Objective: To explore the role that ceramide plays in the activation of mitogen-activated protein kinases (MAPKs) during cerebral ischemia and reperfusion. Methods: Rats were subjected to ischemia by the fourvesse...Objective: To explore the role that ceramide plays in the activation of mitogen-activated protein kinases (MAPKs) during cerebral ischemia and reperfusion. Methods: Rats were subjected to ischemia by the fourvessel occlusion (4-VO) method. The sphingomyelinase inhibitor TPCK was administered to the CA1 subregion of the rat hippocampus before inducing ischemia. Western blot was used to examine the activity of extracellular- signal regulated kinase (ERK) and c-Jun N-terminal protein kinase (JNK) using antibodies against ERK, JNK and diphosphorylated ERK and JNK. Results: At lh reperfusion post-ischemia, JNK reached its peak activity while ERK was undergoing a sharp inactivation (P 〈 0.05). The level of diphosphorylated JNK was significantly reduced but the sharp inactivation of ERK was visibly reversed (P 〈 0.05) by the sphingomyelinase inhibitor. Conclusion: The ceramide signaling pathway is up-regulated through sphingomyelin hydrolysis in brain ischemia, promoting JNK activation and suppressing ERK activation, culminating in the ischemic lesion.展开更多
AIM:To investigate the role of α-fetoprotein(AFP),a cancer-associated fetal glycoprotein,in glucocorticoidinduced precocious maturation in rat colon.METHODS:Colons from suckling Sprague-Dawley rats were used in this ...AIM:To investigate the role of α-fetoprotein(AFP),a cancer-associated fetal glycoprotein,in glucocorticoidinduced precocious maturation in rat colon.METHODS:Colons from suckling Sprague-Dawley rats were used in this study.Corticosterone acetate at a dose of 100 μg/g body weight was given to normal pups on days 7,9 and 11 after birth to induce hypercorticoidism.Control animals were injected with identical volumes of normal saline.Some rats receiving corticosterone 7 d after birth were also treated with mifepristone(RU38486),a glucocorticoid cytoplasm receptor antagonist to investigate the effects of glucocorticoids(GCs).The morphological changes of the crypt depth and villous height of the villous zone in colon were observed as indicesof colon maturation.Expression levels of AFP in colons were detected by reverse transcriptase polymerase chain reaction and Western blotting.To identify the cellular localization of AFP in developing rat colons,double-immunofluorescent staining was performed using antibodies to specific mesenchymal cell marker and AFP.RESULTS:Corticosterone increased the crypt depth and villous height in the colon of 8-and 10-d-old rats with hypercorticoidism compared with that in the control animals(120% in 8-d-old rats and 118% in 10-d-old rats in villous height,P = 0.021;145% in 8-d-old rats and 124% in 10-d-old rats in crypt depth,P = 0.017).These increases were accompanied by an increase of AFP expression in both mRNA and protein(2.5-folds in 8-dold and 2.5-folds in 10-d-old rats higher than in control animals,P = 0.035;1.8-folds in 8-d-old and 1.3-folds in 10-d-old rats higher than in control animals,P = 0.023).Increased crypt depth and villous height and increased expression of AFP in the colon of rats with hypercorticoidism were blocked by mifepristone.Both had positive staining for AFP or vimentin,and overlapped in mesenchymal cells at each tested colon.CONCLUSION:GCs promote the development of rat colon.AFP appears to be involved,in part,in mediating the effects of GCs in the developmental colon.展开更多
