BACKGROUND The efficacy and safety of transarterial chemoembolization(TACE)combined with lenvatinib plus programmed cell death protein-1(PD-1)for unresectable hepato-cellular carcinoma(HCC)have rarely been evaluated a...BACKGROUND The efficacy and safety of transarterial chemoembolization(TACE)combined with lenvatinib plus programmed cell death protein-1(PD-1)for unresectable hepato-cellular carcinoma(HCC)have rarely been evaluated and it is unknown which factors are related to efficacy.AIM To evaluate the efficacy and independent predictive factors of TACE combined with lenvatinib plus PD-1 inhibitors for unresectable HCC.METHODS This study retrospectively enrolled patients with unresectable HCC who received TACE/lenvatinib/PD-1 treatment between March 2019 and April 2022.Overall survival(OS)and progression-free survival(PFS)were determined.The objective response rate(ORR)and disease control rate(DCR)were evaluated in accordance with the modified Response Evaluation Criteria in Solid Tumors.Additionally,the prognostic factors affecting the clinical outcome were assessed.RESULTS One hundred and two patients were enrolled with a median follow-up duration of 12.63 months.The median OS was 26.43 months(95%CI:17.00-35.87),and the median PFS was 10.07 months(95%CI:8.50-11.65).The ORR and DCR were 61.76%and 81.37%,respectively.The patients with Barcelona Clinic Liver Cancer Classification(BCLC)B stage,early neutrophil-to-lymphocyte ratio(NLR)response(decrease),or early alpha-fetoprotein(AFP)response(decrease>20%)had superior OS and PFS than their counterparts.CONCLUSION This study showed that TACE/lenvatinib/PD-1 treatment was well tolerated with encouraging efficacy in patients with unresectable HCC.The patients with BCLC B-stage disease with early NLR response(decrease)and early AFP response(decrease>20%)may achieve better clinical outcomes with this triple therapy.展开更多
Studies have shown that C1q/tumor necrosis factor-related protein-6 (CTRP6) can alleviate renal ischemia/reperfusion injury in mice. However, its role in the brain remains poorly understood. To investigate the role of...Studies have shown that C1q/tumor necrosis factor-related protein-6 (CTRP6) can alleviate renal ischemia/reperfusion injury in mice. However, its role in the brain remains poorly understood. To investigate the role of CTRP6 in cerebral ischemia/reperfusion injury associated with diabetes mellitus, a diabetes mellitus mouse model of cerebral ischemia/reperfusion injury was established by occlusion of the middle cerebral artery. To overexpress CTRP6 in the brain, an adeno-associated virus carrying CTRP6 was injected into the lateral ventricle. The result was that oxygen injury and inflammation in brain tissue were clearly attenuated, and the number of neurons was greatly reduced. In vitro experiments showed that CTRP6 knockout exacerbated oxidative damage, inflammatory reaction, and apoptosis in cerebral cortical neurons in high glucose hypoxia-simulated diabetic cerebral ischemia/reperfusion injury. CTRP6 overexpression enhanced the sirtuin-1 signaling pathway in diabetic brains after ischemia/reperfusion injury. To investigate the mechanism underlying these effects, we examined mice with depletion of brain tissue-specific sirtuin-1. CTRP6-like protection was achieved by activating the sirtuin-1 signaling pathway. Taken together, these results indicate that CTRP6 likely attenuates cerebral ischemia/reperfusion injury through activation of the sirtuin-1 signaling pathway.展开更多
BACKGROUND The combination of programmed cell death protein-1(PD-1)inhibitor and che-motherapy is approved as a standard first-or second-line treatment in patients with advanced oesophageal or gastric cancer.However,i...BACKGROUND The combination of programmed cell death protein-1(PD-1)inhibitor and che-motherapy is approved as a standard first-or second-line treatment in patients with advanced oesophageal or gastric cancer.However,it is unclear whether this combination is superior to chemotherapy alone.AIM To assess the comparative effectiveness and tolerability of combining PD-1 inhibitors with chemotherapy vs chemotherapy alone in patients with advanced gastric cancer,gastroesophageal junction(GEJ)cancer,or oesophageal carcinoma.METHODS We searched the PubMed and Embase databases for studies that compared the efficacy and tolerance of PD-1 inhibitors in combination with chemotherapy vs chemotherapy alone in patients with advanced oesophageal or gastric cancer.We employed either random or fixed models to analyze the