Multiple Fractures in Patient with Graves' Disease Accompanied by Isolated Hypogonadotropic Hypogonadism

DAP1 regulates osteoblast autophagy via the ATG16L1-LC3 axis in Graves' disease-induced osteoporosis

OBJECTIVE

This study aimed to uncover a critical protein and its mechanisms in modulating autophagy in Graves' disease (GD)-induced osteoporosis (OP).

METHODS

We discovered the target protein, death-associated protein 1 (DAP1), using bone proteomics analysis. Furthermore, genetic overexpression and knockdown (KD) of DAP1 in bone and MC3T3-E1 cells revealed DAP1 effects on autophagy and osteogenic markers, and autophagic vacuoles in cells were detected using transmission electron microscopy and the microtubule-associated protein 1 light chain 3 alpha (MAP1LC3/LC3) dual fluorescence system. An autophagy polymerase chain reaction (PCR) array kit was used to identify the key molecules associated with DAP1-regulated autophagy.

RESULTS

DAP1 levels were significantly higher in the bone tissue of GD mice and MC3T3-E1 cells treated with triiodothyronine (T3). DAP1 overexpression reduced LC3 lipidation, autophagic vacuoles, RUNX family transcription factor 2 (RUNX2), and osteocalcin (OCN) expression in MC3T3-E1 cells, whereas DAP1 KD reversed these changes. In vivo experiments revealed that GD mice with DAP1 KD had greater bone mass than control mice. DAP1-overexpressing (OE) cells had lower levels of phosphorylated autophagy-related 16-like 1 (ATG16L1) and LC3 lipidation, whereas DAP1-KD cells had higher levels.

CONCLUSIONS

DAP1 was found to be a critical regulator of autophagy homeostasis in GD mouse bone tissue and T3-treated osteoblasts because it negatively regulated autophagy and osteogenesis in osteoblasts via the ATG16L1-LC3 axis.

Changes in bone mineral density, 25-hydroxyvitamin D3 and inflammatory factors in patients with hyperthyroidism

The present study aimed to evaluate changes in bone mineral density, 25-hydroxyvitamin D³ [25-(OH)D³] and inflammatory factors in patients with hyperthyroidism, in order to determine the correlations with the pathogenesis of hyperthyroidism. A total of 55 patients with hyperthyroidism (observation group) and 53 healthy patients (control group) enrolled at Weifang People's Hospital from March 2017 to February 2018 were randomly enrolled. The thyroid function, bone mineral density, 25-(OH)D³ and inflammatory factors were measured and compared between the two groups. The measurement data are presented as mean ± standard deviation (SD), and Student t-test was performed for the comparison between two groups. Chi-square test was used for enumeration data regarding sex. Pearson correlation analysis was performed for two-variable analysis on L1, 25-(OH)D³, interleukin (IL)-2, IL-6 with FT3, respectively. In regards to the results, no difference in sex, age and body mass index (BMI) between the two groups were found but the thyroid function was markedly enhanced in the observation group compared to the control group. Bone mineral density index and 25-(OH)D³ in the observation group were significantly lower than those in the control group (P<0.05). There were significant differences in the inflammatory factors between the two groups (P<0.05). The L1, 25-(OH)D³ and IL-2 levels were significantly negatively correlated with thyroid function index and free triiodothyronine (FT3) while a statistically positive correlation was found between IL-6 and FT3 (P<0.05). In conclusion, abnormal levels of bone mineral density, 25-(OH)D³ and inflammatory factors are observed in patients with hyperthyroidism, and there are correlations between L1, 25-(OH)D³, IL-2, IL-6 and FT3 in the pathogenesis of hyperthyroidism, which provides new insight for the diagnosis of hyperthyroidism.

Simultaneous bilateral neck of femur fractures in an adolescent secondary to hypocalcaemic seizure

We present a rare case of a previously healthy 16-year-old boy who sustained simultaneous bilateral femoral neck fractures after a single first-time seizure episode. He was diagnosed to have severe vitamin D deficiency and secondary hyperparathyroidism. Symptomatic hypocalcemia was the cause of seizures. Both fractures were treated surgically and united at 3 months. Bilateral femoral neck fractures after seizures are very rare, especially in children. Severe vitamin D deficiency may cause seizures and also weakening of bone, predisposing to fractures without significant trauma. We recommend that paediatric cases of femoral neck fractures after seizures should be investigated for underlying metabolic disease.

Evaluation of the rivastigmine role against botulinum toxin-A-induced osteoporosis in albino rats: A biochemical, histological, and immunohistochemical study

The present study aimed to evaluate the role of rivastigmine against the effect of a single unilateral botulinum toxin-A (BTX-A) injection on the bone and bone marrow of adult albino rats 4 weeks after injection. Twenty-four Wistar albino rats were divided into four equal groups: group I, which received distilled water; group II, which received rivastigmine (0.3 mg/kg daily, intraperitoneally for 4 weeks); group III, which received BTX-A (4 IU in 0.2 mL physiological saline) single dose, intramuscularly; and group IV, which received BTX-A + rivastigmine. The results revealed that BTX-A induced a significant decrease in the calcium level with a significant increase in the phosphorus, alkaline phosphatase, C-reactive protein, and tumor necrosis factor α levels in serum. Furthermore, a significant increase in malondialdehyde with a significant decrease in reduced glutathione activities in both bone and bone marrow. Histologically, a distortion and thinning out of the compact bone and trabeculae of cancellous bone of the rat femur in the BTX-A group with an increase in adipocytes in adjacent bone marrow were detected. Immunohistochemically, Cluster of Differentiation 68 (CD68) showed a significant increase in both osteoclasts and bone marrow macrophage. Rivastigmine treatment could relieve the toxic effects induced by BTX-A. In conclusion, rivastigmine has a protective effect against the hazardous effects of BTX-A on bone and bone marrow.