scholarly journals Involvement of Bone in Systemic Endocrine Regulation

2018 ◽  
pp. 669-677 ◽  
Author(s):  
I. ZOFKOVA

The skeleton shows an unconventional role in the physiology and pathophysiology of the human organism, not only as the target tissue for a number of systemic hormones, but also as endocrine tissue modulating some skeletal and extraskeletal systems. From this point of view, the principal cells in the skeleton are osteocytes. These cells primarily work as mechano-sensors and modulate bone remodeling. Mechanically unloaded osteocytes synthetize sclerostin, the strong inhibitor of bone formation and RANKL, the strong activator of bone resorption. Osteocytes also express hormonally active vitamin D (1,25(OH)2D) and phosphatonins, such as FGF23. Both 1,25(OH)2D and FGF23 have been identified as powerful regulators of the phosphate metabolism, including in chronic kidney disease. Further endocrine cells of the skeleton involved in bone remodeling are osteoblasts. While FGF23 targets the kidney and parathyroid glands to control metabolism of vitamin D and phosphates, osteoblasts express osteocalcin, which through GPRC6A receptors modulates beta cells of the pancreatic islets, muscle, adipose tissue, brain and testes. This article reviews some knowledge concerning the interaction between the bone hormonal network and phosphate or energy homeostasis and/or male reproduction.

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Leila Maghsoumi-Norouzabad ◽  
Ahmad Zare Javid ◽  
Anahita Mansoori ◽  
Mohammadreza Dadfar ◽  
Amirarsalan Serajian

Abstract Background It is suggested that vitamin D may have a beneficial role in male reproduction. The male reproductive system is a target tissue for vitamin D. This study will aim to evaluate the effects of vitamin D supplementation on sperm parameters, seminal and serum levels of oxidative stress and serum endocrine factors in asthenospermia infertile men. Methods/design This randomized, triple-blind, placebo-controlled clinical trial will be conducted on 86 infertile men with idiopathic asthenozoospermia (the mobility of sperm < 40% and rapid progressive sperm motility < 32%), with serum levels of vitamin D less than 30 ng / ml in the “Infertility Clinic of Ahvaz Jahad daneshgahi”, Iran. Main outcomes measure (s) Demographic data, dietary intake, physical activity, sun exposure, anthropometric indices, serum and seminal levels of MDA (Malondialdehyde), 8-hydroxy-2- Dioxy Guanosine (8-OHDG), Total Antioxidant Capacity (TAC) and calcium, sperm DNA fragmentation index (DFI), serum 25-OHD, luteinizing hormone (LH), follicle-stimulating hormone (FSH), total testosterone (T), estradiol (E2), sex hormone-binding globulin (SHBG), free androgen index (FAI = T/SHBG. 100), T/LH and T/E2 ratios, prolactin (PRO), parathyroid hormone (PTH), osteocalcin (OCN), phosphorus and sperm parameters. Discussion The deficiency of vitamin D as an antioxidant is common all over the world. Numerous observational studies have shown a positive association between vitamin D levels and semen quality. However, few clinical studies have been conducted in this area. So considering with the high prevalence of this antioxidant deficiency specifically in infertile men, it seems that the supplementation of vitamin D in infertile men with insufficient levels or deficiency may improve the status of oxidative stress and thereby may affect sperm parameters and endocrine factors involved in male fertility. Trial registration Iran Clinical Trials Registry, ID: IRCT20151128025274N4, registered on 28 March 2018.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Henry Reyer ◽  
Michael Oster ◽  
Siriluck Ponsuksili ◽  
Nares Trakooljul ◽  
Adewunmi O. Omotoso ◽  
...  

Abstract Background Calcium (Ca) and phosphorus (P) are essential nutrients that are linked to a large array of biological processes. Disturbances in Ca and P homeostasis in chickens are associated with a decline in growth and egg laying performance and environmental burden due to excessive P excretion rates. Improved utilization of minerals in particular of P sources contributes to healthy growth while preserving the finite resource of mineral P and mitigating environmental pollution. In the current study, high performance Lohmann Selected Leghorn (LSL) and Lohmann Brown (LB) hens at peak laying performance were examined to approximate the consequences of variable dietary Ca and P supply. The experimental design comprised four dietary groups with standard or reduced levels of either Ca or P or both (n = 10 birds per treatment group and strain) in order to stimulate intrinsic mechanisms to maintain homeostasis. Jejunal transcriptome profiles and the systemic endocrine regulation of mineral homeostasis were assessed (n = 80). Results Endogenous mechanisms to maintain mineral homeostasis in response to variations in the supply of Ca and P were effective in both laying hen strains. However, the LSL and LB appeared to adopt different molecular pathways, as shown by circulating vitamin D levels and strain-specific transcriptome patterns. Responses in LSL indicated altered proliferation rates of intestinal cells as well as adaptive responses at the level of paracellular transport and immunocompetence. Endogenous mechanisms in LB appeared to involve a restructuring of the epithelium, which may allow adaptation of absorption capacity via improved micro-anatomical characteristics. Conclusions The results suggest that LSL and LB hens may exhibit different Ca, P, and vitamin D requirements, which have so far been neglected in the supply recommendations. There is a demand for trial data showing the mechanisms of endogenous factors of Ca and P homeostasis, such as vitamin D, at local and systemic levels in laying hens.


