AIMTo evaluate whether protein tyrosine phosphatase 1B (PTP1B) contributed to initiate human retinal pigment epithelium cells (A)-19 migration and investigate the signaling pathways involved in this process.METHODSARP...AIMTo evaluate whether protein tyrosine phosphatase 1B (PTP1B) contributed to initiate human retinal pigment epithelium cells (A)-19 migration and investigate the signaling pathways involved in this process.METHODSARPE-19 cells were cultured and treated with the siRNA-PTP1B. Expression of PTP1B was confirmed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). AG1478 [a selective inhibitor of epidermal growth factor receptor (EGFR)] and PD98059 (a specific inhibitor of the activation of mitogen-activated protein kinase) were used to help to determine the PTP1B signaling mechanism. Western blot analysis verified expression of EGFR and extracellular signal-regulated kinase (ERK) in ARPE-19 cells. The effect of siRNA-PTP1B on cell differentiation was confirmed by immunostaining for α-smooth muscle actin (α-SMA) and qRT-PCR. Cell migration ability was analyzed by transwell chamber assay.RESULTSThe mRNA levels of PTP1B were reduced by siRNA-PTP1B as determined by qRT-PCR assay. SiRNA-PTP1B activated EGFR and ERK phosphorylation. α-SMA staining and qRT-PCR assay demonstrated that siRNA-PTP1B induced retinal pigment epithelium (RPE) cells to differentiate toward better contractility and motility. Transwell chamber assay proved that PTP1B inhibition improved migration activity of RPE cells. Treatment with AG1478 and PD98059 abolished siRNA-PTP1B-induced activation of EGFR and ERK, α-SMA expression and cell migration.CONCLUSIONPTP1B inhibition promoted myofibroblast differentiation and migration of ARPE-19 cells, and EGFR/ERK signaling pathway played important role in migration process.展开更多
Oleanolic acid derivatives act as newer protein tyrosine phosphatase 1B （PTP-1B） inhibitors for type 2 diabetes mellitus （T2DM）. In order to understand the structural requirement of PTP-1B inhibitors, 52 oleanolic...Oleanolic acid derivatives act as newer protein tyrosine phosphatase 1B （PTP-1B） inhibitors for type 2 diabetes mellitus （T2DM）. In order to understand the structural requirement of PTP-1B inhibitors, 52 oleanolic acid derivatives were divided into a training set （34 compounds） and a test set （18 compounds）. The highly reliable and predictive 3D-QSAR models were constructed by CoMFA, CoMSIA and topomer CoMFA methods, respectively. The results showed that the cross validated coefficient （q2） and non-cross-validated coefficient （R2） were 0.554 and 0.999 in the CoMFA model, 0.675 and 0.971 in the CoMSIA model, and 0.628 and 0.939 in the topomer CoMFA model, which suggests that three models are robust and have good exterior predictive capabilities. Furthermore, ten novel inhibitors with much higher inhibitory potency were designed. Our design strategy was that （i） the electronegative substituents （Cl, -CH2OH, OH and -CH2Cl） were introduced into the double bond of ring C, （ii） the hydrogen bond acceptor groups （C≡N and N atom）, electronegative groups （C≡N, N atom, -COOH and -COOCH3） and bulky substituents （C6H5N） were connected to the C-3 position, which would result in generating potent and selective PTP-1B inhibitors. We expect that the results in this paper have the potential to facilitate the process of design and to develop new potent PTP-1B inhibitors.展开更多
3-bromo-4,5-bis（2,3-dibromo-4,5-dihydroxybenzyl）-l,2-benzenediol （1） is a natural bromophenol isolated from the red algae Rhodomela confervoides that exhibits significant inhibition against protein tyrosine phosph...3-bromo-4,5-bis（2,3-dibromo-4,5-dihydroxybenzyl）-l,2-benzenediol （1） is a natural bromophenol isolated from the red algae Rhodomela confervoides that exhibits significant inhibition against protein tyrosine phosphatase 1B （PTP1B）. Based on its activity, we synthesized two new synthetic bromophenols and their methoxy derivatives from vanillin using the structure of natural bromophenol 1 as a scaffold. The structures of these bromophenols were elucidated from H NMR, 13C NMR, and high resolution electron ionization mass spectrometry as 2,3-dibromo-1-（2＇-bromo-6＇-（3＂,4＂-dimethoxybenzyl）- 3 ＇,4 ＇-dimethoxybenzyl）-4,5 -dimethoxybenzene （2）, 2,3-dibromo- 1 -（2 ＇-bromo-6＇-（2 ＂-bromo-4＂,5 ＂-dimethoxy- benzyl）-3＇,4＇-dimethoxybenzyl）-4,5-dimethoxybenzene （3）, 3,4-dibromo-5-（2＇-bromo-6＇-（2＂-bromo-4＂,5＂- dihydroxybenzyl）-3＇,4＇-dihydroxybenzyl）pyrocatechol （4） and 3,4-dibromo-5-（2＇-bromo-6＇-（3＂,4＂- dihydroxybenzyl）-3＇,4＇-dihydroxybenzyl）pyrocatechol （5）. PTP1B inhibition activities of these compounds were evaluated using a colorimetric assay, and compounds 3 and 4 demonstrated interesting activity against PTP1B.展开更多
