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International Journal of Molecular... Sep 2020With aging, the nervous system gradually undergoes degeneration. Increased oxidative stress, endoplasmic reticulum stress, mitochondrial dysfunction, and cell death are... (Review)
Review
With aging, the nervous system gradually undergoes degeneration. Increased oxidative stress, endoplasmic reticulum stress, mitochondrial dysfunction, and cell death are considered to be common pathophysiological mechanisms of various neurodegenerative diseases (NDDs) such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), organophosphate-induced delayed neuropathy (OPIDN), and amyotrophic lateral sclerosis (ALS). Autophagy is a cellular basic metabolic process that degrades the aggregated or misfolded proteins and abnormal organelles in cells. The abnormal regulation of neuronal autophagy is accompanied by the accumulation and deposition of irregular proteins, leading to changes in neuron homeostasis and neurodegeneration. Autophagy exhibits both a protective mechanism and a damage pathway related to programmed cell death. Because of its "double-edged sword", autophagy plays an important role in neurological damage and NDDs including AD, PD, HD, OPIDN, and ALS. Melatonin is a neuroendocrine hormone mainly synthesized in the pineal gland and exhibits a wide range of biological functions, such as sleep control, regulating circadian rhythm, immune enhancement, metabolism regulation, antioxidant, anti-aging, and anti-tumor effects. It can prevent cell death, reduce inflammation, block calcium channels, etc. In this review, we briefly discuss the neuroprotective role of melatonin against various NDDs via regulating autophagy, which could be a new field for future translational research and clinical studies to discover preventive or therapeutic agents for many NDDs.
Topics: Aging; Alzheimer Disease; Amyotrophic Lateral Sclerosis; Animals; Antioxidants; Autophagy; Autophagy-Related Proteins; Circadian Rhythm; Humans; Huntington Disease; Melatonin; Nervous System; Neurons; Neuroprotective Agents; Parkinson Disease; Pineal Gland
PubMed: 32998479
DOI: 10.3390/ijms21197174 -
European Journal of Radiology Feb 2023To evaluate the effectiveness of diffusion-weighted imaging (DWI) and susceptibility-weighted imaging (SWI) for differentiation between germinoma and other pineal region...
PURPOSE
To evaluate the effectiveness of diffusion-weighted imaging (DWI) and susceptibility-weighted imaging (SWI) for differentiation between germinoma and other pineal region tumors.
METHOD
This retrospective study consisted of 72 patients with pathologically proven pineal region tumors between January 2010 and August 2020. Tumors were classified as germinomas (40), non-germinomatous germ cell tumors (11) (NGGCT), pineal parenchymal tumors (10) (PPT), and other types of tumors (11). Visual scale score, ADC values and SWI intratumoral susceptibility signal (ITSS) score were analyzed and compared to histopathology data.
RESULTS
The mean apparent diffusion coefficient (ADCmean) and minimum apparent diffusion coefficient (ADCmin) ratio of germinoma were significantly lower than NGGCT. ADCmean or ADCmin cut-off ratio of ≤ 1.48 or ≤ 1.32 allowed for discrimination between germinoma and NGGCT with sensitivity and specificity of 100 % and 63.6 %. An ADCmin cut-off ratio of ≥ 0.93 allowed for discrimination between germinoma and PPT with sensitivity and specificity of 60 % and 80.0 %. ADCmin cut-off ratio of ≤ 1.15 allowed for discrimination of germinoma from other types of tumors with sensitivity and specificity of 87.5 % and 54.5 %.
CONCLUSIONS
ADC ratio can differentiate germinoma from other types of pineal region tumors. Our initial results suggest that ITSS score was not significantly correlated with specific histology subtype.
Topics: Humans; Pinealoma; Retrospective Studies; Magnetic Resonance Imaging; Diffusion Magnetic Resonance Imaging; Germinoma; Neoplasms, Germ Cell and Embryonal; Cell Differentiation; Brain Neoplasms; Pineal Gland
PubMed: 36584565
DOI: 10.1016/j.ejrad.2022.110663 -
Physiological Research Dec 2019The pineal gland (glandula pinealis) is neuroendocrine gland located at the epithalamus of the brain secreting melatonin. The aim of this study was to explore effects of...
