, although more studies will be needed to elucidate this interesting connection.

Rhythmic Diurnal Synthesis and Signaling of Retinoic Acid in the Rat Pineal Gland and Its Action to Rapidly Downregulate ERK Phosphorylation

Vitamin A is important for the circadian timing system; deficiency disrupts daily rhythms in activity and clock gene expression, and reduces the nocturnal peak in melatonin in the pineal gland. However, it is currently unknown how these effects are mediated. Vitamin A primarily acts via the active metabolite, retinoic acid (RA), a transcriptional regulator with emerging non-genomic activities. We investigated whether RA is subject to diurnal variation in synthesis and signaling in the rat pineal gland. Its involvement in two key molecular rhythms in this gland was also examined: kinase activation and induction of Aanat, which encodes the rhythm-generating melatonin synthetic enzyme. We found diurnal changes in expression of several genes required for RA signaling, including a RA receptor and synthetic enzymes. The RA-responsive gene Cyp26a1 was found to change between day and night, suggesting diurnal changes in RA activity. This corresponded to changes in RA synthesis, suggesting rhythmic production of RA. Long-term RA treatment in vitro upregulated Aanat transcription, while short-term treatment had no effect. RA was also found to rapidly downregulate extracellular signal-regulated kinase (ERK) 1/2 phosphorylation, suggesting a rapid non-genomic action which may be involved in driving the molecular rhythm in ERK1/2 activation in this gland. These results demonstrate that there are diurnal changes in RA synthesis and activity in the rat pineal gland which are partially under circadian control. These may be key to the effects of vitamin A on circadian rhythms, therefore providing insight into the molecular link between this nutrient and the circadian system.

Foxg1 deletion impairs the development of the epithalamus

The epithalamus, which is dorsal to the thalamus, consists of the habenula, pineal gland and third ventricle choroid plexus and plays important roles in the stress response and sleep-wake cycle in vertebrates. During development, the epithalamus arises from the most dorsal part of prosomere 2. However, the mechanism underlying epithalamic development remains largely unknown. Foxg1 is critical for the development of the telencephalon, but its role in diencephalic development has been under-investigated. Patients suffering from FOXG1-related disorders exhibit severe anxiety, sleep disturbance and choroid plexus cysts, indicating that Foxg1 likely plays a role in epithalamic development. In this study, we identified the specific expression of Foxg1 in the developing epithalamus. Using a "self-deletion" approach, we found that the habenula significantly expanded and included an increased number of habenular subtype neurons. The innervations, particularly the habenular commissure, were severely impaired. Meanwhile, the Foxg1 mutants exhibited a reduced pineal gland and more branched choroid plexus. After ablation of Foxg1 no obvious changes in Shh and Fgf signalling were observed, suggesting that Foxg1 regulates the development of the epithalamus without the involvement of Shh and Fgfs. Our findings provide new insights into the regulation of the development of the epithalamus.

Involvement of Lypge in the formation of eye and pineal gland in zebrafish

The proteins of Ly-6 (lymphocyte antigen-6) family are involved in the regulation of immunoreaction, cell migration and adhesion, and neuronal excitability. However, little is known about the function of Ly-6 proteins in embryogenesis. Herein, we identified a GPI anchored Ly-6 member named ly6 expressed in pineal gland and eye (lypge). Dynamic expression pattern of lypge was revealed by whole mount in situ hybridization. It was strikingly expressed in the pineal gland and cone photoreceptor, and its expression was regulated by orthodenticle homolog 5 (otx5) which has been shown to control the expression of many pineal genes. In addition, we demonstrated that lypge was rhythmically expressed in larvae from 4dpf on. Moreover, knockdown of lypge resulted in small head and small eye formed in zebrafish embryos. These suggest that Lypge is involved in the formation of the eye and pineal gland in early development of zebrafish.

