SRY-related High Mobility Group-box Gene Research Articles

Hypoxia-induced Wnt/β-catenin signaling activation in subchondral bone osteoblasts leads to an osteoarthritis-like phenotype of chondrocytes in articular cartilage.

Background: Osteoarthritis (OA) is a whole-joint disease and characterized by alterations in the articular cartilage, subchondral bone, ligaments, and synovial membrane. The crosstalk between cartilage and subchondral bone plays a crucial role in the pathogenesis and progression of OA. Hypoxia has been reported to play an important role in cartilage degradation and subchondral bone remodeling in OA. In this study, we aimed to identify the involvement of hypoxia in modifying the osteoblast phenotypes and determine whether these alterations could influence the metabolism of chondrocytes. Methods: First, the levels of Hif-1α in subchondral bone of different compartments in patients with OA were assessed using immunohistochemistry (IHC). In in vitro, human primary osteoblasts were cultured under hypoxic and normoxic conditions, and the hypoxic or normoxic conditioned media (HCM and NCM) were used to culture human primary chondrocytes. Then, phenotypic changes in osteoblasts were assessed using reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, and enzyme-linked immunosorbent assay (ELISA). Furthermore, the expression of type II collagen (COL2A1), aggrecan (ACAN), SRY-related high-mobility group-box gene 9 (SOX9), matrix metalloproteinase 13 (MMP13), and matrix metalloproteinase 3 (MMP3) in chondrocytes was measured using RT-PCR. Finally, the serum levels of Wnt-related proteins were determined using ELISA. Results: Hif-1α was significantly increased in severely sclerotic subchondral bone compared to less damaged subchondral bone. β-Catenin and SOST were identified as upregulated and downregulated in hypoxic osteoblasts, respectively. The hypoxia-induced results were confirmed by ELISA. Stimulating human primary chondrocytes with HCM significantly induced MMP13 and MMP3 and inhibited COL2A1, ACAN, and SOX9 mRNA expression. The serum levels of DKK-1 were significantly increased in human OA. Conclusion: Together, these findings revealed that hypoxia in subchondral bone is a key factor in the crosstalk between chondrocytes and osteoblasts and facilitates the shift of chondrocytes toward an OA-like phenotype probably by activating the Wnt/β-catenin signaling pathway in osteoblasts.

Circular RNA_0000326 accelerates breast cancer development via modulation of the miR-9-3p/YAP1 axis.

Circular RNA (circ)_0000326 has been reported in bladder cancer and cervical cancer and is concerned to be involved with the development of cancerous cells. Whereas, there have been no reports concentrating on the influences of circ_0000326 in breast cancer (BC). Therefore, the latent modulatory mechanisms of circ_0000326 in BC are researched. circ_0000326 expression in BC tissues and correlative cells was evaluated via RT-qPCR, and the relevance between circ_0000326 expression and overall survival and the clinicopathological feature was also investigated. After a series of transfection, the effects of circ_0000326, microRNA-9-3p (miR-9-3p), and Yes-associated protein 1 (YAP1) in BC cell growth, invasion, and stemness were studied by CCK-8, flow cytometry, Transwell, and sphere-forming assays. The binding sites and correlation of circ_0000326, miR-9-3p, and YAP1 were certified via starBase website, luciferase reporter assay, and Pearson's χ2 test. The in vivo experiment was evaluated by establishing a subcutaneous tumorigenesis model. High-expressed circ_0000326 in BC tissues and cells was discovered, which was connected with an undesirable prognosis. Silencing of circ_0000326 visibly inhibited MCF-7 and BT549 cell growth, invasion, stemness, meanwhile declining the protein levels of SRY-related high-mobility group box gene 2 (SOX2) and octamer binding transcription factor 4 (OCT4). miR-9-3p was a sponger of circ_0000326, which was negatively regulated by circ_0000326. Moreover, YAP1 was confirmed as a target gene of miR-9-3p. circ_0000326 affected BC cell behaviors via mediating miR-9-3p and YAP1. Furthermore, circ_0000326 silencing prohibited tumor growth of BC in vivo. The research uncovered that circ_0000326 facilitated BC development via mediating the miR-9-3p/YAP1 axis.

Bellidifolin Inhibits SRY-Related High Mobility Group-Box Gene 9 to Block TGF-β Signalling Activation to Ameliorate Myocardial Fibrosis.

