BACKGROUND:During bone remodeling,bone formation and bone resorption are spatially and temporally coordinated,involving intricate interactions between osteoclasts and osteoblasts.Isoginkgetin,a flavonoid found in Ginkgo biloba,has a wide range of anticancer activity and anti-reactive oxygen species activity;however,the effect of isoginkgetin on osteoclast differentiation is unknown.OBJECTIVE:To study the effect and mechanism of action of isoginkgetin on osteoclastogenesis.METHODS:In vitro studies were performed on mouse bone marrow-derived macrophages,and cell counting kit-8 cytotoxicity assay was used to detect the effect of isoginkgetin on cell viability of bone marrow-derived macrophages.Macrophage colony-stimulating factor and receptor activator of nuclear factor kappa-B ligand were used to induce the differentiation of bone marrow-derived macrophages to osteoclasts.Network pharmacology and molecular docking and molecular dynamics simulations were used to predict the processes and targets of the effects of isoginkgetin on the differentiation of osteoclasts.Tartrate-resistant acid phosphatase staining and F-actin staining were used to detect the effects of isoginkgetin on the differentiation and function of osteoclasts.Western blot and RT-PCR were used to detect the effects of isoginkgetin on the expression of genes and proteins related to osteoclast differentiation,reactive oxygen species,and PI3K/AKT pathways.Fluorescent probes were used to detect cellular and mitochondrial reactive oxygen species levels.Flow cytometry technology was used to detect reactive oxygen species levels in cells.RESULTS AND CONCLUSION:(1)Network pharmacology results showed that isoginkgetin affected osteoporosis mainly through the PI3K-AKT pathway and cellular response to drugs and hypoxia,and GSK3β,ESR1,MCL1 and CCNA2 were the key targets.(2)Cell counting kit-8 and tartrate-resistant acid phosphatase staining results showed that isoginkgetin at 8 μmol/L had the most significant inhibitory effect on osteoclastogenesis in vitro,and F-actin results showed that isoginkgetin inhibited osteoclast cytoskeletal actin ring formation in a concentration-dependent manner.(3)Molecular dynamics simulations showed that isoginkgetin bound well to osteoclastogenesis marker proteins(NFATc1,c-Fos,CTSK,and MMP9).Western blot and RT-PCR results indicated that isoginkgetin inhibited the expression of osteoclastogenesis marker proteins and genes(NFATc1,c-Fos,CTSK,and MMP9).(4)Western blot results showed that isoginkgetin inhibited the phosphorylation level of PI3K/AKT/GSK3β and suppressed osteoclastogenesis by activating the PI3K-AKT-GSK3β pathway.(5)The results of reactive oxygen species assay showed that isoginkgetin significantly reduced receptor activator of nuclear factor kappa-B ligand-induced cellular and mitochondrial reactive oxygen species production,and inhibited the differentiation of bone marrow-derived macrophages to osteoclasts.

BACKGROUND:During bone remodeling,bone formation and bone resorption are spatially and temporally coordinated,involving intricate interactions between osteoclasts and osteoblasts.Isoginkgetin,a flavonoid found in Ginkgo biloba,has a wide range of anticancer activity and anti-reactive oxygen species activity;however,the effect of isoginkgetin on osteoclast differentiation is unknown.OBJECTIVE:To study the effect and mechanism of action of isoginkgetin on osteoclastogenesis.METHODS:In vitro studies were performed on mouse bone marrow-derived macrophages,and cell counting kit-8 cytotoxicity assay was used to detect the effect of isoginkgetin on cell viability of bone marrow-derived macrophages.Macrophage colony-stimulating factor and receptor activator of nuclear factor kappa-B ligand were used to induce the differentiation of bone marrow-derived macrophages to osteoclasts.Network pharmacology and molecular docking and molecular dynamics simulations were used to predict the processes and targets of the effects of isoginkgetin on the differentiation of osteoclasts.Tartrate-resistant acid phosphatase staining and F-actin staining were used to detect the effects of isoginkgetin on the differentiation and function of osteoclasts.Western blot and RT-PCR were used to detect the effects of isoginkgetin on the expression of genes and proteins related to osteoclast differentiation,reactive oxygen species,and PI3K/AKT pathways.Fluorescent probes were used to detect cellular and mitochondrial reactive oxygen species levels.Flow cytometry technology was used to detect reactive oxygen species levels in cells.RESULTS AND CONCLUSION:(1)Network pharmacology results showed that isoginkgetin affected osteoporosis mainly through the PI3K-AKT pathway and cellular response to drugs and hypoxia,and GSK3β,ESR1,MCL1 and CCNA2 were the key targets.(2)Cell counting kit-8 and tartrate-resistant acid phosphatase staining results showed that isoginkgetin at 8 μmol/L had the most significant inhibitory effect on osteoclastogenesis in vitro,and F-actin results showed that isoginkgetin inhibited osteoclast cytoskeletal actin ring formation in a concentration-dependent manner.(3)Molecular dynamics simulations showed that isoginkgetin bound well to osteoclastogenesis marker proteins(NFATc1,c-Fos,CTSK,and MMP9).Western blot and RT-PCR results indicated that isoginkgetin inhibited the expression of osteoclastogenesis marker proteins and genes(NFATc1,c-Fos,CTSK,and MMP9).(4)Western blot results showed that isoginkgetin inhibited the phosphorylation level of PI3K/AKT/GSK3β and suppressed osteoclastogenesis by activating the PI3K-AKT-GSK3β pathway.(5)The results of reactive oxygen species assay showed that isoginkgetin significantly reduced receptor activator of nuclear factor kappa-B ligand-induced cellular and mitochondrial reactive oxygen species production,and inhibited the differentiation of bone marrow-derived macrophages to osteoclasts.

