Wenna Liang

Icariin promotes bone formation via the BMP-2/Smad4 signal transduction pathway in the hFOB 1.19 human osteoblastic cell line.

Icariin, the main active compound of the traditional Chinese medicine, Epimedium, is commonly used for the clinical treatment of osteoporosis. However, the precise molecular mechanism of the therapeutic effect of icariin has not been elucidated. The aim of this study was to examine the effect of icariin on cell viability, alkaline phosphatase (ALP) activity, the amount of calcified nodules, and to delineate the molecular mechanism of icariin-enhanced bone formation by investigating the expression of bone morphogenic protein-2 (BMP-2), Smad4, Cbfa1/Runx2, osteoprotegerin (OPG), receptor activator of nuclear factor κ-B ligand (RANKL) and the OPG/RANKL ratio in the hFOB 1.19 human osteoblastic cell line. We found that icariin significantly increased the cell viability, the activity of ALP and the amount of calcified nodules in the hFOB 1.19 cells. Furthermore, we observed that icariin upregulated the expression of BMP-2, Smad4, Cbfa1/Runx2, OPG, RANKL and the OPG/RANKL ratio. Our results indicate that icariin can modulate the process of bone formation via the BMP-2/Smad4 signal transduction pathway in hFOB 1.19 cells.

Quercetin-mediated apoptosis via activation of the mitochondrial-dependent pathway in MG-63 osteosarcoma cells

Quercetin (a natural polyphenolic compound) is a polyphenolic flavonoid compound found in a variety of plants. It has been demonstrated to exert cytostatic activity against a variety of human cancer cell lines, including the human osteosarcoma cell line, MG-63. However, its effects on osteosarcoma cell apoptosis are still undefined. The present study was undertaken to examine the effect of quercetin on cell viability, apoptosis and mitochondrial membrane potential, and to determine the molecular mechanism of quercetin-induced apoptosis by investigating the expression of Bcl-2 family proteins (Bcl-2, Bax), cytochrome C, caspase-9 and caspase-3 in MG-63 cells. We found that quercetin suppressed the viability of MG-63 cells in a dose- and time- dependent manner. Furthermore, we observed that quercetin induced the loss of mitochondrial membrane potential, upregulated the expression of the proapoptotic proteins, Bax and cytochrome C, and activated caspase-9 and caspase-3, and downregulated the expression of antiapoptotic protein, Bcl-2. These data suggest that quercetin may induce apoptosis via the mitochondrial-dependent pathway in MG-63 cells.

Gallic acid induces apoptosis and inhibits cell migration by upregulating miR-518b in SW1353 human chondrosarcoma cells.

Gallic acid (GA), a natural agent, is widely distri-buted in plants with a range of biological effects and has been of potential interest as anticancer agent. However, its effects on chondrosarcoma cell apoptosis are still undefined. In the present study, the possible mechanisms of GA-induced apoptosis were explored in SW1353 cells, a human chondrosarcoma cell line. Our results showed that GA inhibited cell viability dose- and time-dependently. Morphological examination of GA-treated cells exhibited the typical features of cell death, such as rounding up of the cells and cell shrinkage. Wound-healing assay indicated that GA inhibited the migratory abilities of SW1353 cells. Hoechst 33258 staining assay and Annexin V/PI staining assay exhibited apoptosis induction by GA. To determine the molecular mechanism of GA-induced apoptosis, the expression levels Bcl-2, Bax, caspase-3 and caspase-9 were determined in SW1353 cells treated with GA. We found that GA downregulated the expression of the anti-apoptotic protein Bcl-2, and upregulated the expression of the pro-apoptotic protein Bax, and the activation of caspase-3 and caspase-9. To identify the possible mechanisms, the changes of microRNA expression were tested using the miRCURY™ LNA expression array. It was observed that the miR-518b gene was upregulated in treated cells. Taken together, these data show that GA induces apoptosis and inhibits cell migration by upregulating miR-518b in SW1353 cells.

Overexpression of Shox2 Leads to Congenital Dysplasia of the Temporomandibular Joint in Mice

Our previous study reported that inactivation of Shox2 led to dysplasia and ankylosis of the temporomandibular joint (TMJ), and that replacing Shox2 with human Shox partially rescued the phenotype with a prematurely worn out articular disc. However, the mechanisms of Shox2 activity in TMJ development remain to be elucidated. In this study, we investigated the molecular and cellular basis for the congenital dysplasia of TMJ in Wnt1-Cre; pMes-stop Shox2 mice. We found that condyle and glenoid fossa dysplasia occurs primarily in the second week after the birth. The dysplastic TMJ of Wnt1-Cre; pMes-stop Shox2 mice exhibits a loss of Collagen type I, Collagen type II, Ihh and Gli2. In situ zymography and immunohistochemistry further demonstrate an up-regulation of matrix metalloproteinases (MMPs), MMP9 and MMP13, accompanied by a significantly increased cell apoptosis. In addition, the cell proliferation and expressions of Sox9, Runx2 and Ihh are no different in the embryonic TMJ between the wild type and mutant mice. Our results show that overexpression of Shox2 leads to the loss of extracellular matrix and the increase of cell apoptosis in TMJ dysplasia by up-regulating MMPs and down-regulating the Ihh signaling pathway.

