Myogenic exosome miR-140-5p modulates skeletal muscle regeneration and injury repair by regulating muscle satellite cells.

Muscle satellite cells (SCs) play a crucial role in the regeneration and repair of skeletal muscle injuries. Previous studies have shown that myogenic exosomes can enhance satellite cell proliferation, while the expression of miR-140-5p is significantly reduced during the repair process of mouse skeletal muscle injuries induced by BaCl2. This study aims to investigate the potential of myogenic exosomes carrying miR-140-5p inhibitors to activate SCs and influence the regeneration of injured muscles. Myogenic progenitor cell exosomes (MPC-Exo) and contained miR-140-5p mimics/inhibitors myogenic exosomes (MPC-Exo140+ and MPC-Exo140-) were employed to treat SCs and use the model. The results demonstrate that miR-140-5p regulates SC proliferation by targeting Pax7. Upon the addition of MPC-Exo and MPC-Exo140-, Pax7 expression in SCs significantly increased, leading to the transition of the cell cycle from G1 to S phase and an enhancement in cell proliferation. Furthermore, the therapeutic effect of MPC-Exo140- was validated in animal model, where the expression of muscle growth-related genes substantially increased in the gastrocnemius muscle. Our research demonstrates that MPC-Exo140- can effectively activate dormant muscle satellite cells, initiating their proliferation and differentiation processes, ultimately leading to the formation of new skeletal muscle cells and promoting skeletal muscle repair and remodeling.

Exercise-inducible circulating extracellular vesicle irisin promotes browning and the thermogenic program in white adipose tissue.

AIM: Exercise can reduce body weight and promote white fat browning, but the underlying mechanisms remain largely unknown. This study investigated the role of fibronectin type III domain-containing protein 5 (FNDC5)/Irisin, a hormone released from exercising muscle, in the browning of white fat in circulating extracellular vesicles (EVs). METHODS: Mice were subjected to a 4 weeks of running table exercise, and fat browning was analyzed via histology, protein blotting and qPCR. Circulating EVs were extracted by ultrahigh-speed centrifugation, and ELISA was used to measure the irisin concentration in the circulating EVs. Circulating EVs that differentially expressed irisin were applied to adipocytes, and the effect of EV-irisin on adipocyte energy metabolism was analyzed by immunofluorescence, protein blotting, and cellular oxygen consumption rate analysis. RESULTS: During sustained exercise, the mice lost weight and developed fat browning. FNDC5 was induced, cleaved, and secreted into irisin, and irisin levels subsequently increased in the plasma during exercise. Interestingly, irisin was highly expressed in circulating EVs that effectively promoted adipose browning. Mechanistically, the circulating EV-irisin complex is transported intracellularly by the adipocyte membrane receptor integrin αV, which in turn activates the AMPK signaling pathway, which is dependent on mitochondrial uncoupling protein 1 to cause mitochondrial plasmonic leakage and promote heat production. After inhibition of the AMPK signaling pathway, the effects of the EV-irisin on promoting fat browning were minimal. CONCLUSION: Exercise leads to the accumulation of circulating EV-irisin, which enhances adipose energy metabolism and thermogenesis and promotes white fat browning in mice, leading to weight loss.

Endurance Exercise-Induced Fgf21 Promotes Skeletal Muscle Fiber Conversion through TGF-ß1 and p38 MAPK Signaling Pathway.

Fgf21 has been identified as playing a regulatory role in muscle growth and function. Although the mechanisms through which endurance training regulates skeletal muscle have been widely studied, the contribution of Fgf21 remains poorly understood. Here, muscle size and function were measured, and markers of fiber type were evaluated using immunohistochemistry, immunoblots, or qPCR in endurance-exercise-trained wild-type and Fgf21 KO mice. We also investigated Fgf21-induced fiber conversion in C2C12 cells, which were incubated with lentivirus and/or pathway inhibitors. We found that endurance exercise training enhanced the Fgf21 levels of liver and GAS muscle and exercise capacity and decreased the distribution of skeletal muscle fiber size, and fast-twitch fibers were observed converting to slow-twitch fibers in the GAS muscle of mice. Fgf21 promoted the markers of fiber-type transition and eMyHC-positive myotubes by inhibiting the TGF-ß1 signaling axis and activating the p38 MAPK signaling pathway without apparent crosstalk. Our findings suggest that the transformation and function of skeletal muscle fiber types in response to endurance training could be mediated by Fgf21 and its downstream signaling pathways. Our results illuminate the mechanisms of Fgf21 in endurance-exercise-induced fiber-type conversion and suggest a potential use of Fgf21 in improving muscle health and combating fatigue.

