Astrocytes and microglia play an orchestrated role following spinal cord injury;however,the molecular mechanisms through which microglia regulate astrocytes after spinal cord injury are not yet fully understood.Herein...Astrocytes and microglia play an orchestrated role following spinal cord injury;however,the molecular mechanisms through which microglia regulate astrocytes after spinal cord injury are not yet fully understood.Herein,microglia were pharmacologically depleted and the effects on the astrocytic response were examined.We further explored the potential mechanisms involving the signal transducers and activators of transcription 3(STAT3)pathway.For in vivo experiments,we constructed a contusion spinal cord injury model in C57BL/6 mice.To deplete microglia,all mice were treated with colony-stimulating factor 1 receptor inhibitor PLX3397,starting 2 weeks prior to surgery until they were sacrificed.Cell proliferation was examined by 5-ethynyl-2-deoxyuridine(EdU)and three pivotal inflammatory cytokines were detected by a specific Bio-Plex Pro^(TM) Reagent Kit.Locomotor function,neuroinflammation,astrocyte activation and phosphorylated STAT3(pSTAT3,a maker of activation of STAT3 signaling)levels were determined.For in vitro experiments,a microglia and astrocyte coculture system was established,and the small molecule STA21,which blocks STAT3 activation,was applied to investigate whether STAT3 signaling is involved in mediating astrocyte proliferation induced by microglia.PLX3397 administration disrupted glial scar formation,increased inflammatory spillover,induced diffuse tissue damage and impaired functional recovery after spinal cord injury.Microglial depletion markedly reduced EdU+proliferating cells,especially proliferating astrocytes at 7 days after spinal cord injury.RNA sequencing analysis showed that the JAK/STAT3 pathway was downregulated in mice treated with PLX3397.Double immunofluorescence staining confirmed that PLX3397 significantly decreased STAT3 expression in astrocytes.Importantly,in vitro coculture of astrocytes and microglia showed that microglia-induced astrocyte proliferation was abolished by STA21 administration.These findings suggest that microglial depletion impaired astrocyte proliferation and astrocytic scar formation,and induced inflammatory diffusion partly by inhibiting STAT3 phosphorylation in astrocytes following spinal cord injury.展开更多
1, 3, 4-Oxadiazole derivatives(4 a–5 f) were previously synthesized to investigate their anticancer properties.However, studies relating to their antioxidant potential and signal transducer and activator of transcrip...1, 3, 4-Oxadiazole derivatives(4 a–5 f) were previously synthesized to investigate their anticancer properties.However, studies relating to their antioxidant potential and signal transducer and activator of transcription(STAT) inhibition have not been performed. We investigated previously synthesized 1, 3, 4-oxadiazole derivatives(4 a–5 f) for various radical scavenging properties using several in vitro antioxidant assays and also for direct inhibition of STAT3 through molecular docking. The data obtained from various antioxidant assays such as 2, 2,-diphenyl-1-picrylhydrazyl radical(DPPH), nitric oxide, hydrogen peroxide, and superoxide anion radical revealed that among all the derivatives, compound 5 e displayed high antioxidant activities than the standard antioxidant L-ascorbic acid. Additionally, the total reduction assay and antioxidant capacity assay further confirmed the antioxidant potential of compound 5 e. Furthermore, the molecular docking studies performed for all derivatives along with the standard inhibitor STX-0119 showed that binding energy released in direct binding with the SH2 domain of STAT3 was the highest for compound 5 e(-9.91 kcal/mol).Through virtual screening, compound 5 e was found to exhibit optimum competency in inhibiting STAT3 activity. Compound 5 e decreased the activation of STAT3 as observed with Western blot. In brief, compound5 e was identified as a potent antioxidant agent and STAT3 inhibitor and effective agent for cancer treatment.展开更多