The pineal gland (glandula pinealis) is neuroendocrine gland located at the epithalamus of the brain secreting melatonin. The aim of this study was to explore effects of prenatal hypoxia in rats at the age of 33 weeks on the occurrence of pineal gland calcification. Distribution and chemical composition of calcerous material by light, scanning and transmission electron microscopy was investigated. Melatonin concentrations in blood plasma by direct radioimmunoassay were measured. Rats were exposed to prenatal hypoxia for 12 h at day 20 of development and second group to prenatal hypoxia for 2x8 h at days 19 and 20 of development. Vacuoles of intracellular edema in the pineal samples after 12 h hypoxia were found. Their size ranges up to 30 µm. Some of them were filled with the flocculent and fibrous material. Samples of pineal glands after 2 x 8 h hypoxia revealed the pericellular edema of pinealocytes. The amount of calcium rich particles in 2 x 8 h hypoxia group was lower than in 12 h hypoxia group. Plasma melatonin levels did not differ between control and both hypoxia groups. We concluded that calcification is a process induced by osteoblasts and osteocytes with melatonin as a promotor and it is favored under hypoxic conditions.
Topics: Animals; Calcinosis; Hypoxia; Male; Pineal Gland; Rats, Wistar
PubMed: 32118471
DOI: 10.33549/physiolres.934378 -
Current Neuropharmacology Mar 2022Melatonin, a vital hormone synthesized by the pineal gland, has been implicated in various physiological functions and circadian rhythm regulation. Its role in the... (Review)
Review
Melatonin, a vital hormone synthesized by the pineal gland, has been implicated in various physiological functions and circadian rhythm regulation. Its role in the protection against the non-ionizing electromagnetic field (EMF), known to disrupt the body's oxidative/anti-oxidative balance, has been called into question due to inconsistent results observed across studies. This review provides the current knowledge on the interwoven relationship between melatonin, EMF, and oxidative stress. Based on synthesized evidence, we present a model that best describes the mechanisms underlying the protective effects of melatonin against RF/ELF-EMF-induced oxidative stress. It has been observed that the free radical scavenger activity of melatonin can be enabled by reducing the radical pair singlet-triplet conversion rate and the concentration of the triplet products. Moreover, this review aims to highlight the potential therapeutic benefits of melatonin against the detrimental effects of EMF, in general, and electromagnetic hypersensitivity (EHS), in particular.
Topics: Circadian Rhythm; Electromagnetic Fields; Electromagnetic Radiation; Humans; Melatonin; Oxidative Stress; Pineal Gland
PubMed: 34635042
DOI: 10.2174/1570159X19666210609163946 -
NeuroImage. Clinical 2021Magnetic resonance imaging (MRI) studies reported pineal gland atrophy in schizophrenia patients and individuals at a clinical high risk of developing psychosis,...
BACKGROUND
Magnetic resonance imaging (MRI) studies reported pineal gland atrophy in schizophrenia patients and individuals at a clinical high risk of developing psychosis, implicating abnormalities in melatonin secretion in the pathophysiology of psychosis. However, it currently remains unclear whether the morphology of the pineal gland contributes to symptomatology and sociocognitive functions.
METHODS
This MRI study examined pineal gland volumes and the prevalence of pineal cysts as well as their relationship with clinical characteristics in 57 at risk mental state (ARMS) subjects, 63 patients with schizophrenia, and 61 healthy controls. The Social and Occupational Functioning Assessment Scale (SOFAS), the Schizophrenia Cognition Rating Scale (SCoRS), and the Brief Assessment of Cognition in Schizophrenia (BACS) were used to assess sociocognitive functions, while the Positive and Negative Syndrome Scale was employed to evaluate clinical symptoms in ARMS subjects and schizophrenia patients.
RESULTS
Pineal gland volumes were significantly smaller in the ARMS and schizophrenia groups than in the controls, while no significant differences were observed in the prevalence of pineal cysts. Although BACS, SCoRS, and SOFAS scores were not associated with pineal morphology, patients with pineal cysts in the schizophrenia group exhibited severe positive psychotic symptoms with rather mild negative symptoms.
CONCLUSION
The present results indicate the potential of pineal atrophy as a vulnerability marker in various stages of psychosis and suggest that pineal cysts influence the clinical subtype of schizophrenia.