RNA-binding Protein QKI Inhibits Osteogenic Differentiation Via Suppressing Wnt Pathway.

BACKGROUND: Dysregulation of MSCs differentiation is associated with many pathophysiological processes. Genetically modified MSCs transplantation helps restore bone loss efficiently. METHODS: BMSCs-specific QKI overexpressing and knockdown mice were built to explore QKI's role in bone formation and fat accumulation. Primary BMSCs with QKI overexpression and knockout were subjected to osteogenic and adipogenic differentiation. ALP staining and oil red O staining were performed to evaluate the differences between the groups. RNA immunoprecipitation was performed to identify the QKI-related pathway. QKI deficient BMSCs were transplanted into mice with glucocorticoid-induced osteoporosis to evaluate its therapeutic potential. RESULTS: Mice harboring BMSC-specific transgenic QKI exhibited reduced bone mass, while BMSC-specific QKI-deficient mice showed an increase in bone mass. Osteogenic differentiation of QKI deficient BMSCs was promoted and adipogenic differentiation was inhibited, while QKI overexpression in BMSCs displayed the opposite effects. To define the underlying mechanisms, RIP sequencing was performed. Wnt pathway-related genes were the putative direct target mRNAs of QKI, Canonical Wnt pathway activation was involved in QKI's effects on osteogenic differentiation. RNA immunoprecipitation quantitative real-time Polymerase Chain Reaction (PCR) and RNA fluorescence in situ hybridization experiments further validated that QKI repressed the expressions of Wnt5b, Fzd7, Dvl3 and ß-catenin via direct binding to their putative mRNA specific sites. Glucocorticoid-induced osteoporotic mice transplanted with QKI deficient BMSCs exhibited less bone loss compared with mice transplanted with control BMSCs. CONCLUSIONS: QKI suppressed BMSCs osteogenic differentiation by downregulating the expressions of Wnt5b, Fzd7, Dvl3 and ß-catenin. Loss of QKI in BMSCs transplantation may provide a new strategy for the treatment of orthopedic diseases such as osteoporosis.

Deep Learning in Medical Hyperspectral Images: A Review.

With the continuous progress of development, deep learning has made good progress in the analysis and recognition of images, which has also triggered some researchers to explore the area of combining deep learning with hyperspectral medical images and achieve some progress. This paper introduces the principles and techniques of hyperspectral imaging systems, summarizes the common medical hyperspectral imaging systems, and summarizes the progress of some emerging spectral imaging systems through analyzing the literature. In particular, this article introduces the more frequently used medical hyperspectral images and the pre-processing techniques of the spectra, and in other sections, it discusses the main developments of medical hyperspectral combined with deep learning for disease diagnosis. On the basis of the previous review, tne limited factors in the study on the application of deep learning to hyperspectral medical images are outlined, promising research directions are summarized, and the future research prospects are provided for subsequent scholars.

Myoblast-derived exosomes promote the repair and regeneration of injured skeletal muscle in mice.