The bromodomain and extraterminal domain (Bet) family are the regulators of the epigenome and also the pivotal driving factors for the expression of tumor related genes that tumor cells depend on for survival and proliferation. Bromodomain-containing protein 4 (Brd4) is a member of the Bet protein family. Generally, Brd4 identifies acetylated histones and binds to the promoter or enhancer region of target genes to initiate and maintain expression of tumor related genes. Brd4 is closely related to the regulation of multiple transcription factors and chromatin modification and is involved in DNA damage repair and maintenance of telomere function, thus maintaining the survival of tumor cells. This review summarizes the structure and function of Brd4 protein and the application of its inhibitors in tumor research.
Humans ; Transcription Factors/metabolism* ; Nuclear Proteins/metabolism* ; Histones ; Cell Cycle Proteins/metabolism* ; Neoplasms/metabolism* ; Protein Domains

A 74-year-old male patient underwent aortic valve replacement and coronary artery bypass grafting under general anesthesia and cardiopulmonary bypass for valvular heart disease. After cardiopulmonary bypass, protamine sulfate injection 50 mg (5 ml) was slowly intravenously injected to neutralize heparin sodium. At about 3 minutes of the injection (injection dose was about 15 mg), the patient suddenly developed decreased blood pressure, increased heart rate, and shortness of breath. Redness appeared on the skin around the injection site and there were light red rashes. In consideration of protamine allergy, the infusion was stopped immediately and anti-allergic drugs such as diphenhydramine, dexamethasone, and adrenaline were injected intravenously. After about 30 minutes, his blood pressure increased, heart rate decreased, and the rashes gradually subsided. Due to insufficient dose of protamine, the patient had more oozing and exudation in the thoracic cavity, resulting in a decrease in blood pressure and prolonged prothrombin time. Then protamine sulfate injection 50 mg (5 ml) diluted in 0.9% sodium chloride injection 100 ml was given by intravenous injection at a rate of 60 drops/min. The patient did not have any allergy again, the pleural drainage fluid was gradually reduced, and his blood pressure returned to normal.

A 74-year-old male patient underwent aortic valve replacement and coronary artery bypass grafting under general anesthesia and cardiopulmonary bypass for valvular heart disease. After cardiopulmonary bypass, protamine sulfate injection 50 mg (5 ml) was slowly intravenously injected to neutralize heparin sodium. At about 3 minutes of the injection (injection dose was about 15 mg), the patient suddenly developed decreased blood pressure, increased heart rate, and shortness of breath. Redness appeared on the skin around the injection site and there were light red rashes. In consideration of protamine allergy, the infusion was stopped immediately and anti-allergic drugs such as diphenhydramine, dexamethasone, and adrenaline were injected intravenously. After about 30 minutes, his blood pressure increased, heart rate decreased, and the rashes gradually subsided. Due to insufficient dose of protamine, the patient had more oozing and exudation in the thoracic cavity, resulting in a decrease in blood pressure and prolonged prothrombin time. Then protamine sulfate injection 50 mg (5 ml) diluted in 0.9% sodium chloride injection 100 ml was given by intravenous injection at a rate of 60 drops/min. The patient did not have any allergy again, the pleural drainage fluid was gradually reduced, and his blood pressure returned to normal.

To investigate the effect of naringenin on ovariectomy-induced postmenopausal osteoporosis comprehensively and systemically, thirty-two virgin Sprague-Dawley rats about 3-month-old were used and randomly divided into 4 groups: sham control group (Sham), OVX control group (OVX), naringenin treatment group and 17β-estradiol (E2) treatment group. After 12 weeks treatment with different drugs, 24 h urine were collected, organs were weighed and the organ indies were computed. Uterine pathological changes were observed by making paraffin section. Biochemical parameters and bone turnover markers: serum osteocalcin (BGP) and urine deoxypyridinoline (DPD) were analyzed with automatic biochemical analyzer or ELISA assay. Bone mineral density (BMD) and bone mineral content (BMC) were analyzed by DEXA, bone biomechanical properties was measured by three point bending test and the trabecular bone microarchitecture was evaluated by Micro CT. From the results, we can see that: the gaining of weight and the increasing of bone turnover markers such as serum BGP and urinary DPD could be inhibited by naringenin. The treatment could also enhance the bone strength and prevent the deterioration of trabecular microarchitecture, increase the bone volume, trabecular number and thickness, and decrease the trabecular space. The effects mentioned above were not accompanied with stimulating effects on uterus. Long-term using of naringenin had no obvious influence on other organs and the liver and kidney functions. The study suggests that naringenin had obvious antiosteoporotic effect on ovariectomized rats and it had the potential value for the treatment of postmenopausal osteoporosis.