Based on a mechanism analogous to the serine/threonine ligation, the aspartic acid ligation, which is facilitated by the γ-amino alcohol based ligation and oxidation, is developed and applied to the synthesis of cycl...Based on a mechanism analogous to the serine/threonine ligation, the aspartic acid ligation, which is facilitated by the γ-amino alcohol based ligation and oxidation, is developed and applied to the synthesis of cyclic peptides. The γ-hydroxyl group triggers the ring-chain tautomerization via a 6-endo-trig process,while the δ-hydroxyl group facilitates the oxidative cleavage of the vicinal diol to give carboxylic acid.展开更多
BACKGROUND Ameloblastomas are common benign epithelial odontogenic neoplasms that present an aggressive and unpredictable behavior that may modify treatment strategies.Different signaling pathways that participate in ...BACKGROUND Ameloblastomas are common benign epithelial odontogenic neoplasms that present an aggressive and unpredictable behavior that may modify treatment strategies.Different signaling pathways that participate in the progression of these tumors have been identified.B-raf proto-oncogene serine/threonine kinase(BRAF)is a protein involved in the behavior of ameloblastomas,and it is related to many cell mechanisms.BRAF gene mutations have been identified in ameloblastomas,of which the BRAF V600E(valine substituted by glutamic acid at amino acid 600)mutation has been the most common and can be present concomitantly with other mutations that may be involved in its behavior.Targeted therapies have been used as an alternative in the case of resistance or contraindications to conventional treatments.AIM To document the presence of BRAF V600E and additional mutations,their behavior,and targeted therapies in these tumors.METHODS An electronic literature search was conducted according to PRISMA guidelines in PubMed/MEDLINE,Cochrane,EMBASE,and SpringerLink using the terms“ameloblastomas”,“BRAF V600E”,“additional mutations”,and“targeted therapies”.Ameloblastomas were classified according to WHO guidelines.Inclusion criteria were articles in English,published not more than 10 years ago,and studies with laboratory works related to BRAF V600E.Articles were evaluated by two independent reviewers and retrieved for full-text evaluation.The EBLIP Critical Appraisal Checklist was used to evaluate the quality of the eligible studies.Descriptive statistical analysis was performed.RESULTS Two independent reviewers,with a substantial concordance indicated by a kappa coefficient of k=0.76,evaluated a total of 19 articles that were included in this study.The analysis registered 521 conventional ameloblastomas(AM),81 unicystic ameloblastomas(UA),13 ameloblastic carcinomas(AC),three metastatic ameloblastomas(MA),and six peripheral ameloblastomas(PA),of which the histopathological type,anatomic location,laboratory tests,expression of BRAF mutation,and additional mutations were registered.The BRAF V600E mutation was found in 297 AM(57%),63 UA(77.7%),3 AC(23%),1 MA(50%),and 5 PA(83.3%).Follicular type predominated with a total of 116 cases(40%),followed by plexiform type with 63 cases(22.1%).Furthermore,both types presented additional mutations,in which alterations in JAK3 P132T,SMARCB1,PIK3CA,CTNNB1,SMO,and BRAF G606E genes were found.Four case reports were found with targeted therapy to BRAF V600E.CONCLUSION The identification of BRAF V600E and additional mutations as an aid in targeted therapies has been a breakthrough in alternative treatments of ameloblastomas where surgical treatments are contraindicated.展开更多