When skeletal muscle is damaged, satellite cells (SCs) are activated to proliferate rapidly and fuse with the damaged muscle fibers to form new muscle fibers, thereby promoting muscle growth and remodeling and repair of trauma. Exosomes from differentiating human skeletal muscle cells trigger myogenesis of stem cells and provide biochemical cues for skeletal muscle regeneration. Therefore, we hypothesized that, when muscles are injured, myoblast-derived exosomes may regulate muscle repair and regeneration. Here, we investigated the underlying mechanism by applying C2C12-derived exosomes to injured mouse skeletal muscles. The expression levels of skeletal muscle regeneration factors paired box 7 and lipid-promoting factor peroxisome proliferator-activated receptor γ were upregulated, whereas the expression levels of fibrosis factors collagen-1 and α-smooth muscle actin decreased. The expression of proliferating cell nuclear antigen was elevated after applying C2C12-derived exosomes to SCs. Application of C2C12-derived exosomes to fibro-adipogenic progenitors resulted in an increase in peroxisome proliferator-activated receptor γ expression and adipogenesis capacity, whereas α-smooth muscle actin expression and fibrosis capacity decreased. Analysis of the transcriptome and proteome of SCs after treatment with exosomes showed the involvement of multiple biological processes, including proliferation and differentiation of SCs, muscle regeneration, skeletal muscle atrophy, and the inflammatory response after muscle injury. Hence, our data suggest that C2C12-derived exosomes can promote the regeneration of skeletal muscle fibers, accelerate the production of fat from damaged muscles, inhibit the fibrosis of damaged muscles, and accelerate injury repair, which is related to exosome-mediated regulation of the proliferation of SCs, differentiation of fibro-adipogenic progenitors, and modulation of SC mRNA expression and protein formation and decomposition.

QKI deficiency leads to osteoporosis by promoting RANKL-induced osteoclastogenesis and disrupting bone metabolism.

Quaking (QKI), an RNA-binding protein, has been reported to exhibit numerous biological functions, such as mRNA regulation, cancer suppression, and anti-inflammation. However, little known about the effects of QKI on bone metabolism. In this study, we used a monocyte/macrophage-specific QKI knockout transgenic mouse model to investigate the effects of QKI deficiency on receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis. The loss of QKI promoted the formation of multinucleated tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts (OCs) from bone marrow macrophages, and upregulated the expression of OC-specific markers, including TRAP (Acp5) and cathepsin K (Ctsk). The pro-osteoclastogenesis effect of QKI deficiency was achieved by amplifying the signaling cascades of the NF-κB and mitogen-activated protein kinase (MAPK) pathways; then, signaling upregulated the activation of nuclear factor of activated T cells c1 (NFATc1), which is considered to be the core transcription factor that regulates OC differentiation. In addition, QKI deficiency could inhibit osteoblast (OB) formation through the inflammatory microenvironment. Taken together, our data suggest that QKI deficiency promoted OC differentiation and disrupted bone metabolic balance, and eventually led to osteopenia under physiological conditions and aggravated the degree of osteoporosis under pathological conditions.

A colorimetric probe for detection of Cu2+ by the naked eye and application in test paper.

A novel colorimetric probe RP1 was synthesized using rhodamine derivatives and heterocyclic compounds for the purpose of detecting Cu2+ . RP1 showed good selectivity, high sensitivity and affinity toward Cu2+ over other competing ions in CH3 OH-H2 O (1/1, v/v) solution. Absorbance intensity showed a good linear fit between probe R1 and Cu2+ over the concentration range 1-8 µM and the association constant was also calculated to be 1.145 × 105 M-1 . The sensing mechanism was deduced using Job's plot, Fourier transform infrared spectroscopy, and density functional theory studies. In addition, the colorimetric experiment indicated that probe RP1 could be made into test paper to detect Cu2+ with a colour change from colourless to pink.

MOTS-c inhibits Osteolysis in the Mouse Calvaria by affecting osteocyte-osteoclast crosstalk and inhibiting inflammation.

