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International Journal of Molecular... Nov 2020For years the thymus gland (TG) and the pineal gland (PG) have been subject of increasingly in-depth studies, but only recently a link that can associate the activities... (Review)
Review
For years the thymus gland (TG) and the pineal gland (PG) have been subject of increasingly in-depth studies, but only recently a link that can associate the activities of the two organs has been identified. Considering, on the one hand, the well-known immune activity of thymus and, on the other, the increasingly emerging immunological roles of circadian oscillators and the rhythmically secreted main pineal product, melatonin, many studies aimed to analyse the possible existence of an interaction between these two systems. Moreover, data confirmed that the immune system is functionally associated with the nervous and endocrine systems determining an integrated dynamic network. In addition, recent researches showed a similar, characteristic involution process both in TG and PG. Since the second half of the 20th century, evidence led to the definition of an effectively interacting thymus-pineal axis (TG-PG axis), but much has to be done. In this sense, the aim of this review is to summarize what is actually known about this topic, focusing on the impact of the TG-PG axis on human life and ageing. We would like to give more emphasis to the implications of this dynamical interaction in a possible therapeutic strategy for human health. Moreover, we focused on all the products of TG and PG in order to collect what is known about the role of peptides other than melatonin. The results available today are often unclear and not linear. These peptides have not been well studied and defined over the years. In this review we hope to awake the interest of the scientific community in them and in their future pharmacological applications.
Topics: Aging; Animals; Circadian Rhythm; Humans; Melatonin; Peptides; Pineal Gland; Thymus Gland
PubMed: 33233845
DOI: 10.3390/ijms21228806 -
Child's Nervous System : ChNS :... Sep 2023Histological and molecular characterization is essential for the diagnosis of pediatric brain tumors. In the pineal region tumors, it is necessary to remove a sufficient... (Review)
Review
Histological and molecular characterization is essential for the diagnosis of pediatric brain tumors. In the pineal region tumors, it is necessary to remove a sufficient tumor volume to make a diagnosis. However, surgery in this region is challenging due to its deep anatomical location and surrounded by critical structures and complex venous system. Knowledge of the anatomy and function of the pineal region and tumor histological types is imperative for the successful management of pineal region tumors. This article describes surgical approaches to pineal tumors, focusing on the occipital transtentorial approach and adding the author's experience to what has been known in the literature. Recent innovations have made this approach more popular and can be applied to occipital fossa lesions.
Topics: Child; Humans; Pinealoma; Brain Neoplasms; Pineal Gland; Neurosurgical Procedures
PubMed: 37436474
DOI: 10.1007/s00381-023-06071-3 -
Chronobiology International Sep 2019There continues to be considerable interest in the physiological role(s) of the hormone melatonin and its potential as a drug more than 60 years after its discovery.... (Review)
Review
There continues to be considerable interest in the physiological role(s) of the hormone melatonin and its potential as a drug more than 60 years after its discovery. While there is an emphasis on human studies, there is still a need for animal models in biology. Laboratory strains of mice remain at the forefront of much biomedical research for many reasons. However, in the case of melatonin research, mice represent a problem that is often not recognized by researchers entering from other fields of biomedicine. In this review, I have brought together the results of a large number of studies in which melatonin was measured in the pineal gland and blood of different mouse strains. The unequivocal conclusion to be drawn from the review is that the majority of laboratory mouse strains do not produce melatonin, whereas the CBA and C3H strains produce substantial amounts of melatonin during the late dark period. Of course, this has been known from studies conducted more than 30 years ago, but papers continue to be published that report high levels of melatonin in the pineal glands and blood and melatonin metabolites in the urine of melatonin deficient strains. Reasons for these erroneous results are discussed and center around the use of unvalidated, poorly documented immunoassays and inadequate sample preparation (i.e. direct versus extracted assays). Finally, I discuss the validity of using extraordinary high doses (as high as 200 mg/kg) of melatonin administered to melatonin deficient mice in experiments. It is hoped that the presentation of multiple sources of data in one place documenting the actual melatonin deficiency of the various strains will reduce the uncritical use of unreliable results to support the use of melatonin deficient strains in melatonin research.