AIM:To explore mutations in serine/threonine kinase 11(STK11) gene in Peutz-Jeghers syndrome(PJS) with gastrointestinal(GI) hamartomatous polyps.METHODS:Six Japanese PJS patients in 3 families were enrolled in this st...AIM:To explore mutations in serine/threonine kinase 11(STK11) gene in Peutz-Jeghers syndrome(PJS) with gastrointestinal(GI) hamartomatous polyps.METHODS:Six Japanese PJS patients in 3 families were enrolled in this study.Each of the cases had hamartomatous polyposis in the gastrointestinal tract,including the small intestine,along with mucocutaneous hyperpigmentation.Narrow-band imaging(NBI)-magnification endoscopy was employed to detect microvascular and microsurface irregularities in the GI lesions.NBI magnification findings could be classified into three groups(type A,type B,or type C).Endoscopic polypectomy was performed using double-balloon enteroscopy or colonoscopy.Genomic DNA was extracted from a whole blood sample from each subject.All of the coding exons of STK11 gene,its boundary regions,and the promoter region containing the polymorphic regions were amplified by polymerase chain reaction,and direct sequencing was performed to assess the germline mutations.RESULTS:NBI-magnification endoscopic observation could detect the abnormalities in microvessels and microsurface structures of GI polyps.Overall,we found 5 cases of type A and one case without the examination for the gastric polyps,while there were 4 cases of type B and 2 case of type A for the colorectal polyps.Seventy-nine small-bowel and 115 colorectal polyps over 27 sessions for each were resected endoscopically without significant complications.The only delayed complication included the occurrence of bleeding in a case,and this was successfully managed with hemoclips.Resected polyps contained no malignant components.Based on mutation analysis,all 3 cases in Family I exhibited the +658C>T nonsense mutation in exon 5,which resulted in the production of a truncated protein(Q220X).In Family II,a case had-252C>A and-193C>A in the promoter region.In Family III,a case was found to have the +1062C>G(F342L) mutation in exon 8.CONCLUSION:We found two novel mutations of STK11 in association with PJS.Endoscopic polypectomy of GI polyps in PJS patients appears to be useful to prevent emergency laparotomies and reduce the cancer risk.展开更多
Microtubule-associated serine/threonine kinase(MASTL)functions to regulate chromosome condensation and mitotic progression.Therefore,aberrant MASTL expression is commonly implicated in various human cancers.This study...Microtubule-associated serine/threonine kinase(MASTL)functions to regulate chromosome condensation and mitotic progression.Therefore,aberrant MASTL expression is commonly implicated in various human cancers.This study analyzed MASTL expression in gastric cancer vs.adjacent normal tissue for elucidating the association with clinicopathological data from patients.This work was then extended to investigate the effects of MASTL knockdown on tumor cells in vitro.The level of MASTL expression in gastric cancer tissue was assessed from the UALCAN,GEPIA,and Oncomine online databases.Lentivirus carrying MASTL or negative control shRNA was infected into gastric cancer cells.RT-qPCR,Western blotting,cell viability,cell counting,flow cytometric apoptosis and cell cycle,and colony formation assays were performed.MASTL was upregulated in gastric cancer tissue compared to the adjacent normal tissue,and the MASTL expression was associated with advanced tumor stage,Helicobacter pylori infection and histological subtypes.On the other hand,knockdown of MASTL expression significantly reduced tumor cell viability and proliferation,and arrested cell cycle at G2/M stage but promoted tumor cells to undergo apoptosis.At protein level,knockdown of MASTL expression enhanced levels of cleaved PARP1,cleaved caspase-3,Bax and p-ERK1/2 expression,but downregulated expression levels of BCL-2 and p-NF-κB-p65 protein in AGS and MGC-803 cells.MASTL overexpression in gastric cancer tissue may be associated with gastric cancer development and progression,whereas knockdown of MASTL expression reduces tumor cell proliferation and induces apoptosis.Further study will evaluate MASTL as a potential target of gastric cancer therapeutic strategy.展开更多