Insulin sensitizing medicines are currently limited, and identification of new drug candidate is a chal- lenge. Protein tyrosine phosphatase 1B （PTP1 B） negatively regulates insulin signaling pathway, and its inhibi...Insulin sensitizing medicines are currently limited, and identification of new drug candidate is a chal- lenge. Protein tyrosine phosphatase 1B （PTP1 B） negatively regulates insulin signaling pathway, and its inhibition is anticipated to improve insulin resistance. This study investigated the pharmacological profiles of compound CX08005, a new PTP1B inhibitor, with therapeutic potential for insulin resistance in vivo and in vitro, respective- ly. Recombinant human PTP1B protein was used to measure the enzyme activity. The docking simulation was per- formed to explore the interactions between the compound and the protein. The insulin sensitivity was evaluated in Diet-induced obesity mice and/or T2DM KKAy mice by glucose tolerance test （GTT）, the blood glucose level, glucose stimulated insulin secretion （GSIS）, homeostasis model assessment of insulin resistance index （HOMA-IR） and the whole-body insulin sensitivity （ISwb） index, respectively. The hyperinsulinemic-euglycemic clamp was performed to evaluate the insulin stimulated glucose disposal both in whole body and in insulin-sensitive tissues （muscle and fat）. Furthermore, its direct effect in muscle, fat and liver cells was observed. We found that CX08005 was a competitive inhibitor of PTP1B with dose-dependent activity （IC50=5.95 × 10^-7 M）. Docking simulation demonstrated that CX08005 binds to PTP1B at the catalytic P-loop through hydrogen bonds. In DIO mice, treatment with CX08005 effectively ameliorated glucose intolerance in a dose-dependent manner （50- 200 mg. kg^-1 · d^-l）, and decreased HOMA-IR values. We also demonstrated that oral administration of 50 mg ~ kg^-1· d^-1 CX08005 improved hyperglycemia, hyperinsulinemia, HOMA-IR and ISwb in KKAy mice. In hyperin- sulinemic-euglycemic clamp test, CX08005 increased glucose infusion rate and glucose uptake in muscle and fat of DIO mice. In 3T3-L1 adipocytes and C2C12 myotubes, CX08005 enhanced insulin-induced glucose uptake. In HepG2 hepatocyte, CX08005 enhanced insulin-stimulated tyrosine phosphorylation of IRβ/IRS1 in a dose-depend- ent manner, respectively; furthermore, the phosphorylation of several downstream molecules, including Akt, Foxol and GSK3β was also increased, indicating this compound could augment insulin＇s ability to suppress hepatic glu- cose output （HGO）. Our results strongly suggest that compound CX08005 directly enhances insulin action in vitro and in vivo with therapeutic potential for insulin resistance.展开更多
Proteintyrosine phosphatase 1B(PTP1B)inhibitionis consideredas a potentialtherapeuticfor the treatmentof cancer,type2 diabetes,andobesity.Inour presentwork,weinvestigatedtheanti-diabeticpotentialof8-hydroxydiospyrin(8...Proteintyrosine phosphatase 1B(PTP1B)inhibitionis consideredas a potentialtherapeuticfor the treatmentof cancer,type2 diabetes,andobesity.Inour presentwork,weinvestigatedtheanti-diabeticpotentialof8-hydroxydiospyrin(8-HDN)from D.lotus against the PTP1B enzyme.It showed significant inhibitory activity of PTP1B with an IC 50 value of 18.37±0.02μM.A detailed molecular docking study was carried out to analyze the binding orientation,binding energy,and mechanism of inhibition.A comparative investigation of 8-HDN in the catalytic,as well as the allosteric site of PTP1B,was performed.Binding energy data showed that compound 8-HDN is more selective for the allosteric site and hence avoids the problems associated with catalytic site inhibition.The inhibition mechanism of 8-HDN can be further investigated as an active lead compound against PTP1B by using in vitro and in vivo models.展开更多
Guava leaf tea has been used as a folk medicine for treating hyperglycemic conditions in Asia and Africa. The hypoglycemic efficacy of guava leaf has been documented by many scientists in these regions, but the hypogl...Guava leaf tea has been used as a folk medicine for treating hyperglycemic conditions in Asia and Africa. The hypoglycemic efficacy of guava leaf has been documented by many scientists in these regions, but the hypoglycemic mechanism is poorly understood. Guava leaves were extracted with methanol and the crude extract was partitioned against hexane, ethyl acetate, and butanol in sequence. The leftover in water is defined as the aqueous partition. A second smaller batch was extracted with hot water directly. Oral