outcomes of each clinical trial,en-compassing data on overall survival(OS),progression-free survival(PFS),objective response rate,and adverse events(AEs).RESULTS Nine phase 3 clinical trials(7016 advanced oesophageal and gastric cancer patients)met the inclusion criteria.Our meta-analysis demonstrated that the pooled PD-1 inhibitor+chemotherapy group had a significantly longer OS than the chemotherapy-alone group[hazard ratio(HR)=0.76,95%confidence interval(CI):0.71-0.81];the pooled PFS result was consistent with that of OS(HR=0.67,95%CI:0.61-0.74).The count of patients achieving an objective response in the PD-1 inhibitor+chemotherapy group surpassed that of the chemotherapy-alone group[odds ratio(OR)=1.86,95%CI:1.59-2.18].AE incidence was also higher in the combination-therapy group than in the chemotherapy-alone group,regardless of whether≥grade 3 only(OR=1.30,95%CI:1.07-1.57)or all AE grades(OR=1.88,95%CI:1.39-2.54)were examined.We performed a subgroup analysis based on the programmed death-ligand 1(PD-L1)combined positive score(CPS)and noted extended OS and PFS durations within the CPS≥1,CPS≥5,and CPS≥10 subgroups of the PD-1 inhibitor+chemotherapy group.CONCLUSION In contrast to chemotherapy alone,the combination of PD-1 inhibitor and chemotherapy appears to present a more favorable option for initial or subsequent treatment in patients with gastric cancer,GEJ tumor,or oesophageal cancer.This holds true particularly for individuals with PD-L1 CPS scores of≥5 and≥10.展开更多
背景:程序性细胞死亡受体1(programmed death receptor-1,PD-1)在高糖环境下影响骨髓间充质干细胞成骨分化的作用机制尚不清楚。目的:探讨高糖环境中PD-1对大鼠骨髓间充质干细胞成骨分化的影响及其调控机制。方法:将大鼠骨髓间充质干细...背景:程序性细胞死亡受体1(programmed death receptor-1,PD-1)在高糖环境下影响骨髓间充质干细胞成骨分化的作用机制尚不清楚。目的:探讨高糖环境中PD-1对大鼠骨髓间充质干细胞成骨分化的影响及其调控机制。方法:将大鼠骨髓间充质干细胞随机分为正常糖组(5.6 mmol/L)、高糖组(30 mmol/L)、PD-1过表达组、PD-1过表达空载组、PD-1敲低组、PD-1敲低空载组、PI3K/AKT通路抑制剂组(PD-1敲低+5μmol/L LY294002)。通过在高糖培养基中培养大鼠骨髓间充质干细胞来模拟体外糖尿病环境,采用qRT-PCR检测大鼠骨髓间充质干细胞中PD-1及其配体PD-L1和成骨标志物Runx2、OSX的mRNA表达,采用碱性磷酸酶染色和茜素红S染色观察成骨分化能力,采用CCK-8检测细胞增殖情况,采用Western blot检测PD-1、PD-L1、p-PI3K、p-AKT的蛋白表达。结果与结论:①高糖组PD-1及PD-L1表达显著高于正常糖组,高糖组骨髓间充质干细胞的成骨分化能力较正常糖组显著下降;②敲低PD-1表达可以促进骨髓间充质干细胞的成骨分化、增加细胞增殖活性,同时激活PI3K/AKT通路;③加入PI3K/AKT通路抑制剂LY294002后,骨髓间充质干细胞成骨分化能力显著下降。结果表明:PD-1依赖于PI3K/AKT信号通路抑制高糖环境下大鼠骨髓间充质干细胞的成骨分化。展开更多
ALKBH1 was recently discovered as a demethylase for DNA N6-methyladenine (N6-mA), a new epigenetic modification, and interacts with the core transcriptional pluripotency network of embryonic stem cells. However, the...ALKBH1 was recently discovered as a demethylase for DNA N6-methyladenine (N6-mA), a new epigenetic modification, and interacts with the core transcriptional pluripotency network of embryonic stem cells. However, the role of ALKBH1 and DNA N6-mA in regulating osteogenic differentiation is largely unknown. In this study, we demonstrated that the expression of ALKBH1 in human mesenchymal stem cells (MSCs) was upregulated during osteogenic induction. Knockdown of ALKBH1 increased the genomic DNA N6-mA levels and significantly reduced the expression of osteogenic-related genes, alkaline phosphatase activity, and mineralization. ALKBHl-depleted MSCs also exhibited a restricted capacity for bone formation in vivo. By contrast, the ectopic overexpression of ALKBH1 enhanced osteoblastic differentiation. Mechanically, we found that the depletion of ALKBH1 resulted in the accumulation of N6-mA on the promoter region of ATF4, which subsequently silenced ATF4 transcription. In addition, restoring the expression of ATP by adenovirus-mediated transduction successfully rescued osteogenic differentiation. Taken together, our results demonstrate that ALKBH1 is indispensable for the osteogenic differentiation of MSCs and indicate that DNA N6-mA modifications area new mechanism for the epigenetic regulation of stem cell differentiation.展开更多
AFF1 and AFF4 belong to the AFF (AF4/FMR2) family of proteins, which function as scaffolding proteins linking two different transcription elongation factors, positive elongation factor b (P-TEFb) and ELL1/2, in su...AFF1 and AFF4 belong to the AFF (AF4/FMR2) family of proteins, which function as scaffolding proteins linking two different transcription elongation factors, positive elongation factor b (P-TEFb) and ELL1/2, in super elongation complexes (SECs). Both AFF1 and AFF4 regulate gene transcription through elongation and chromatln remodeling. However, their function in the osteogenic differentiation of mesenchymal stem cells (MSCs) is unknown. In this study, we show that small interfering RNA (siRNA)-mediated depletion