The effects of tacrolimus postconditioning on protein-serine-threonine kinases （Akt） phos- phorylation and apoptotic cell death in rats after spinal cord ischemia-reperfusion injury were investi- gated. Ninety male ...The effects of tacrolimus postconditioning on protein-serine-threonine kinases （Akt） phos- phorylation and apoptotic cell death in rats after spinal cord ischemia-reperfusion injury were investi- gated. Ninety male SD rats were randomly divided into sham operation group, ischemia-reperfusion group and tacrolimus postconditioning group. The model of spinal cord ischemia was established by means of catheterization through femoral artery and balloon dilatation. The spinal cord was reperfused 20 min after ischemia via removing saline out of balloon. The corresponding spinal cord segments were excised and determined for Akt activity in spinal cord tissue by using Western blotting at 5, 15, and 60 min after reperfusion respectively. Spinal cord tissue sections were stained immunohistochemically for detection of the phosphorylated Akt expression at 15 min after reperfusion. Flow cytometry was applied to assess apoptosis of neural cells, and dry-wet weights method was employed to measure water content in spinal cord tissue at 24 h after reperfusion. The results showed that the activities of Akt in tarcolimus postconditioning group were significantly higher than those in ischemia-reperfusion group at 5, 15, and 60 min after reperfusion （P〈0.05, P〈0.01）. The Akt activities reached the peak at 15 min after reperfu- sion in ischemia-reperfusion group and tacrolimus postconditioning group. The percentage of apoptotic cells and water content in spinal cord tissue were significantly reduced （P〈0.01） in tacrolimus postcon- ditioning group as compared with those in ischemia-reperfusion group at 24 h after reperfusion. It is concluded that tacrolimus postconditioning can increase Akt activity in spinal cord tissue of rats, inhibit apoptosis of neural cells as well as tissue edema, and thereby alleviate spinal cord ischemia-reperfusion injury.展开更多
The signaling mechanisms underlying ischemia-induced nerve cell apoptosis are poorly understood. We investigated the effects of apoptosis-related signal transduction pathways following ischemic spinal cord injury, inc...The signaling mechanisms underlying ischemia-induced nerve cell apoptosis are poorly understood. We investigated the effects of apoptosis-related signal transduction pathways following ischemic spinal cord injury, including extracellular signal-regulated kinase（ERK）, serine-threonine protein kinase（Akt） and c-Jun N-terminal kinase（JNK） signaling pathways. We established a rat model of acute spinal cord injury by inserting a catheter balloon in the left subclavian artery for 25 minutes. Rat models exhibited notable hindlimb dysfunction. Apoptotic cells were abundant in the anterior horn and central canal of the spinal cord. The number of apoptotic neurons was highest 48 hours post injury. The expression of phosphorylated Akt（pAkt） and phosphorylated ERK（p-ERK） increased immediately after reperfusion, peaked at 4 hours（p-Akt） or 2 hours（p-ERK）, decreased at 12 hours, and then increased at 24 hours. Phosphorylated JNK expression reduced after reperfusion, increased at 12 hours to near normal levels, and then showed a downward trend at 24 hours. Pearson linear correlation analysis also demonstrated that the number of apoptotic cells negatively correlated with p-Akt expression. These findings suggest that activation of Akt may be a key contributing factor in the delay of neuronal apoptosis after spinal cord ischemia, particularly at the stage of reperfusion, and thus may be a target for neuronal protection and reduction of neuronal apoptosis after spinal cord injury.展开更多
目的探究脂肪含量和肥胖相关蛋白(fat mass and obesity-associated protein,FTO)和丝氨酸-苏氨酸激酶蛋白激酶D2(serine-threonine kinase protein kinase D2,PRKD2)在糖尿病肾病(diabetic kidney disease,DKD)进展中的调控作用和调节...目的探究脂肪含量和肥胖相关蛋白(fat mass and obesity-associated protein,FTO)和丝氨酸-苏氨酸激酶蛋白激酶D2(serine-threonine kinase protein kinase D2,PRKD2)在糖尿病肾病(diabetic kidney disease,DKD)进展中的调控作用和调节机制。方法采用35 mmol/L葡萄糖对足细胞(MPC5细胞)进行高糖刺激24h构建DKD体外模型。采用FTO过表达载体(pcDNA-FTO)和PRKD2过表达载体(pcDNA-PRKD2),或空载体(vector)转染高糖诱导的MPC5细胞。通过RT-qPCR检测FTO和PRKD2过表达效率;MeRIP检测PRKD2 mRNA的N6-甲基腺苷(N6-methyladenosine,m6A)修饰水平;ELISA检测Caspase-3活性、IL-6,TNF-α和单核细胞趋化蛋白-1(monocyte chemotactic protein-1,MCP-1)分泌量;流式细胞术分析细胞凋亡率;Western blot评估FTO和PRKD2蛋白水平,以及SIRT1/HIF-1α通路关键蛋白表达水平;Pearson分析FTO和PRKD2水平的相关性。结果与无高糖诱导对照组比较,高糖诱导的足细胞中FTO蛋白(0.51±0.04 vs 1.00±0.03)和PRKD2蛋白(0.45±0.03 vs 1.01±0.04)水平显著下调,差异具有统计学意义(t=13.17,16.76,均P<0.001)。高糖诱导的足细胞中FTO蛋白水平和PRKD2蛋白水平呈正相关(r2=0.7051,P<0.001)。