Overexpression of heat shock protein 27(HSP27)in gastric cancer is correlated with poor clinical prognosis.Melatonin,an endogenous hormone,shows promise in gastric cancer therapy.However,there is limited study on the ...Overexpression of heat shock protein 27(HSP27)in gastric cancer is correlated with poor clinical prognosis.Melatonin,an endogenous hormone,shows promise in gastric cancer therapy.However,there is limited study on the biological activity of HSP27 in response to melatonin treatment.In this study,we show an anti-proliferative action of melatonin on human gastric cancer cell lines BGC-823 and MGC-803.Biochemically,the inhibitory effect of melatonin is accompanied by the upregulation of HSP27 phosphorylation level.Transfection of gastric cancer cells with HSP27-specific siRNA effectively reduces HSP27 phosphorylation and potentiated melatonininduced inhibitory effect on cell proliferation.The reduction of cyclin D1 in melatonin-treated cells is also aggravated by HSP27 depletion.Moreover,melatonin stimulation increases p38 phosphorylation.Pretreatment with p38 inhibitor SB203580 not only remarkably suppresses melatonin-induced HSP27 phosphorylation,but also augment the inhibitory effect of melatonin on cyclin D1 expression as well as cell proliferation.Taken together,our study indicates the protective pathway of p38/HSP27 against melatonin-induced inhibitory effect on gastric cancer cell proliferation,suggesting that combined with p38/HSP27 pathway inhibitor,the therapeutic efficacy of melatonin on gastric cancer may be improved.展开更多
Small non-coding RNAs with important regulatory roles are not confined to eukaryotes. Recent work has uncovered a growing number of bacterial small RNAs (sRNAs), some of which have been shown to regulate critical ce...Small non-coding RNAs with important regulatory roles are not confined to eukaryotes. Recent work has uncovered a growing number of bacterial small RNAs (sRNAs), some of which have been shown to regulate critical cellular processes. Computational approaches, in combination with molecular experiments, have played an important role in the identification of these sRNAs. At present, there is no information on the presence of small non-coding RNAs and their genes in the Agrobacterium tumefaciens genome. To identify potential sRNAs in this important bacterium, deep sequencing of the short RNA populations isolated from Agrobacterium tumefaciens C58 was carried out. From a data set of more than 10,000 short sequences, 16 candidate sRNAs have been tentatively identified based on computational analysis. All of these candidates can form stem-loop structures by RNA folding predictions and the majority of the secondary structures are rich in GC base-pairs::Some are followed by a short stretch of U residues, indicative of a rho-independent transcription terminator, whereas some of the short RNAs are found in the stem region of the hairpin, indicative of eukaryotic-like sRNAs. Experimental strategies will need to be used to verify these candidates. The study of an expanded list of candidate sRNAs in Agrobacterium will allow a more complete understanding of the range of roles played by regulatory RNAs in prokaryotes.展开更多
Infectious microbes that spread easily in healthcare facilities remain as the severe threat for the public health,especially among immunocompromised populations.Given the intricate problem of dramatic increase in resi...Infectious microbes that spread easily in healthcare facilities remain as the severe threat for the public health,especially among immunocompromised populations.Given the intricate problem of dramatic increase in resistance to common biocides,the development of safe and efficient biocide formulated agents to alleviate drug resistance is highly demanding.In this study,Schiff-base ligands were successfully formed on natural biopolymer of epsilon-poly-L-lysine(ε-PL)decorated aldehyde functionalized mesoporous silica SBA-15(CHO-SBA-15)for the selective coordination of silver ions,which was affirmed by various physicochemical methods.Besides the identified broad-spectrum antibacterial activities,the as-prepared Schiff-base silver nanocomplex(CHO-SBA-15/ε-PL/Ag,CLA-1)exhibited an