Combining Porous Se@SiO2 Nanocomposites and dECM Enhances the Myogenic Differentiation of Adipose-Derived Stem Cells.

Background: Volumetric Muscle Loss (VML) denotes the traumatic loss of skeletal muscle, a condition that can result in chronic functional impairment and even disability. While the body can naturally repair injured skeletal muscle within a limited scope, patients experiencing local and severe muscle loss due to VML surpass the compensatory capacity of the muscle itself. Currently, clinical treatments for VML are constrained and demonstrate minimal efficacy. Selenium, a recognized antioxidant, plays a crucial role in regulating cell differentiation, anti-inflammatory responses, and various other physiological functions. Methods: We engineered a porous Se@SiO2 nanocomposite (SeNPs) with the purpose of releasing selenium continuously and gradually. This nanocomposite was subsequently combined with a decellularized extracellular matrix (dECM) to explore their collaborative protective and stimulatory effects on the myogenic differentiation of adipose-derived mesenchymal stem cells (ADSCs). The influence of dECM and NPs on the myogenic level, reactive oxygen species (ROS) production, and mitochondrial respiratory chain (MRC) activity of ADSCs was evaluated using Western Blot, ELISA, and Immunofluorescence assay. Results: Our findings demonstrate that the concurrent application of SeNPs and dECM effectively mitigates the apoptosis and intracellular ROS levels in ADSCs. Furthermore, the combination of dECM with SeNPs significantly upregulated the expression of key myogenic markers, including MYOD, MYOG, Desmin, and myosin heavy chain in ADSCs. Notably, this combination also led to an increase in both the number of mitochondria and the respiratory chain activity in ADSCs. Conclusion: The concurrent application of SeNPs and dECM effectively diminishes ROS production, boosts mitochondrial function, and stimulates the myogenic differentiation of ADSCs. This study lays the groundwork for future treatments of VML utilizing the combination of SeNPs and dECM.

Ginkgolide K delays the progression of osteoarthritis by regulating YAP to promote the formation of cartilage extracellular matrix.

Osteoarthritis (OA) is a degenerative disease characterized by cartilage wear and degradation. Ginkgolide K (GK) is a natural compound extracted from Ginkgo biloba leaves and possesses anti-inflammatory and anti-apoptotic effects. We found that the biological characteristics of GK were highly consistent with those of OA medications. This study aimed to determine and verify the therapeutic effect of GK on OA and mechanism of its therapeutic effect. For the in vivo experiment, OA rats were regularly injected in the articular cavity with GK, and the curative effects were observed after 4 and 8 weeks. For the in vitro experiment, we treated OA chondrocytes with different concentrations of GK and then detected the related indices of OA. Through the in vivo and in vitro experiments, we found that GK could promote the production of major components of the cartilage extracellular matrix. Transcriptome sequencing revealed that GK may activate hypoxia-inducible factor 1 alpha via the hypoxia signaling pathway, which, in turn, activates yes-associated protein and inhibits apoptosis of OA chondrocytes. GK has a therapeutic effect on OA and, therefore, has the potential to be developed into a new drug for OA treatment.

Emodin promotes fibroblast apoptosis and prevents epidural fibrosis through PERK pathway in rats.

BACKGROUND: Laminectomy is usually classed as a common orthopedic surgery, but postoperative epidural fibrosis often leads to less-than-desirable clinical outcomes. As demonstrated by prior studies, emodin (EMO) exerts an anti-fibrotic effect. Here, we carried out investigation into the inhibitory effect created by EMO application on epidural fibrosis after laminectomy in rats. METHODS: The paper conducts a series of experiment. In vitro, we observed the effect of EMO on fibroblasts by Cell Counting Kit-8 (CCK-8) assay. Apoptosis of fibroblasts induced by EMO was detected by western blot, TUNEL assay, and flow cytometry. The results revealed that EMO was capable of inducing fibroblast apoptosis, and the proteins of PERK pathway also changed accordingly. In vivo, the effect of EMO on epidural fibrosis in 12 male Sprague-Dawley rats was observed by histological staining. RESULTS: CCK-8 assay indicated that EMO was effective in reducing fibroblast viability in a time- and a dose-dependent manner. TUNEL assay and flow cytometry analysis have demonstrated that the apoptotic rate of fibroblasts increased as the EMO concentration rose. Western blot analysis proved that EMO promoted the relative expression of p-perk and p-eIF2α and that the expression of its downstream proteins CHOP and GRP78 was also enhanced. The expression of apoptotic protein Bax and cleaved PARP was upregulated, whereas the expression of anti-apoptotic protein Bcl-2 was downregulated. In addition, histological and immunohistochemical analysis demonstrated that EMO functioned to inhibit epidural fibrosis and increase GRP78 expression in fibrous tissue by promoting apoptosis of fibroblasts. CONCLUSIONS: EMO could have inhibitory effect on epidural fibrosis in a concentration-dependent manner. The potential mechanism might be through PERK signaling pathway to promote fibroblast apoptosis. It has a possibility to be taken as a novel method for the treatment of epidural fibrosis.

Negative regulation of PI3K/AKT/mTOR axis regulates fibroblast proliferation, apoptosis and autophagy play a vital role in triptolide-induced epidural fibrosis reduction.