与vector组相比,pcDNA-FTO组PRKD2 mRNA的m6A水平(0.56±0.09 vs1.01±0.13)降低,PRKD2 mRNA水平(3.16±0.14 vs 1.03±0.02)显著升高,差异具有统计学意义(t=51.37,11.82,均P<0.001)。与control组(IL-6:512.76±61.85 pg/ml,TNF-α:28.17±2.83 pg/ml,MCP-1:157.31±17.69 pg/ml)和vector组(IL-6:498.41±87.51 pg/ml,TNF-α:26.35±5.47 pg/ml,MCP-1:165.52±16.87 pg/ml)比较,pcDNA-PRKD2组IL-6(301.86±21.85 pg/ml),TNF-α(11.06±4.12 pg/ml),MCP-1分泌量(81.45±9.03pg/ml)显著减少,差异具有统计学意义(F=7.51,10.47,61.97,均P<0.01)。与control组(Caspase-3:689.65±79.5U/L,细胞凋亡率:22.31%±2.69%)和vector组(Caspase-3:715.91±113.58 U/L,细胞凋亡率:21.07%±3.28%)比较,pcDNA-PRKD2组Caspase-3活性(437.64±104.76 U/L)和细胞凋亡率(8.41%±3.15%)下降,差异具有统计学意义(F=2.35,79.13,均P<0.01)。与control组(SIRT1:1.01±0.05,HIF-1α:1.03±0.07)和vector组(SIRT1:0.97±0.05,HIF-1α:1.02±0.03)相比,pcDNA-PRKD2组SIRT1蛋白(3.51±0.15)水平升高,HIF-1α蛋白(0.37±0.07)水平降低,差异具有统计学意义(F=31.54,8.31,均P<0.01)。结论FTO介导m6A修饰的PRKD2通过SIRT1/HIF-1α通路抑制高糖诱导的足细胞炎症反应和细胞凋亡。展开更多
基金supported by the Research Grants Council (Nos. 17309616, C6009-15G) of Hong KongThe National Science Foundation of China (Nos. 21672180, 91753101)the Area of Excellence Scheme of the University of Grants Committee of Hong Kong (No. AoE/P-705/16)
文摘Based on a mechanism analogous to the serine/threonine ligation, the aspartic acid ligation, which is facilitated by the γ-amino alcohol based ligation and oxidation, is developed and applied to the synthesis of cyclic peptides. The γ-hydroxyl group triggers the ring-chain tautomerization via a 6-endo-trig process,while the δ-hydroxyl group facilitates the oxidative cleavage of the vicinal diol to give carboxylic acid.
文摘BACKGROUND Ameloblastomas are common benign epithelial odontogenic neoplasms that present an aggressive and unpredictable behavior that may modify treatment strategies.Different signaling pathways that participate in the progression of these tumors have been identified.B-raf proto-oncogene serine/threonine kinase(BRAF)is a protein involved in the behavior of ameloblastomas,and it is related to many cell mechanisms.BRAF gene mutations have been identified in ameloblastomas,of which the BRAF V600E(valine substituted by glutamic acid at amino acid 600)mutation has been the most common and can be present concomitantly with other mutations that may be involved in its behavior.Targeted therapies have been used as an alternative in the case of resistance or contraindications to conventional treatments.AIM To document the presence of BRAF V600E and additional mutations,their behavior,and targeted therapies in these tumors.METHODS An electronic literature search was conducted according to PRISMA guidelines in PubMed/MEDLINE,Cochrane,EMBASE,and SpringerLink using the terms“ameloblastomas”,“BRAF V600E”,“additional mutations”,and“targeted therapies”.Ameloblastomas were classified according to WHO guidelines.Inclusion criteria were articles in English,published not more than 10 years ago,and studies with laboratory works related to BRAF V600E.Articles were evaluated by two independent reviewers and retrieved for full-text evaluation.The EBLIP Critical Appraisal Checklist was used to evaluate the quality of the eligible studies.Descriptive statistical analysis was performed.RESULTS Two independent reviewers,with a substantial concordance indicated by a kappa coefficient of k=0.76,evaluated a total of 19 articles that were included in this study.The analysis registered 521 conventional ameloblastomas(AM),81 unicystic ameloblastomas(UA),13 ameloblastic carcinomas(AC),three metastatic ameloblastomas(MA),and six peripheral ameloblastomas(PA),of which the histopathological type,anatomic location,laboratory tests,expression of BRAF mutation,and additional mutations were registered.The BRAF V600E mutation was found in 297 AM(57%),63 UA(77.7%),3 AC(23%),1 MA(50%),and 5 PA(83.3%).Follicular type predominated with a total of 116 cases(40%),followed by plexiform type with 63 cases(22.1%).Furthermore,both types presented additional mutations,in which alterations in JAK3 P132T,SMARCB1,PIK3CA,CTNNB1,SMO,and BRAF G606E genes were found.Four case reports were found with targeted therapy to BRAF V600E.CONCLUSION The identification of BRAF V600E and additional mutations as an aid in targeted therapies has been a breakthrough in alternative treatments of ameloblastomas where surgical treatments are contraindicated.