2017 ◽  
Vol 45 (7) ◽  
pp. 887-893 ◽  
Author(s):  
Katherine J. Motyl ◽  
Anyonya R. Guntur ◽  
Adriana Lelis Carvalho ◽  
Clifford J. Rosen

Biological processes utilize energy and therefore must be prioritized based on fuel availability. Bone is no exception to this, and the benefit of remodeling when necessary outweighs the energy costs. Bone remodeling is important for maintaining blood calcium homeostasis, repairing micro cracks and fractures, and modifying bone structure so that it is better suited to withstand loading demands. Osteoclasts, osteoblasts, and osteocytes are the primary cells responsible for bone remodeling, although bone marrow adipocytes and other cells may also play an indirect role. There is a renewed interest in bone cell energetics because of the potential for these processes to be targeted for osteoporosis therapies. In contrast, due to the intimate link between bone and energy homeostasis, pharmaceuticals that treat metabolic disease or have metabolic side effects often have deleterious bone consequences. In this brief review, we will introduce osteoporosis, discuss how bone cells utilize energy to function, evidence for bone regulating whole body energy homeostasis, and some of the unanswered questions and opportunities for further research in the field.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Doaa Abou-Taleb AE ◽  
◽  
Mahran AM ◽  
Mahmoud MA ◽  
Gaber MA ◽  
...  

Background: Although vitamin D receptor (VDR) is expressed in human sperm, little is known about the role of vitamin D (Vit. D) in male reproduction. Our objective was to assess Vit. D levels both in serum and seminal fluid and to establish the relation between serum and seminal Vit. D levels, semen parameters, male sex hormones and serum calcium level in Egyptian infertile men. Patients and Methods: We conducted a prospective case control study including 30 healthy fertile males as a control group and 60 male patients with infertility of unknown etiology. Semen samples were collected and semen parameters were evaluated. Also, seminal Vit. D level was measured. Blood samples were taken as serum levels of Vit. D, calcium, testosterone, Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH) were estimated. Results: There was significant decrease of both serum and seminal Vit. D level in groups of male infertility compared to control group. A significant positive correlation was found between serum and seminal Vit. D levels in different study groups. Also, significant positive correlation between serum Vit. D level and non-progressive sperm motility. Conclusion: Our results support the role of Vit. D in semen parameters and male fertility status.


2003 ◽  
Vol 88 (11) ◽  
pp. 5175-5179 ◽  
Author(s):  
Franck Grados ◽  
Michel Brazier ◽  
Saïd Kamel ◽  
Marc Mathieu ◽  
Nathalie Hurtebize ◽  
...  

Abstract The aim of this study was to determine whether early changes in bone markers could predict long-term response in bone mineral density (BMD) after calcium (500 mg) and vitamin D (400 IU) supplementation twice daily in ambulatory elderly women with vitamin D insufficiency (25-hydroxyvitamin D, &lt;12 ng/ml). One hundred and ninety-two women (mean age, 75 ± 7 yr) were randomized to receive either the supplementation (n = 95) or a placebo (n = 97) in a double-blind, controlled clinical trial for 1 yr. In comparison with the placebo group, supplementation significantly increased BMD, normalized 25-hydroxyvitamin D and significantly decreased intact PTH and bone remodeling markers. The initial values of telopeptide cross-links were correlated with improvement in total body BMD [urinary N-telopeptides (NTX), r = 0.38; C-telopeptides (CTX), r = 0.32; serum CTX, r = 0.28], and the 3-month changes in the same markers were correlated with improvement in total body (urinary N-telopeptides, r = −0.29; serum CTX, r = −0.26) and vertebral BMD (CTX, r = −0.26; all P &lt; 0.05). We concluded that short-term changes in bone resorption markers can predict long-term variations in BMD in elderly women with vitamin D insufficiency receiving calcium and vitamin D supplementation.


2020 ◽  
Vol 58 (3) ◽  
pp. 290-293
Author(s):  
S. S. Safarova ◽  
S. S. Safarova

Diabetic osteopathy is one of the little studied complications of diabetes mellitus (DM), which leads to common lowtrauma fractures and, as a consequence, disability and death. The level of insulin is connected with bone functional and morphological changes followed by decreased bone mineral density (BMD) in the early stages of diabetic osteopathy. Objective: to study bone morphofunctional properties in males with type 1 and 2 DM (T1DM and T2DM). Subjects and methods. Examinations were made in 41 male patients with T1DM and 52 male patients with T2DM without a history of fractures. Their age varied from 40 to 70 years (mean age, 55.8±0.7 years and 58.4±0.9 years, respectively). A control group consisted of 34 patients (mean age, 55.9±0.9 years) without a history of DM. Patients with other endocrine disorders, end-stage complications, or chronic liver and kidney diseases were excluded from the investigation. BMD was determined by dual-energy X-ray absorptiometry (DXA). Serum bone remodeling markers (procollagen type 1 amino-terminal propeptide and C-terminal telopeptide), as well as 25(OH)D, parathyrin, insulin, glycated hemoglobin (HbA1c), and electrolytes (Ca2+, P+) were evaluated. Results and discussion. An association of BMD with renal function, HbA1c, and body mass index was observed in patients with T2DM. In the T1MD group, BMD was closely related to insulin deficiency and was significantly lower than that in the control group. In patients with vitamin D deficiency, BMD was significantly lower than in those with normal vitamin D levels (p<0.05). The patients with T1DM displayed both a decrease in BMD (p<0.05) and a pronounced change in the levels of bone markers (p<0.05). Those with T2DM had impaired bone remodeling processes, which was determined by the level of these markers (p<0.05) and observed in the presence of normal BMD due to the complex pathophysiology of the underlying disease. Conclusion. Vitamin D deficiency, insufficient and decreased insulin sensitivity, hyperglycemia, and overweight are important causes of osteopathy in patients with DM. The markers of bone remodeling may become promising indicators for diagnosing osteopathy, but additional studies are needed to elaborate recommendations for their use in routine practice in order to predict and prevent this complication of DM.


Sign in / Sign up

Export Citation Format

Share Document