Myocardial fibrosis is the main morphological change of ventricular remodelling caused by cardiovascular diseases, mainly manifested due to the excessive production of collagen proteins. SRY-related high mobility group-box gene 9 (SOX9) is a new target regulating myocardial fibrosis. Bellidifolin (BEL), the active component of G. acuta, can prevent heart damage. However, it is unclear whether BEL can regulate SOX9 to alleviate myocardial fibrosis. The mice were subjected to isoproterenol (ISO) to establish myocardial fibrosis, and human myocardial fibroblasts (HCFs) were activated by TGF-β1 in the present study. The pathological changes of cardiac tissue were observed by HE staining. Masson staining was applied to reveal the collagen deposition in the heart. The measurement for expression of fibrosis-related proteins, SOX9, and TGF-β1 signalling molecules adopted Western blot and immunohistochemistry. The effects of BEL on HCFs, activity were detected by CCK-8. The result showed that BEL did not affect cell viability. And, the data indicated that BEL inhibited the elevations in α-SMA, Collagen I, and Collagen III by decreasing SOX9 expression. Additionally, SOX9 suppression by siRNA downregulated the TGF-β1 expression and prevented Smad3 phosphorylation, as supported by reducing the expression of α-SMA, Collagen I, and Collagen III. In vivo study verified that BEL ameliorated myocardial fibrosis by inhibiting SOX9. Therefore, BEL inhibited SOX9 to block TGF-β1 signalling activation to ameliorate myocardial fibrosis.

Development of the nervous system in mouse liver

BACKGROUNDThe role of the hepatic nervous system in liver development remains unclear. We previously created functional human micro-hepatic tissue in mice by co-culturing human hepatic endodermal cells with endothelial and mesenchymal cells. However, they lacked Glisson’s sheath [the portal tract (PT)]. The PT consists of branches of the hepatic artery (HA), portal vein, and intrahepatic bile duct (IHBD), collectively called the portal triad, together with autonomic nerves.AIMTo evaluate the development of the mouse hepatic nervous network in the PT using immunohistochemistry.METHODSLiver samples from C57BL/6J mice were harvested at different developmental time periods, from embryonic day (E) 10.5 to postnatal day (P) 56. Thin sections of the surface cut through the hepatic hilus were examined using protein gene product 9.5 (PGP9.5) and cytokeratin 19 (CK19) antibodies, markers of nerve fibers (NFs), and biliary epithelial cells (BECs), respectively. The numbers of NFs and IHBDs were separately counted in a PT around the hepatic hilus (center) and the peripheral area (periphery) of the liver, comparing the average values between the center and the periphery at each developmental stage. NF-IHBD and NF-HA contacts in a PT were counted, and their relationship was quantified. SRY-related high mobility group-box gene 9 (SOX9), another BEC marker; hepatocyte nuclear factor 4α (HNF4α), a marker of hepatocytes; and Jagged-1, a Notch ligand, were also immunostained to observe the PT development.RESULTSHNF4α was expressed in the nucleus, and Jagged-1 was diffusely positive in the primitive liver at E10.5; however, the PGP9.5 and CK19 were negative in the fetal liver. SOX9-positive cells were scattered in the periportal area in the liver at E12.5. The Jagged-1 was mainly expressed in the periportal tissue, and the number of SOX9-positive cells increased at E16.5. SOX9-positive cells constructed the ductal plate and primitive IHBDs mainly at the center, and SOX-9-positive IHBDs partly acquired CK19 positivity at the same period. PGP9.5-positive bodies were first found at E16.5 and HAs were first found at P0 in the periportal tissue of the center. Therefore, primitive PT structures were first constructed at P0 in the center. Along with remodeling of the periportal tissue, the number of CK19-positive IHBDs and PGP9.5-positive NFs gradually increased, and PTs were also formed in the periphery until P5. The numbers of NFs and IHBDs were significantly higher in the center than in the periphery from E16.5 to P5. The numbers of NFs and IHBDs reached the adult level at P28, with decreased differences between the center and periphery. NFs associated more frequently with HAs than IHBDs in PTs at the early phase after birth, after which the number of NF-IHBD contacts gradually increased.CONCLUSIONMouse hepatic NFs first emerge at the center just before birth and extend toward the periphery. The interaction between NFs and IHBDs or HAs plays important roles in the morphogenesis of PT structure.

