May polymorphisms of DHFR, CBS and MTHFR genes modulate metabolic and bone remodeling parameters associated with reduced bone mineral density?

2018 ◽  
Author(s):  
Joana Freitas ◽  
Carla Carvalho ◽  
Carolina Ribeiro ◽  
David Sarmento ◽  
Barbosa Ana Paula ◽  
...  
2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Md Mizanur Rahman ◽  
Amina El Jamali ◽  
Ganesh V. Halade ◽  
Allal Ouhtit ◽  
Haissam Abou-Saleh ◽  
...  

Despite increasing evidence suggesting a role for NADPH oxidases (Nox) in bone pathophysiology, whether Nox enzymes contribute to obesity-mediated bone remodeling remains to be clearly elucidated. Nox2 is one of the predominant Nox enzymes expressed in the bone marrow microenvironment and is a major source of ROS generation during inflammatory processes. It is also well recognized that a high-fat diet (HFD) induces obesity, which negatively impacts bone remodeling. In this work, we investigated the effect of Nox2 loss of function on obesity-mediated alteration of bone remodeling using wild-type (WT) and Nox2-knockout (KO) mice fed with a standard lab chow diet (SD) as a control or a HFD as an obesity model. Bone mineral density (BMD) of mice was assessed at the beginning and after 3 months of feeding with SD or HFD. Our results show that HFD increased bone mineral density to a greater extent in KO mice than in WT mice without affecting the total body weight and fat mass. HFD also significantly increased the number of adipocytes in the bone marrow microenvironment of WT mice as compared to KO mice. The bone levels of proinflammatory cytokines and proosteoclastogenic factors were also significantly elevated in WT-HFD mice as compared to KO-HFD mice. Furthermore, the in vitro differentiation of bone marrow cells into osteoclasts was significantly increased when using bone marrow cells from WT-HFD mice as compared to KO-HFD mice. Our data collectively suggest that Nox2 is implicated in HFD-induced deleterious bone remodeling by enhancing bone marrow adipogenesis and osteoclastogenesis.


2018 ◽  
Vol 4 (4) ◽  
pp. 37 ◽  
Author(s):  
Giuseppina E. Grieco ◽  
Dorica Cataldo ◽  
Elena Ceccarelli ◽  
Laura Nigi ◽  
Giovanna Catalano ◽  
...  

Type 1 diabetes (T1D) is characterized by bone loss and altered bone remodeling, resulting into reduction of bone mineral density (BMD) and increased risk of fractures. Identification of specific biomarkers and/or causative factors of diabetic bone fragility is of fundamental importance for an early detection of such alterations and to envisage appropriate therapeutic interventions. MicroRNAs (miRNAs) are small non-coding RNAs which negatively regulate genes expression. Of note, miRNAs can be secreted in biological fluids through their association with different cellular components and, in such context, they may represent both candidate biomarkers and/or mediators of bone metabolism alterations. Here, we aimed at identifying miRNAs differentially expressed in serum of T1D patients and potentially involved in bone loss in type 1 diabetes. We selected six miRNAs previously associated with T1D and bone metabolism: miR-21; miR-24; miR-27a; miR-148a; miR-214; and miR-375. Selected miRNAs were analyzed in sera of 15 T1D patients (age: 33.57 ± 8.17; BMI: 21.4 ± 1.65) and 14 non-diabetic subjects (age: 31.7 ± 8.2; BMI: 24.6 ± 4.34). Calcium, osteocalcin, parathormone (PTH), bone ALkaline Phoshatase (bALP), and Vitamin D (VitD) as well as main parameters of bone health were measured in each patient. We observed an increased expression of miR-148a (p = 0.012) and miR-21-5p (p = 0.034) in sera of T1D patients vs non-diabetic subjects. The correlation analysis between miRNAs expression and the main parameters of bone metabolism, showed a correlation between miR-148a and Bone Mineral Density (BMD) total body (TB) values (p = 0.042) and PTH circulating levels (p = 0.033) and the association of miR-21-5p to Bone Mineral Content-Femur (BMC-FEM). Finally, miR-148a and miR-21-5p target genes prediction analysis revealed several factors involved in bone development and remodeling, such as MAFB, WNT1, TGFB2, STAT3, or PDCD4, and the co-modulation of common pathways involved in bone homeostasis thus potentially assigning a role to both miR-148a and miR-21-5p in bone metabolism alterations. In conclusion, these results lead us to hypothesize a potential role for miR-148a and miR-21-5p in bone remodeling, thus representing potential biomarkers of bone fragility in T1D.


