Increasing evidences show that aberrant subchondral bone remodeling plays an important role in the development of osteoarthritis(OA).However,how subchondral bone formation is activated and the mechanism by which incre...Increasing evidences show that aberrant subchondral bone remodeling plays an important role in the development of osteoarthritis(OA).However,how subchondral bone formation is activated and the mechanism by which increased subchondral bone turnover promotes cartilage degeneration during OA remains unclear.Here,we show that the mechanistic target of rapamycin complex 1(mTORC1)pathway is activated in subchondral bone preosteoblasts(Osterix+)from OA patients and mice.Constitutive activation of mTORC1 in preosteoblasts by deletion of the mTORC1 upstream inhibitor,tuberous sclerosis 1,induced aberrant subchondral bone formation,and sclerosis with little-to-no effects on articular cartilage integrity,but accelerated posttraumatic OA development in mice.In contrast,inhibition of mTORC1 in preosteoblasts by disruption of Raptor(mTORC1-specific component)reduced subchondral bone formation and cartilage degeneration,and attenuated post-traumatic OA in mice.Mechanistically,mTORC1 activation promoted preosteoblast expansion and Cxcl12 secretion,which induced subchondral bone remodeling and cartilage degeneration during OA.A Cxcl12-neutralizing antibody reduced cartilage degeneration and alleviated OA in mice.Altogether,these findings demonstrate that mTORC1 activation in subchondral preosteoblasts is not sufficient to induce OA,but can induce aberrant subchondral bone formation and secrete of Cxcl12 to accelerate disease progression following surgical destabilization of the joint.Pharmaceutical inhibition of the pathway presents a promising therapeutic approach for OA treatment.展开更多
Osteoporosis is a highly prevalent public health burden associated with an increased risk of bone fracture, particularly in aging women. Estrogen, an important medicinal component for the preventative and therapeutic ...Osteoporosis is a highly prevalent public health burden associated with an increased risk of bone fracture, particularly in aging women. Estrogen, an important medicinal component for the preventative and therapeutic treatment of postmenopausal osteoporosis, induces osteogenesis by activating the estrogen receptor signaling pathway and upregulating the expression of osteogenic genes, such as bone morphogenetic proteins(BMPs). The epigenetic regulation of estrogen-mediated osteogenesis,however, is still unclear. In this report, we found that estrogen significantly induced the expression of lysine-specific demethylase 6B(KDM6B) and that KDM6B depletion by shRNAs led to a significant reduction in the osteogenic potential of DMSCs.Mechanistically, upon estrogen stimulation, estrogen receptor-α(ERα) was recruited to the KDM6B promoter, directly enhancing KDM6B expression. Subsequently, KDM6B was recruited to the BMP2 and HOXC6 promoters, resulting in the removal of H3K27me3 marks and activating the transcription of BMP2 and HOXC6, the master genes of osteogenic differentiation. Furthermore, we found that estrogen enhanced DMSC osteogenesis during calvarial bone regeneration and that estrogen’s pro-osteogenic effect was dependent on KDM6B in vivo. Taken together, our results demonstrate the vital role of the ERα/KDM6B regulatory axis in the epigenetic regulation of the estrogen-dependent osteogenic response.展开更多
An astroglial cell line was established from the brain of half smooth tongue sole （Cynoglossus semilaevis） and was designated as CSAC. CSAC shows the morphological homogeneity of epithelial cells. The cell identity ...An astroglial cell line was established from the brain of half smooth tongue sole （Cynoglossus semilaevis） and was designated as CSAC. CSAC shows the morphological homogeneity of epithelial cells. The cell identity was tested by the presence of glial fibrillary acidic protein （GFAP）, which was revealed by RT-PCR and immunofluorescence. The cell line was optimally maintained at 24 ℃ in minimum essential medium supplemented with HEPES, antibiotics, 20% fetal bovine serum, 2- Mercaptoethanol （2-Me） and basic fibroblast growth factor. Chromosome analysis revealed that the CSAC cells maintained a normal diploid chromosome number （2n=42）. The fluorescent signals were observed in CSAC after the cells were transfected with green fluorescent protein （GFP） reporter plasmids. The CSAC cell line may serve as a valuable tool for studies on the potential functions of fish astroglial cells.展开更多
Mitochondria are well-acknowledged as ideal targets for tumor therapy due to their important role in energy supply and cellular signal regulation.Mitochondria-specific photosensitizers have been reported to be critica...Mitochondria are well-acknowledged as ideal targets for tumor therapy due to their important role in energy supply and cellular signal regulation.Mitochondria-specific photosensitizers have been reported to be critical for inducing cell apoptosis.Two-photon fluorescence imaging provides a new technique for delineating biological structures and activities in deep tissues.Herein,we developed a new aggregation-induced emission(AIE)active photosensitizer by attaching a pyridinium group for mitochondrial target-ing.The rationally designed photosensitizer(TTTP)exhibited excellent photophysical properties,good biocompatibility,reactive oxygen species(ROS)stimulation ability,anticancer efficacy,and two-photon imaging properties.TTTP was highly taken up by cells and accumulated specifically in mitochondria but was selectively cytotoxic to cancer cells.Under light irradiation,the generation of ROS was significantly boosted,leading to actively induced apoptosis.The in vivo tumor photodynamic therapeutic efficacy of TTTP showed significant inhibition of tumor growth.Furthermore,the underlying mechanism of TTTP tu-mor suppression revealed that the apoptosis agonist Bax was markedly up-regulated while the antagonist Bcl-xL was down-regulated.This research provides a potential mitochondrial-targeted phototherapeutic agent for effective therapy and two-photon fluorescence imaging.展开更多
基金supported by grants from National Natural Science Foundation of China (Grant Nos.81371990,81625015,81601945,and 81530070)the Program for Changjiang Scholars and Innovative Research Team in University (IRT_16R37)
文摘Increasing evidences show that aberrant subchondral bone remodeling plays an important role in the development of osteoarthritis(OA).However,how subchondral bone formation is activated and the mechanism by which increased subchondral bone turnover promotes cartilage degeneration during OA remains unclear.Here,we show that the mechanistic target of rapamycin complex 1(mTORC1)pathway is activated in subchondral bone preosteoblasts(Osterix+)from OA patients and mice.Constitutive activation of mTORC1 in preosteoblasts by deletion of the mTORC1 upstream inhibitor,tuberous sclerosis 1,induced aberrant subchondral bone formation,and sclerosis with little-to-no effects on articular cartilage integrity,but accelerated posttraumatic OA development in mice.In contrast,inhibition of mTORC1 in preosteoblasts by disruption of Raptor(mTORC1-specific component)reduced subchondral bone formation and cartilage degeneration,and attenuated post-traumatic OA in mice.Mechanistically,mTORC1 activation promoted preosteoblast expansion and Cxcl12 secretion,which induced subchondral bone remodeling and cartilage degeneration during OA.A Cxcl12-neutralizing antibody reduced cartilage degeneration and alleviated OA in mice.Altogether,these findings demonstrate that mTORC1 activation in subchondral preosteoblasts is not sufficient to induce OA,but can induce aberrant subchondral bone formation and secrete of Cxcl12 to accelerate disease progression following surgical destabilization of the joint.Pharmaceutical inhibition of the pathway presents a promising therapeutic approach for OA treatment.