Etomidate ameliorated advanced glycation end-products (AGEs)-induced reduction of extracellular matrix genes expression in chondrocytes

ABSTRACT Osteoarthritis (OA) is a rheumatic disease common in the elderly. AGEs are the end products of glycation reactions and play an important role in the development of OA. Etomidate is a general anesthesia-inducing agent recently reported to exert significant anti-inflammatory effects. The present study aims to explore the protective effect of Etomidate against advanced glycation end-products (AGEs)-induced reduction of extracellular matrix gene expression in chondrocytes. In the present study, we found that AGEs significantly reduced the expression of Collagen II (COL2A1) and Aggrecan (ACAN) at the gene level. Furthermore, AGEs inhibited the expression of SRY-related high mobility group-box gene 9 (SOX-9), promoting the expression of COL2A1 and ACAN. COL2A1, ACAN, and SOX-9 in chondrocytes were significantly elevated by treatment with Etomidate alone. Consistently, Etomidate ameliorated AGEs-induced downregulation of COL2A1, ACAN, and SOX-9 in a dose-dependent manner. Importantly, we found that knockdown of SOX-9 eliminated the beneficial effects of Etomidate against AGEs-induced decrease in COL2A1 and ACAN genes. Based on these findings, we demonstrated that Etomidate could ameliorate AGEs-induced reduction of extracellular matrix gene expression in chondrocytes by upregulating SOX-9.

MicroRNA-30e up-regulation alleviates myocardial ischemia-reperfusion injury and promotes ventricular remodeling via SOX9 repression

AimAt present, studies have focused on microRNAs (miRNAs) in myocardial ischemia-reperfusion injury (MI/RI). But the specific role of miR-30e hasn’t been fully explored. Thus, this study is to uncover the mechanism of miR-30e in MI/RI. MethodsMI/RI models of rats and hypoxia/reoxygenation injury (H/R) models of H9C2 cardiomyocytes were established. Rats were injected with miR-30e and SRY-related high mobility group-box gene 9 (SOX9)-related oligonucleotides or vectors to explore their roles in MI/RI. H9C2 cardiomyocytes were transfected with restored miR-30e and depleted SOX9 to decipher their function in H/R injury. miR-30e and SOX9 expression in myocardial tissues and cardiomyocytes were detected. Online website prediction and luciferase activity assay were applied to validate the targeting relationship between miR-30e and SOX9. ResultsDecreased miR-30e and increased SOX9 were found in myocardial tissues of MI/RI rats and H/R-treated cardiomyocytes. miR-30e targeted SOX9. miR-30e up-regulation or SOX9 down-regulation reduced cardiac function damage and suppressed oxidative stress, inflammation, cardiomyocyte apoptosis and myocardial enzymes in myocardial tissues of MI/RI rats. Restoring miR-30e or silencing SOX9 energized cell viability and inhibited apoptosis of H/R-treated cardiomyocytes. Down-regulating SOX9 reversed the effects of miR-30e down-regulation on myocardial injury, ventricular remodeling, cardiomyocyte damage and apoptosis in MI/RI. ConclusionIt is concluded that miR-30e elevation alleviated cardiac function damage and promoted ventricular remodeling via SOX9 repression.

Synovial mesenchymal stem cells effectively alleviate osteoarthritis through promoting the proliferation and differentiation of meniscus chondrocytes.

To investigate the relationship between the meniscal defect area and OA progression and explore the effect and mechanism of SMSCs cell therapy in knee osteoarthritis (OA) rat model. For animal experiments, knee osteoarthritis (OA) model was constructed in Sprague Dawley (SD) rats by removing the medial meniscus of the right knee. Synovial mesenchymal stem cells (SMSCs) were engrafted by injecting into the right knee cavity. For in vitro experiments, CCK-8 assay was performed to evaluate the proliferation and differentiation of BMSCs and ATDC5 cells after co-cultured with SMSCs. qRT-PCR analysis was performed to detect the expressions of chondrogenic genes in BMSCs and ATDC5 cells after co-cultured with SMSCs. Western blot analysis was conducted to detect the phosphorylations of c-Jun N-terminal kinase (JNK) and extracellular regulated protein kinases (ERK) in MAPK signaling of BMSCs and ATDC5 cells. Enzyme-linked immunosorbent assay (ELISA) was performed to detect the serum levels of interleukin (IL)-1β, IL-1β, IL-6, IL-18 and C-reactive protein (CRP). Results showed that meniscus damaged area is positively correlated to serum inflammatory factor levels. In vitro study showed that the proliferation and differentiation of BMSCs and ATDC5 cells were promoted after co-cultured with SMSCs. By co-culturing with SMSCs, the MAPK signaling pathway was activated and the expression of chondrogenic markers such as aggrecan (acan), SRY-related high mobility group-box gene 9 (sox9) and Type II collagen a1 (col2a1), was up-regulated both in BMSCs and ATDC5 cells. In vivo study showed SMSCs cell therapy significantly decreased serum inflammatory factor levels and protected cartilage by upregulating the expression of chondrogenic genes of meniscus chondrocytes derived from OA rats. For the first time, we found the positive correlation between meniscal defect area and OA progression and demonstrated the effect and mechanism of SMSCs cell therapy in knee osteoarthritis (OA) treatment.