The Mitochondrial-derived peptide MOTS-c has recently been reported as a 16-amino acid peptide regulating metabolism and homeostasis in different cells. However, its effects on immune cells and bone metabolism are rarely reported. Here we demonstrate that MOTS-c treatment in ultra-high molecular weight polyethylene (UHMWPE) particle-induced osteolysis mouse model alleviated bone erosion and inflammation. MOTS-c increased osteoprotegerin (OPG)/ receptor activator of nuclear factor kappa-B ligand (RANKL) ratio in osteocytes, leading to inhibition of osteoclastogenesis. In primary bone marrow macrophages (BMMs) MOTS-c alleviated STAT1 and NF-κB phosphorylation triggered by UHMWPE particles. Promoting ROS production or suppressing peroxisome proliferator-activated receptor γ (PPARγ) coactivator-1α (PGC-1α) by adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) repression blocked these anti-inflammatory effects of MOTS-c treatment. Taken together, these findings provide evidence that the small peptide inhibits osteoclastogenesis by regulating osteocyte OPG/RANKL secretion and suppressing inflammation via restraining NF-κB and STAT1 pathway. Moreover, its effects on NF-κB activation is dependent on the AMPK-PGC-1α-ROS axis, suggesting its potential use in osteolysis and other inflammation disorders.

A Highly Selective "Turn-on" Fluorescent Probe for Detection of Fe3+ in Cells.

A new "turn-on" fluorescent probe Py based on rhodamine and piperonaldehyde was designed and synthesized for detecting Fe3+ in cells. The free probe Py was non-fluorescent. While only upon addition of Fe3+, the significant increase of the fluorescence and color were observed which could be visible directly by "naked-eye". The probe Py shows high selectivity and sensitivity for Fe3+ over other common metal ions in EtOH-H2O (3/2, v/v) mixed solution. The association constant and the detection limit were calculated to be 4.81 × 104 M-1 and 1.18 × 10-8 mol/L respectively. The introduction of piperonaldehyde unit could increase probe rigidity which could enhance its optical properties. Meanwhile, the binding mode between Py and Fe3+ was found to be a 1:1 complex formation. The density functional theory (DFT) calculations were performed which would further confirm the recognition mechanism between probe Py and Fe3+. In addition, the probe has been proved to be reversible for detecting Fe3+. Moreover, the probe Py was used to detect Fe3+ in cells successfully.

Metformin protects bone mass in ultra-high-molecular-weight polyethylene particle-induced osteolysis by regulating osteocyte secretion.

Metformin, an anti-hyperglycemic agent used for type 2 diabetes, has recently been found to have more effects apart from glucose regulation. We found that, in ultra-high-molecular-weight polyethylene particle-induced osteolysis mouse models, metformin had bone protect property and reduced the negative regulator of bone formation sclerostin (SOST) and Dickkopf-related protein 1 (DKK1), and increased osteoprotegerin (OPG) secretion and the ratio of OPG/Receptor Activator for Nuclear Factor-κB Ligand (RANKL). In vitro, we established a 3D co-culture system in which metformin affects osteoblasts and osteoclasts through mature osteocytes secretion. Metformin (50 µM) significantly decreased SOST and DKK1 mRNA expression, stimulating alkaline phosphatase activity and proliferation of osteoblast, and increased OPG secretion and the ratio of OPG/RANKL, inhibiting osteoclastogenesis. Moreover, the effect on OPG was reversed by adenosine 5'-monophosphate-activated protein kinase inhibitor, Compound C. Our finding suggests that metformin induces differentiation and mineralization of osteoblasts, while inhibits osteoclastogenesis via mature osteocytes secretion. Therefore, the drug might be beneficial for not only diabetes but also in other bone disorders by acting on mature osteocytes.

Metformin suppresses UHMWPE particle-induced osteolysis in the mouse calvaria by promoting polarization of macrophages to an anti-inflammatory phenotype.