improved inhibitory effect on infectious pathogen growth typified by Escherichia coli and Staphylococcus aureus in comparison with two control silver complexes without Schiff-base conjugates,SBA-15/ε-PL/Ag and CHO-SBA-15/Ag,respectively.In addition,CLA-1 remarkably inhibited the growth of Mycobacterium tuberculosis due to the excellent antimicrobial activity of silver species.Significantly,CLA-1 kills Candida albicans cells,inhibits biofilm formation,and eliminates preformed biofilms,with no development of resistance during continuous serial passaging.The antifungal activity is connected to disruption of bacterial cell membranes and increased levels of intracellular reactive oxygen species.In mouse models of multidrug-resistant C.albicans infection,CLA-1 exhibited efficient in vivo fungicidal efficacy superior to two antifungal drugs,amphotericin B and fluconazole.Moreover,CLA-1 treatment induces negligible toxicity against normal tissues with safety.Therefore,this study reveals the pivotal role of the molecular design of Schiff-base silver nanocomplex formation on biopolymer surface-functionalized silica mesopores as a green and efficient nanoplatform to tackle infectious microbes.展开更多
Oxysterol binding protein like 2(OSBPL2), an important regulator in cellular lipid metabolism and transport, was identified as a novel deafness-causal gene in our previous work. To resemble the phenotypic features of ...Oxysterol binding protein like 2(OSBPL2), an important regulator in cellular lipid metabolism and transport, was identified as a novel deafness-causal gene in our previous work. To resemble the phenotypic features of OSBPL2 mutation in animal models and elucidate the potential genotypephenotype associations, the OSBPL2-disrupted Bama miniature(BM) pig model was constructed using CRISPR/Cas9-mediated gene editing, somatic cell nuclear transfer(SCNT) and embryo transplantation approaches, and then subjected to phenotypic characterization of auditory function and serum lipid profiles. The OSBPL2-disrupted pigs displayed progressive hearing loss(HL) with degeneration/apoptosis of cochlea hair cells(HCs) and morphological abnormalities in HC stereocilia, as well as hypercholesterolaemia. High-fat diet(HFD) feeding aggravated the development of HL and led to more severe hypercholesterolaemia. The dual phenotypes of progressive HL and hypercholesterolaemia resembled in OSBPL2-disrupted pigs confirmed the implication of OSBPL2 mutation in nonsydromic hearing loss(NSHL) and contributed to the potential linkage between auditory dysfunction and dyslipidaemia/hypercholesterolaemia.展开更多
基金supported by grants from the National Natural Science Foundation of China (No.30871200)the Practice and Innovation Training Program for Students in Colleges and Universities of Jiangsu Province (NO.20090370)
文摘Objective: To explore the role that ceramide plays in the activation of mitogen-activated protein kinases (MAPKs) during cerebral ischemia and reperfusion. Methods: Rats were subjected to ischemia by the fourvessel occlusion (4-VO) method. The sphingomyelinase inhibitor TPCK was administered to the CA1 subregion of the rat hippocampus before inducing ischemia. Western blot was used to examine the activity of extracellular- signal regulated kinase (ERK) and c-Jun N-terminal protein kinase (JNK) using antibodies against ERK, JNK and diphosphorylated ERK and JNK. Results: At lh reperfusion post-ischemia, JNK reached its peak activity while ERK was undergoing a sharp inactivation (P 〈 0.05). The level of diphosphorylated JNK was significantly reduced but the sharp inactivation of ERK was visibly reversed (P 〈 0.05) by the sphingomyelinase inhibitor. Conclusion: The ceramide signaling pathway is up-regulated through sphingomyelin hydrolysis in brain ischemia, promoting JNK activation and suppressing ERK activation, culminating in the ischemic lesion.
