The binding property and function of melatonin receptor in peripheral tissues-chick embryonic vessels and young rat leydig cells

2001 ◽  
Author(s):  
Xiaofei Wang
Keyword(s):  
Leydig Cells ◽  
Binding Property ◽  
Melatonin Receptor ◽  
Peripheral Tissues ◽  
Young Rat ◽  
And Function ◽  
Embryonic Vessels

scholarly journals Vitamin A Transporters in Visual Function: A Mini Review on Membrane Receptors for Dietary Vitamin A Uptake, Storage, and Transport to the Eye

Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 3987
Author(s):  
Nicasio Martin Ask ◽  
Matthias Leung ◽  
Rakesh Radhakrishnan ◽  
Glenn P. Lobo
Keyword(s):  
Cell Growth ◽  
Vitamin A ◽  
Visual Function ◽  
Binding Protein ◽  
Retinol Binding Protein ◽  
Dietary Vitamin ◽  
Peripheral Tissues ◽  
Retinol Binding Protein 4 ◽  
Retinyl Esters ◽  
And Function

Vitamins are essential compounds obtained through diet that are necessary for normal development and function in an organism. One of the most important vitamins for human physiology is vitamin A, a group of retinoid compounds and carotenoids, which generally function as a mediator for cell growth, differentiation, immunity, and embryonic development, as well as serving as a key component in the phototransduction cycle in the vertebrate retina. For humans, vitamin A is obtained through the diet, where provitamin A carotenoids such as β-carotene from plants or preformed vitamin A such as retinyl esters from animal sources are absorbed into the body via the small intestine and converted into all-trans retinol within the intestinal enterocytes. Specifically, once absorbed, carotenoids are cleaved by carotenoid cleavage oxygenases (CCOs), such as Beta-carotene 15,15’-monooxygenase (BCO1), to produce all-trans retinal that subsequently gets converted into all-trans retinol. CRBP2 bound retinol is then converted into retinyl esters (REs) by the enzyme lecithin retinol acyltransferase (LRAT) in the endoplasmic reticulum, which is then packaged into chylomicrons and sent into the bloodstream for storage in hepatic stellate cells in the liver or for functional use in peripheral tissues such as the retina. All-trans retinol also travels through the bloodstream bound to retinol binding protein 4 (RBP4), where it enters cells with the assistance of the transmembrane transporters, stimulated by retinoic acid 6 (STRA6) in peripheral tissues or retinol binding protein 4 receptor 2 (RBPR2) in systemic tissues (e.g., in the retina and the liver, respectively). Much is known about the intake, metabolism, storage, and function of vitamin A compounds, especially with regard to its impact on eye development and visual function in the retinoid cycle. However, there is much to learn about the role of vitamin A as a transcription factor in development and cell growth, as well as how peripheral cells signal hepatocytes to secrete all-trans retinol into the blood for peripheral cell use. This article aims to review literature regarding the major known pathways of vitamin A intake from dietary sources into hepatocytes, vitamin A excretion by hepatocytes, as well as vitamin A usage within the retinoid cycle in the RPE and retina to provide insight on future directions of novel membrane transporters for vitamin A in retinal cell physiology and visual function.

scholarly journals Microglia, Cytokines, and Neural Activity: Unexpected Interactions in Brain Development and Function

2021 ◽  
Vol 12 ◽  
Author(s):  
Austin Ferro ◽  
Yohan S. S. Auguste ◽  
Lucas Cheadle
Keyword(s):  
Brain Development ◽  
Signaling Pathways ◽  
Immune Cells ◽  
Neural Activity ◽  
Signaling Molecules ◽  
Evolutionary Strategy ◽  
Inflammatory Signaling ◽  
Peripheral Tissues ◽  
And Function ◽  
The Brain