2019 ◽  
Vol 13 (1) ◽  
pp. 22-29
Author(s):  
Samar Ben Jemaa ◽  
Lassaad Chtourou ◽  
Rim Akrout ◽  
Khansa Chaabouni ◽  
Tarek Chaabouni ◽  
...  

Background:A high prevalence of osteopenia and osteoporosis is observed in patients with Inflammatory Bowel Disease (IBD).Objective:The aim of our study was to investigate the prevalence of bone loss, bone remodeling and risk factors in Tunisian patient with IBD.Patients and Methods:The study included 40 patients with IBD and 32 age- and sex-matched healthy controls subjects. All participants underwent bone densitometry by dual energy X-ray absorptiometry at the femoral neck and lumbar spine. Serum levels of 25-hydroxy vitamin D (25(OH)D), parathyroid hormone (PTH), osteocalcin(OC), and urinary degradation products of C-terminal telopeptide of type I collagen (CTXI) were measured in all participants to assess the bone metabolism status.Results:Twelve (30%) patients were normal, 32.5% were osteopenic and 37.5% were osteoporotic. Osteoporosis was more frequent in IBD patients than controls (p=0.0001). Age and inflammation were associated with low bone mineral density (BMD). Mean calcium, phosphorus and alkaline phosphatase levels were similar in both groups. Median 25(OH) D levels were significantly lower in IBD patients compared with controls (p=0.0001). Median urinary CTXI levels were significantly higher in IBD patients compared with healthy controls (p=0.007). No significant differences between IBD patients and controls concerning the median serum OC and PTH levels were found.Conclusion:In our study, there is a high prevalence of low BMD in IBD patients and an increase in bone resorption without a change of bone formation. Low BMI and hypovitaminoses D were identified as risk factors for low BMD.


2003 ◽  
Vol 268 (4) ◽  
pp. 309-316 ◽  
Author(s):  
U. Ulrich ◽  
P. B. Miller ◽  
D. R. Eyre ◽  
C. H. Chesnut ◽  
H. Schlebusch ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
Sain S. Safarova

Aim. The study aims to develop a practical model for screening bone turnover state in patients with diabetes and evaluate its clinical usefulness to identify diabetic osteopathy. Materials. The study was conducted in 2015–2017 in the Endocrinology Department of the Therapeutic Clinic of AM University. A total of 235 patients were assessed in the study (98 with T1DM and 137 with T2DM). 89 nondiabetic subjects served as controls. Bone mineral density (BMD) [by dual energy X-ray absorptiometry (DXA)] and serum markers of bone remodeling [aminoterminal propeptide of procollagen type I (P1NP) and c-terminal telopeptide of type I collagen (CTX)], parathyrin, and 25(OH)D were measured in all 235 patients. Results. Our results show that patients with T2DM have lower b-CTx values and relatively higher levels of P1NP, reflecting less pronounced changes in bone metabolism compared to patients with T1DM, regardless of age or duration of the disease. Osteoporosis was detected in 50% of patients with T1DM, compared to 13% of patients with T2DM. Conclusion. In some cases, bone remodeling markers are useful for improving the assessment of the state of bone tissue in early stages of diabetes, while alterations in bone microarchitecture may not always be captured by bone mineral density measurements.


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