of AFF1 in human MSCs leads to increased alkaline phosphatase (ALP) activity, enhanced mineralization and upregulated expression of osteogenic-related genes. On the contrary, depletion of AFF4 significantly inhibits the osteogenic potential of MSCs. In addition, we confirm that overexpression of AFF1 and AFF4 differentially affects osteogenic differentiation in vitro and MSC-mediated bone formation in vivo. Mechanistically, we find that AFFI regulates the expression of DKK1 via binding to its promoter region. Depletion of DKK1 in HA-AFFl-overexpressing MSCs abrogates the impairment of osteogenic differentiation. Moreover, we detect that AFF4 is enriched in the promoter region of ID1. AFF4 knockdown blunts the BRE luciferase activity, SP7 expression and ALP activity induced by BMP2 treatment. In conclusion, our data indicate that AFF1 and AFF4 differentially regulate the osteogenic differentiation of human MSCs.AFF1 and AFF4 belong to the AFF (AF4/FMR2) family of proteins, which function as scaffolding proteins linking two different transcription elongation factors, positive elongation factor b (P-TEFb) and ELL1/2, in super elongation complexes (SECs). Both AFFI and AFF4 regulate gene transcription through elongation and chromatln remodeling. However, their function in the osteogenic differentiation of mesenchymal stem cells (MSCs) is unknown. In this study, we show that small interfering RNA (siRNA)-mediated depletion of AFF1 in human MSCs leads to increased alkaline phosphatase (ALP) activity, enhanced mineralization and upregulated expression of osteogenic-related genes. On the contrary, depletion of AFF4 significantly inhibits the osteogenic potential of MSCs. In addition, we confirm that overexpression of AFF1 and AFF4 differentially affects osteogenic differentiation in vitro and MSC-mediated bone formation in vivo. Mechanistically, we find that AFFI regulates the expression of DKK1 via binding to its promoter region. Depletion of DKK1 in HA-AFFl-overexpressing MSCs abrogates the impairment of osteogenic differentiation. Moreover, we detect that AFF4 is enriched in the promoter region of ID1. AFF4 knockdown blunts the BRE luciferase activity, SP7 expression and ALP activity induced by BMP2 treatment. In conclusion, our data indicate that AFF1 and AFF4 differentially regulate the osteogenic differentiation of human MSCs.展开更多
Bone tissue engineering may be hindered by underlying osteoporosis because of a decreased osteogenic ability of autologous seed cells and an unfavorably changed microenvironment in these patients. Epigenetic regulatio...Bone tissue engineering may be hindered by underlying osteoporosis because of a decreased osteogenic ability of autologous seed cells and an unfavorably changed microenvironment in these patients. Epigenetic regulation plays an important role in the developmental origins of osteoporosis; however, few studies have investigated the potential of epigenetic therapy to improve or rescue the osteogenic ability of bone marrow mesenchymal stem cells(BMMSCs) under osteoporotic conditions. Here, we investigated pargyline, an inhibitor of lysine-specific demethylase 1(LSD1), which mainly catalyzes the demethylation of the di- and mono-methylation of H3K4. We demonstrated that 1.5 mmol·Lpargyline was the optimal concentration for the osteogenic differentiation of human BMMSCs. Pargyline rescued the osteogenic differentiation ability of mouse BMMSCs under osteoporotic conditions by enhancing the dimethylation level of H3K4 at the promoter regions of osteogenesis-related genes. Moreover, pargyline partially rescued or prevented the osteoporotic conditions in aged or ovariectomized mouse models, respectively. By introducing the concept of epigenetic therapy into the field of osteoporosis, this study demonstrated that LSD1 inhibitors could improve the clinical practice of MSC-based bone tissue engineering and proposes their novel use to treat osteoporosis.展开更多
