Regulatory Effects of Polyunsaturates on Bone Modeling and Cartilage Function

Author(s):  
B.A. Watkins
2003 ◽  
Vol 70 ◽  
pp. 125-133 ◽  
Author(s):  
Tim E. Cawston ◽  
Jenny M. Milner ◽  
Jon B. Catterall ◽  
Andrew D. Rowan

We have investigated proteinases that degrade cartilage collagen. We show that pro-inflammatory cytokines act synergistically with oncastatin M to promote cartilage collagen resorption by the up-regulation and activation of matrix metalloproteinases (MMPs). The precise mechanisms are not known, but involve the up-regulation of c-fos, which binds to MMP promoters at a proximal activator protein-1 (AP-1) site. This markedly up-regulates transcription and leads to higher levels of active MMP proteins.


2019 ◽  
Vol 89 (1-2) ◽  
pp. 80-88 ◽  
Author(s):  
Juliana Soares Severo ◽  
Jennifer Beatriz Silva Morais ◽  
Taynáh Emannuelle Coelho de Freitas ◽  
Ana Letícia Pereira Andrade ◽  
Mayara Monte Feitosa ◽  
...  

Abstract. Thyroid hormones play an important role in body homeostasis by facilitating metabolism of lipids and glucose, regulating metabolic adaptations, responding to changes in energy intake, and controlling thermogenesis. Proper metabolism and action of these hormones requires the participation of various nutrients. Among them is zinc, whose interaction with thyroid hormones is complex. It is known to regulate both the synthesis and mechanism of action of these hormones. In the present review, we aim to shed light on the regulatory effects of zinc on thyroid hormones. Scientific evidence shows that zinc plays a key role in the metabolism of thyroid hormones, specifically by regulating deiodinases enzymes activity, thyrotropin releasing hormone (TRH) and thyroid stimulating hormone (TSH) synthesis, as well as by modulating the structures of essential transcription factors involved in the synthesis of thyroid hormones. Serum concentrations of zinc also appear to influence the levels of serum T3, T4 and TSH. In addition, studies have shown that Zinc transporters (ZnTs) are present in the hypothalamus, pituitary and thyroid, but their functions remain unknown. Therefore, it is important to further investigate the roles of zinc in regulation of thyroid hormones metabolism, and their importance in the treatment of several diseases associated with thyroid gland dysfunction.


1989 ◽  
Vol 16 (1) ◽  
pp. 177-186 ◽  
Author(s):  
Fernando Ortiz Monasterio ◽  
Ernesto J. Ruas

2020 ◽  
Vol 3 (1) ◽  
pp. 58-76 ◽  
Author(s):  
Bohan Rong ◽  
Qiong Wu ◽  
Chao Sun

Melatonin is a well-known molecule for its involvement in circadian rhythm regulation and its contribution to protection against oxidative stress in organisms including unicellular alga, animals and plants. Currently, the bio-regulatory effects of melatonin on the physiology of various peripheral tissues have drawn a great attention of scientists. Although melatonin was previously defined as a neurohormone secreted from pineal gland, recently it has been identified that virtually, every cell has the capacity to synthesize melatonin and the locally generated melatonin has multiple pathophysiological functions, including regulations of obesity and metabolic syndromes. Herein, we focus on the effects of melatonin on fat deposition in various peripheral organs/tissues. The two important regulatory mechanisms related to the topic, i.e., the improvements of circadian rhythms and antioxidative capacity will be thoroughly discussed since they are linked to several biomarkers involved in obesity and energy imbalance, including metabolism and immunity. Furthermore, several other functions of melatonin which may serve to prevent or promote obesity and energy dysmetabolism-induced pathological states are also addressed. The organs of special interest include liver, pancreas, skeletal muscle, adipose tissue and the gut microbiota.


Author(s):  
Tara A Shrout

Titin is the largest known protein in the human body, and forms the backbone of all striated muscle sarcomeres. The elastic nature of titin is an important component of muscle compliance and functionality. A significant amount of energy is expended to synthesize titin, thus we postulate that titin gene expression is under strict regulatory control in order to conserve cellular resources. In general, gene expression is mediated in part by post-transcriptional control elements located within the 5’ and 3’ untranslated regions (UTRs) of mature mRNA. The 3’UTR in particular contains structural features that affect binding capacity to other RNA components, such as MicroRNA, which control mRNA localization, translation, and degradation. The degree and significance of the regulatory effects mediated by two determined variants of titin’s 3’ UTR were evaluated in Neonatal Rat Ventricular Myocyte and Human Embryonic Kidney cell lines. Recombinant plasmids to transfect these cells lines were engineered by insertion of the variant titin 3’UTR 431- and 1047-base pairs sequences into luciferase reporter vectors. Expression due to an unaltered reporter vector served as the control. Quantitative changes in luciferase activity due to the recombinants proportionally represented the effect titin’s respective 3’UTR conferred on downstream post-transcriptional expression relative to the control. The effect due to titin’s shorter 3’UTR sequence was inconclusive; however, results illustrated that titin’s longer 3’UTR sequence caused a 35 percent decrease in protein expression. Secondary structural analysis of the two sequences revealed differential folding patterns that affect the stability and degree of MicroRNA-binding within titin’s variant 3’UTR sequences.


2019 ◽  
Vol 70 (2) ◽  
Author(s):  
Gianni Belcaro ◽  
Beatrice Feragalli ◽  
Umberto Cornelli ◽  
Roberto Cotellese ◽  
Shu Hu ◽  
...  
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