BACKGROUND: Implant failure remains a major obstacle to successful treatment via TJA. Periprosthetic osteolysis and aseptic loosening are considered as proof of wear debris-induced disruption of local regulatory mechanisms related to excessive bone resorption associated with osteolysis and the damage at the bone-prosthesis interface. Therefore, there is an immediate need to explore strategies for limiting and curing periprosthetic osteolysis and aseptic loosening. METHODS: We analyzed the in vitro cytokine production by primary mouse bone marrow macrophages (BMMs) that were exposed to ultra-high molecular weight polyethylene (UHMWPE) particles and treated with metformin at different concentrations with or without 5-aminoimidazole-4-carboxamide ribonucleoside to activate or inhibit AMPK. A mouse calvarial model was used to examine the in vivo effects of metformin on UHMWPE particle-induced osteolysis. RESULTS: With particles, primary mouse BMMs secreted more pro-inflammatory cytokines tumor necrosis factor-α and interleukin (IL)-6. Treatment with metformin inhibited these variations and promoted the release of cytokine IL-10 with anti-inflammatory capability. In vivo, metformin reduced the production of pro-inflammatory cytokines, osteoclastogenesis, and osteolysis, increasing IL-10 production. Metformin also promoted the polarization of macrophages to an anti-inflammatory phenotype in vivo via AMPK activation. DISCUSSION: A crucial point in limiting and correcting the periprosthetic osteolysis and aseptic loosening is the inhibition of inflammatory factor production and osteoclast activation induced by activated macrophages. The ability of metformin to attenuate osteolysis induced in mouse calvaria by the particles was related to a reduction in osteoclast number and polarization of macrophages to an anti-inflammatory functional phenotype. CONCLUSIONS: Metformin could limit the osteolysis induced by implant debris. Therefore, we hypothesized that metformin could be a potential drug for osteolysis induced by implant debris.

Azoramide, a novel regulator, favors adipogenesis against osteogenesis through inhibiting the GLP-1 receptor-PKA-ß-catenin pathway.

BACKGROUND: The reciprocal fate decision of mesenchymal stem cells (MSCs) to either bone or adipocytes is determined by Wnt-related signaling and the glucagon-like peptide-1 receptor (GLP-1R). Azoramide, an ER stress alleviator, was reported to have an antidiabetic effect. In this study, we investigated the function of azoramide in regulating the lineage determination of MSCs for either adipogenic or osteogenic differentiation. METHODS: In this study, microcomputed tomography and histological analysis on bone morphogenetic protein (BMP)2-induced parietal periosteum bone formation assays, C3H10T1/2 and mouse bone marrow MSC-derived bone formation and adipogenesis assays, and specific staining for bone tissue and lipid droplets were used to evaluate the role of azoramide on the lineage determination of MSC differentiation. Cells were harvested for Western blot and quantitative real-time polymerase chain reaction (PCR), and immunofluorescence staining was used to explore the potential mechanism of azoramide for regulating MSC differentiation. RESULTS: Based on MSC-derived bone formation assays both in vivo and in vitro, azoramide treatment displayed a cell fate determining ability in favor of adipogenesis over osteogenesis. Further mechanistic characterizations disclosed that both the GLP-1R agonist peptide exendin-4 (Ex-4) and GLP-1R small interfering (si)RNA abrogated azoramide dual effects. Moreover, cAMP-protein kinase A (PKA)-mediated nuclear ß-catenin activity was responsible for the negative function of azoramide on bone formation in favor of adipogenesis. CONCLUSIONS: These data provide the first evidence to show that azoramide may serve as an antagonist against GLP-1R in MSC lineage determination.

Let-7b regulates alpaca hair growth by downregulating ectodysplasin A.

Hypohidrotic ectodermal dysplasia (HED), also known as anhidrotic ectodermal dysplasia, is characterized by the clinical manifestations of less sweat or no sweat, sparse or no hair, tooth agenesis and/or abnormal tooth morphology. The characteristics of alpaca ear hair differ from the back hair. The ectodysplasin A (EDA) signaling pathway has a regulatory effect on skin development and hair growth. The aim of the present study was to study the effects of EDA on alpaca hair growth by examining the mRNA and protein expression levels of EDA in alpaca ear and back skin by reverse transcription­quantitative polymerase chain reaction and western blot analysis, respectively. Results indicated that EDA expression was higher in the ear skin compared with the back skin. The expression levels of let­7b in the skin of healthy alpacas varies; the difference between let­7b expression levels of the ear and back have been reported to be >2­fold, suggesting a role for let­7b in the development of adult alpaca skin and hair follicles. A dual­luciferase reporter vector was constructed to verify the targeting relationship between microRNA let­7b and EDA, and the results revealed that EDA was a target gene of let­7b. Alpaca skin fibroblasts were transfected with a let­7b eukaryotic expression vector to investigate the regulatory relationship between let­7b and EDA. The expression of EDA was decreased in the transfected group; immunocytochemical results demonstrated that the EDA protein was abundantly expressed in the fibroblast cytoplasm. EDA protein expression was weaker in the transfected cells than in the untransfected cells. These results suggested that EDA may serve a role in alpaca hair growth and is probably a target gene of let­7b; let­7b downregulated EDA mRNA and protein expressions, which suggested that let­7b may regulate alpaca hair growth. These conclusions suggested that let­7b may be associated with HED.