glucose tolerance test was carried out on healthy mice instead of diabetic mice that lack endogenous insulin. Glucose uptake was examined with 3T3-L1 adipocytes. Oxidative effect on PTP1B （protein tyrosine phosphatase 1b） was carried out with real-time PTP1B enzymatic assay. The aqueous partition of guava leaf extract possesses a potent inhibitory effect on PTP1B enzymatic activity and this PTP1B inhibition is through a slow oxidative but reversible inactivation on the enzyme. The reversible inactivation would suggest guava leaf extract may augment PTP1B inhibition alongside the endogenous H2O2 which itself is induced by insulin. In addition, our study confirmed the hypoglycemic efficacy being associated with guava leaf and found the most effective molecules reside in the aqueous partition which is also less cytotoxic to Chinese hamster ovary cells when compared to other less polar partitions. The guava leaf extract can modulate insulin activity through a redox regulation on PP1B enzymatic activity. It is speculated that a compound similar to gallocatechin in the aqueous partition can reduce an oxygen molecule to hydrogen peroxide which in turn oxidizes the catalytic residue Cys in PTP1B. Therefore, the guava leaf tea can serve as a functional hypoglycemic drink that is suitable for either healthy or diabetic subjects.展开更多
Objective:To determine the inhibitory effects of pachymic acid on lung adenocarcinoma(LUAD)cells and elucidate its underlying mechanism.Methods:CCK-8,wound healing,Transwell,Western blot,tube formation,and immunofluor...Objective:To determine the inhibitory effects of pachymic acid on lung adenocarcinoma(LUAD)cells and elucidate its underlying mechanism.Methods:CCK-8,wound healing,Transwell,Western blot,tube formation,and immunofluorescence assays were carried out to measure the effects of various concentrations of pachymic acid on LUAD cell proliferation,metastasis,angiogenesis as well as autophagy.Subsequently,molecular docking technology was used to detect the potential targeted binding association between pachymic acid and protein tyrosine phosphatase 1B(PTP1B).Moreover,PTP1B was overexpressed in A549 cells to detect the specific mechanisms of pachymic acid.Results:Pachymic acid suppressed LUAD cell viability,metastasis as well as angiogenesis while inducing cell autophagy.It also targeted PTP1B and lowered PTP1B expression.However,PTP1B overexpression reversed the effects of pachymic acid on metastasis,angiogenesis,and autophagy as well as the expression of Wnt3a andβ-catenin in LUAD cells.Conclusions:Pachymic acid inhibits metastasis and angiogenesis,and promotes autophagy in LUAD cells by modulating the Wnt/β-catenin signaling pathway via targeting PTP1B.展开更多
Objective： To construct eukaryotic expression vector containing B7-1/GFP geneand study its expression in osteosarcoma cell line LM8. Methods： By using gene cloning technique, eukaxyotic expression vector pEGFP-C1 wa...Objective： To construct eukaryotic expression vector containing B7-1/GFP geneand study its expression in osteosarcoma cell line LM8. Methods： By using gene cloning technique, eukaxyotic expression vector pEGFP-C1 was used to construct the murine B7-1 recombinant plasmid （pEGFP-C1/B7）. Recombinant plasmid was transfected into LM8 cells with liposome and was confirmed by restriction endonuclease digestion and DNA sequencing. The expression of the fusion protein was detected using fluorescence microscope and Western blot analysis. Results： The recombinant eukaryotic expression plasmid pEGFP-C1/B7 was successfully constructed, which was confirmed by DNA sequencing, RT-PGR and restriction enzymes analysis. The green fluorescent protein could be detected in the transfected LM8 with fluorescence microscope. The expected B7-1 and green fluorescent protein （GFP） fusion protein was detected by RT-PCR and Western blot. Conclusion： The eukaryotic expression vector containing B7-1/GFP gene was constructed successfully, and it could be expressed in LM8 after transfection.展开更多