Topics: Animals; Circadian Rhythm; Humans; Immunoassay; Melatonin; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Mice, Inbred CBA; Models, Animal; Pineal Gland; Species Specificity
PubMed: 31198062
DOI: 10.1080/07420528.2019.1624373 -
Methods in Molecular Biology (Clifton,... 2022The pineal gland presents a powerful genetic tool to study a broad range of physiological processes. It has been instrumental as a model in understanding transduction...
The pineal gland presents a powerful genetic tool to study a broad range of physiological processes. It has been instrumental as a model in understanding transduction processes and daily changes in gene expression and holds great promise in understanding development. Currently, the field is at an exciting point, with methods available for the isolation of individual cells and, as presented here, the preparation of these single cells for sequencing. The resulting cellular transcriptomes have played a role in categorizing cells in the pineal gland, with current estimates including two types of pinealocytes, three types of astrocytes, two types of microglia, and two types of endothelial cells, including the poorly understood vascular and meningeal cell. The methods described in this chapter will serve to support and advance cellular studies of the pineal gland in the twenty-first century.
Topics: Astrocytes; Endothelial Cells; Microglia; Pineal Gland; Sequence Analysis, RNA
PubMed: 36180683
DOI: 10.1007/978-1-0716-2593-4_14 -
International Journal of Molecular... Nov 2021Melatonin is a highly conserved molecule found in prokaryotes and eukaryotes that acts as the darkness hormone, translating environmental lighting to the whole body, and... (Review)
Review
Melatonin is a highly conserved molecule found in prokaryotes and eukaryotes that acts as the darkness hormone, translating environmental lighting to the whole body, and as a moderator of innate and acquired defense, migration, and cell proliferation processes. This review evaluates the importance of pineal activity in monitoring PAMPs and DAMPs and in mounting an inflammatory response or innate immune response. Activation of the immune-pineal axis, which coordinates the pro-and anti-inflammatory phases of an innate immune response, is described. PAMPs and DAMPs promote the immediate suppression of melatonin production by the pineal gland, which allows leukocyte migration. Monocyte-derived macrophages, important phagocytes of microbes, and cellular debris produce melatonin locally and thereby initiate the anti-inflammatory phase of the acute inflammatory response. The role of locally produced melatonin in organs that directly contact the external environment, such as the skin and the gastrointestinal and respiratory tracts, is also discussed. In this context, as resident macrophages are self-renewing cells, we explore evidence indicating that, besides avoiding overreaction of the immune system, extra-pineal melatonin has a fundamental role in the homeostasis of organs and tissues.
Topics: Animals; Humans; Immunity, Innate; Inflammation; Macrophages; Melatonin; Pineal Gland
PubMed: 34830026
DOI: 10.3390/ijms222212143 -
Advances in Experimental Medicine and... 2023Pineal region tumors fall into five broad categories: benign pineal region tumors, glial tumors, papillary tumors, pineal parenchymal tumors, and germ cell tumors....
Pineal region tumors fall into five broad categories: benign pineal region tumors, glial tumors, papillary tumors, pineal parenchymal tumors, and germ cell tumors. Genetic and transcriptional studies have identified key chromosomal alterations in germinomas (RUNDC3A, ASAH1, LPL) and in pineocytomas/pineoblastomas (DROSHA/DICER1, RB1). Pineal region tumors generally present with symptoms of hydrocephalus including nausea, vomiting, papilledema, and the classical Parinaud's triad of upgaze paralysis, convergence-retraction nystagmus, and light-near pupillary dissociation. Workup requires neuroimaging and tissue diagnosis via biopsy. In germinoma cases, diagnosis may be made based on serum or CSF studies for alpha-fetoprotein or beta-HCG making the preferred treatment radiosurgery, thereby preventing the need for unnecessary surgeries. Treatment generally involves three steps: CSF diversion in cases of hydrocephalus, biopsy through endoscopic or stereotactic methods, and open surgical resection. Multiple surgical approaches are possible for approach to the pineal region. The original approach to the pineal region was the interhemispheric transcallosal first described by Dandy. The most common approach is the supracerebellar infratentorial approach as it utilizes a natural anatomic corridor for access to the pineal region. The paramedian or lateral supracerebellar infratentorial approach is another improvement that uses a similar anatomic corridor but allows for preservation of midline bridging veins; this minimizes the chance for brainstem or cerebellar venous infarction. Determination of the optimal approach relies on tumor characteristics, namely location of deep venous structures to the tumor along with the lateral eccentricity of the tumor. The immediate post-operative period is important as hemorrhage or swelling can cause obstructive hydrocephalus and lead to rapid deterioration. Adjuvant therapy, whether chemotherapy or radiation, is based on tumor pathology. Improvements within pineal surgery will require improved technology for access to the pineal region along with targeted therapies that can effectively treat and prevent recurrence of malignant pineal region tumors.