Aim To investigate the effects of JAK inhibitor （SHR0302） on adjuvant-induced arthritis （AA） rats and the partial mechanisms focused on T, B lymphocyte subsets through JAK1-STAT3 pathway, including Thl7, Treg, tot...Aim To investigate the effects of JAK inhibitor （SHR0302） on adjuvant-induced arthritis （AA） rats and the partial mechanisms focused on T, B lymphocyte subsets through JAK1-STAT3 pathway, including Thl7, Treg, total B cells and memory B cells. Methods Animals were divided randomly into 6 groups including normal control, AA, SHR0302 （0.3, 1.0, 3.0 nag · kg^-1, ig） and MTX （0.5 nag · kg^-1 , ig） . The effects of SHR0302 on AA rats by evaluating arthritis index, arthritis global assessment and paw swelling degree, histopathology of joint and spleen, inflammatory cytokine and antibody production in serum. We examined the proliferation of T, B and FLS by CCK8 kit; Thl7, Treg, total B and memory B cell proportion was measured by flow cytometry; Cytokines TNF-αβ, IL-1β, IL-10, IL-17 and antibody IgG1, IgG2a levels in serum were measured by ELISA kits; The ex- pression of p-JAK1 and p-STAT3 was measured by Western blot analysis. Results SHR0302 suppressed the se- verity of AA rats by attenuating the arthritis index, arthritis global assessment and paw swelling degree, and allevia- ted histopathology of spleen and joint of AA rats. SHR0302 can inhibit the proliferation of T, B and FLS, and down-regulated cytokines TNF-α, IL-1β, IL-17 and antibody IgG1, IgG2a levels, and suppressed the proportion of Thl7 and total B, and inhibited JAK1-STAT3 phosphorylation; There was no significant effect on Treg function and memory B cell proportion. Conclusion SHR0302 may attenuate the severity of AA rats, partially through signifi- cantly reducing Thl7 function and total B cell proportion by inhibiting JAK1-STAT3 phosphorylation.展开更多
Background:Abnormal myocardial voltage-gated sodium channel 1.5(Nav1.5)expression and function cause lethal ventricular arrhythmias during myocardial ischemia–reperfusion(I/R).Protein inhibitor of activated STAT Y(PI...Background:Abnormal myocardial voltage-gated sodium channel 1.5(Nav1.5)expression and function cause lethal ventricular arrhythmias during myocardial ischemia–reperfusion(I/R).Protein inhibitor of activated STAT Y(PIASy)-mediated caveolin-3(Cav-3)small ubiquitin-related modifier(SUMO)modification affects Cav-3 binding to the Nav1.5.PIASy activity is increased after myocardial I/R,but it is unclear whether this is attributable to plasma membrane Nav1.5 downregulation and ventricular arrhythmias.Methods:Using recombinant adeno-associated virus subtype 9(AAV9),rat cardiac PIASy was silenced using intraventricular injection of PIASy short hairpin RNA(shRNA).After two weeks,rat hearts were subjected to I/R and electrocardiography was performed to assess malignant arrhythmias.Tissues from peri-infarct areas of the left ventricle were collected for molecular biological measurements.Results:PIASy was upregulated by I/R(P<0.01),with increased SUMO2/3 modification of Cav-3 and reduced membrane Nav1.5 density(P<0.01).AAV9-PIASy shRNA intraventricular injection into the rat heart down-regulated PIASy after I/R,at both mRNA and protein levels(P<0.05 vs.Scramble-shRNA+I/R group),decreased SUMO-modified Cav-3 levels,enhanced Cav-3 binding to Nav1.5,and prevented I/R-induced decrease of Nav1.5 and Cav-3co-localization in the intercalated disc and lateral membrane.PIASy silencing in rat hearts reduced I/R-induced fatal arrhythmias,which was reflected by a modest decrease in the duration of ventricular fibrillation(VF;P<0.05 vs.Scramble-shRNA+I/R group)and a significantly reduced arrhythmia score(P<0.01 vs.Scramble-shRNA+I/R group).The anti-arrhythmic effects of PIASy silencing were also evidenced by decreased episodes of ventricular tachycardia(VT),sustained VT and VF,especially at the time 5–10 min after ischemia(P<0.05 vs.Scramble-shRNA+IR group).Using in vitro human embryonic kidney 293 T(HEK293T)cells and isolated adult rat cardiomyocyte models exposed to hypoxia/reoxygenation(H/R),we confirmed that increased PIASy promoted Cav-3 modification by SUMO2/3 