AIM: To identify the novel mutation alleles in the CYP1B1 gene of primary congenital glaucoma(PCG) patients at Shandong Province of China, and investigate their correlation with glaucomatous features.METHODS: The DNA ...AIM: To identify the novel mutation alleles in the CYP1B1 gene of primary congenital glaucoma(PCG) patients at Shandong Province of China, and investigate their correlation with glaucomatous features.METHODS: The DNA from the peripheral blood of 13 congenital glaucoma patients and 50 ethnically matched healthy controls from the affiliated hospital of Qingdao University were extracted. The coding region of the CYP1B1 gene was amplified by PCR and direct DNA sequencing was performed. Disease causing-variants were analyzed by comparing the sequences and the structures of wild type and mutant CYP1B1 proteins by PyMOL software.RESULTS: Two missense mutations, including A330 F caused by c.988 G>T&c.989 C>T, and R390H caused by c.1169 G>A, were identified in one of the 13 PCG patients analyzed in our study. A330F mutation was observed to be novel in the Chinese Han population, which dramatically altered the protein structure of CYP1B1 gene, including the changes in the ligand-binding pocket. Furthermore, R390H mutation caused the changes in heme-protein binding site of this gene. In addition, the clinical phenotype displayed by PCG patient with these mutations was more pronounced than other PCG patients without these mutations. Multiple surgeries and combined drug treatment were not effective in reducing the elevated intraocular pressure in this patient.CONCLUSION: A novel A330F mutation is identified in the CYP1B1 gene of Chinese PCG patient. Moreover, in combination with other mutation R390H, this PCG patient shows significant difference in the CYP1B1 protein structure, which may specifically contribute to severe glaucomatous phenotype.展开更多
A new isochromanone,cladosporinisochromanone(1),accompanied by 15 known compounds(2–16)were obtained from secondary metabolites produced by marine-derived fungus Cladosporium sp.DLT-5.NMR and HRESIMS spectra elucidat...A new isochromanone,cladosporinisochromanone(1),accompanied by 15 known compounds(2–16)were obtained from secondary metabolites produced by marine-derived fungus Cladosporium sp.DLT-5.NMR and HRESIMS spectra elucidation determined the planar structure of 1.Subsequent electronic circular dichroism(ECD)experiment assigned the absolute configuration of 1.Compounds 1,2,4–6,and 10 displayed different degrees of neuroprotective activities on human neuroblastoma cells SH-SY5Y.Five compounds(1,3–5,and 13)emerged resistance to protein tyrosine phosphatase 1B(PTP1B),further kinetic analysis and molecular docking study indicated that the most potent compound 13(IC50value of 10.74±0.61μmol/L)was found as a noncompetitive inhibitor for PTP1B.Surface plasmon resonance(SPR)and molecular docking studies also demonstrated the interaction between compound 12 and Niemann-Pick C1 Like 1(NPC1L1),which has been identified as significant therapeutic target for hypercholesteremia.In addition,compounds 3,6,and 14 showed attractive inhibitory activity against the phytopathogenic fungi:Colletotrichum capsici.Therefore,library of Cladosporium metabolites is enriched and new active uses of known compounds are explored.展开更多
基金Supported by Shandong Provincial Natural Science Foundation,China(No.ZR2012HQ004)the Research Fund for Fundamental Research Project of Qingdao(No.13-1-4-180-jch)+1 种基金the Scientific Research Fund of Huangdao District of Qingdao City(No.2014-1-74)the Young People Scientific Research Fund of Affiliated Hospital,Qingdao University(No.QDFY134)
文摘AIMTo evaluate whether protein tyrosine phosphatase 1B (PTP1B) contributed to initiate human retinal pigment epithelium cells (A)-19 migration and investigate the signaling pathways involved in this process.METHODSARPE-19 cells were cultured and treated with the siRNA-PTP1B. Expression of PTP1B was confirmed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). AG1478 [a selective inhibitor of epidermal growth factor receptor (EGFR)] and PD98059 (a specific inhibitor of the activation of mitogen-activated protein kinase) were used to help to determine the PTP1B signaling mechanism. Western blot analysis verified expression of EGFR and extracellular signal-regulated kinase (ERK) in ARPE-19 cells. The effect of siRNA-PTP1B on cell differentiation was confirmed by immunostaining for α-smooth muscle actin (α-SMA) and qRT-PCR. Cell migration ability was analyzed by transwell chamber assay.RESULTSThe mRNA levels of PTP1B were reduced by siRNA-PTP1B as determined by qRT-PCR assay. SiRNA-PTP1B activated EGFR and ERK phosphorylation. α-SMA staining and qRT-PCR assay demonstrated that siRNA-PTP1B induced retinal pigment epithelium (RPE) cells to differentiate toward better contractility and motility. Transwell chamber assay proved that PTP1B inhibition improved migration activity of RPE cells. Treatment with AG1478 and PD98059 abolished siRNA-PTP1B-induced activation of EGFR and ERK, α-SMA expression and cell migration.CONCLUSIONPTP1B inhibition promoted myofibroblast differentiation and migration of ARPE-19 cells, and EGFR/ERK signaling pathway played important role in migration process.