Topics: Humans; Pinealoma; Pineal Gland; Brain Neoplasms; Glioma; Hydrocephalus; Ribonuclease III; DEAD-box RNA Helicases
PubMed: 37452938
DOI: 10.1007/978-3-031-23705-8_6 -
The Journals of Gerontology. Series A,... Aug 2023In this work, we report preliminary results about the involution of the human pineal gland involution. The detailed analysis of pineal structure was done on autopsy...
In this work, we report preliminary results about the involution of the human pineal gland involution. The detailed analysis of pineal structure was done on autopsy material of 77 persons in age 27-96 using x-ray phase-contrast tomography, histology, and immunohistochemistry. Our study suggests that the pineal gland alteration in older adults may be more profound than has been reported to date. We identified and described a new form of pineal gland involution that eventually led to the total degradation of the pineal gland. To our knowledge, this study is the first to report on the complete replacement of pineal gland parenchyma with connective tissue in older adults.
Topics: Humans; Aged; Aged, 80 and over; Pineal Gland; Cysts; Immunohistochemistry; Autopsy
PubMed: 36966358
DOI: 10.1093/gerona/glad091 -
Molecular Neurodegeneration Jul 2019Alzheimer's disease (AD) is a globally common neurodegenerative disease, which is accompanied by alterations to various lifestyle patterns, such as sleep disturbance.... (Review)
Review
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.
Topics: Alzheimer Disease; Animals; Circadian Rhythm; Humans; Melatonin; Neurodegenerative Diseases; Neurogenesis; Pineal Gland
PubMed: 31296240
DOI: 10.1186/s13024-019-0330-8 -
Journal of Neurological Surgery. Part... Jan 2022Pineal apoplexy is a rare condition, with unknown incidence and clinical significance. To elucidate this clinical condition, we analyzed our own case series and... (Review)
Review
BACKGROUND
Pineal apoplexy is a rare condition, with unknown incidence and clinical significance. To elucidate this clinical condition, we analyzed our own case series and performed a review of the literature.
METHODS
We enrolled all patients with a hemorrhagic pineal apoplexy who were referred to our department between January 2000 and January 2020. Hemorrhagic pineal apoplexy was defined as the presence of fluid-fluid levels inside the pineal cyst (PC) on an axial or sagittal magnetic resonance scan. In one patient, after PC apoplexy, we performed a circadian melatonin sampling from peripheral blood to determine the function of the pineal gland. The PubMed database was searched for publications using the terms "pineal" and "apoplexy."
RESULTS
Eight patients were enrolled, of which three patients underwent surgical treatment and five patients were managed conservatively. One patient was tested for circadian melatonin secretion. Results confirmed melatonin secretion with preserved physiologic circadian rhythm.Our search of the literature led us to 31 studies that comprised 30 patients with apoplectic PC, 9 with apoplectic pineal tumor, and 1 with bleeding into the normal pineal gland. Most patients presented with headache, nausea, and vomiting, less frequently with acute hydrocephalus and gaze palsy. Twenty patients with a PC underwent resection or aspiration. Two patients underwent shunt placement as the only procedure and five received both shunt and surgical removal. Six patients with a PC were observed without surgical treatment. All the nine patients with a pineal tumor were operated on. In indicated cases, four patients received radiation therapy and one received chemotherapy.
CONCLUSION
Clinical significance of hemorrhagic pineal apoplexy ranges from an asymptomatic course to rapid deterioration and death. In patients with mild symptoms, observation is indicated, whereas surgical treatment is reserved for severe cases presenting with obstructive hydrocephalus and includes cerebrospinal fluid diversion, resection of apoplectic pineal lesions, or both.
Topics: Cysts; Humans; Hydrocephalus; Magnetic Resonance Imaging; Pineal Gland; Stroke
PubMed: 34077982
DOI: 10.1055/s-0041-1723813 -
International Journal of Radiation... Aug 2019
Topics: Brain Neoplasms; Germinoma; Humans; Pineal Gland
PubMed: 31327426
DOI: 10.1016/j.ijrobp.2018.05.030