文摘AIM:To investigate the role of α-fetoprotein(AFP),a cancer-associated fetal glycoprotein,in glucocorticoidinduced precocious maturation in rat colon.METHODS:Colons from suckling Sprague-Dawley rats were used in this study.Corticosterone acetate at a dose of 100 μg/g body weight was given to normal pups on days 7,9 and 11 after birth to induce hypercorticoidism.Control animals were injected with identical volumes of normal saline.Some rats receiving corticosterone 7 d after birth were also treated with mifepristone(RU38486),a glucocorticoid cytoplasm receptor antagonist to investigate the effects of glucocorticoids(GCs).The morphological changes of the crypt depth and villous height of the villous zone in colon were observed as indicesof colon maturation.Expression levels of AFP in colons were detected by reverse transcriptase polymerase chain reaction and Western blotting.To identify the cellular localization of AFP in developing rat colons,double-immunofluorescent staining was performed using antibodies to specific mesenchymal cell marker and AFP.RESULTS:Corticosterone increased the crypt depth and villous height in the colon of 8-and 10-d-old rats with hypercorticoidism compared with that in the control animals(120% in 8-d-old rats and 118% in 10-d-old rats in villous height,P = 0.021;145% in 8-d-old rats and 124% in 10-d-old rats in crypt depth,P = 0.017).These increases were accompanied by an increase of AFP expression in both mRNA and protein(2.5-folds in 8-dold and 2.5-folds in 10-d-old rats higher than in control animals,P = 0.035;1.8-folds in 8-d-old and 1.3-folds in 10-d-old rats higher than in control animals,P = 0.023).Increased crypt depth and villous height and increased expression of AFP in the colon of rats with hypercorticoidism were blocked by mifepristone.Both had positive staining for AFP or vimentin,and overlapped in mesenchymal cells at each tested colon.CONCLUSION:GCs promote the development of rat colon.AFP appears to be involved,in part,in mediating the effects of GCs in the developmental colon.
基金supported by the Training Programs of Innovation and Entrepreneurship for Undergraduates by Jiangsu Province(201810312018Z)to Jun Du,Chenchen Zhu,Kaiquan Lithe Training Programs of Innovation and Entrepreneurship for Undergraduates by Nanjing Medical University to Jun Du,Yuting Wang
文摘Overexpression of heat shock protein 27(HSP27)in gastric cancer is correlated with poor clinical prognosis.Melatonin,an endogenous hormone,shows promise in gastric cancer therapy.However,there is limited study on the biological activity of HSP27 in response to melatonin treatment.In this study,we show an anti-proliferative action of melatonin on human gastric cancer cell lines BGC-823 and MGC-803.Biochemically,the inhibitory effect of melatonin is accompanied by the upregulation of HSP27 phosphorylation level.Transfection of gastric cancer cells with HSP27-specific siRNA effectively reduces HSP27 phosphorylation and potentiated melatonininduced inhibitory effect on cell proliferation.The reduction of cyclin D1 in melatonin-treated cells is also aggravated by HSP27 depletion.Moreover,melatonin stimulation increases p38 phosphorylation.Pretreatment with p38 inhibitor SB203580 not only remarkably suppresses melatonin-induced HSP27 phosphorylation,but also augment the inhibitory effect of melatonin on cyclin D1 expression as well as cell proliferation.Taken together,our study indicates the protective pathway of p38/HSP27 against melatonin-induced inhibitory effect on gastric cancer cell proliferation,suggesting that combined with p38/HSP27 pathway inhibitor,the therapeutic efficacy of melatonin on gastric cancer may be improved.
文摘Small non-coding RNAs with important regulatory roles are not confined to eukaryotes. Recent work has uncovered a growing number of bacterial small RNAs (sRNAs), some of which have been shown to regulate critical cellular processes. Computational approaches, in combination with molecular experiments, have played an important role in the identification of these sRNAs. At present, there is no information on the presence of small non-coding RNAs and their genes in the Agrobacterium tumefaciens genome. To identify potential sRNAs in this important bacterium, deep sequencing of the short RNA populations isolated from Agrobacterium tumefaciens C58 was carried out. From a data set of more than 10,000 short sequences, 16 candidate sRNAs have been tentatively identified based on computational analysis. All of these candidates can form stem-loop structures by RNA folding predictions and the majority of the secondary structures are rich in GC base-pairs::Some are followed by a short stretch of U residues, indicative of a rho-independent transcription terminator, whereas some of the short RNAs are found in the stem region of the hairpin, indicative of eukaryotic-like sRNAs. Experimental strategies will need to be used to verify these candidates. The study of an expanded list of candidate sRNAs in Agrobacterium will allow a more complete understanding of the range of roles played by regulatory RNAs in prokaryotes.