Toll-like receptor (TLR)-mediated inflammatory response could negatively affect bone metabolism. In this study, we determined how osteogenesis is regulated during inflammatory responses that are downstream of TLR si...Toll-like receptor (TLR)-mediated inflammatory response could negatively affect bone metabolism. In this study, we determined how osteogenesis is regulated during inflammatory responses that are downstream of TLR signaling. Human primary osteoblasts were cultured in collagen gels. Pam3CSK4 (P3C) and Escherichia coli lipopolysaccharide (EcLPS) were used as TLR2 and TLR4 ligand respectively. Porphyromonas gingivalis LPS having TLR2 activity with either TLR4 agonism (Pg1690) or TLR4 antagonism (Pg1449) and mutant E. coli LPS (LPxE/LPxF/WSK) were used. IL-lp, SH2-containing inositol phosphatase-1 (SHIP1) that has regulatory roles in osteogenesis, alkaline phosphatase and mineralization were analyzed. 3α-Aminocholestane (3AC) was used to inhibit SHIP1. Our results suggest that osteoblasts stimulated by P3C, poorly induced IL-1β but strongly upregulated SHIP1 and enhanced osteogenic mediators. On the contrary, EcLPS significantly induced IL-1β and osteogenic mediators were not induced. While Pg1690 downmodulated osteogenic mediators, Pg1449 enhanced osteogenic responses, suggesting that TLR4 signaling annuls osteogenesis even with TLR2 activity. Interestingly, mutant E. coli LPS that induces weak inflammation upregulated osteogenesis, but SHIP1 was not induced. Moreover, inhibiting SHIP1 significantly upregulated TLR2-mediated inflammatory response and downmodulated osteogenesis. In conclusion, these results suggest that induction of weak inflammatory response through TLR2 (with SHIP1 activity) and mutant TLR4 ligands could enhance osteogenesis.展开更多
To study the osteogenic potential of cultured bone marrow stromal cells transfected with transforming growth factor β 1 gene in vitro , cultured BMSCs were transfected with the complexes of pcDNA 3 TGF β ...To study the osteogenic potential of cultured bone marrow stromal cells transfected with transforming growth factor β 1 gene in vitro , cultured BMSCs were transfected with the complexes of pcDNA 3 TGF β 1 and Lipofectamine Reagent in vitro . The cell proliferation was detected by MTT method and the morphological features of transfected BMSCs was observed. ALP stains and PNP method were used to measure ALP activity. In addition, the collagen type Ⅰ propeptides and mineralized matrixes were examined by immunohistochemical staining and tetracycline fluorescence labeling respectively. The morphological and biological characters of the transfected BMSCs were similar to those of osteoblasts and the cell proliferation was promoted. The cell layer displayed strong positive reaction for ALP stains and immunohistochemical staining. ALP activity and collagen type Ⅰ expression increased remarkably after transfection. Mineralized matrixes formed earlier and more in transfected BMSCs as compared with control group. It is concluded that transfecting with TGF β 1 gene could promote the osteogenic potential of cultured BMSCs.展开更多
In this editorial,we comment on the article(World J Gastrointest Oncol 2024;16:1236-1247),which is a retrospective study of transarterial chemoembolization(TACE)combined with multi-targeted tyrosine kinase inhibitor(T...In this editorial,we comment on the article(World J Gastrointest Oncol 2024;16:1236-1247),which is a retrospective study of transarterial chemoembolization(TACE)combined with multi-targeted tyrosine kinase inhibitor(TKI)and programmed cell death protein-1(PD-1)inhibitor for the treatment of unresectable hepatocellular carcinoma(HCC).Herein,we focus specifically on the mechanisms of this triple therapy,administration sequence and selection of each medication,and implications for future clinical trials.Based on the interaction mechanisms between medications,the triple therapy of TACE+TKI+PD-1 is proposed to complement the deficiency of each monotherapy,and achieve synergistic antitumor effects.Although this triple therapy has been evaluated by several retrospective trials,it is still controversial whether the triple therapy achieves better clinical benefits,due to the flawed study design and heterogeneity in medications.In addition,the administration sequence,which may greatly affect the clinical benefit,needs to be fully considered at clinical decision-making for obtaining better prognosis.We hope that this editorial could contribute to the design and optimization of future trials.展开更多