Treatment Effects of the Second-Generation Tyrosine Kinase Inhibitor Dasatinib on Autoimmune Arthritis.

Rheumatoid arthritis (RA) is a multifactorial autoimmune disease that primarily manifests as persistent synovitis and progressive joint destruction. Imatinib exhibited a therapeutic effect in murine collagen-induced arthritis (CIA) via selective inhibition tyrosine kinases. The second-generation tyrosine kinase inhibitor dasatinib exhibits more durable hematological and cytogenetic effects and more potency compared to imatinib. However, the effect of dasatinib on CIA is poorly understood. The present study investigated the treatment effect of dasatinib on autoimmune arthritis. We demonstrated that dasatinib alleviated arthritis symptoms and histopathological destruction in CIA mice. Dasatinib treatment inhibited the production of proinflammatory cytokines including IL-1ß, TNF-α, and IL-6, and promoted the production of the anti-inflammatory cytokine IL-10. Dasatinib treatment also suppressed the expression of anti-mouse CII antibodies including total IgG, IgG1, IgG2, and IgG2b, in CIA mice. We further demonstrated that dasatinib inhibited the migration and proliferation of fibroblast-like synoviocytes (FLS) from RA patients and promoted FLS apoptosis. The mRNA expression of MMP13, VEGF, FGF, and DKK1 was down-regulated in FLS treated with dasatinib. Our findings suggest that dasatinib exhibited treatment effects on CIA mice and that FLS are an important target cell of dasatinib treatment in autoimmune arthritis.

Effectiveness and Safety of Fixed-Dose Tranexamic Acid in Simultaneous Bilateral Total Knee Arthroplasty: A Randomized Double-Blind Controlled Trial.

BACKGROUND: Simultaneous bilateral total knee arthroplasty (TKA) can lead to greater blood loss and higher risk of venous thromboembolism. The effectiveness and safety of tranexamic acid (TXA) in simultaneous bilateral TKAs have not been clearly defined. We presumed that a fixed dose of TXA may be a preferable alternative for ease of administration in patients undergoing simultaneous bilateral TKAs. METHODS: We prospectively randomized 120 primary simultaneous bilateral TKAs to a fixed dose of TXA or equivalent volume of normal saline intravenously. The primary outcome measure was total blood loss. The secondary outcome measures were blood transfusion rate, transfusion units, intraoperative blood loss, drainage volumes, hidden blood loss, maximum decline of hemoglobin, and postoperative suprapatellar girth increment. RESULTS: There were statistically significant lower total blood loss, blood transfusion rate, drainage volumes, transfusion units, and maximum decline of hemoglobin in the TXA group than in the control group (P < .05), without increasing incidence of asymptomatic and symptomatic venous thromboembolism. However, TXA did not significantly reduce the hidden blood loss (P = .123). No differences were observed in suprapatellar girth increments between both groups on postoperative day 5 and week 6 (P = .251 and .299). CONCLUSION: Fixed dose of TXA for patients undergoing simultaneous bilateral TKAs was effective and safe in reducing total blood loss and allogeneic blood transfusion needs without any additional thromboembolic risk. However, TXA administered intravenously did not significantly reduce the hidden blood loss.

MiR-210 inhibits NF-κB signaling pathway by targeting DR6 in osteoarthritis.