文摘AIM:To explore mutations in serine/threonine kinase 11(STK11) gene in Peutz-Jeghers syndrome(PJS) with gastrointestinal(GI) hamartomatous polyps.METHODS:Six Japanese PJS patients in 3 families were enrolled in this study.Each of the cases had hamartomatous polyposis in the gastrointestinal tract,including the small intestine,along with mucocutaneous hyperpigmentation.Narrow-band imaging(NBI)-magnification endoscopy was employed to detect microvascular and microsurface irregularities in the GI lesions.NBI magnification findings could be classified into three groups(type A,type B,or type C).Endoscopic polypectomy was performed using double-balloon enteroscopy or colonoscopy.Genomic DNA was extracted from a whole blood sample from each subject.All of the coding exons of STK11 gene,its boundary regions,and the promoter region containing the polymorphic regions were amplified by polymerase chain reaction,and direct sequencing was performed to assess the germline mutations.RESULTS:NBI-magnification endoscopic observation could detect the abnormalities in microvessels and microsurface structures of GI polyps.Overall,we found 5 cases of type A and one case without the examination for the gastric polyps,while there were 4 cases of type B and 2 case of type A for the colorectal polyps.Seventy-nine small-bowel and 115 colorectal polyps over 27 sessions for each were resected endoscopically without significant complications.The only delayed complication included the occurrence of bleeding in a case,and this was successfully managed with hemoclips.Resected polyps contained no malignant components.Based on mutation analysis,all 3 cases in Family I exhibited the +658C>T nonsense mutation in exon 5,which resulted in the production of a truncated protein(Q220X).In Family II,a case had-252C>A and-193C>A in the promoter region.In Family III,a case was found to have the +1062C>G(F342L) mutation in exon 8.CONCLUSION:We found two novel mutations of STK11 in association with PJS.Endoscopic polypectomy of GI polyps in PJS patients appears to be useful to prevent emergency laparotomies and reduce the cancer risk.
基金grants from Lanzhou Science and Technology Planning Project(No.2016-3-113)University Research Project of Gansu Province(No.2018A049)+2 种基金the Foundation of the Fundamental Scientific Research Funds for Colleges and Universities in Gansu Province[No.(2014)63-15]the China’s National Science and Technology Program for Public Wellbeing(No.2012GS620101)National Key Research and Development Planning(No.2017YFC0908302).