Bone defects and non-union are prevalent in clinical orthopedy,and the outcomes of current treatments are often suboptimal.Bone tissue engineering offers a promising approach to treating these conditions effectively.B...Bone defects and non-union are prevalent in clinical orthopedy,and the outcomes of current treatments are often suboptimal.Bone tissue engineering offers a promising approach to treating these conditions effectively.Bone morphogenetic protein 9(BMP9)can commit mesenchymal stem cells to osteogenic lineage,and a knowledge of the underlying mechanisms may help advance the field of bone tissue engineering.Leucine-rich repeats con-taining G protein-coupled receptor 4(LGR4),a member of G protein-coupled receptors,is essential for modulating bone development.This study is aimed at investigating the impact of LGR4 on BMP9-induced osteogenesis in mesenchymal stem cells as well as the underlying mechanisms.Bone marrow stromal cells from BMp9-knockout mice exhibited diminished LGR4 expression,and exogenous LGR4 clearly restored the impaired osteogenic potency of the bone marrow stromal cells.Furthermore,LGR4 expression was increased by BMP9 in C3H10T1/2 cells.LGR4 augmented the benefits of BMP9-induced osteogenic markers and bone formation,whereas LGR4 inhibition restricted these effects.Meanwhile,the BMP9-induced li-pogenic markers were increased by LGR4 inhibition.The protein levels of Raptor and p-Stat3 were elevated by BMP9.Raptor knockdown or p-Stat3 suppression attenuated the osteoblastic markers and LGR4 expression brought on by BMP9.LGR4 significantly reversed the blocking ef-fect of Raptor knockdown or p-Stat3 suppression on the BMP9-induced osteoblastic markers.Raptor interacts with p-Stat3,and p-Stat3 activates the LGR4 promoter activity.In conclusion,LGR4 boosts BMP9 osteoblastic potency in mesenchymal stem cells,and BMP9 may up-regulate LGR4 via the mTORC1/Stat3 signal activation.展开更多
文摘BACKGROUND The efficacy and safety of transarterial chemoembolization(TACE)combined with lenvatinib plus programmed cell death protein-1(PD-1)for unresectable hepato-cellular carcinoma(HCC)have rarely been evaluated and it is unknown which factors are related to efficacy.AIM To evaluate the efficacy and independent predictive factors of TACE combined with lenvatinib plus PD-1 inhibitors for unresectable HCC.METHODS This study retrospectively enrolled patients with unresectable HCC who received TACE/lenvatinib/PD-1 treatment between March 2019 and April 2022.Overall survival(OS)and progression-free survival(PFS)were determined.The objective response rate(ORR)and disease control rate(DCR)were evaluated in accordance with the modified Response Evaluation Criteria in Solid Tumors.Additionally,the prognostic factors affecting the clinical outcome were assessed.RESULTS One hundred and two patients were enrolled with a median follow-up duration of 12.63 months.The median OS was 26.43 months(95%CI:17.00-35.87),and the median PFS was 10.07 months(95%CI:8.50-11.65).The ORR and DCR were 61.76%and 81.37%,respectively.The patients with Barcelona Clinic Liver Cancer Classification(BCLC)B stage,early neutrophil-to-lymphocyte ratio(NLR)response(decrease),or early alpha-fetoprotein(AFP)response(decrease>20%)had superior OS and PFS than their counterparts.CONCLUSION This study showed that TACE/lenvatinib/PD-1 treatment was well tolerated with encouraging efficacy in patients with unresectable HCC.The patients with BCLC B-stage disease with early NLR response(decrease)and early AFP response(decrease>20%)may achieve better clinical outcomes with this triple therapy.
基金supported by the National Natural Science Foundation of China,Nos.82102295(to WG),82071339(to LG),82001119(to JH),and 81901994(to BZ).
文摘Studies have shown that C1q/tumor necrosis factor-related protein-6 (CTRP6) can alleviate renal ischemia/reperfusion injury in mice. However, its role in the brain remains poorly understood. To investigate the role of CTRP6 in cerebral ischemia/reperfusion injury associated with diabetes mellitus, a diabetes mellitus mouse model of cerebral ischemia/reperfusion injury was established by occlusion of the middle cerebral artery. To overexpress CTRP6 in the brain, an adeno-associated virus carrying CTRP6 was injected into the lateral ventricle. The result was that oxygen injury and inflammation in brain tissue were clearly attenuated, and the number of neurons was greatly reduced. In vitro experiments showed that CTRP6 knockout exacerbated oxidative damage, inflammatory reaction, and apoptosis in cerebral cortical neurons in high glucose hypoxia-simulated diabetic cerebral ischemia/reperfusion injury. CTRP6 overexpression enhanced the sirtuin-1 signaling pathway in diabetic brains after ischemia/reperfusion injury. To investigate the mechanism underlying these effects, we examined mice with depletion of brain tissue-specific sirtuin-1. CTRP6-like protection was achieved by activating the sirtuin-1 signaling pathway. Taken together, these results indicate that CTRP6 likely attenuates cerebral ischemia/reperfusion injury through activation of the sirtuin-1 signaling pathway.