Intercellular signaling molecules such as cytokines and their receptors enable immune cells to communicate with one another and their surrounding microenvironments. Emerging evidence suggests that the same signaling pathways that regulate inflammatory responses to injury and disease outside of the brain also play powerful roles in brain development, plasticity, and function. These observations raise the question of how the same signaling molecules can play such distinct roles in peripheral tissues compared to the central nervous system, a system previously thought to be largely protected from inflammatory signaling. Here, we review evidence that the specialized roles of immune signaling molecules such as cytokines in the brain are to a large extent shaped by neural activity, a key feature of the brain that reflects active communication between neurons at synapses. We discuss the known mechanisms through which microglia, the resident immune cells of the brain, respond to increases and decreases in activity by engaging classical inflammatory signaling cascades to assemble, remodel, and eliminate synapses across the lifespan. We integrate evidence from (1) in vivo imaging studies of microglia-neuron interactions, (2) developmental studies across multiple neural circuits, and (3) molecular studies of activity-dependent gene expression in microglia and neurons to highlight the specific roles of activity in defining immune pathway function in the brain. Given that the repurposing of signaling pathways across different tissues may be an important evolutionary strategy to overcome the limited size of the genome, understanding how cytokine function is established and maintained in the brain could lead to key insights into neurological health and disease.

scholarly journals The Emerging Roles of the RNA Binding Protein QKI in Cardiovascular Development and Function

2021 ◽  
Vol 9 ◽  
Author(s):  
Xinyun Chen ◽  
Jianwen Yin ◽  
Dayan Cao ◽  
Deyong Xiao ◽  
Zhongjun Zhou ◽  
...  
Keyword(s):  
Cancer Progression ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Property ◽  
Cardiovascular Development ◽  
Potential Link ◽  
Alternatively Spliced ◽  
Unique Cell ◽  
Carboxy Terminal ◽  
And Function

RNA binding proteins (RBPs) have a broad biological and physiological function and are critical in regulating pre-mRNA posttranscriptional processing, intracellular migration, and mRNA stability. QKI, also known as Quaking, is a member of the signal transduction and activation of RNA (STAR) family, which also belongs to the heterogeneous nuclear ribonucleoprotein K- (hnRNP K-) homology domain protein family. There are three major alternatively spliced isoforms, QKI-5, QKI-6, and QKI-7, differing in carboxy-terminal domains. They share a common RNA binding property, but each isoform can regulate pre-mRNA splicing, transportation or stability differently in a unique cell type-specific manner. Previously, QKI has been known for its important role in contributing to neurological disorders. A series of recent work has further demonstrated that QKI has important roles in much broader biological systems, such as cardiovascular development, monocyte to macrophage differentiation, bone metabolism, and cancer progression. In this mini-review, we will focus on discussing the emerging roles of QKI in regulating cardiac and vascular development and function and its potential link to cardiovascular pathophysiology.

scholarly journals High Doses of Caffeine during the Peripubertal Period in the Rat Impair the Growth and Function of the Testis

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Minji Park ◽  
Yuri Choi ◽  
Hyeonhae Choi ◽  
Ju-Yearn Yim ◽  
Jaesook Roh
Keyword(s):  
Leydig Cells ◽  
Ex Vivo ◽  
Body Weight Gain ◽  
Male Rats ◽  
Male Rat ◽  
Control Group ◽  
High Doses ◽  
And Function ◽  
The Impact ◽  
Caffeine Exposure

Prenatal caffeine exposure adversely affects the development of the reproductive organs of male rat offspring. Thus, it is conceivable that peripubertal caffeine exposure would also influence physiologic gonadal changes and function during this critical period for sexual maturation. This study investigated the impact of high doses of caffeine on the testes of prepubertal male rats. A total of 45 immature male rats were divided randomly into three groups: a control group and 2 groups fed 120 and 180 mg/kg/day of caffeine, respectively, via the stomach for 4 weeks. Caffeine caused a significant decrease in body weight gain, accompanied by proportional decreases in lean body mass and body fat. The caffeine-fed animals had smaller and lighter testes than those of the control that were accompanied by negative influences on the histologic parameters of the testes. In addition, stimulated-testosterone ex vivo production was reduced in Leydig cells retrieved from the caffeine-fed animals. Our results demonstrate that peripubertal caffeine consumption can interfere with the maturation and function of the testis, possibly by interrupting endogenous testosterone secretion and reducing the sensitivity of Leydig cells to gonadotrophic stimulation. In addition, we confirmed that pubertal administration of caffeine reduced testis growth and altered testis histomorphology.