and Nav1.5/Cav-3 dissociation after H/R.Mutation of SUMO consensus lysine sites in Cav-3(K38R or K144R)altered the membrane expression levels of Nav1.5 and Cav-3 before and after H/R in HEK293T cells.Conclusions:I/R-induced cardiac PIASy activation increased Cav-3 SUMOylation by SUMO2/3 and dysregulated Nav1.5-related ventricular arrhythmias.Cardiac-targeted PIASy silencing mediated Cav-3 deSUMOylation and partially prevented I/R-induced Nav1.5 downregulation in the plasma membrane of cardiomyocytes,and subsequent ventricular arrhythmias in rats.PIASy was identified as a potential therapeutic target for life-threatening arrhythmias in patients with ischemic heart diseases.展开更多
Background:Several clinical studies have uncovered a negative correlation between baseline tumor burden and the efficacy of immune checkpoint inhibitor(ICI)treatment.This study aimed to uncover the specific mechanisms...Background:Several clinical studies have uncovered a negative correlation between baseline tumor burden and the efficacy of immune checkpoint inhibitor(ICI)treatment.This study aimed to uncover the specific mechanisms underlying the difference in sensitivity to ICI treatment between tumors with high(HTB)and low(LTB)tumor burden.Methods:For in vivo studies,several mouse models of subcutaneous tumors were established,and transcriptome sequencing,immunohistochemistry,and flow cytometry assays were used to detect the immune status in these subcutaneous tumors.For in vitro experiments,co-culture models,cytokine antibody arrays,western blotting,flow cytometry,and enzyme-linked immunosorbent assays were used to explore the underlying molecular mechanisms Results:We found that MC38 or B16 subcutaneous tumors from the HTB group did not show any response to anti-programmed cell death protein-1(PD-1)therapy.Through flow cytometry assays,we found that the infiltration with CD8^(+)T cellswas significantly decreasedwhereasM2-like macrophageswere enriched in subcutaneous tumors of HTB groups compared with those of LTB group.These changes were not affected by the initial number of injected tumor cells or tumor age,nor could they be reversed by surgical tumor reduction.Intraperitoneal colony-stimulating factor 1 receptor(CSF-1R)inhibitor PLX3397 injection at different time points of tumor growth only had an effect when administered in the early tumor stage to maintain the“heat”of the tumor microenvironment during the process of tumor growth,thereby achieving a response to ICI treatment when the tumor grew to a large size.Mechanistically,we found that insulin-like growth factor binding protein 2(IGFBP2)expression levelswere significantly elevated in HTB tumor tissues.IGFBP2 promoted the programmed death-ligand 1(PD-L1)expression in M2-like macrophages by activating signal transducer and activator of transcription 3(STAT3),and PD-L1^(+)M2-likemacrophages exerted an immunosuppressive effect by inhibiting the proliferation and activation of CD8^(+)T cells in a PD-L1-dependent fashion.Conclusions:This study suggested that the low efficacy of ICI treatment in HTB tumors is mainly attributed to the intratumoral accumulation of PD-L1^(+)M2-like macrophages via the IGFBP2-STAT3-PD-L1 signaling pathway and their substantial inhibitory effects on T cell proliferation and activation.展开更多
目的构建信号传导与转录激活因子3(signal transducer and activator of transcription factor 3,STAT3)二聚化抑制剂筛选模型,为STAT3抑制剂筛选提供实验方法。方法分别构建pECFP-N1-STAT3和pEYFP-N1-STAT3的荧光报告载体,利用脂质体...目的构建信号传导与转录激活因子3(signal transducer and activator of transcription factor 3,STAT3)二聚化抑制剂筛选模型,为STAT3抑制剂筛选提供实验方法。方法分别构建pECFP-N1-STAT3和pEYFP-N1-STAT3的荧光报告载体,利用脂质体转染技术将二者共转入HEK-293T细胞,利用ECFP和EYFP 2种荧光蛋白之间能量共振转移,检测磷酸化STAT3分子的二聚化水平,并检测Stattic对二聚化的影响。结果成功构建了pECFP-N1-STAT3和pEYFP-N1-STAT3的荧光报告载体。将2种荧光报告载体共转染HEK-293T细胞后,Western Blot检测结果显示STAT3以及p-STAT3的表达水平明显增加。以458nm波长激发ECFP,其发射波长可激发EYFP。加入STAT3二聚化抑制剂Stattic后,荧光强度降低,且呈现一定的剂量依赖性。结论基于荧光共振能量转移技术的STAT3二聚化抑制剂筛选模型构建成功。展开更多