文摘BACKGROUND The combination of programmed cell death protein-1(PD-1)inhibitor and che-motherapy is approved as a standard first-or second-line treatment in patients with advanced oesophageal or gastric cancer.However,it is unclear whether this combination is superior to chemotherapy alone.AIM To assess the comparative effectiveness and tolerability of combining PD-1 inhibitors with chemotherapy vs chemotherapy alone in patients with advanced gastric cancer,gastroesophageal junction(GEJ)cancer,or oesophageal carcinoma.METHODS We searched the PubMed and Embase databases for studies that compared the efficacy and tolerance of PD-1 inhibitors in combination with chemotherapy vs chemotherapy alone in patients with advanced oesophageal or gastric cancer.We employed either random or fixed models to analyze the outcomes of each clinical trial,en-compassing data on overall survival(OS),progression-free survival(PFS),objective response rate,and adverse events(AEs).RESULTS Nine phase 3 clinical trials(7016 advanced oesophageal and gastric cancer patients)met the inclusion criteria.Our meta-analysis demonstrated that the pooled PD-1 inhibitor+chemotherapy group had a significantly longer OS than the chemotherapy-alone group[hazard ratio(HR)=0.76,95%confidence interval(CI):0.71-0.81];the pooled PFS result was consistent with that of OS(HR=0.67,95%CI:0.61-0.74).The count of patients achieving an objective response in the PD-1 inhibitor+chemotherapy group surpassed that of the chemotherapy-alone group[odds ratio(OR)=1.86,95%CI:1.59-2.18].AE incidence was also higher in the combination-therapy group than in the chemotherapy-alone group,regardless of whether≥grade 3 only(OR=1.30,95%CI:1.07-1.57)or all AE grades(OR=1.88,95%CI:1.39-2.54)were examined.We performed a subgroup analysis based on the programmed death-ligand 1(PD-L1)combined positive score(CPS)and noted extended OS and PFS durations within the CPS≥1,CPS≥5,and CPS≥10 subgroups of the PD-1 inhibitor+chemotherapy group.CONCLUSION In contrast to chemotherapy alone,the combination of PD-1 inhibitor and chemotherapy appears to present a more favorable option for initial or subsequent treatment in patients with gastric cancer,GEJ tumor,or oesophageal cancer.This holds true particularly for individuals with PD-L1 CPS scores of≥5 and≥10.
基金supported by grants from the National Natural Science Foundation of China (No.81271178 and 81470777)
文摘ALKBH1 was recently discovered as a demethylase for DNA N6-methyladenine (N6-mA), a new epigenetic modification, and interacts with the core transcriptional pluripotency network of embryonic stem cells. However, the role of ALKBH1 and DNA N6-mA in regulating osteogenic differentiation is largely unknown. In this study, we demonstrated that the expression of ALKBH1 in human mesenchymal stem cells (MSCs) was upregulated during osteogenic induction. Knockdown of ALKBH1 increased the genomic DNA N6-mA levels and significantly reduced the expression of osteogenic-related genes, alkaline phosphatase activity, and mineralization. ALKBHl-depleted MSCs also exhibited a restricted capacity for bone formation in vivo. By contrast, the ectopic overexpression of ALKBH1 enhanced osteoblastic differentiation. Mechanically, we found that the depletion of ALKBH1 resulted in the accumulation of N6-mA on the promoter region of ATF4, which subsequently silenced ATF4 transcription. In addition, restoring the expression of ATP by adenovirus-mediated transduction successfully rescued osteogenic differentiation. Taken together, our results demonstrate that ALKBH1 is indispensable for the osteogenic differentiation of MSCs and indicate that DNA N6-mA modifications area new mechanism for the epigenetic regulation of stem cell differentiation.