文摘Microtubule-associated serine/threonine kinase(MASTL)functions to regulate chromosome condensation and mitotic progression.Therefore,aberrant MASTL expression is commonly implicated in various human cancers.This study analyzed MASTL expression in gastric cancer vs.adjacent normal tissue for elucidating the association with clinicopathological data from patients.This work was then extended to investigate the effects of MASTL knockdown on tumor cells in vitro.The level of MASTL expression in gastric cancer tissue was assessed from the UALCAN,GEPIA,and Oncomine online databases.Lentivirus carrying MASTL or negative control shRNA was infected into gastric cancer cells.RT-qPCR,Western blotting,cell viability,cell counting,flow cytometric apoptosis and cell cycle,and colony formation assays were performed.MASTL was upregulated in gastric cancer tissue compared to the adjacent normal tissue,and the MASTL expression was associated with advanced tumor stage,Helicobacter pylori infection and histological subtypes.On the other hand,knockdown of MASTL expression significantly reduced tumor cell viability and proliferation,and arrested cell cycle at G2/M stage but promoted tumor cells to undergo apoptosis.At protein level,knockdown of MASTL expression enhanced levels of cleaved PARP1,cleaved caspase-3,Bax and p-ERK1/2 expression,but downregulated expression levels of BCL-2 and p-NF-κB-p65 protein in AGS and MGC-803 cells.MASTL overexpression in gastric cancer tissue may be associated with gastric cancer development and progression,whereas knockdown of MASTL expression reduces tumor cell proliferation and induces apoptosis.Further study will evaluate MASTL as a potential target of gastric cancer therapeutic strategy.
基金supported by the Hubei Provincial Natural Science Foundation of China(No.2012FFB04406)
文摘The effects of tacrolimus postconditioning on protein-serine-threonine kinases （Akt） phos- phorylation and apoptotic cell death in rats after spinal cord ischemia-reperfusion injury were investi- gated. Ninety male SD rats were randomly divided into sham operation group, ischemia-reperfusion group and tacrolimus postconditioning group. The model of spinal cord ischemia was established by means of catheterization through femoral artery and balloon dilatation. The spinal cord was reperfused 20 min after ischemia via removing saline out of balloon. The corresponding spinal cord segments were excised and determined for Akt activity in spinal cord tissue by using Western blotting at 5, 15, and 60 min after reperfusion respectively. Spinal cord tissue sections were stained immunohistochemically for detection of the phosphorylated Akt expression at 15 min after reperfusion. Flow cytometry was applied to assess apoptosis of neural cells, and dry-wet weights method was employed to measure water content in spinal cord tissue at 24 h after reperfusion. The results showed that the activities of Akt in tarcolimus postconditioning group were significantly higher than those in ischemia-reperfusion group at 5, 15, and 60 min after reperfusion （P〈0.05, P〈0.01）. The Akt activities reached the peak at 15 min after reperfu- sion in ischemia-reperfusion group and tacrolimus postconditioning group. The percentage of apoptotic cells and water content in spinal cord tissue were significantly reduced （P〈0.01） in tacrolimus postcon- ditioning group as compared with those in ischemia-reperfusion group at 24 h after reperfusion. It is concluded that tacrolimus postconditioning can increase Akt activity in spinal cord tissue of rats, inhibit apoptosis of neural cells as well as tissue edema, and thereby alleviate spinal cord ischemia-reperfusion injury.
基金supported by the National Natural Science Foundation of ChinaNo.81271387+3 种基金the Research Special Fund of Public Welfare and Health Department of ChinaNo.201402009the National Key Technology R&D Program in ChinaNo.Z141107002514031
文摘The signaling mechanisms underlying ischemia-induced nerve cell apoptosis are poorly understood. We investigated the effects of apoptosis-related signal transduction pathways following ischemic spinal cord injury, including extracellular signal-regulated kinase（ERK）, serine-threonine protein kinase（Akt） and c-Jun N-terminal kinase（JNK） signaling pathways. We established a rat model of acute spinal cord injury by inserting a catheter balloon in the left subclavian artery for 25 minutes. Rat models exhibited notable hindlimb dysfunction. Apoptotic cells were abundant in the anterior horn and central canal of the spinal cord. The number of apoptotic neurons was highest 48 hours post injury. The expression of phosphorylated Akt（pAkt） and phosphorylated ERK（p-ERK） increased immediately after reperfusion, peaked at 4 hours（p-Akt） or 2 hours（p-ERK）, decreased at 12 hours, and then increased at 24 hours. Phosphorylated JNK expression reduced after reperfusion, increased at 12 hours to near normal levels, and then showed a downward trend at 24 hours. Pearson linear correlation analysis also demonstrated that the number of apoptotic cells negatively correlated with p-Akt expression. These findings suggest that activation of Akt may be a key contributing factor in the delay of neuronal apoptosis after spinal cord ischemia, particularly at the stage of reperfusion, and thus may be a target for neuronal protection and reduction of neuronal apoptosis after spinal cord injury.