基金supported by the National Key R&D Programs of China(No.2018YFC0311003 to H.B.)the National Natural Science Foundation of China(No.U1703118 to J.C.)+5 种基金the Natural Science Foundation of Jiangsu Province(No.BK20181364 to J.C.)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD,to J.C.)the Cooperative Project between Southeast University and Nanjing Medical University(No.2018DN0004 to J.C.)the National Science Foundation of the Jiangsu Higher Education Institutions of China(No.18KJA310002 to H.B.,No.19KJA310003 to J.C)the Jiangsu Specially Appointed Professor and Jiangsu Medical Specialist Programs of China(to H.B.)Jiangsu Province“Innovative and Entrepreneurial Team”Program.
文摘Infectious microbes that spread easily in healthcare facilities remain as the severe threat for the public health,especially among immunocompromised populations.Given the intricate problem of dramatic increase in resistance to common biocides,the development of safe and efficient biocide formulated agents to alleviate drug resistance is highly demanding.In this study,Schiff-base ligands were successfully formed on natural biopolymer of epsilon-poly-L-lysine(ε-PL)decorated aldehyde functionalized mesoporous silica SBA-15(CHO-SBA-15)for the selective coordination of silver ions,which was affirmed by various physicochemical methods.Besides the identified broad-spectrum antibacterial activities,the as-prepared Schiff-base silver nanocomplex(CHO-SBA-15/ε-PL/Ag,CLA-1)exhibited an improved inhibitory effect on infectious pathogen growth typified by Escherichia coli and Staphylococcus aureus in comparison with two control silver complexes without Schiff-base conjugates,SBA-15/ε-PL/Ag and CHO-SBA-15/Ag,respectively.In addition,CLA-1 remarkably inhibited the growth of Mycobacterium tuberculosis due to the excellent antimicrobial activity of silver species.Significantly,CLA-1 kills Candida albicans cells,inhibits biofilm formation,and eliminates preformed biofilms,with no development of resistance during continuous serial passaging.The antifungal activity is connected to disruption of bacterial cell membranes and increased levels of intracellular reactive oxygen species.In mouse models of multidrug-resistant C.albicans infection,CLA-1 exhibited efficient in vivo fungicidal efficacy superior to two antifungal drugs,amphotericin B and fluconazole.Moreover,CLA-1 treatment induces negligible toxicity against normal tissues with safety.Therefore,this study reveals the pivotal role of the molecular design of Schiff-base silver nanocomplex formation on biopolymer surface-functionalized silica mesopores as a green and efficient nanoplatform to tackle infectious microbes.
基金supported by grants from the National Natural Science Foundation of China (81771000 and 31571302)the Key Research and Development Program of Jiangsu Province (Social Development: BE2016762)+2 种基金the Key Project of Science and Technology Innovation of Nanjing Medical University (2017NJMUCX001)grants from the China Postdoctoral Science Foundation (2016M600431)the Jiangsu Planned Projects for Postdoctoral Research Funds (1601071B)
文摘Oxysterol binding protein like 2(OSBPL2), an important regulator in cellular lipid metabolism and transport, was identified as a novel deafness-causal gene in our previous work. To resemble the phenotypic features of OSBPL2 mutation in animal models and elucidate the potential genotypephenotype associations, the OSBPL2-disrupted Bama miniature(BM) pig model was constructed using CRISPR/Cas9-mediated gene editing, somatic cell nuclear transfer(SCNT) and embryo transplantation approaches, and then subjected to phenotypic characterization of auditory function and serum lipid profiles. The OSBPL2-disrupted pigs displayed progressive hearing loss(HL) with degeneration/apoptosis of cochlea hair cells(HCs) and morphological abnormalities in HC stereocilia, as well as hypercholesterolaemia. High-fat diet(HFD) feeding aggravated the development of HL and led to more severe hypercholesterolaemia. The dual phenotypes of progressive HL and hypercholesterolaemia resembled in OSBPL2-disrupted pigs confirmed the implication of OSBPL2 mutation in nonsydromic hearing loss(NSHL) and contributed to the potential linkage between auditory dysfunction and dyslipidaemia/hypercholesterolaemia.