基金supported by grants from the National Natural Science Foundation of China(NSFC,81722014,81571001,81500354,and 81621062)Sichuan Province Science and Technology Innovation Team Program(2017TD0016)State Key Laboratory of Oral Diseases(SKLOD201704)
文摘AFF1 and AFF4 belong to the AFF (AF4/FMR2) family of proteins, which function as scaffolding proteins linking two different transcription elongation factors, positive elongation factor b (P-TEFb) and ELL1/2, in super elongation complexes (SECs). Both AFF1 and AFF4 regulate gene transcription through elongation and chromatln remodeling. However, their function in the osteogenic differentiation of mesenchymal stem cells (MSCs) is unknown. In this study, we show that small interfering RNA (siRNA)-mediated depletion of AFF1 in human MSCs leads to increased alkaline phosphatase (ALP) activity, enhanced mineralization and upregulated expression of osteogenic-related genes. On the contrary, depletion of AFF4 significantly inhibits the osteogenic potential of MSCs. In addition, we confirm that overexpression of AFF1 and AFF4 differentially affects osteogenic differentiation in vitro and MSC-mediated bone formation in vivo. Mechanistically, we find that AFFI regulates the expression of DKK1 via binding to its promoter region. Depletion of DKK1 in HA-AFFl-overexpressing MSCs abrogates the impairment of osteogenic differentiation. Moreover, we detect that AFF4 is enriched in the promoter region of ID1. AFF4 knockdown blunts the BRE luciferase activity, SP7 expression and ALP activity induced by BMP2 treatment. In conclusion, our data indicate that AFF1 and AFF4 differentially regulate the osteogenic differentiation of human MSCs.AFF1 and AFF4 belong to the AFF (AF4/FMR2) family of proteins, which function as scaffolding proteins linking two different transcription elongation factors, positive elongation factor b (P-TEFb) and ELL1/2, in super elongation complexes (SECs). Both AFFI and AFF4 regulate gene transcription through elongation and chromatln remodeling. However, their function in the osteogenic differentiation of mesenchymal stem cells (MSCs) is unknown. In this study, we show that small interfering RNA (siRNA)-mediated depletion of AFF1 in human MSCs leads to increased alkaline phosphatase (ALP) activity, enhanced mineralization and upregulated expression of osteogenic-related genes. On the contrary, depletion of AFF4 significantly inhibits the osteogenic potential of MSCs. In addition, we confirm that overexpression of AFF1 and AFF4 differentially affects osteogenic differentiation in vitro and MSC-mediated bone formation in vivo. Mechanistically, we find that AFFI regulates the expression of DKK1 via binding to its promoter region. Depletion of DKK1 in HA-AFFl-overexpressing MSCs abrogates the impairment of osteogenic differentiation. Moreover, we detect that AFF4 is enriched in the promoter region of ID1. AFF4 knockdown blunts the BRE luciferase activity, SP7 expression and ALP activity induced by BMP2 treatment. In conclusion, our data indicate that AFF1 and AFF4 differentially regulate the osteogenic differentiation of human MSCs.
基金supported by grants from the National Natural Science Foundation of China(81200763 to WG and 81070809 to YZ)the Program for New Century Excellent Talents(NCET)at the University from Ministry of Education of China(NCET-11-0026)+1 种基金the PKU School of Stomatology for Talented Young Investigators(PKUSS20150107)the Construction Program for the National Key Clinical Specialty from the National Health and Family Planning Commission of China(2011)
文摘Bone tissue engineering may be hindered by underlying osteoporosis because of a decreased osteogenic ability of autologous seed cells and an unfavorably changed microenvironment in these patients. Epigenetic regulation plays an important role in the developmental origins of osteoporosis; however, few studies have investigated the potential of epigenetic therapy to improve or rescue the osteogenic ability of bone marrow mesenchymal stem cells(BMMSCs) under osteoporotic conditions. Here, we investigated pargyline, an inhibitor of lysine-specific demethylase 1(LSD1), which mainly catalyzes the demethylation of the di- and mono-methylation of H3K4. We demonstrated that 1.5 mmol·Lpargyline was the optimal concentration for the osteogenic differentiation of human BMMSCs. Pargyline rescued the osteogenic differentiation ability of mouse BMMSCs under osteoporotic conditions by enhancing the dimethylation level of H3K4 at the promoter regions of osteogenesis-related genes. Moreover, pargyline partially rescued or prevented the osteoporotic conditions in aged or ovariectomized mouse models, respectively. By introducing the concept of epigenetic therapy into the field of osteoporosis, this study demonstrated that LSD1 inhibitors could improve the clinical practice of MSC-based bone tissue engineering and proposes their novel use to treat osteoporosis.
基金supported by Elam M. and Georgina E.Hack Memorial Research Funds,Department of Periodontics,University of Washington,Seattle,WA,USAsupported by WVCTSI funds,West Virginia University,Morgantown,WV,USA
文摘Toll-like receptor (TLR)-mediated inflammatory response could negatively affect bone metabolism. In this study, we determined how osteogenesis is regulated during inflammatory responses that are downstream of TLR signaling. Human primary osteoblasts were cultured in collagen gels. Pam3CSK4 (P3C) and Escherichia coli lipopolysaccharide (EcLPS) were used as TLR2 and TLR4 ligand respectively. Porphyromonas gingivalis LPS having TLR2 activity with either TLR4 agonism (Pg1690) or TLR4 antagonism (Pg1449) and mutant E. coli LPS (LPxE/LPxF/WSK) were used. IL-lp, SH2-containing inositol phosphatase-1 (SHIP1) that has regulatory roles in osteogenesis, alkaline phosphatase and mineralization were analyzed. 3α-Aminocholestane (3AC) was used to inhibit SHIP1. Our results suggest that osteoblasts stimulated by P3C, poorly induced IL-1β but strongly upregulated SHIP1 and enhanced osteogenic mediators. On the contrary, EcLPS significantly induced IL-1β and osteogenic mediators were not induced. While Pg1690 downmodulated osteogenic mediators, Pg1449 enhanced osteogenic responses, suggesting that TLR4 signaling annuls osteogenesis even with TLR2 activity. Interestingly, mutant E. coli LPS that induces weak inflammation upregulated osteogenesis, but SHIP1 was not induced. Moreover, inhibiting SHIP1 significantly upregulated TLR2-mediated inflammatory response and downmodulated osteogenesis. In conclusion, these results suggest that induction of weak inflammatory response through TLR2 (with SHIP1 activity) and mutant TLR4 ligands could enhance osteogenesis.