Observing the development of the temporomandibular joint in embryonic and post-natal mice using various staining methods

The temporomandibular joint (TMJ) is a specialized synovial joint that is essential for the movement and function of the mammalian jaw. The TMJ develops from two mesenchymal condensations, and is composed of the glenoid fossa that originates from the otic capsule by intramembranous ossification, the mandibular condyle of the temporal bone and a fibrocartilagenous articular disc derived from a secondary cartilaginous joint by endochondral ossification. However, the development of the TMJ remains unclear. In the present study, the formation and development of the mouse TMJ was investigated between embryonic day 13.5 and post-natal day 180 in order to elucidate the morphological and molecular alterations that occur during this period. TMJ formation appeared to proceed in three stages: Initiation or blastema stage; growth and cavitation stage; and the maturation or completion stage. In order to investigate the activity of certain transcription factors on TMJ formation and development, the expression of extracellular matrix (ECM), sex determining region Y-box 9, runt-related transcription factor 2, Indian hedgehog homolog, Osterix, collagen I, collagen II, aggrecan, total matrix metalloproteinase (MMP), MMP-9 and MMP-13 were detected in the TMJ using in situ and/or immunohistochemistry. The results indicate that the transcription factors, ECM and MMP serve critical functions in the formation and development of the mouse TMJ. In summary, the development of the mouse TMJ was investigated, and the molecular regulation of mouse TMJ formation was partially characterized. The results of the present study may aid the systematic understanding of the physiological processes underlying TMJ formation and development in mice.

Tongue coating microbiome regulates the changes in tongue texture and coating in patients with post-menopausal osteoporosis of Gan-shen deficiency syndrome type

Tongue inspection is a unique and important method of diagnosis in traditional Chinese medicine (TCM). It is a diagnostic approach which involves observing the changes in the tongue proper and tongue coating in order to understand the physiological functions and pathological changes of the body. However, the biological basis of TCM tongue diagnosis remains to be poorly understood and lacks systematic investigation at the molecular level. In this study, we evaluated the effects of tongue coating microbiome on changes in the tongue texture and coating in patients with post-menopausal osteoporosis (PMO) of Gan‑shen deficiency syndrome type. Our aim was to delineate the mechanisms of tongue coating microbiome-induced changes in the tongue texture and coating by investigating the histomorphological changes and performing a bacterial analysis of the tongue coating. We found that the number of intermediate cells in the red tongue with a thin coating was higher, while the number of superficial cells in the red tongue with a thin coating was lower. The maturation value (MV) of tongue exfoliated cells in the red tongue with a thin coating decreased, compared with that in the pale red tongue with a thin white coating. Furthermore, the total bacterial count, oral streptococcus, Gram‑positive (G+) and Gram‑negative (G-) anaerobic bacteria in the red tongue with a thin coating was significantly decreased compared with the pale red tongue with a thin white coating. The results of ultrastructural examination demonstrated that the number of epithelial cells and bacteria in the red tongue with a thin coating decreased compared with that in the pale red tongue with a thin white coating. These observations indicate that the tongue coating microbiome may be an important factor contributing to changes in the tongue in patients with PMO of Gan‑shen deficiency syndrome type.

Bushen Zhuangjin Decoction promotes chondrocyte proliferation by stimulating cell cycle progression

Bushen Zhuangjin Decoction (BZD), a well-known formulation in Traditional Chinese Medicine, has been widely used for the treatment of osteoarthritis (OA). Due to the poor intrinsic repair capacity of chondrocytes, promoting the proliferation of chondrocytes is an efficient treatment to delay the progression of cartilage degradation. The present study, therefore, focused on the effect of BZD on chondrocyte proliferation, exploring the mechanism of BZD on the inhibition of cartilage degradation. Chondrocytes isolated from the knee articular cartilage of Sprague Dawley rats were cultured and identified by type II collagen immunohistochemistry. It was found that BZD promoted chondrocyte viability in a dose- and time-dependent manner. To investigate if BZD promoted the chondrocyte viability by stimulating the cell cycle progression a flow cytometer was used, and the results showed that the percentage proportion of G0/G1 cells was significantly lower, and the percentage proportion of S cells was significantly higher, in treated cells compared with that in untreated cells. To gain insight into the mechanism underlying the effect of BZD on the cell cycle progression, the mRNA and protein expression of cyclin D1, cyclin-dependent kinase 4 (CDK4), CDK6 and p21 was measured by reverse transcription-polymerase chain reaction and western blotting, respectively. The mRNA and protein expression of cyclin D1, CDK4 and CDK6 in the BZD-treated chondrocytes was significantly upregulated, while the mRNA and protein expression of p21 was significantly downregulated, compared with that in the untreated chondrocytes. These results suggested that BZD promoted chondrocyte proliferation by accelerating G1/S transition, indicating that BZD is a potential therapeutic agent for the treatment of OA.