Backgroud Angiotensin Ⅱ （Ang Ⅱ）, a principal effector of renin-angiotensin system （RAS） and increased in aging tissues, can stimulate JAK/STAT pathway via the G-protein-coupled Ang Ⅱ receptor type Ⅰ （AT1） an...Backgroud Angiotensin Ⅱ （Ang Ⅱ）, a principal effector of renin-angiotensin system （RAS） and increased in aging tissues, can stimulate JAK/STAT pathway via the G-protein-coupled Ang Ⅱ receptor type Ⅰ （AT1） and induce nuclear translocation of signal transducers and activators of transcription （STAT）. To further explore the role of Ang Ⅱ in aging, we examined the effect of Ang Ⅱ on human replicative senescent diploid fibroblast WI-38 cells.展开更多
Leukemia inhibitory factor (LIF), and its receptor (LIFR), are commonly over-expressed in many solid cancers and recent studies have implicated LIF/LIFR axis as a promising clinical target for cancer therapy. LIF/LIFR...Leukemia inhibitory factor (LIF), and its receptor (LIFR), are commonly over-expressed in many solid cancers and recent studies have implicated LIF/LIFR axis as a promising clinical target for cancer therapy. LIF/LIFR activate oncogenic signaling pathways including JAK/STAT3 as immediate effectors and MAPK, AKT, mTOR further downstream. LIF/LIFR signaling plays a key role in tumor growth, progression, metastasis, stemness and therapy resistance. Many solid cancers show overexpression of LIF and autocrine stimulation of the LIF/LIFR axis;these are associated with a poorer relapse-free survival. LIF/LIFR signaling also plays a role in modulating multiple immune cell types present in tumor micro environment (TME). Recently, two targeted agents that target LIF (humanized anti-LIF antibody, MSC-1) and LIFR inhibitor (EC359) were under development. Both agents showed effectivity in preclinical models and clinical trials using MSC-1 antibody are in progress. This article reviews the significance of LIF/LIFR pathways and inhibitors that disrupt this process for the treatment of cancer.展开更多
基金supported by the Natural Science Foundation of Guangdong Province,No.2020A1515010090(to ZLZ)the Science and Technology Project Foundation of Guangzhou City,No.202002030004(to HZ).
文摘Astrocytes and microglia play an orchestrated role following spinal cord injury;however,the molecular mechanisms through which microglia regulate astrocytes after spinal cord injury are not yet fully understood.Herein,microglia were pharmacologically depleted and the effects on the astrocytic response were examined.We further explored the potential mechanisms involving the signal transducers and activators of transcription 3(STAT3)pathway.For in vivo experiments,we constructed a contusion spinal cord injury model in C57BL/6 mice.To deplete microglia,all mice were treated with colony-stimulating factor 1 receptor inhibitor PLX3397,starting 2 weeks prior to surgery until they were sacrificed.Cell proliferation was examined by 5-ethynyl-2-deoxyuridine(EdU)and three pivotal inflammatory cytokines were detected by a specific Bio-Plex Pro^(TM) Reagent Kit.Locomotor function,neuroinflammation,astrocyte activation and phosphorylated STAT3(pSTAT3,a maker of activation of STAT3 signaling)levels were determined.For in vitro experiments,a microglia and astrocyte coculture system was established,and the small molecule STA21,which blocks STAT3 activation,was applied to investigate whether STAT3 signaling is involved in mediating astrocyte proliferation induced by microglia.PLX3397 administration disrupted glial scar formation,increased inflammatory spillover,induced diffuse tissue damage and impaired functional recovery after spinal cord injury.Microglial depletion markedly reduced EdU+proliferating cells,especially proliferating astrocytes at 7 days after spinal cord injury.RNA sequencing analysis showed that the JAK/STAT3 pathway was downregulated in mice treated with PLX3397.Double immunofluorescence staining confirmed that PLX3397 significantly decreased STAT3 expression in astrocytes.Importantly,in vitro coculture of astrocytes and microglia showed that microglia-induced astrocyte proliferation was abolished by STA21 administration.These findings suggest that microglial depletion impaired astrocyte proliferation and astrocytic scar formation,and induced inflammatory diffusion partly by inhibiting STAT3 phosphorylation in astrocytes following spinal cord injury.