文摘To study the osteogenic potential of cultured bone marrow stromal cells transfected with transforming growth factor β 1 gene in vitro , cultured BMSCs were transfected with the complexes of pcDNA 3 TGF β 1 and Lipofectamine Reagent in vitro . The cell proliferation was detected by MTT method and the morphological features of transfected BMSCs was observed. ALP stains and PNP method were used to measure ALP activity. In addition, the collagen type Ⅰ propeptides and mineralized matrixes were examined by immunohistochemical staining and tetracycline fluorescence labeling respectively. The morphological and biological characters of the transfected BMSCs were similar to those of osteoblasts and the cell proliferation was promoted. The cell layer displayed strong positive reaction for ALP stains and immunohistochemical staining. ALP activity and collagen type Ⅰ expression increased remarkably after transfection. Mineralized matrixes formed earlier and more in transfected BMSCs as compared with control group. It is concluded that transfecting with TGF β 1 gene could promote the osteogenic potential of cultured BMSCs.
基金The National Natural Science Foundation of China,No.82104525The Natural Science Foundation of the Jiangsu Higher Education Institutions of China,No.21KJB360009.
文摘In this editorial,we comment on the article(World J Gastrointest Oncol 2024;16:1236-1247),which is a retrospective study of transarterial chemoembolization(TACE)combined with multi-targeted tyrosine kinase inhibitor(TKI)and programmed cell death protein-1(PD-1)inhibitor for the treatment of unresectable hepatocellular carcinoma(HCC).Herein,we focus specifically on the mechanisms of this triple therapy,administration sequence and selection of each medication,and implications for future clinical trials.Based on the interaction mechanisms between medications,the triple therapy of TACE+TKI+PD-1 is proposed to complement the deficiency of each monotherapy,and achieve synergistic antitumor effects.Although this triple therapy has been evaluated by several retrospective trials,it is still controversial whether the triple therapy achieves better clinical benefits,due to the flawed study design and heterogeneity in medications.In addition,the administration sequence,which may greatly affect the clinical benefit,needs to be fully considered at clinical decision-making for obtaining better prognosis.We hope that this editorial could contribute to the design and optimization of future trials.
基金All animal experiments were approved by The Ethics Committee of Chongqing Medical University(No.2022030).
文摘Bone defects and non-union are prevalent in clinical orthopedy,and the outcomes of current treatments are often suboptimal.Bone tissue engineering offers a promising approach to treating these conditions effectively.Bone morphogenetic protein 9(BMP9)can commit mesenchymal stem cells to osteogenic lineage,and a knowledge of the underlying mechanisms may help advance the field of bone tissue engineering.Leucine-rich repeats con-taining G protein-coupled receptor 4(LGR4),a member of G protein-coupled receptors,is essential for modulating bone development.This study is aimed at investigating the impact of LGR4 on BMP9-induced osteogenesis in mesenchymal stem cells as well as the underlying mechanisms.Bone marrow stromal cells from BMp9-knockout mice exhibited diminished LGR4 expression,and exogenous LGR4 clearly restored the impaired osteogenic potency of the bone marrow stromal cells.Furthermore,LGR4 expression was increased by BMP9 in C3H10T1/2 cells.LGR4 augmented the benefits of BMP9-induced osteogenic markers and bone formation,whereas LGR4 inhibition restricted these effects.Meanwhile,the BMP9-induced li-pogenic markers were increased by LGR4 inhibition.The protein levels of Raptor and p-Stat3 were elevated by BMP9.Raptor knockdown or p-Stat3 suppression attenuated the osteoblastic markers and LGR4 expression brought on by BMP9.LGR4 significantly reversed the blocking ef-fect of Raptor knockdown or p-Stat3 suppression on the BMP9-induced osteoblastic markers.Raptor interacts with p-Stat3,and p-Stat3 activates the LGR4 promoter activity.In conclusion,LGR4 boosts BMP9 osteoblastic potency in mesenchymal stem cells,and BMP9 may up-regulate LGR4 via the mTORC1/Stat3 signal activation.