Needle-knife therapy improves the clinical symptoms of knee osteoarthritis by inhibiting the expression of inflammatory cytokines

Knee osteoarthritis (KOA) is a degenerative joint disease that occurs mainly in the elderly population. However, there are currently no effective treatments for treating this condition. In this study, the efficacy of needle-knife therapy, a technique of traditional Chinese medicine that has been widely used to treat KOA was investigated. Patients (n=170) with KOA were randomly divided for needle-knife therapy (treatment group) and acupuncture therapy (control group). Outcome evaluation included stiffness, pain, physiological function, overall changes, total symptom score, clinical curative effects and the concentrations of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) in the synovial fluid. The trial was completed in 151 patients (233 knees) from a total of 170 patients (264 knees); the treatment group comprised 76 patients (117 knees) who completed the trial and 9 patients (14 knees) who were removed from the study, and the control group comprised 75 patients (116 knees) who completed the trial and 10 patients (17 knees) who were removed from the study. The symptom scores of KOA in stages I–IV were reduced significantly in the treatment group and those of stages I–III were decreased significantly in the control group. The effective rate of the KOA therapy in the patients of stages III and IV in the treatment group was significantly higher than that in the control group. After treatment, the decrements of IL-1β, IL-6 and TNF-α in the treatment group were greater than those in the control group. These results showed that the use of needle-knife therapy to treat KOA effectively improved the clinical symptoms by inhibiting the expression of inflammatory cytokines.

Tougu Xiaotong capsule promotes chondrocyte autophagy by regulating the Atg12/LC3 conjugation systems.

We have previously reported that Tougu Xiaotong capsule (TXC) inhibits tidemark replication and cartilage degradation by regulating chondrocyte autophagy in vivo. Autophagy, a cell protective mechanism for maintaining cellular homeostasis, has been shown to be a constitutively active and protective process for chondrocyte survival. However, it remains unclear whether TXC promotes chondrocyte autophagy by regulating the autophagy-related (Atg)12/microtubule-associated protein 1 light chain 3 (LC3) conjugation systems. Thus, in the present study, we investigated the effects of TXC on primary chondrocytes treated with cobalt chloride (CoCl2). We found that CoCl2 induced a decrease in chondrocyte viability and the autophagosome formation of chondrocytes, indicating that CoCl2 induced autophagic death in a dose- and time-dependent manner. To determine the effects of TXC on CoCl2-exposed chondrocytes, we assessed cell viability by MTT assay. Our results revealed that TXC enhanced the viability of CoCl2-exposed chondrocytes. To gain insight into the mechanisms responsible for the enhancing effects of TXC on CoCl2-exposed chondrocytes, the expression of Atg genes was assessed in chondrocytes exposed to CoCl2 and treated with or without TXC. The results revealed that the expression of beclin 1, Atg3, Atg5, Atg7, Atg10, Atg12 and LC3 II/LC3 I in the chondrocytes treated with TXC increased, compared to that in the untreated chondrocytes. In addition, ultrastructural analysis indicated that treated chondrocytes contained more autophagosomes than the untreated cells, suggesting that TXC increased the formation of autophagosomes in the chondrocytes to clear the CoCl2-induced autophagic death. Therefore, these data suggest that TXC is a potential therapeutic agent for the reduction of cartilage degradation that occurs in osteoarthritis.

Expressing human SHOX in Shox2SHOX KI/KI mice leads to congenital osteoarthritis‑like disease of the temporomandibular joint in postnatal mice

The temporomandibular joint (TMJ), a unique synovial joint whose development differs from that of other synovial joints, develops from two distinct mesenchymal condensations that grow toward each other and ossify through different mechanisms. The short stature homeobox 2 (Shox2) gene serves an important role in TMJ development and previous studies have demonstrated that Shox2SHOX KI/KI mice display a TMJ defective phenotype, congenital dysplasia and premature eroding of the articular disc, which is clinically defined as a TMJ disorder. In the present study, Shox2SHOX KI/KI mouse models were used to investigate the mechanisms of congenital osteoarthritis (OA)-like disease during postnatal TMJ growth. Shox2SHOX KI/KI mice were observed to develop a severe muscle wasting syndrome from day 7 postnatal. Histological examination indicated that the condyle and glenoid fossa of Shox2SHOX KI/KI mice was reduced in size in the second week after birth. The condyles of Shox2SHOX KI/KI mice exhibited reduced expression levels of collagen type II and Indian hedgehog, and increased expression of collagen type I. A marked increase in matrix metalloproteinase 9 (MMP9) and MMP13 in the condyles was also observed. These cellular and molecular defects may contribute to the observed (OA)-like phenotype of Shox2SHOX KI/KI mouse TMJs.