Late-onset vanishing testis-like syndrome in a 38,XX/38,XY agonadic pig (Sus scrofa).

Here we describe the case of a pig with intersex traits including ambiguous external genitalia, sex chromosome abnormalities and a late-onset vanishing testis-like syndrome. It was identified shortly after birth by presenting a predominantly female phenotype with two large scrotal masses resembling testes. The karyotype is 38,XX (53%)/38,XY (47%). Sex steroid levels were undetectable at 1 and 7 months old, whereas circulating cortisol levels were typical. DNA studies excluded gene alterations in sex-determining region Y (SRY), dosage-sensitive sex reversal-congenital adrenal hypoplasia critical region on the X chromosome protein 1 (DAX1), SRY-related high mobility group-box gene 9 (SOX9), nuclear receptor subfamily 5, group a, member 1 (NR5A1), nuclear receptor subfamily 3, group c, member 4 (NR3C4) and steroid 5-alpha-reductase 2 (SRD5A2). At 8 months of age the XX/XY pig evinced delayed growth; however, the most striking phenotypic change was that the testes-like structures completely vanished in a 2-3-week period. The internal genitalia were found to consist of a portion of a vagina and urethra. No fallopian tubes, uterus or remnants of Wolffian derivatives were observed. More importantly, no testes, ovaries, ovotestis or gonadal streaks could be identified. The XX/XY sex chromosome dosage and/or overexpression of the DAX1 gene on the X chromosome in the presence of a wild-type SRY gene may have caused this predominantly female phenotype. This specimen represents an atypical case of 38,XX/38,XY chimeric, ovotesticular disorder of sex development associated with agonadism.

Molecular mechanism of Wnt pathway in regulating osteogenic and chondrogenic differentiation of adipose stem cells

Objective To explore the mechanism of Wingless-type MMTV integration site family (Wnt) pathway and SRY-related high mobility group-box gene 9 (Sox9) and Bone morphogenetic protein 2 (BMP-2) feedback regulation in regulating chondrogenic and osteogenic differentiation of adipose-derived stem cells (ADSCs). Methods The cartilage and osteogenic differentiation of ADSCs were stimulated by Lithium Chloride (LiCl) and Dickkopf related protein 1 (DKK-1). The markers of cartilage and osteogenic differentiation Collagen2a, Aggrecan, Core binding factor alphal 1 (Runx2), wingless-type MMTV integration site family, member 5A (Wnt5a) and Wnt pathway key proteins Sox9, BMP-2, β-catenin, Glycogen synthase kinase-3β (GSK-3β) were detected in early, middle and late stages. The full-length gene sequences of Sox9 and BMP-2 were transfected into ADSCs by lentivirus, respectively, then the expression levels of various indexes were detected again while stably expressed. Apply SPSS 20.0 statistical software for analysis and explore molecular mechanisms. Results During the cartilage differentiation of ADSCs, the Wnt pathway promotes its rapid proliferation and induces chondrogenic differentiation in the early and middle stages. The expression of Collagen 2a and Aggrecan was not significantly increased in the early, while significantly increased in the middle and late stages (t=1.484, 0.792, 8.598, 8.788, 3.333, 8.285, P 0.05). The expression of Runx2 was significantly increased in the middle and late stages (t=13.452, 12.148, 16.535, P<0.05), while the expression of Wnt5a was decreased (t=-4.017, -19.901, -7.181, P<0.05); overexpression expressed feedback activation of Wnt The pathway up-regulated β-catenin (0.26±0.08 vs. 0.64±0.05, t=8.789, P<0.05) and down-regulated Wnt5a (1.35±0.23 vs. 0.51±0.26, t=-5.233, P<0.05). The expression of BMP-2 was up-regulated in both groups (0.26±0.03 vs. 0.64±0.05; 0.47±0.03 vs. 1.15±0.15; 0.63±0.11 vs. 1.31±0.098, t=16.340, 8.750, 29.721, P<0.01). Conclusion The Wnt pathway regulates the cartilage and osteogenic differentiation of ADSCs by regulating Sox9 and BMP-2, respectively, and its regulatory mechanisms are distinct at different stages of differentiation. Key words: Adpose-derived stem cells; Chondrogenic differentiation; Osteogenic differentiation; Wingless-type MMTV integration site family/β-catenin signaling pathway