基金supported by UGC (University Grant Commission) (F no.- 43-172/2014 (SR))
文摘1, 3, 4-Oxadiazole derivatives(4 a–5 f) were previously synthesized to investigate their anticancer properties.However, studies relating to their antioxidant potential and signal transducer and activator of transcription(STAT) inhibition have not been performed. We investigated previously synthesized 1, 3, 4-oxadiazole derivatives(4 a–5 f) for various radical scavenging properties using several in vitro antioxidant assays and also for direct inhibition of STAT3 through molecular docking. The data obtained from various antioxidant assays such as 2, 2,-diphenyl-1-picrylhydrazyl radical(DPPH), nitric oxide, hydrogen peroxide, and superoxide anion radical revealed that among all the derivatives, compound 5 e displayed high antioxidant activities than the standard antioxidant L-ascorbic acid. Additionally, the total reduction assay and antioxidant capacity assay further confirmed the antioxidant potential of compound 5 e. Furthermore, the molecular docking studies performed for all derivatives along with the standard inhibitor STX-0119 showed that binding energy released in direct binding with the SH2 domain of STAT3 was the highest for compound 5 e(-9.91 kcal/mol).Through virtual screening, compound 5 e was found to exhibit optimum competency in inhibiting STAT3 activity. Compound 5 e decreased the activation of STAT3 as observed with Western blot. In brief, compound5 e was identified as a potent antioxidant agent and STAT3 inhibitor and effective agent for cancer treatment.
文摘Aim To investigate the effects of JAK inhibitor （SHR0302） on adjuvant-induced arthritis （AA） rats and the partial mechanisms focused on T, B lymphocyte subsets through JAK1-STAT3 pathway, including Thl7, Treg, total B cells and memory B cells. Methods Animals were divided randomly into 6 groups including normal control, AA, SHR0302 （0.3, 1.0, 3.0 nag · kg^-1, ig） and MTX （0.5 nag · kg^-1 , ig） . The effects of SHR0302 on AA rats by evaluating arthritis index, arthritis global assessment and paw swelling degree, histopathology of joint and spleen, inflammatory cytokine and antibody production in serum. We examined the proliferation of T, B and FLS by CCK8 kit; Thl7, Treg, total B and memory B cell proportion was measured by flow cytometry; Cytokines TNF-αβ, IL-1β, IL-10, IL-17 and antibody IgG1, IgG2a levels in serum were measured by ELISA kits; The ex- pression of p-JAK1 and p-STAT3 was measured by Western blot analysis. Results SHR0302 suppressed the se- verity of AA rats by attenuating the arthritis index, arthritis global assessment and paw swelling degree, and allevia- ted histopathology of spleen and joint of AA rats. SHR0302 can inhibit the proliferation of T, B and FLS, and down-regulated cytokines TNF-α, IL-1β, IL-17 and antibody IgG1, IgG2a levels, and suppressed the proportion of Thl7 and total B, and inhibited JAK1-STAT3 phosphorylation; There was no significant effect on Treg function and memory B cell proportion. Conclusion SHR0302 may attenuate the severity of AA rats, partially through signifi- cantly reducing Thl7 function and total B cell proportion by inhibiting JAK1-STAT3 phosphorylation.
