Aerobic and resistance training improve alveolar bone quality and interferes with bone-remodeling during orthodontic tooth movement in mice
BONE
Authors: Pereira, Luciano J.; Macari, Soraia; Coimbra, Candido C.; Pereira, Thais dos S. F.; Barrioni, Breno Rocha; Gomez, Ricardo Santiago; Silva, Tarcilia A.; Paiva, Saul Martins
Abstract
The direct effects of physical activity on long bones are already recognized. However, little information is available regarding distant osseous sites, such as maxillary bone. We evaluated the influence of physical training on alveolar bone quality, with and without mechanically-induced load during orthodontic tooth movement in mice. Forty-two C57BL/6 mice were divided into sedentary, resistance and aerobic training groups. Training period lasted for eight weeks and mechanical loads (orthodontic tooth movement - OTM) were applied during the last 14 days of training. Both types of training enhanced the quality of maxillary bone, increasing bone mineral density (BMD), trabecular bone volume (BV) and bone volume/total volume ratio (BV/TV). OTM significantly reduced in trained groups. Consistently, the number of osteoblasts increased whereas the number of osteoclasts decreased on the OTM side in trained groups in comparison to the sedentary group. IGF-1, RUNX2 and OPG genes expression were also increased. The RANKL/OPG ratio and IL-6 expression were reduced in the maxillary bone. Similar results were verified in the femoral bone. In line with these findings, physical training resulted in a decrease of osteoclast differentiation from femoral bone marrow; as well as the force required to fracture the tibia of trained animals increased. Physical training also caused EDL muscle hypertrophy and increased expression of IGF-1 and IGF-1/Myostatin ratio in the gastrocnemius muscle, whereas FNDC5 gene expression was similar among groups in femur, but decreased in alveolar bone submitted to OTM. In conclusion, physical training increased bone quality, not only on long bones, but also in a distant site such as the maxilla. Differences were more evident in the course of maxillary mechanical loading. Mechanisms involve systemic and local effects on bone cells and target molecules as RANKL, OPG, IL-6 and IGF-1.
SNPs of miR-23b, miR-107 and HMGA2 and their Relations with the Response to Medical Treatment in Acromegaly Patients
EXPERIMENTAL AND CLINICAL ENDOCRINOLOGY & DIABETES
Authors: Armagan, Derya Metin; Akdemir, Ayse Seda; Ozkaya, Hande Mefkure; Korkmaz, Ozge Polat; Gazioglu, Nurperi; Kadioglu, Pinar; Tanriover, Necmettin; Dagistanli, Fatma-Kaya; Dirican, Ahmet; Ozturk, Melek
Abstract
Introduction Acromegaly is a chronic disease of increased growth hormone (GH) secretion and elevated insulin-like growth factor-I (IGF-I) levels induced by a pituitary adenoma. HMGA2 (high mobility group A2) and AIP (aryl hydrocarbon receptor-interacting protein) expression levels are related to GH-secreting adenomas, and also a response to Somatostatin Analogs (SSAs). We studied SNPs in miR-107 and miR-23b that related with AIP and HMGA2 genes respectively and control their expression, and also SNP in the 3'UTR of HMGA2 gene. Our aim was to investigate genotype distributions of the studied SNPs, as well as the possible relationship between disease and/or response to SSAs treatment in patients with acromegaly. Material and Methods Genotypes were determined by qRT-PCR method from DNA materials obtained blood samples of acromegaly patients (141) and healthy individuals (99). The genotype distributions of patients and healthy groups, as well as the relationship between the clinical data of the disease and genotypes were statistically compared. Results In acromegaly patients with T-allele, p53 expression (p = 0.049) was significantly higher. In patients with CT + TT genotype and T-allele who were responder to SSA-treatment Ki-67 index (respectively p = 0.019, p = 0.020 respectively) was higher. We did not observe the genotypes for miR-23b and miR-107 polymorphisms in the patients and control group of Turkish population. Conclusion The genetic variations of the miRNAs genes related with HMGA2 and AIP genes were not seen in our study. Although there is no relationship between HMGA2-rs1351394 polymorphism and acromegaly disease, T allele was associated with some clinical features related to adenoma in patients with acromegaly.