Fibroblasts excessive proliferation was considered as a decisive reason for epidural fibrosis, which was known as a serious complication of lumbar laminectomy. As a traditional Chinese medicine, triptolide (TP) was used to be proved effective in preventing several fibrosis scar formation diseases. However, little is known about the effect of TP on preventing epidural fibrosis and its possible mechanism. Here, we performed in vitro and in vivo experiments to detect the possible mechanism of TP in preventing epidural fibrosis. In vitro, the effect of TP on impacting fibroblasts proliferation activities was detected by CCK-8, cell cycle assay and EdU incorporation assay. Also, the expressions of cell proliferation protein markers and the expressions of p-PI3K, p-AKT, p-mTOR were detect by Western blot. Besides, the effect of TP on inducing fibroblast apoptosis and autophagy was tested by Western blots, flow cytometry, TUNEL staining, Transmission electron microscope (TEM) analysis and LC3 immunofluorescent staining. The results suggested that TP could suppress the activation of PI3K/AKT/mTOR signaling pathway. Meanwhile, TP could inhibit fibroblast proliferation and induce fibroblast apoptosis as well as autophagy, which was known as two cellular self-destructions. Furthermore, we speculated the possible molecular pathway, through which that TP could inhibit fibroblast proliferation, induce fibroblast apoptosis and autophagy. We used PI3-kinase activator (740Y-P) to activate the PI3K/AKT/mTOR signaling. Activation of PI3K/AKT/mTOR signaling pathway increase the proliferation of fibroblasts and suppressed the autophagy and apoptosis induced by TP. In vivo, we built epidural fibrosis models in rats and locally applied TP of various concentrations. Hematoxylin-eosin (HE) and Masson's trichrome were used to detect the effect of TP on reducing epidural fibrosis. And the results showed that TP could significantly reduce the surgery-induced epidural fibrosis. In conclusion, the results above shown that TP could reduce epidural fibrosis formation, and the potential mechanism might through inhibiting fibroblast proliferation and stimulating apoptosis and autophagy via suppressing PI3K/AKT/mTOR signaling pathway. It might provide a novel thought for reducing surgery-induced epidural fibrosis.

Scutellarin inhibits RANKL-mediated osteoclastogenesis and titanium particle-induced osteolysis via suppression of NF-κB and MAPK signaling pathway.

Aseptic prosthetic loosening is a major complication after hip joint replacement. Wear particle-induced periprosthetic osteolysis plays a key role in aseptic prosthetic loosening. Attempting to modulate receptor activator of nuclear factor-κB (RANKL) mediated signaling pathways is a promising strategy to prevent aseptic prosthetic loosening. In the present study, we determined the effect of scutellarin (SCU) on titanium (Ti) particle-induced osteolysis in a mouse calvarial model and RANKL-mediated osteoclastogenesis. We determined that SCU, the major effective constituent of breviscapine isolated from a Chinese herb, has potential effects on preventing Ti particle-caused osteolysis in calvarial model of mouse. In vitro, SCU could suppress RANKL-mediated osteoclastogenesis, the function of osteoclast bone resorption, and the expression levels of osteoclast-specific genes (tartrate-resistant acid phosphatase (TRAP), cathepsin K, c-Fos, NFATc1). Further investigation indicated that SCU could inhibit RANKL-mediated MAPK and NF-κB signaling pathway, including JNK1/2, p38, ERK1/2, and IκBα phosphorylation. Taken together, these results indicate that SCU could inhibit osteoclastogenesis and prevent Ti particle-induced osteolysis by suppressing RANKL-mediated MAPK and NF-κB signaling pathway. These results suggest that SCU is a promising therapeutic agent for preventing wear particle-induced periprosthetic osteolysis.

Reduction of intraarticular adhesion of knee by local application of rapamycin in rabbits via inhibition of fibroblast proliferation and collagen synthesis.

BACKGROUND: The formation of intraarticular adhesion is a common complication after total knee arthroplasty or anterior cruciate ligament reconstruction. Previously, little research was reported regarding whether the local application of rapamycin (RAPA) could reduce intraarticular adhesion following knee surgery. In our present study, we determined the therapeutic effect of RAPA by local application on the reduction of intraarticular adhesion following knee surgery in rabbits. METHODS: In this study, we built the model of knee surgery according to a previous study. The decorticated areas of the cortical bone were exposed and covered with cotton pads soaked with different concentrations of RAPA or physiological saline for 10 min. All of the rabbits were euthanized 4 weeks after the surgery. Macroscopic evaluation of the hydroxyproline content, the histological morphological analysis and collagen density and fibroblast density were used to evaluate the effect of RAPA on reducing intraarticular adhesion. RESULTS: The results shown that RAPA could significantly inhibit the proliferation of fibroblasts and reduce collagen synthesis; in the rabbit model of knee surgery, there were weak scar tissues around the decorticated areas in the 0.2 mg/ml RAPA group; moderate scar tissues were found in the 0.1 mg/ml RAPA group. However, severe fibrous adhesions were found in the 0.05 mg/ml RAPA group and the control group. The hydroxyproline content and the fibroblast density in the 0.2 mg/ml and 0.1 mg/ml RAPA groups were significantly less than those of the control group. CONCLUSIONS: We concluded that the local application of RAPA could reduce intraarticular adhesion after knee surgery in the rabbit model; this effect was mediated by inhibition of fibroblast proliferation and collagen synthesis, which may provide a new method for reducing intraarticular adhesion after clinical knee surgery.