Effect of Matrix Metalloproteinase 3 Gene Silencing and SRY-Related High Mobility Group-Box Gene 9 Gene Overexpression on Human Degeneration Nucleus Pulposus Cells In Vitro

This study aims to detect the biological effects of matrix metalloproteinase 3 (MMP3) and SRY-related high mobility group-box gene 9 (SOX9) gene regulation in the human intervertebral disc degeneration of nucleus pulposus cells mediated by lentiviral vectors in vitro. The culture and development of human degenerated intervertebral disc nucleus pulposus cells was performed. The cell morphology and structure were observed, as identified by hematoxylin and eosin (H&amp;E) staining. The experiment was divided into five groups: blank control group, SOX9 gene overexpression group, MMP3 gene silencing group, SOX9 gene overexpression+MMP3 gene silencing group, and blank vector group. RT-PCR and western blot were performed to detect the influence of MMP3 gene silencing and SOX9 gene overexpression on degenerated human intervertebral disc nucleus pulposus cells, include the secretion of polysaccharide and expression of type II collagen, at the mRNA and protein level. The originally generated degenerated human intervertebral disc nucleus pulposus cells had the same cellular morphology. The MTT assay revealed that the blank group and blank vector group had no statistical significance in cell proliferation. The MMP3 gene silencing and SOX9 gene overexpression could promote the proliferation of degenerated human intervertebral disc nucleus pulposus cells, when compared with the blank control group and blank vector group, and this more obvious in the MMP3 gene silencing group and SOX9 gene overexpression group. RT-PCR and western blot revealed that MMP3 gene silencing and SOX9 gene overexpression can promote cells to secrete polysaccharide and type-II collagen (P &lt; 0.05). MMP3 gene silencing and SOX9 gene overexpression can promote the proliferation of degenerated human intervertebral disc nucleus pulposus cells, and their ability to secrete polysaccharide and type-II collagen.

Low-intensity pulsed ultrasound promotes chondrogenesis of mesenchymal stem cells via regulation of autophagy

BackgroundLow-intensity pulsed ultrasound (LIPUS) can induce mesenchymal stem cell (MSC) differentiation, although the mechanism of its potential effects on chondrogenic differentiation is unknown. Since autophagy is known to regulate the differentiation of MSCs, the aim of our study was to determine whether LIPUS induced chondrogenesis via autophagy regulation.MethodsMSCs were isolated from the rat bone marrow, cultured in either standard or chondrogenic medium, and stimulated with 3 MHz of LIPUS given in 20% on–off cycles, with or without prior addition of an autophagy inhibitor or agonist. Chondrogenesis was evaluated on the basis of aggrecan (AGG) organization and the amount of type II collagen (COL2) and the mRNA expression of AGG, COL2, and SRY-related high mobility group-box gene 9 (SOX9) genes.ResultsLIPUS promoted the chondrogenic differentiation of MSCs, as shown by the changes in the extracellular matrix (ECM) proteins and upregulation of chondrogenic genes, and these effects were respectively augmented and inhibited by the autophagy inhibitor and agonist.ConclusionsTaken together, these results indicate that LIPUS promotes MSC chondrogenesis by inhibiting autophagy.

The function and mechanism of histone deacetylase 4 in osteoarthritis

Many factors contributes the process during the onset and development of osteoarthritis (OA), makes this process extremely complex. Histone deacetylase 4 (HDAC4) is very important to the OA pathological process because it can receive several crucial cellcularfactors’regulation and regulate many cytokines which involved in chondrocyte hypertrophy at the same time. During this process, Parathyroid hormone-related protein (PTHrP) can promote the nuclear location of HDAC4 through maintain phosphorylation of HDAC4 therefor repress runt-related transcription factor-2 (Runx-2)’s production and function at genetic and molecular level. The reduction of Runx-2 can repress the production of matrix metalloproteinase-13 (MMP-13), which on one hand decrease the digestion of type Ⅱ collagen and Aggrecan, on the other hand release the repression of SRY-related high mobility group-box gene (Sox-9). Therefore successfully increase the production of Type Ⅱ collagen. So, knowing the function and mechanism of HDAC4 in OA is important to understand it’ s pathological process. This review aims to summarize the latest progress of HDAC4 and cellcular factors involved in OA. Key words: Osteoarthritis; Histone deacetylase 4; Cytokines