基金supported by grants from the National Natural Science Foundation of China(81770824,81270239)。
文摘Background:Abnormal myocardial voltage-gated sodium channel 1.5(Nav1.5)expression and function cause lethal ventricular arrhythmias during myocardial ischemia–reperfusion(I/R).Protein inhibitor of activated STAT Y(PIASy)-mediated caveolin-3(Cav-3)small ubiquitin-related modifier(SUMO)modification affects Cav-3 binding to the Nav1.5.PIASy activity is increased after myocardial I/R,but it is unclear whether this is attributable to plasma membrane Nav1.5 downregulation and ventricular arrhythmias.Methods:Using recombinant adeno-associated virus subtype 9(AAV9),rat cardiac PIASy was silenced using intraventricular injection of PIASy short hairpin RNA(shRNA).After two weeks,rat hearts were subjected to I/R and electrocardiography was performed to assess malignant arrhythmias.Tissues from peri-infarct areas of the left ventricle were collected for molecular biological measurements.Results:PIASy was upregulated by I/R(P<0.01),with increased SUMO2/3 modification of Cav-3 and reduced membrane Nav1.5 density(P<0.01).AAV9-PIASy shRNA intraventricular injection into the rat heart down-regulated PIASy after I/R,at both mRNA and protein levels(P<0.05 vs.Scramble-shRNA+I/R group),decreased SUMO-modified Cav-3 levels,enhanced Cav-3 binding to Nav1.5,and prevented I/R-induced decrease of Nav1.5 and Cav-3co-localization in the intercalated disc and lateral membrane.PIASy silencing in rat hearts reduced I/R-induced fatal arrhythmias,which was reflected by a modest decrease in the duration of ventricular fibrillation(VF;P<0.05 vs.Scramble-shRNA+I/R group)and a significantly reduced arrhythmia score(P<0.01 vs.Scramble-shRNA+I/R group).The anti-arrhythmic effects of PIASy silencing were also evidenced by decreased episodes of ventricular tachycardia(VT),sustained VT and VF,especially at the time 5–10 min after ischemia(P<0.05 vs.Scramble-shRNA+IR group).Using in vitro human embryonic kidney 293 T(HEK293T)cells and isolated adult rat cardiomyocyte models exposed to hypoxia/reoxygenation(H/R),we confirmed that increased PIASy promoted Cav-3 modification by SUMO2/3 and Nav1.5/Cav-3 dissociation after H/R.Mutation of SUMO consensus lysine sites in Cav-3(K38R or K144R)altered the membrane expression levels of Nav1.5 and Cav-3 before and after H/R in HEK293T cells.Conclusions:I/R-induced cardiac PIASy activation increased Cav-3 SUMOylation by SUMO2/3 and dysregulated Nav1.5-related ventricular arrhythmias.Cardiac-targeted PIASy silencing mediated Cav-3 deSUMOylation and partially prevented I/R-induced Nav1.5 downregulation in the plasma membrane of cardiomyocytes,and subsequent ventricular arrhythmias in rats.PIASy was identified as a potential therapeutic target for life-threatening arrhythmias in patients with ischemic heart diseases.
基金National Natural Science Foundation of China,Grant/Award Numbers:82073303,82103335,82102731Science and Technology Planning Project of Guangzhou,Grant/Award Number:202201011560Natural Science Foundation of Guangdong Province of China,Grant/Award Number:2022A1515012418。
文摘Background:Several clinical studies have uncovered a negative correlation between baseline tumor burden and the efficacy of immune checkpoint inhibitor(ICI)treatment.This study aimed to uncover the specific mechanisms underlying the difference in sensitivity to ICI treatment between tumors with high(HTB)and low(LTB)tumor burden.Methods:For in vivo studies,several mouse models of subcutaneous tumors were established,and transcriptome sequencing,immunohistochemistry,and flow cytometry assays were used to detect the immune status in these subcutaneous tumors.For in vitro experiments,co-culture models,cytokine antibody arrays,western blotting,flow cytometry,and enzyme-linked immunosorbent assays were used to explore the underlying molecular mechanisms Results:We found that MC38 or B16 subcutaneous tumors from the HTB group did not show any response to anti-programmed cell death protein-1(PD-1)therapy.Through flow cytometry assays,we found that the infiltration with CD8^(+)T cellswas significantly decreasedwhereasM2-like macrophageswere enriched in subcutaneous tumors of HTB groups compared with those of LTB group.These changes were not affected by the initial number of injected tumor cells or tumor age,nor could they be reversed by surgical tumor reduction.Intraperitoneal colony-stimulating factor 1 receptor(CSF-1R)inhibitor PLX3397 injection at different time points of tumor growth only had an effect when administered in the early tumor stage to maintain the“heat”of the tumor microenvironment during the process of tumor growth,thereby achieving a response to ICI treatment when the tumor grew to a large size.Mechanistically,we found that insulin-like growth factor binding protein 2(IGFBP2)expression levelswere significantly elevated in HTB tumor tissues.IGFBP2 promoted the programmed death-ligand 1(PD-L1)expression in M2-like macrophages by activating signal transducer and activator of transcription 3(STAT3),and PD-L1^(+)M2-likemacrophages exerted an immunosuppressive effect by inhibiting the proliferation and activation of CD8^(+)T cells in a PD-L1-dependent fashion.Conclusions:This study suggested that the low efficacy of ICI treatment in HTB tumors is mainly attributed to the intratumoral accumulation of PD-L1^(+)M2-like macrophages via the IGFBP2-STAT3-PD-L1 signaling pathway and their substantial inhibitory effects on T cell proliferation and activation.
