Prolactin decreases expression of Runx2, osteoprotegerin, and RANKL in primary osteoblasts derived from tibiae of adult female rats

2008 ◽  
Vol 86 (5) ◽  
pp. 240-248 ◽  
Author(s):  
Narattaphol Charoenphandhu ◽  
Jarinthorn Teerapornpuntakit ◽  
Methajit Methawasin ◽  
Kannikar Wongdee ◽  
Kanogwun Thongchote ◽  
...  

Hyperprolactinemia caused by physiological or pathological conditions, such as those occurring during lactation and prolactinoma, respectively, results in progressive osteopenia. The underlying mechanisms, however, are controversial. Prolactin (PRL) may directly attenuate the functions of osteoblasts, since these bone cells express PRL receptors. The present study therefore aimed to investigate the effects of PRL on the expression of genes related to the osteoblast functions by using quantitative real-time PCR technique. Herein, we used primary osteoblasts that were derived from the tibiae of adult rats and displayed characteristics of differentiated osteoblasts, including in vitro mineralization. Osteoblasts exposed for 48 h to 1000 ng/mL PRL, but not to 10 or 100 ng/mL PRL, showed decreases in the mRNA expression of Runx2, osteoprotegerin (OPG), and receptor activator of nuclear factor κB ligand (RANKL) by 60.49%, 72.74%, and 87.51%, respectively. Nevertheless, PRL did not change the RANKL/OPG ratio, since expression of OPG and RANKL were proportionally decreased. These concentrations of PRL had no effect on the mRNA expression of osteocalcin and osteopontin, nor on mineralization. High pathologic concentrations of PRL (1000 ng/mL) may downregulate expression of genes that are essential for osteoblast differentiation and functions. The present results explained the clinical findings of hyperprolactinemia-induced bone loss.

2001 ◽  
pp. 687-690 ◽  
Author(s):  
O Gualillo ◽  
JE Caminos ◽  
M Kojima ◽  
K Kangawa ◽  
E Arvat ◽  
...  

OBJECTIVE: The recently isolated endogenous GH secretagogue, named ghrelin, is a gastric peptide of 28 amino acids with an n-octanoylation in the serine 3 that confers the biological activity to this factor. Ghrelin has been shown to directly stimulate GH release in vivo and in vitro and to be involved in the regulation of gastric acid secretion and motility. In the present work we have studied gender and gonadal dependency of ghrelin mRNA expression in rat stomach. DESIGN AND METHODS: We analysed ghrelin mRNA expression in rat stomach by Northern blot analysis. We also examined the effect of gonadal steroid deprivation on ghrelin mRNA expression. RESULTS AND CONCLUSIONS: The results obtained showed clearly that ghrelin gastric mRNA expression increased with age in young rats (up to 90 days old) but exhibited no significant sex difference at each age tested. Ghrelin mRNA levels were lowest at postnatal day 9, reaching a stable level of expression at day 40 in both female and male rats, although the increase in female rats appears much more gradual than that in males. Moreover, neither ovariectomy nor orchidectomy significantly modified ghrelin mRNA gastric levels in adult rats. In conclusion, these data indicate that ghrelin mRNA expression is associated with age and that a progressive increase is present from the perinatal period up to a stable level after puberty. Gonadal hormones did not alter ghrelin mRNA levels. Taken together, these data showed that ghrelin mRNA levels in young rats are age but not gender dependent, and are not influenced by gonadal steroids.


2020 ◽  
Vol 31 (6) ◽  
pp. 617-622
Author(s):  
Paula Katherine Vargas-Sanchez ◽  
Roger Rodrigo Fernandes ◽  
Flávia Aparecida Chaves Furlaneto ◽  
Luiz Gustavo de Sousa ◽  
Selma Siéssere ◽  
...  