Topics: Atrophy; Cysts; Humans; Magnetic Resonance Imaging; Pineal Gland; Psychotic Disorders; Schizophrenia
PubMed: 34461434
DOI: 10.1016/j.nicl.2021.102805 -
International Journal of Molecular... Jul 2021Noncoding RNAs have been known to contribute to a variety of fundamental life processes, such as development, metabolism, and circadian rhythms. However, much remains...
Noncoding RNAs have been known to contribute to a variety of fundamental life processes, such as development, metabolism, and circadian rhythms. However, much remains unrevealed in the huge noncoding RNA datasets, which require further bioinformatic analysis and experimental investigation-and in particular, the coding potential of lncRNAs and the functions of lncRNA-encoded peptides have not been comprehensively studied to date. Through integrating the time-course experimentation with state-of-the-art computational techniques, we studied tens of thousands of zebrafish lncRNAs from our own experiments and from a published study including time-series transcriptome analyses of the testis and the pineal gland. Rhythmicity analysis of these data revealed approximately 700 rhythmically expressed lncRNAs from the pineal gland and the testis, and their GO, COG, and KEGG pathway functions were analyzed. Comparative and conservative analyses determined 14 rhythmically expressed lncRNAs shared between both the pineal gland and the testis, and 15 pineal gland lncRNAs as well as 3 testis lncRNAs conserved among zebrafish, mice, and humans. Further, we computationally analyzed the conserved lncRNA-encoded peptides, and revealed three pineal gland and one testis lncRNA-encoded peptides conserved among these three species, which were further investigated for their three-dimensional (3D) structures and potential functions. Our computational findings provided novel annotations and regulatory mechanisms for hundreds of rhythmically expressed pineal gland and testis lncRNAs in zebrafish, and set the stage for their experimental studies in the near future.
Topics: Animals; Circadian Rhythm; Computational Biology; Gene Expression Profiling; Male; Peptide Fragments; Pineal Gland; RNA, Long Noncoding; Testis; Transcriptome; Zebrafish; Zebrafish Proteins
PubMed: 34360576
DOI: 10.3390/ijms22157810 -
Anatomia, Histologia, Embryologia Jul 2022The pineal gland and melatonin secreted from the gland regulate the biological clock and adaptation to seasonal changes, glucose balance, nutrition and locomotor...
The pineal gland and melatonin secreted from the gland regulate the biological clock and adaptation to seasonal changes, glucose balance, nutrition and locomotor activities. In this study, the pineal gland of the Lake Van fish was examined anatomically and histologically. The melatonin level secreted from the pineal gland was determined in fish plasma sampled from both lakes and streams during reproduction migration. The pineal gland in the Lake Van fish, as in other teleost fish, is located in the head, under the translucent pineal window, which does not contain many pigment cells. The gland consists of pineal vesicle and pineal stalk parts on the dorsal sac in the Lake Van fish. It was determined that the pineal gland showed good vascularity. The presence of pinealocytes and different types of cells in the pineal organ was determined histologically. Pinealocytes were intensely localized in the lumen of the pineal vesicle. The plasma melatonin level increased in fish passing from lake to stream for reproductive migration.
Topics: Animals; Fishes; Lakes; Melatonin; Pineal Gland; Rivers
PubMed: 35285548
DOI: 10.1111/ahe.12802 -
Neurology India 2021Pineal parenchymal tumors account for less than 0.3% of all CNS tumors and "Pineal parenchymal tumor of intermediate differentiation" (PPTID; World Health Organization... (Review)
Review
BACKGROUND
Pineal parenchymal tumors account for less than 0.3% of all CNS tumors and "Pineal parenchymal tumor of intermediate differentiation" (PPTID; World Health Organization (WHO) grades II and III) exhibit intermediary differentiation and prognosis. However "Papillary tumor of the pineal region" (PTPR; WHO grades II and III) is a distinct entity.
OBJECTIVES
This combination of rarity and apparent similarity often leads to perplexity regarding the treatment and prognosis among neurosurgeons. In this review, we have tried to elucidate the differences in clinical as well as treatment modalities and outcomes of these two entities.
METHODS
We used the PubMed Database to search for all relevant articles using the keywords "pineal parenchymal tumor of intermediate differentiation" and "Papillary tumor of the pineal region." Articles having details regarding demographic and clinical variables along with treatment and outcomes were chosen for this study. Full text of these articles was analyzed, and data tabulated.