Osteoarthritis (OA) is characterized by degradation of articular cartilage and joint inflammation. MicroRNAs have been proved to play an important role in the regulation of chondrogenesis. Previous study showed that microRNA-210 (miR-210) was probably associated with osteoarthritis, while the function of miR-210 in osteoarthritis still remains unknown. The aim of the present study was to investigate the protective effect of miR-210 on osteoarthritis. In the in vitro study, miR-210 level in chondrocytes was decreased after treatment with lipopolysaccharide (LPS). Transfection with miR-210 mimic inhibited LPS-induced pro-inflammatory cytokines production, cell viability reduction and cell apoptosis. Results of luciferase activity assay showed that miR-210 targeted 3'-UTR of death receptor 6 (DR6) to inhibit its expression. MiR-210 mimic and DR6 siRNA transfection inhibited the activation of NF-κB pathway and cell apoptosis of chondrocytes. For the in vivo study, OA model was established on rats by anterior cruciate ligament transection (ACLT). MiR-210 expression is reduced in OA rats. MiR-210 over-expressing lentivirus was injected into the OA rats. Cytokines production, and NF-κB and DR6 expression in OA rats was inhibited by miR-210 overexpression. The results demonstrated that miR-210 decreased inflammation in articular cavity in OA rats by targeting DR6 and inhibiting NF-κB signaling pathway.

Osteoprotective effect of cordycepin on estrogen deficiency-induced osteoporosis in vitro and in vivo.

The purpose of this study was to verify the effect of cordycepin on ovariectomized osteopenic rats. Fifty Wistar female rats used were divided into 5 groups: (1) sham-operation rats (control), (2) ovariectomized (OVX) rats with osteopenia, and (3) OVX'd rats with osteopenia treated with cordycepin (5 mg, 10 mg, and 20 mg) for 8 weeks. After the rats were treated orally with cordycepin, serum alkaline phosphatase (ALP), tartrate resistant acid phosphatase (TRAP), serum osteocalcin (OC), homocysteine (HCY) , C-terminal crosslinked telopeptides of collagen type I (CTX) level, and oxidative stress were examined, respectively. The femoral neck was used for mechanical compression testing. At the same time, we further investigated the effect of cordycepin in vitro assay. The beneficial effects of cordycepin on improvement of osteoporosis in rats were attributable mainly to decrease ALP activity, TRAP activity, and CTX level. At the same time, cordycepin also increases the OC level in ovariectomized osteopenic rats. The histological examination clearly showed that dietary cordycepin can prevent bone loss caused by estrogen deficiency. These experimental results suggest that complement cordycepin is protective after ovariectomized osteopenic in specific way.

Hyperglycemia promotes vasculogenesis in choroidal neovascularization in diabetic mice by stimulating VEGF and SDF-1 expression in retinal pigment epithelial cells.

To investigate the influence of hyperglycemia on the severity of choroidal neovascularization (CNV) in diabetic mice, especially the involvement of bone marrow-derived cells (BMCs) and underlying molecular mechanisms. The mice were randomly divided into control group, diabetes group and diabetes treated with insulin group, which were laser treated to induce CNV. The CNV severity was evaluated by fundus fluorescein angiography, HE staining and choroidal flatmount. The BMCs recruitment and differentiation in CNV were examined in GFP chimeric mice by choroidal flatmount and immunofluorescence. The bone marrow-derived mesenchymal stem cells (BMSCs) recruitment and migration were tested in vivo and in vitro. VEGF and SDF-1 production in vivo and in vitro were tested by realtime PCR and ELISA. The CNV severity and expression of VEGF and SDF-1 were enhanced in DM mice compared with control mice and that insulin treatment decreased CNV severity in DM mice. The DM mice demonstrated more BMCs and bone marrow-derived mesenchymal stem cells (BMSCs) recruited and incorporated into CNV, increased ratio of BMCs expressing endothelial cell marker or macrophage marker, and up-regulated expression of VEGF and SDF-1 in CNV. Human BMSCs migration and expression of VEGF and SDF-1 in retinal pigment epithelial (RPE) cells increased when cultured under high glucose. This study suggested that hyperglycemia enhanced the expression of VEGF and SDF-1 in RPE cells, and promoted recruitment and incorporation of BMCs and affected differentiation of BMCs in CNV, which led to more severe CNV in diabetic mice.