Increase of SOX9 promotes hepatic ischemia/reperfusion (IR) injury by activating TGF-β1

Ischemia/reperfusion (IR) injury causes damage in aerobically metabolizing organs or tissues, which is an essential injury mechanism in various clinical settings. SRY-related high mobility group-Box gene 9 (SOX9) is a transcription factor of the SRY family, modulating various cellular processes, including fibrosis formation and tumor growth. However, the effects of SOX9 on hepatic IR injury have not been explored. In the present study, a hepatic IR injury model was established, supported by a significant histological alteration with high Suzuki scores, and a remarkable up-regulation of aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Importantly, we found that SOX9 was over-expressed in liver of mice after IR operation. Suppressing SOX9 markedly reduced inflammatory response, as evidenced by the reduced mRNA expressions of tumor necrosis factor α (TNF-α), interleukin (IL)-6 and IL-1β and inactivation of inhibitor of κBα (IκBα)/nuclear factor (NF)-κB pathway. In addition, SOX9 suppression alleviated apoptosis in liver of mice after IR injury, as supported by the reduced number of terminal deoxyribonucleotidyl transferse (TdT)-mediated biotin-16-dUTP nick-end labelling (TUNEL)-staining cells and decreased expression of Caspase-3 in liver tissue sections. The role of SOX9 in accelerating hepatic IR injury was further confirmed in primary hepatocytes under hypoxiaand reoxygenation (HR) treatment by enhancing inflammatory response and apoptosis. Of note, we found that transforming growth factor (TGF)-β1 was highly induced in liver of mice after IR injury. HR treatment also stimulated TGF-β1 expressions in vitro. Significantly, SOX9 over-expression-induced inflammation and apoptosis were obviously reduced by pirfenidone (Pirf), TGF-β1 inhibitor. In contrast, TGF-β1 exposure to cells further enhanced inflammation and apoptosis in HR-operated cells either with SOX9 knockdown or over-expression. Therefore, we identified a novel SOX9-dependent pathway that contributed to hepatic IR injury through enhancing inflammation and apoptosis by activating TGF-β1.

Evaluation of Magnetic Nanoparticle-Labeled Chondrocytes Cultivated on a Type II Collagen-Chitosan/Poly(Lactic-co-Glycolic) Acid Biphasic Scaffold.

Chondral or osteochondral defects are still controversial problems in orthopedics. Here, chondrocytes labeled with magnetic nanoparticles were cultivated on a biphasic, type II collagen–chitosan/poly(lactic-co-glycolic acid) scaffold in an attempt to develop cultures with trackable cells exhibiting growth, differentiation, and regeneration. Rabbit chondrocytes were labeled with magnetic nanoparticles and characterized by scanning electron microscopy (SEM), transmission electron (TEM) microscopy, and gene and protein expression analyses. The experimental results showed that the magnetic nanoparticles did not affect the phenotype of chondrocytes after cell labeling, nor were protein and gene expression affected. The biphasic type II collagen–chitosan/poly(lactic-co-glycolic) acid scaffold was characterized by SEM, and labeled chondrocytes showed a homogeneous distribution throughout the scaffold after cultivation onto the polymer. Cellular phenotype remained unaltered but with increased gene expression of type II collagen and aggrecan, as indicated by cell staining, indicating chondrogenesis. Decreased SRY-related high mobility group-box gene (Sox-9) levels of cultured chondrocytes indicated that differentiation was associated with osteogenesis. These results are encouraging for the development of techniques for trackable cartilage regeneration and osteochondral defect repair which may be applied in vivo and, eventually, in clinical trials.

Huang Qi Decoction Prevents BDL-Induced Liver Fibrosis Through Inhibition of Notch Signaling Activation.