Modulation of rat testes lipid composition by hormones: effect of PRL and hCG

1988 ◽  
Vol 255 (4) ◽  
pp. E442-E448 ◽  
Author(s):  
E. Sebokova ◽  
A. Wierzbicki ◽  
M. T. Clandinin
Keyword(s):  
Chorionic Gonadotropin ◽  
Leydig Cells ◽  
Binding Capacity ◽  
Total Phospholipid ◽  
Testicular Tissue ◽  
Phospholipid Content ◽  
Refractory State ◽  
Phospholipid Ratio ◽  
High Doses ◽  
And Function

The effect of prolactin (PRL) and human chorionic gonadotropin (hCG) administration for 7 days on the composition and function of rat testicular plasma membrane was investigated. Refractory state in Leydig cells desensitized by hCG decreased the binding capacity for 125I-labeled hCG and also luteinizing hormone (LH)-induced adenosine 3',5'-cyclic monophosphate (cAMP) and testosterone production. In testicular membranes of hCG-treated animals, a depletion of cholesterol and an increase in total phospholipid content was observed after gonadotropin injection, thereby decreasing the cholesterol-to-phospholipid ratio. Injection of high doses of PRL had no effect on the binding capacity or affinity of the LH-hCG receptor but decreased the response of Leydig cells to LH in terms of cAMP and testosterone synthesis. PRL also increased total and esterified cholesterol and decreased free cholesterol and membrane phospholipid content. The fatty acid composition of testicular lipids was significantly and selectively influenced by both hormonal treatments. These observations suggest that metabolism of cholesterol and long-chain polyunsaturated fatty acids in testicular tissue is affected by chorionic gonadotropin and PRL and may provide the mechanism for regulating steroidogenic functions.

scholarly journals Effects of maternal nicotine exposure on thyroid hormone metabolism and function in adult rat progeny

2015 ◽  
Vol 224 (3) ◽  
pp. 315-325 ◽  
Author(s):  
P C Lisboa ◽  
E de Oliveira ◽  
A C Manhães ◽  
A P Santos-Silva ◽  
C R Pinheiro ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Uncoupling Protein ◽  
Saline Control ◽  
Lower Sensitivity ◽  
Nicotine Exposure ◽  
Peripheral Tissues ◽  
Brown Adipose ◽  
Tsh Secretion ◽  
And Function

Postnatal nicotine exposure leads to obesity and hypothyroidism in adulthood. We studied the effects of maternal nicotine exposure during lactation on thyroid hormone (TH) metabolism and function in adult offspring. Lactating rats received implants of osmotic minipumps releasing nicotine (NIC, 6 mg/kg per day s.c.) or saline (control) from postnatal days 2 to 16. Offspring were killed at 180 days. We measured types 1 and 2 deiodinase activity and mRNA, mitochondrial α-glycerol-3-phosphate dehydrogenase (mGPD) activity, TH receptor (TR), uncoupling protein 1 (UCP1), hypothalamic TRH, pituitary TSH, andin vitroTRH-stimulated TSH secretion. Expression of deiodinase mRNAs followed the same profile as that of the enzymatic activity. NIC exposure caused lower 5′-D1 and mGPD activities; lower TRβ1 content in liver as well as lower 5′-D1 activity in muscle; and higher 5′-D2 activity in brown adipose tissue (BAT), heart, and testis, which are in accordance with hypothyroidism. Although deiodinase activities were not changed in the hypothalamus, pituitary, and thyroid of NIC offspring, UCP1 expression was lower in BAT. Levels of both TRH and TSH were lower in offspring exposed to NIC, which presented higher basalin vitroTSH secretion, which was not increased in response to TRH. Thus, the hypothyroidism in NIC offspring at adulthood was caused, in part, byin vivoTRH–TSH suppression and lower sensitivity to TRH. Despite the hypothyroid status of peripheral tissues, these animals seem to develop an adaptive mechanism to preserve thyroxine to triiodothyronine conversion in central tissues.

Exposure to cadmium during gestation and lactation affects development and function of Leydig cells in male offspring

2017 ◽  
Vol 33 (3) ◽  
pp. 351-360 ◽  
Author(s):  
Huajian Tian ◽  
Shaomin Chen ◽  
Yang Leng ◽  
Teng Li ◽  
Zengli Li ◽  
...  
Keyword(s):  
Leydig Cells ◽  
Male Offspring ◽  
And Function

Effects of prolactin on the morphology and function of rat Leydig cells: short-term versus long-term administration

1990 ◽  
Vol 262 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Giuseppina Mazzocchi ◽  
Letizia Cavallini ◽  
Aldona Kasprzak ◽  
Piera Rebuffat ◽  
Gastone G. Nussdorfer
Keyword(s):  
Leydig Cells ◽  
Short Term ◽  
Term Administration ◽  
And Function
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