Search

Osteoporosis is a common disorder characterized by decreased bone mineral density (BMD) and increased fracture risk. The current techniques detect real‑time BMD precisely but do not provide adequate information to predict early bone loss. If bone loss could be diagnosed and predicted early, severe osteoporosis and unexpected fractures could be prevented, allowing for an improved quality of life for individuals. In the present study, an ovariectomized rat model of bone loss was established and the serum levels of 78 potential cytokines were determined using a protein array. The BMD of ovariectomized rats was dynamically measured by micro‑CT and the early stage of bone loss was defined at the fourth week after surgery. The expression of several serum protein cytokines was indicated to be altered in the ovariectomized rats during an 8‑week time‑course of bone loss. Linear regression analysis revealed that the serum levels of C‑C motif chemokine ligand 2 (CCL2, also known as monocyte chemoattractant protein 1) and C‑X‑C motif chemokine ligand 1 (CXCL1) were significantly associated with a reduction in BMD. The significance of these two factors in indicating bone mass reduction was further verified by analyzing serum samples from 24 patients with BMD using ELISA and performing a linear regression analysis. The serum levels of CCL2 and CXCL1 were inversely correlated with the bone mass. Therefore, the cytokines CCL2 and CXCL1 may be potential novel predictors of early bone loss and may be clinically relevant for the early diagnosis and prevention of osteoporosis.

Postmenopausal osteoporosis is one of the most prominent worldwide public health problems and the morbidity is increasing with the aging population. It has been demonstrated that early diagnosis and intervention delay the disease progression and improve the outcome. Therefore, searching for biomarkers that are able to identify postmenopausal women at high risk for developing osteoporosis is an effective way to improve the quality of life of patients, and alleviate social and economic burdens. In the present study, a protein array was used to identify potential biomarkers. The bone mineral densities of 10 rats were dynamically measured in an ovariectomized model by micro‑computed tomography assessment, and the early stage of osteoporosis was defined. Through the protein array‑based screening, the expression levels of six serum protein biomarkers in ovariectomized rats were observed to alter at the initiation stage of the postmenopausal osteoporosis. Fractalkine, tissue inhibitor of metalloproteinases‑1 and monocyte chemotactic protein‑1 were finally demonstrated to be increased in the serum of eight enrolled postmenopausal osteoporosis patients using ELISA assay and were correlated with the severity of progressive bone loss. These biomarkers may be explored as potential early biomarkers to readily evaluate and diagnose postmenopausal osteoporosis in the clinic.

Long‑term glucocorticoid therapy results in various side effects, including a high incidence of glucocorticoid‑induced osteoporosis (GIOP), which is the most common form of secondary osteoporosis. Excess glucocorticoids reduce the viability of bone marrow‑derived mesenchymal stem cells (BMSCs) and prolong osteoclast survival. These two types of cell are essential in the balance between bone formation and resorption. Tetramethylpyrazine (TMP), the pharmacologically active component extracted from Chuanxiong, has been reported to protect BMSCs from glucocorticoid‑induced apoptosis. In the present study, the protective effects of TMP on BMSC differentiation and osteoclasts maturation in GIOP were investigated in vivo and in vitro. The immunostaining of osterix (OSX) and tartrate‑resistant acid phosphatase (TRAP) staining indicated that TMP promoted osteogenesis and inhibited osteoclastogenesis in a rat model of GIOP. Treatment with 10‑6 M dexamethasone (Dex) significantly inhibited BMSC differentiation and increased TRAP‑positive cells in vitro. However, different concentrations of TMP (50, 100 and 200 µM) ameliorated the negative effects of Dex by promoting the activity of alkaline phosphatase (ALP) and the calcium mineralization of BMSCs following osteogenic induction, which increased the expression levels of osteogenic genes, including ALP, collagen type I α1, osteocalcin and OSX, and decreased osteoclastogenesis‑related genes, including TRAP, nuclear factor of T‑cells cytoplasmic 1 and cathepsin K. In addition, it was found that the inhibition of receptor activator of nuclear factor‑κB ligand and intereleukin‑6 in BMSCs may be a possible mechanism for the protective effects of TMP against glucocorticoid‑induced osteoclastogenesis. These results are the first, to the best of our knowledge, to demonstrate that TMP promotes BMSC differentiation and inhibits osteoclastogenesis to ameliorate bone mass change in GIOP.