Notch signaling has been demonstrated to be involved in ductular reactions and fibrosis. Previous studies have shown that Huang Qi Decoction (HQD) can prevent the progression of cholestatic liver fibrosis (CLF). However, whether HQD affects the Notch signaling pathway is unclear. In this study, CLF was established by common bile duct ligation (BDL) in rats. At the end of the first week, the rats were randomly divided into a model group (i.e., BDL), an HQD group, and a sorafenib positive control group (SORA) and were treated for 3 weeks. Bile duct proliferation and liver fibrosis were determined by tissue staining. Activation of the Notch signaling pathway was evaluated by analyzing expressions of Notch-1, -2, -3, and -4, Jagged (JAG) 1, and Delta like (DLL)-1, -3, and -4. The results showed that HQD significantly reduced the deposition of collagen and the Hyp content of liver tissue and inhibited the activation of HSCs compared with the BDL group. In addition, HQD significantly decreased the protein and mRNA expressions of TGF-[Formula: see text]1 and [Formula: see text]-SMA. In contrast, HQD significantly enhanced expression of the Smad 7 protein. HQD also reduced biliary epithelial cell proliferation, and reduced the mRNA levels of CK7, CK8, CK18, SRY-related high mobility group-box gene (SOX) 9, epithelial cell adhesion molecule (EpCAM) and the positive areas of CK19 and OV6. In addition, the mRNA and protein expressions of Notch-3, -4, JAG1, and DLL-1, -3 were significantly reduced in the HQD compared to the BDL group. These results demonstrated that HQD may prevent biliary liver fibrosis through inhibition of the Notch signaling pathway, and it may be a potential treatment for cholestatic liver disease.

Intermittent Cyclic Mechanical Tension Promotes Degeneration of Endplate Cartilage via the Nuclear Factor-κB Signaling Pathway: an in Vivo Study.

To establish a rabbit model for investigating the effects of intermittent cyclic mechanical tension (ICMT) on promoting degeneration of endplate cartilage. Forty New Zealand white rabbits were subjected to surgery and randomly divided into three equal groups as follows: control group (no treatment, n = 10), sham group (animals underwent a sham operation but were not subjected to mechanical tensile strain, n = 15) and loaded group (discs were subjected to 1.5 MPa external tensile loading by using an external loading device during the animals' daily activity, n = 15). Mechanical tensile strain was applied for 8 h/d. The animals were examined radiologically after 8 weeks treatment and then killed for removal of endplate cartilage tissue samples from their spines. Histological staining was performed to examine the morphology of endplate cartilage tissue. Multiple strategies were employed to examine degeneration of endplate cartilage and nuclear factor (NF)-κB signaling pathway activation. After ICMT loading for 56 days, radiology revealed ossification, hyperosteogeny and stenosis in the intervertebral spaces. Examination of hematoxylin and eosin staining of sections of endplate cartilage showed significant damage as the load duration increased in the ICMT loading group. Expression of aggrecan (ACAN), type II collagen (COL-2A), SRY-related high mobility group-box gene 9 (SOX9) was down-regulated (FACAN = 21.515, P < 0.01; FCOL-2A = 6.670, P = 0.05; FSOX9 = 7.888, P < 0.05), whereas that of matrix metallopeptidase 13 (MMP13) was up-regulated (FMMP13 = 14.120, P < 0.01) after ICMT. Western blot and immunofluorescence revealed that expression of protein was consistent with gene expression results. Additionally, ICMT loading can lead to NF-κB signaling pathway activation as well as degeneration of endplate cartilage. These experiments indicate that ICMT contributes to the activation of NF-κB signaling pathway in vivo and that the NF-κB signaling pathway further up-regulates MMP13, leading to degeneration of endplate cartilage.

MicroRNA-495 Inhibits Chondrogenic Differentiation in Human Mesenchymal Stem Cells by TargetingSox9

The chondrogenic differentiation process of human mesenchymal stem cells (hMSCs) passes through multiple stages, which are carried out by various factors and their interactions. Recently, microRNAs that regulate chondrogenic differentiation have been reported. However, microRNA that regulates SRY-related high mobility group-box gene 9 (Sox9), a chondrogenic key factor, has not been identified in hMSC. In this study, we identified that microRNA-495 (miR-495) is an important regulator of hMSC chondrogenic differentiation. In our microarray, miR-495 was downregulated during transforming growth factor (TGF)-β3-induced chondrogenic differentiation of hMSCs in vitro. We found that there is an miR-495 binding site in the 3' untranslated region (3'UTR) of Sox9. We confirmed opposite expression between miR-495 and Sox9 by using real-time polymerase chain reaction. Further, overexpression of miR-495 inhibited Sox9 expression, and repression of miR-495 increased expression of Sox9 in SW1353 cells and hMSCs. Additionally, luciferase analysis revealed that miR-495 directly binds to the Sox9 3'UTR, and we confirmed a seed sequence of miR-495 on the Sox9 3'UTR. Subsequently, overexpression of miR-495 repressed the expression of the extracellular matrix (ECM) protein, such as type II collagen (Col2A1), aggrecan, and proteoglycan products, whereas inhibition of miR-495 increased their expression. Collectively, this study indicates that miR-495 directly targets Sox9, ultimately leading to the regulation of chondrogenic differentiation in hMSCs.