基金Supported by the Natural Science Foundation of Guangxi Province(Nos.2013GXNSFAA019019 and 2013GXNSFAA019041)
文摘Oleanolic acid derivatives act as newer protein tyrosine phosphatase 1B （PTP-1B） inhibitors for type 2 diabetes mellitus （T2DM）. In order to understand the structural requirement of PTP-1B inhibitors, 52 oleanolic acid derivatives were divided into a training set （34 compounds） and a test set （18 compounds）. The highly reliable and predictive 3D-QSAR models were constructed by CoMFA, CoMSIA and topomer CoMFA methods, respectively. The results showed that the cross validated coefficient （q2） and non-cross-validated coefficient （R2） were 0.554 and 0.999 in the CoMFA model, 0.675 and 0.971 in the CoMSIA model, and 0.628 and 0.939 in the topomer CoMFA model, which suggests that three models are robust and have good exterior predictive capabilities. Furthermore, ten novel inhibitors with much higher inhibitory potency were designed. Our design strategy was that （i） the electronegative substituents （Cl, -CH2OH, OH and -CH2Cl） were introduced into the double bond of ring C, （ii） the hydrogen bond acceptor groups （C≡N and N atom）, electronegative groups （C≡N, N atom, -COOH and -COOCH3） and bulky substituents （C6H5N） were connected to the C-3 position, which would result in generating potent and selective PTP-1B inhibitors. We expect that the results in this paper have the potential to facilitate the process of design and to develop new potent PTP-1B inhibitors.
基金Supported by the National Major Research Program of China"The Creation for Significant Innovative Drugs"(No.2009ZX09103-148)the Natural Science Foundation of Shandong(No.BS2009YY011)+1 种基金the Natural Science Foundation of Qingdao(No.10-3-4-8-2-JCH)the Program of Qingdao Shinan District(No.2009-HY-2-14)
文摘3-bromo-4,5-bis（2,3-dibromo-4,5-dihydroxybenzyl）-l,2-benzenediol （1） is a natural bromophenol isolated from the red algae Rhodomela confervoides that exhibits significant inhibition against protein tyrosine phosphatase 1B （PTP1B）. Based on its activity, we synthesized two new synthetic bromophenols and their methoxy derivatives from vanillin using the structure of natural bromophenol 1 as a scaffold. The structures of these bromophenols were elucidated from H NMR, 13C NMR, and high resolution electron ionization mass spectrometry as 2,3-dibromo-1-（2＇-bromo-6＇-（3＂,4＂-dimethoxybenzyl）- 3 ＇,4 ＇-dimethoxybenzyl）-4,5 -dimethoxybenzene （2）, 2,3-dibromo- 1 -（2 ＇-bromo-6＇-（2 ＂-bromo-4＂,5 ＂-dimethoxy- benzyl）-3＇,4＇-dimethoxybenzyl）-4,5-dimethoxybenzene （3）, 3,4-dibromo-5-（2＇-bromo-6＇-（2＂-bromo-4＂,5＂- dihydroxybenzyl）-3＇,4＇-dihydroxybenzyl）pyrocatechol （4） and 3,4-dibromo-5-（2＇-bromo-6＇-（3＂,4＂- dihydroxybenzyl）-3＇,4＇-dihydroxybenzyl）pyrocatechol （5）. PTP1B inhibition activities of these compounds were evaluated using a colorimetric assay, and compounds 3 and 4 demonstrated interesting activity against PTP1B.