Panax notoginseng saponins (PNS) are among the most important compounds extracted from Panax notoginseng root, and have long been used in traditional Chinese medicine to control bleeding. PNS have recently garnered attention for the treatment of circulatory system diseases. The present study aimed to evaluate the effects of PNS on angiogenesis in vitro and to explore the molecular mechanisms underlying their actions. The present results demonstrated that the proliferative ability of human umbilical vein endothelial cells (HUVECs) was augmented following treatment with PNS. In addition, wound healing and Boyden chamber assays indicated that PNS may enhance HUVEC motility and increase the number of capillary‑like tube branches in HUVECs. These effects were suppressed by 5' adenosine monophosphate‑activated protein kinase (AMPK) and endothelial nitric oxide synthase (eNOS) inhibitors. Furthermore, western blot analysis demonstrated that PNS stimulated the phosphorylation of AMPK and eNOS at Thr‑172 and Ser‑1179, respectively. These results suggested that PNS may promote tube formation in endothelial cells through AMPK‑ and eNOS‑dependent signaling pathways.

The present study aimed to identify the genetic mutations in two families affected with congenital cataracts. Detailed family histories and clinical data of the family members were recorded. The family members with affected phenotypes were recruited, and candidate gene sequencing was performed to determine the disease‑causing mutation. Bioinformatics analysis was performed to predict the function of the mutant gene. Green fluorescent protein‑tagged human wild‑type CRYAA and GJA8 were sub‑cloned, and the mutants were generated by site‑directed mutagenesis. A novel mutation, c.416T>C (p.L139P), in CRYAA and a known mutation, c.139G>A (p.D47N), in GJA8 were identified. These mutations co‑segregated with all affected individuals in each family and were not observed in the unaffected family members or in unrelated controls. The results of the bioinformatics analysis indicated that the amino acid at position 139 was highly conserved and that the p.L139P mutation was predicted to be damaging, as with p.D47N. Finally, overexpression of the two mutants revealed marked alterations, compared with the wild‑type proteins. These results extend the mutation spectrum of CRYAA and provides further evidence that the p.D47N mutation in GJA8 is a hot-spot mutation.

The regressive biological function of human bone marrow‑derived mesenchymal stem cells (hBMSCs) is one of the key factors resulting in the decrease of bone mass in senile osteoporosis. MicroRNAs (miRs) are non‑coding small RNAs involved in various gene regulation processes. Whether any miR(s) are involved in the progression of osteoporosis by regulating the biological function of hBMSCs remains to be elucidated. The present study aimed to compare the expression levels of miR‑125b in hBMSCs derived from senile osteoporotic patients with that of control (normal) subjects. A significantly upregulated expression of miR‑125b in osteoporotic hBMSCs was detected. To elucidate the biological function of miR‑125b in senile osteoporosis, the effects of miR‑125b expression on proliferation and osteogenic differentiation of hBMSCs were assessed using gain‑ and loss‑of‑function studies. It was evident that the overexpression of a miR‑125b mimic was able to suppress the proliferative and osteogenic differentiation of senile hBMSCs. In contrast, repression of the function of miR‑125b by transfection of an miR‑125b inhibitor promoted the proliferation and osteogenic differentiation of hBMSCs. Furthermore, the potential target gene of miR‑125b, osterix (Osx), was examined. The results of the present study strongly suggested that miR‑125b may regulate osteogenic differentiation of hBMSCs through the modulation of Osx expression.