Different levels of testicular organization during gonadal differentiation in B6.YTir mice manifesting sex reversal

B6.Y(Tir) (mice with Y chromosome from a strain in Tirano, Italy, and autosomes and X-chromosomes from the B6 strain) mice provide an excellent model for analysing sex development that occurs during gonadal differentiation; however, the molecular mechanisms that contribute to sex reversal are unclear. Our aim has been to establish which molecular events participate in this sex reversal. The pattern of gene expression related to testicular [Sry (sex-determining region of the Y chromosome), Sox9 (Sry-related high-mobility group box gene 9) and Mis (Müllerian-inhibiting substance)] and ovarian [Wnt4 (Wingless-type MMTV (murine-mammary-tumour virus) integration site family, member 4), Rspo1 (cysteine-rich secretory protein containing a thrombospondin type 1 repeat) and Stra8 (stimulated by retinoic acid gene 8)] differentiation was analysed by applying immunofluorescence and real-time RT-PCR (reverse transcription-PCR), focusing on XY gonads from the B6.Y(Tir) mouse, but also analysing the normal strains CD-1 and C57BL/6J (B6). The expression of genes related to the process of sexual differentiation was altered in the case of the B6.Y(Tir) strain, both at the transcript and protein level, inducing differentiation of ovaries and ovotestes, but not the formation of the testes, which were normal. Our results indicate that the expression of testicular genes is inhibited at various levels, permitting the expression of ovarian genes such as Wnt4, Stra8 and Rspo1. However, their activity was not clear when the data were averaged. Correlation analysis indicated that an ovary differentiation pathway is activated when the testicular differentiation pathway is inhibited.

MicroRNA-145 Regulates Chondrogenic Differentiation of Mesenchymal Stem Cells by Targeting Sox9

Chondrogenic differentiation of mesenchymal stem cells (MSCs) is accurately regulated by essential transcription factors and signaling cascades. However, the precise mechanisms involved in this process still remain to be defined. MicroRNAs (miRNAs) regulate various biological processes by binding target mRNA to attenuate protein synthesis. To investigate the mechanisms for miRNAs-mediated regulation of chondrogenic differentiation, we identified that miR-145 was decreased during transforming growth factor beta 3 (TGF-β3)-induced chondrogenic differentiation of murine MSCs. Subsequently, dual-luciferase reporter gene assay data demonstrated that miR-145 targets a putative binding site in the 3′-UTR of SRY-related high mobility group-Box gene 9 (Sox9) gene, the key transcription factor for chondrogenesis. In addition, over-expression of miR-145 decreased expression of Sox9 only at protein levels and miR-145 inhibition significantly elevated Sox9 protein levels. Furthermore, over-expression of miR-145 decreased mRNA levels for three chondrogenic marker genes, type II collagen (Col2a1), aggrecan (Agc1), cartilage oligomeric matrix protein (COMP), type IX collagen (Col9a2) and type XI collagen (Col11a1) in C3H10T1/2 cells induced by TGF-β3, whereas anti-miR-145 inhibitor increased the expression of these chondrogenic marker genes. Thus, our studies demonstrated that miR-145 is a key negative regulator of chondrogenic differentiation by directly targeting Sox9 at early stage of chondrogenic differentiation.

MicroRNA regulation associated chondrogenesis of mouse MSCs grown on polyhydroxyalkanoates

Microbial polyhydroxyalkanoates (PHA) including poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) were found to induce chondrogenesis of mesenchymal stem cells (MSCs) and preserve chondrocytic phenotype as well as support chondrocytes-specific extracellular matrix (ECM) secretion. In this study, mouse MSCs cultured on the PHBHHx films for 24 h showed up-regulated expression of chondrogenic marker genes including aggrecan, col2, sox9, col10 and pthrp. To further illustrate this phenomonon, chondrogenesis-related microRNA expression profiling was examined by quantitative real-time PCR (RT-PCR) based on results of microRNA array obtained from comparison between mouse MSCs and mature mouse chondrocytes. Among 44 microRNAs related to chondrogenesis on microrray studies, considering only broadly-conserved microRNAs, seven differentially-expressed microRNAs were selected to study their target genes related to chondrogenesis. Two microRNAs out of the seven, namely, miR-29a and miR-29b, were revealed to directly target 3′ UTR of col2a1 encoding type II collagen by dual-luciferase assay, and their activity was under the regulation of Sox9, the SRY-related high mobility group-box gene 9. For the first time microRNAs were shown to regulate the stem cell differentiation processes mediated by cell–material interactions.