文摘目的构建信号传导与转录激活因子3(signal transducer and activator of transcription factor 3,STAT3)二聚化抑制剂筛选模型,为STAT3抑制剂筛选提供实验方法。方法分别构建pECFP-N1-STAT3和pEYFP-N1-STAT3的荧光报告载体,利用脂质体转染技术将二者共转入HEK-293T细胞,利用ECFP和EYFP 2种荧光蛋白之间能量共振转移,检测磷酸化STAT3分子的二聚化水平,并检测Stattic对二聚化的影响。结果成功构建了pECFP-N1-STAT3和pEYFP-N1-STAT3的荧光报告载体。将2种荧光报告载体共转染HEK-293T细胞后,Western Blot检测结果显示STAT3以及p-STAT3的表达水平明显增加。以458nm波长激发ECFP,其发射波长可激发EYFP。加入STAT3二聚化抑制剂Stattic后,荧光强度降低,且呈现一定的剂量依赖性。结论基于荧光共振能量转移技术的STAT3二聚化抑制剂筛选模型构建成功。
基金This work was supported by grants from the Creative Research Group Fund of the Natural Science Foundation of China (No.30121005) the National Science Foundation of China (No.30370559) the Medical Health Research Fund of People's Liberation Army of China (No. 04T6003) the Major Basic Project of China (973) (No.G2000057000).
文摘Backgroud Angiotensin Ⅱ （Ang Ⅱ）, a principal effector of renin-angiotensin system （RAS） and increased in aging tissues, can stimulate JAK/STAT pathway via the G-protein-coupled Ang Ⅱ receptor type Ⅰ （AT1） and induce nuclear translocation of signal transducers and activators of transcription （STAT）. To further explore the role of Ang Ⅱ in aging, we examined the effect of Ang Ⅱ on human replicative senescent diploid fibroblast WI-38 cells.
基金This work was supported by the DOD BCRP (No. W81XWH-18-1-0016 (R.K.V)W81XWH-18-1-0015 (H.B.N)+2 种基金NCI R44CA235991 (H.B.N))NCI Cancer Center Support (No. P30CA054174-17)Elsa U. Pardee foundation (No. 166675-44096 (S.V), NIH (No. 1R01CA179120-01 (R.K.V)).Acknow。
文摘Leukemia inhibitory factor (LIF), and its receptor (LIFR), are commonly over-expressed in many solid cancers and recent studies have implicated LIF/LIFR axis as a promising clinical target for cancer therapy. LIF/LIFR activate oncogenic signaling pathways including JAK/STAT3 as immediate effectors and MAPK, AKT, mTOR further downstream. LIF/LIFR signaling plays a key role in tumor growth, progression, metastasis, stemness and therapy resistance. Many solid cancers show overexpression of LIF and autocrine stimulation of the LIF/LIFR axis;these are associated with a poorer relapse-free survival. LIF/LIFR signaling also plays a role in modulating multiple immune cell types present in tumor micro environment (TME). Recently, two targeted agents that target LIF (humanized anti-LIF antibody, MSC-1) and LIFR inhibitor (EC359) were under development. Both agents showed effectivity in preclinical models and clinical trials using MSC-1 antibody are in progress. This article reviews the significance of LIF/LIFR pathways and inhibitors that disrupt this process for the treatment of cancer.