Abstract Recent studies suggest that osteoporosis, in addition to the damage caused in long bones, may cause deterioration in the jaws, especially in alveolar bone sites, with effects in the progress of periodontal disease as well as in bone healing. The aim of this study was to evaluate the effect of osteoporosis in the metabolism of rat alveolar bone osteoblasts. There were used 10 female rats divided in two experimental groups (Sham and OVX), which were ovariectomized and after 8 weeks euthanized to collect mandibular bone samples in order to isolate osteoblastic cells. The cells were cultured in 24-well plates to perform the in vitro experiments. After 7, 10 and 14 days, there were evaluated cell proliferation by MTT assay, in situ detection of alkaline phosphatase (ALP) as well as mineralized nodules and expression of genes associated to bone remodeling. Results showed that at 7, 10 and 14 days cell proliferation was lower for OVX group. In situ detection of ALP was higher at 7 days and lower at 10 and 14 days in OVX group. At 17 and 21 days, OVX group had a significative decrease of mineralization nodules. There was a downregulation in the expression of Alp, Bglap and Runx2 genes and an upregulation of Opg in OVX group, whereas Opn and Rankl modulation was similar between the evaluated groups. Our results suggest that osteoporosis has a deleterious effect on alveolar bone cells from ovariectomized rats, which might affect the treatment of diseases associated to the jaw bones.


2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Pei-Yao Liu ◽  
Cheng-Cheung Chen ◽  
Chia-Ying Chin ◽  
Te-Jung Liu ◽  
Wen-Chiuan Tsai ◽  
...  

AbstractIn obese adults, nonalcoholic fatty liver disease (NAFLD) is accompanied by multiple metabolic dysfunctions. Although upregulated hepatic fatty acid synthesis has been identified as a crucial mediator of NAFLD development, the underlying mechanisms are yet to be elucidated. In this study, we reported upregulated expression of gene related to anergy in lymphocytes (GRAIL) in the livers of humans and mice with hepatic steatosis. Grail ablation markedly alleviated the high-fat diet-induced hepatic fat accumulation and expression of genes related to the lipid metabolism, in vitro and in vivo. Conversely, overexpression of GRAIL exacerbated lipid accumulation and enhanced the expression of lipid metabolic genes in mice and liver cells. Our results demonstrated that Grail regulated the lipid accumulation in hepatic steatosis via interaction with sirtuin 1. Thus, Grail poses as a significant molecular regulator in the development of NAFLD.


1976 ◽  
Vol 83 (3) ◽  
pp. 604-620 ◽  
Author(s):  
B. P. Lisboa ◽  
M. Holtermann

ABSTRACT In vitro experiments carried out with uterus preparations of ovariectomized adult rats indicate the presence in this tissue of a 20β-hydroxysteroid-oxidoreductase which catalyzes the conversion of 20β-hydroxy-4-pregnen-3-one to progesterone. Since a hepatic 20β-hydroxysteroid-oxidoreductase is absent in adult female rats, the myometrial enzyme can be responsible for the biological activity of 20β-hydroxy-4-pregnen-3-one in these animals. Besides progesterone five metabolites were isolated and identified after incubation of [4-14C]20β-hydroxy-4-pregnen-3-one with uterine tissue: 20β-hydroxy-5α-pregnan-3-one, 20β-hydroxy-5β-pregnan-3-one, 5α-pregnane-3α,20β-diol, 4-pregnene-3α,20β-diol and 4-pregnene-3β,20β-diol. The conversion of 20β-hydroxy-4-pregnen-3-one to progesterone permits us to regard all five steroids isolated as progesterone metabolites in the rat uterus. 20β-hydroxy-5β-pregnan-3-one is the first C21-metabolite with a 5β(H)-configuration isolated in the rat uterus, which indicates the presence of 5β-reductase in this tissue.


2020 ◽  
Vol 11 (12) ◽  
Author(s):  
Ze-nan Zheng ◽  
Guang-zhao Huang ◽  
Qing-qing Wu ◽  
Heng-yu Ye ◽  
Wei-sen Zeng ◽  
...  

AbstractOral squamous cell carcinoma (OSCC) is the most common oral cancer. The molecular mechanisms of this disease are not fully understood. Our previous studies confirmed that dysregulated function of long non-coding RNA (lncRNA) AC007271.3 was associated with a poor prognosis and overexpression of AC007271.3 promoted cell proliferation, migration, invasion, and inhibited cell apoptosis in vitro, and promoted tumor growth in vivo. However, the underlying mechanisms of AC007271.3 dysregulation remained obscure. In this study, our investigation showed that AC007271.3 functioned as competing endogenous RNA by binding to miR-125b-2-3p and by destabilizing primary miR-125b-2, resulted in the upregulating expression of Slug, which is a direct target of miR-125b-2-3p. Slug also inhibited the expression of E-cadherin but N-cadherin, vimentin, and β-catenin had no obvious change. The expression of AC007271.3 was promoted by the canonical nuclear factor-κB (NF-κB) pathway. Taken together, these results suggested that the classical NF-κB pathway-activated AC007271.3 regulates EMT by miR-125b-2-3p/Slug/E-cadherin axis to promote the development of OSCC, implicating it as a novel potential target for therapeutic intervention in this disease.


Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 567
Author(s):  
Wenyu Si ◽  
Hailing Li ◽  
Tiezhu Kang ◽  
Jing Ye ◽  
Zhiqiu Yao ◽  
...  

This study explored the role of γ-aminobutyric acid transaminase (GABA-T) in the puberty and reproductive performance of female rats. Immunofluorescence technique, quantitative real-time PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) were used to detect the distribution of GABA-T and the expression of genes and hormones in female rats, respectively. The results showed that GABA-T was mainly distributed in the arcuate nucleus (ARC), paraventricular nucleus (PVN) and periventricular nucleus (PeN) of the hypothalamus, and in the adenohypophysis, ovarian granulosa cells and oocytes. Abat mRNA level at 28 d was lowest in the hypothalamus and the pituitary; at puberty, it was lowest in the ovary. Abat mRNA level was highest in adults in the hypothalamus; at infancy and puberty, it was highest in the pituitary; and at 21 d it was highest in the ovary. After vigabatrin (GABA-T irreversible inhibitor) was added to hypothalamus cells, the levels of Abat mRNA and Rfrp-3 mRNA were significantly reduced, but Gnrh mRNA increased at the dose of 25 and 50 μg/mL; Kiss1 mRNA was significantly increased but Gabbr1 mRNA was reduced at the 50 μg/mL dose. In prepubertal rats injected with vigabatrin, puberty onset was delayed. Abat mRNA, Kiss1 mRNA and Gnrh mRNA levels were significantly reduced, but Rfrp-3 mRNA level increased in the hypothalamus. Vigabatrin reduced the concentrations of GABA-T, luteinizing hormone (LH) and progesterone (P4), and the ovarian index. Lactation performance was reduced in adult rats with vigabatrin treatment. Four hours after vigabatrin injection, the concentrations of GABA-T and LH were significantly reduced in adult and 25 d rats, but follicle-stimulating hormone (FSH) increased in 25 d rats. In conclusion, GABA-T affects the reproductive function of female rats by regulating the levels of Gnrh, Kiss1 and Rfrp-3 in the hypothalamus as well as the concentrations of LH and P4.


Author(s):  
Shanjun Gao ◽  
Guangzhi Liu ◽  
Jianguo Li ◽  
Jing Chen ◽  
Lina Li ◽  
...  

Compared to mono-species biofilm, biofilms formed by cross-kingdom pathogens are more refractory to conventional antibiotics, thus complicating clinical treatment and causing significant morbidity. Lemongrass essential oil and its bioactive component citral were previously demonstrated to possess strong antimicrobial efficacy against pathogenic bacteria and fungi. However, their effects on polymicrobial biofilms remain to be determined. In this study, the efficacy of lemongrass (Cymbopogon flexuosus) essential oil and its bioactive part citral against dual-species biofilms formed by Staphylococcus aureus and Candida species was evaluated in vitro. Biofilm staining and viability test showed both lemongrass essential oil and citral were able to reduce biofilm biomass and cell viability of each species in the biofilm. Microscopic examinations showed these agents interfered with adhesive characteristics of each species and disrupted biofilm matrix through counteracting nucleic acids, proteins and carbohydrates in the biofilm. Moreover, transcriptional analyses indicated citral downregulated hyphal adhesins and virulent factors of Candida albicans, while also reducing expression of genes involved in quorum sensing, peptidoglycan and fatty acids biosynthesis of S. aureus. Taken together, our results demonstrate the potential of lemongrass essential oil and citral as promising agents against polymicrobial biofilms as well as the underlying mechanisms of their activity in this setting.