基金supported by NIH/NIDCR grants K08DE024603, R01DE16513, and R01DE024828
文摘Osteoporosis is a highly prevalent public health burden associated with an increased risk of bone fracture, particularly in aging women. Estrogen, an important medicinal component for the preventative and therapeutic treatment of postmenopausal osteoporosis, induces osteogenesis by activating the estrogen receptor signaling pathway and upregulating the expression of osteogenic genes, such as bone morphogenetic proteins(BMPs). The epigenetic regulation of estrogen-mediated osteogenesis,however, is still unclear. In this report, we found that estrogen significantly induced the expression of lysine-specific demethylase 6B(KDM6B) and that KDM6B depletion by shRNAs led to a significant reduction in the osteogenic potential of DMSCs.Mechanistically, upon estrogen stimulation, estrogen receptor-α(ERα) was recruited to the KDM6B promoter, directly enhancing KDM6B expression. Subsequently, KDM6B was recruited to the BMP2 and HOXC6 promoters, resulting in the removal of H3K27me3 marks and activating the transcription of BMP2 and HOXC6, the master genes of osteogenic differentiation. Furthermore, we found that estrogen enhanced DMSC osteogenesis during calvarial bone regeneration and that estrogen’s pro-osteogenic effect was dependent on KDM6B in vivo. Taken together, our results demonstrate the vital role of the ERα/KDM6B regulatory axis in the epigenetic regulation of the estrogen-dependent osteogenic response.
基金supported by grants from the National Natural Science Foundation of China(31130057)the State863 High-Technology R&D Project of China(2012AA10A408)+1 种基金the Taishan Scholar Project Fund of Shandong Province of Chinathe Special Scientific Research Funds for the Central Non-profit Institutes,Chinese Academy of Fishery Sciences(2013A0402)
文摘An astroglial cell line was established from the brain of half smooth tongue sole （Cynoglossus semilaevis） and was designated as CSAC. CSAC shows the morphological homogeneity of epithelial cells. The cell identity was tested by the presence of glial fibrillary acidic protein （GFAP）, which was revealed by RT-PCR and immunofluorescence. The cell line was optimally maintained at 24 ℃ in minimum essential medium supplemented with HEPES, antibiotics, 20% fetal bovine serum, 2- Mercaptoethanol （2-Me） and basic fibroblast growth factor. Chromosome analysis revealed that the CSAC cells maintained a normal diploid chromosome number （2n=42）. The fluorescent signals were observed in CSAC after the cells were transfected with green fluorescent protein （GFP） reporter plasmids. The CSAC cell line may serve as a valuable tool for studies on the potential functions of fish astroglial cells.
基金supported by the Natural Sci-ence Foundation of Fujian Province(No.2021J011374)the Science and Technology Program of Guangzhou(No.202002030486)the Science and Technology Project of Guangdong Province(No.2018B090944002).
文摘Mitochondria are well-acknowledged as ideal targets for tumor therapy due to their important role in energy supply and cellular signal regulation.Mitochondria-specific photosensitizers have been reported to be critical for inducing cell apoptosis.Two-photon fluorescence imaging provides a new technique for delineating biological structures and activities in deep tissues.Herein,we developed a new aggregation-induced emission(AIE)active photosensitizer by attaching a pyridinium group for mitochondrial target-ing.The rationally designed photosensitizer(TTTP)exhibited excellent photophysical properties,good biocompatibility,reactive oxygen species(ROS)stimulation ability,anticancer efficacy,and two-photon imaging properties.TTTP was highly taken up by cells and accumulated specifically in mitochondria but was selectively cytotoxic to cancer cells.Under light irradiation,the generation of ROS was significantly boosted,leading to actively induced apoptosis.The in vivo tumor photodynamic therapeutic efficacy of TTTP showed significant inhibition of tumor growth.Furthermore,the underlying mechanism of TTTP tu-mor suppression revealed that the apoptosis agonist Bax was markedly up-regulated while the antagonist Bcl-xL was down-regulated.This research provides a potential mitochondrial-targeted phototherapeutic agent for effective therapy and two-photon fluorescence imaging.