RESULTS
A total of 25 articles for PPTID and 45 for PTPR were found suitable for inclusion in this study. The studies were either case reports or small retrospective series with only one systemic review for each pathology. Despite the poor quality of data, some trends were apparent. Surgical resection offered a survival benefit in both pathologies. Radiotherapy was effective in increasing the survival in PPTID, while there was little to no effect in PPTR. Chemotherapy was not found to be beneficial in either.
CONCLUSION
Both of these tumors have moderate growth rate and potential for malignant behavior. This continuum of characteristics makes their optimal treatment strategy difficult and confusing. The discussion on comprehensive literature review should give information for neurosurgeons to decide on optimal treatment strategies.
Topics: Brain Neoplasms; Humans; Pineal Gland; Pinealoma; Prognosis; Retrospective Studies
PubMed: 34747779
DOI: 10.4103/0028-3886.329550 -
Medical Sciences (Basel, Switzerland) Jan 2023Melanoma is the most aggressive type of skin cancer, with a greater risk of metastasis and a higher prevalence and mortality rate. This cancer type has been demonstrated... (Review)
Review
Melanoma is the most aggressive type of skin cancer, with a greater risk of metastasis and a higher prevalence and mortality rate. This cancer type has been demonstrated to develop resistance to the known treatment options such as conventional therapeutic agents and targeted therapy that are currently being used as the standard of care. Drug repurposing has been explored as a potential alternative treatment strategy against disease pathophysiologies, including melanoma. To that end, multiple studies have suggested that melatonin produced by the pineal gland possesses anti-proliferative and oncostatic effects in experimental melanoma models. The anticarcinogenic activity of melatonin is attributed to its ability to target a variety of oncogenic signaling pathways, including the MAPK pathways which are involved in regulating the behavior of cancer cells, including cell survival and proliferation. Additionally, preclinical studies have demonstrated that melatonin in combination with chemotherapeutic agents exerts synergistic effects against melanoma. The goal of this review is to highlight the mechanistic insights of melatonin as a monotherapy or combinational therapy for melanoma treatment.
Topics: Animals; Melatonin; Skin Neoplasms; Pineal Gland; Melanoma, Experimental; Signal Transduction
PubMed: 36649046
DOI: 10.3390/medsci11010009 -
Journal of Analytical Toxicology Oct 2022Since 2015, the North Carolina Office of the Chief Medical Examiner has investigated seven deaths of infants and toddlers, aged 2 months to 3 years, with exogenous...
Since 2015, the North Carolina Office of the Chief Medical Examiner has investigated seven deaths of infants and toddlers, aged 2 months to 3 years, with exogenous melatonin detected upon toxicological analysis. Melatonin concentrations ranged from 3 to 1,400 ng/mL in postmortem whole blood. While the cause and the manner of all seven deaths were classified as undetermined, the analytical findings are noteworthy. Melatonin is generally considered a safe, natural product appearing in many over-the-counter supplements geared toward young children to facilitate calmness and improve sleep. Melatonin is a neurohormone, which regulates not only circadian rhythms and natural sleep but also other physiological functions. Endogenous melatonin production, derived from essential amino acid metabolism, does not begin until pineal gland maturation at ∼3 months of age with concentrations in plasma peaking during periods of darkness at ∼0.2 ng/mL. Administering commercially available melatonin supplements to infants results in levels substantially greater than endogenous sources, which should not be assumed to be safe just because of their endogenous nature. The finding of exogenous concentrations in some postmortem pediatric cases warrants attention. Several topics of interest surrounding these postmortem melatonin findings will be considered, such as minimal regulatory control over commercial products as well as the potential impact on hazardous sleeping conditions. This manuscript will outline the physiological effects of melatonin and detail the case studies from the North Carolina medical examiner system. Forensic toxicology laboratories should consider including melatonin at exogenous concentrations in their testing schemes for appropriate postmortem infant and toddler cases.
Topics: Amino Acids, Essential; Biological Products; Child; Child, Preschool; Dietary Supplements; Humans; Infant; Melatonin; Pineal Gland
PubMed: 35639879
DOI: 10.1093/jat/bkac033