Nutrients ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1386 ◽  
Author(s):  
Danyelle M. Liddle ◽  
Meaghan E. Kavanagh ◽  
Amanda J. Wright ◽  
Lindsay E. Robinson

Adipose tissue (AT) expansion induces local hypoxia, a key contributor to the chronic low-grade inflammation that drives obesity-associated disease. Apple flavonols phloretin (PT) and phlorizin (PZ) are suggested anti-inflammatory molecules but their effectiveness in obese AT is inadequately understood. Using in vitro models designed to reproduce the obese AT microenvironment, 3T3-L1 adipocytes were cultured for 24 h with PT or PZ (100 μM) concurrent with the inflammatory stimulus lipopolysaccharide (LPS; 10 ng/mL) and/or the hypoxia mimetic cobalt chloride (CoCl2; 100 μM). Within each condition, PT was more potent than PZ and its effects were partially mediated by peroxisome proliferator-activated receptor (PPAR)-γ (p < 0.05), as tested using the PPAR-γ antagonist bisphenol A diglycidyl ether (BADGE). In LPS-, CoCl2-, or LPS + CoCl2-stimulated adipocytes, PT reduced mRNA expression and/or secreted protein levels of inflammatory and macrophage chemotactic adipokines, and increased that of anti-inflammatory and angiogenic adipokines, which was consistent with reduced mRNA expression of M1 polarization markers and increased M2 markers in RAW 264.7 macrophages cultured in media collected from LPS + CoCl2-simulated adipocytes (p < 0.05). Further, within LPS + CoCl2-stimulated adipocytes, PT reduced reactive oxygen species accumulation, nuclear factor-κB activation, and apoptotic protein expression (p < 0.05). Overall, apple flavonols attenuate critical aspects of the obese AT phenotype.


2020 ◽  
Vol 21 (21) ◽  
pp. 8396
Author(s):  
Hyung Joon Kim ◽  
Hwa-Sik Seong ◽  
YunJeong Choi ◽  
Soon Chul Heo ◽  
Yong-Deok Kim

Letrozole is a reversible nonsteroidal aromatase inhibitor that is widely used in postmenopausal breast cancer patients. It is well established that letrozole decreases bone density owing to estrogen depletion; however, few studies have reported its direct effect on bone cells in vitro. Therefore, we investigated the effect of letrozole on bone metabolism, focusing on osteoclastogenesis. Letrozole did not affect the viability, proliferation, or migration of bone marrow-derived macrophages (BMMs); however, it reduced the multinucleation of immature osteoclasts and subsequent bone resorption in vitro. Overall, letrozole inhibited the expression of dendritic cell-specific transmembrane protein (DC-STAMP), tartrate-resistant acid phosphatase, calcitonin receptor, and cathepsin K. Among them, the reduced expression of DC-STAMP was the most prominent. However, this downregulation of DC-STAMP expression following letrozole treatment was not related to the inhibition of major osteoclastogenesis pathways, such as the nuclear factor-κB (NF-κB), c-Fos, and nuclear factor of activated T cell c1 (NFATc1) pathways, but was attributed to the inhibition of p38, which is known to reside upstream of DC-STAMP expression. Notably, the anti-osteoclastogenic effect of letrozole was abolished following treatment with the p38 activator anisomycin. Contrary to our expectations, these results strongly suggest a previously unknown anti-osteoclastogenic activity of letrozole, mediated by the downregulation of the p38/DC-STAMP pathway.


1992 ◽  
Vol 126 (5) ◽  
pp. 467-473 ◽  
Author(s):  
Christoph Schmid ◽  
Irene Schläpfer ◽  
Eva Futo ◽  
Margaretha Waldvogel ◽  
Jürg Schwander ◽  
...  

Osteoblast-like cells prepared from neonatal rat calvariae and grown under serum-free conditions produce IGF-1 and IGFBPs. In contrast to growth hormone, T3 and PTH increased both IGF-1 mRNA expression and net IGF-1 release in calvaria cells. In addition, they stimulated net production of IGFBP-3 and of an IGFBP with an apparent molecular weight of 32 kDa which was recognized by an antiserum against rat IGFBP-2. Bone cells expressed remarkably high levels of mRNA for IGFBP-2, the predominant IGFBP in serum of newborn rats. T3 at low physiological concentrations but not growth hormone stimulated IGFBP-2 mRNA expression and IGFBP-2 production in bone cells in vitro. Thus, IGFBPs are differentially regulated by these hormones and may play an autocrine/paracrine regulatory role in bone.


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