Polycystic pancreatic disease associated with pineal cyst in an adolescent: a case report and literature overview

Pancreatic polycystosis is one of rare causes of recurrent abdominal pain of pancreatic origin in children frequently associated with other organ's cysts which are to be searched. Association with pineal cyst is exceptional, and link between the two locations is to be elucidated. MRI is highly valuable to characterize cysts.

The implication of neuronimmunoendocrine (NIE) modulatory network in the pathophysiologic process of Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder implicitly marked by the substantia nigra dopaminergic neuron degeneration and explicitly characterized by the motor and non-motor symptom complexes. Apart from the nigrostriatal dopamine depletion, the immune and endocrine study findings are also frequently reported, which, in fact, have helped to broaden the symptom spectrum and better explain the pathogenesis and progression of PD. Nevertheless, based on the neural, immune, and endocrine findings presented above, it is still difficult to fully recapitulate the pathophysiologic process of PD. Therefore, here, in this review, we have proposed the neuroimmunoendocrine (NIE) modulatory network in PD, aiming to achieve a more comprehensive interpretation of the pathogenesis and progression of this disease. As a matter of fact, in addition to the classical motor symptoms, NIE modulatory network can also underlie the non-motor symptoms such as gastrointestinal, neuropsychiatric, circadian rhythm, and sleep disorders in PD. Moreover, the dopamine (DA)-melatonin imbalance in the retino-diencephalic/mesencephalic-pineal axis also provides an alternative explanation for the motor complications in the process of DA replacement therapy. In conclusion, the NIE network can be expected to deepen our understanding and facilitate the multi-dimensional management and therapy of PD in future clinical practice.

Conservative and Surgical Treatment of Patients with Pineal Cysts: Prospective Case Series of 110 Patients

BACKGROUND

A pineal cyst is a relatively common benign condition of the pineal gland. The clinical management of patients with a pineal cyst remains controversial, especially when patients present with nonspecific symptoms.

METHODS

We performed a prospective study between 2000 and 2016. All patients with a pineal cyst >7 mm were included. Epidemiologic data, presenting symptoms, surgical results, and radiographic and clinical follow-up were documented.

RESULTS

A total of 110 patients were enrolled in the present study. The most common presenting symptoms were tension headache (62.7%), vertigo (16.4%), migraine (12.7%), syncope (10.9%), nausea (8.2%), and diplopia (8.2%). Symptoms worsened during the follow-up period in 17 patients (15.5%), improved in 13 patients (11.8%), and remained stable in 81 patients (73.6%). The mean follow-up was 79.2 months. A pineal cyst increased in size during the follow-up in 6 patients (5.5%) and decreased in size in 9 patients (8.2%). Twenty-one patients underwent pineal cyst resection; 20 patients (95.2%) reported some improvement in their presenting symptoms, and 10 patients (47.6%) were symptom free after the surgery.

CONCLUSION

We present the largest clinical series of patients with pineal cysts. Surgery, if indicated properly, is a legitimate treatment modality for symptomatic patients with satisfactory results. Relief of symptoms, even nonspecific ones, is achieved in the majority of cases. Simple growth of the cyst in the first decades of life is a part of the natural course and should not be considered as an indication for surgery.

Teratoma of the nervous system: A case series

Teratoma is a common form of germ cell tumors composed of multiple tissues foreign to the site in which arise with a histological representation of all three germ cell layers. Intracranial teratomas are very rare. In this study, we report three cases of intracranial teratomas with an interesting clinical course, neuroradiology, and outcome. In addition, we review the literature and convey important messages to the neuroscience community regarding issues related to the management of these rare tumors. The present cases are interesting examples of intracranial teratoma in terms of location of the tumor and neuroimaging findings. Delay in surgical intervention may complicate the course of the disease with progressive enlargement of tumors and development of complication including hydrocephalus. Using endoscopic surgical techniques may emerge as the preferred intervention option as compared to other traditional methods. We recommend the establishment of a national and international registry for intracranial tumors.