文摘Insulin sensitizing medicines are currently limited, and identification of new drug candidate is a chal- lenge. Protein tyrosine phosphatase 1B （PTP1 B） negatively regulates insulin signaling pathway, and its inhibition is anticipated to improve insulin resistance. This study investigated the pharmacological profiles of compound CX08005, a new PTP1B inhibitor, with therapeutic potential for insulin resistance in vivo and in vitro, respective- ly. Recombinant human PTP1B protein was used to measure the enzyme activity. The docking simulation was per- formed to explore the interactions between the compound and the protein. The insulin sensitivity was evaluated in Diet-induced obesity mice and/or T2DM KKAy mice by glucose tolerance test （GTT）, the blood glucose level, glucose stimulated insulin secretion （GSIS）, homeostasis model assessment of insulin resistance index （HOMA-IR） and the whole-body insulin sensitivity （ISwb） index, respectively. The hyperinsulinemic-euglycemic clamp was performed to evaluate the insulin stimulated glucose disposal both in whole body and in insulin-sensitive tissues （muscle and fat）. Furthermore, its direct effect in muscle, fat and liver cells was observed. We found that CX08005 was a competitive inhibitor of PTP1B with dose-dependent activity （IC50=5.95 × 10^-7 M）. Docking simulation demonstrated that CX08005 binds to PTP1B at the catalytic P-loop through hydrogen bonds. In DIO mice, treatment with CX08005 effectively ameliorated glucose intolerance in a dose-dependent manner （50- 200 mg. kg^-1 · d^-l）, and decreased HOMA-IR values. We also demonstrated that oral administration of 50 mg ~ kg^-1· d^-1 CX08005 improved hyperglycemia, hyperinsulinemia, HOMA-IR and ISwb in KKAy mice. In hyperin- sulinemic-euglycemic clamp test, CX08005 increased glucose infusion rate and glucose uptake in muscle and fat of DIO mice. In 3T3-L1 adipocytes and C2C12 myotubes, CX08005 enhanced insulin-induced glucose uptake. In HepG2 hepatocyte, CX08005 enhanced insulin-stimulated tyrosine phosphorylation of IRβ/IRS1 in a dose-depend- ent manner, respectively; furthermore, the phosphorylation of several downstream molecules, including Akt, Foxol and GSK3β was also increased, indicating this compound could augment insulin＇s ability to suppress hepatic glu- cose output （HGO）. Our results strongly suggest that compound CX08005 directly enhances insulin action in vitro and in vivo with therapeutic potential for insulin resistance.
基金funded by Higher Education commission,Pakistan(HEC),Grant No.NRPU649.
文摘Proteintyrosine phosphatase 1B(PTP1B)inhibitionis consideredas a potentialtherapeuticfor the treatmentof cancer,type2 diabetes,andobesity.Inour presentwork,weinvestigatedtheanti-diabeticpotentialof8-hydroxydiospyrin(8-HDN)from D.lotus against the PTP1B enzyme.It showed significant inhibitory activity of PTP1B with an IC 50 value of 18.37±0.02μM.A detailed molecular docking study was carried out to analyze the binding orientation,binding energy,and mechanism of inhibition.A comparative investigation of 8-HDN in the catalytic,as well as the allosteric site of PTP1B,was performed.Binding energy data showed that compound 8-HDN is more selective for the allosteric site and hence avoids the problems associated with catalytic site inhibition.The inhibition mechanism of 8-HDN can be further investigated as an active lead compound against PTP1B by using in vitro and in vivo models.
文摘Guava leaf tea has been used as a folk medicine for treating hyperglycemic conditions in Asia and Africa. The hypoglycemic efficacy of guava leaf has been documented by many scientists in these regions, but the hypoglycemic mechanism is poorly understood. Guava leaves were extracted with methanol and the crude extract was partitioned against hexane, ethyl acetate, and butanol in sequence. The leftover in water is defined as the aqueous partition. A second smaller batch was extracted with hot water directly. Oral glucose tolerance test was carried out on healthy mice instead of diabetic mice that lack endogenous insulin. Glucose uptake was examined with 3T3-L1 adipocytes. Oxidative effect on PTP1B （protein tyrosine phosphatase 1b） was carried out with real-time PTP1B enzymatic assay. The aqueous partition of guava leaf extract possesses a potent inhibitory effect on PTP1B enzymatic activity and this PTP1B inhibition is through a slow oxidative but reversible inactivation on the enzyme. The reversible inactivation would suggest guava leaf extract may augment PTP1B inhibition alongside the endogenous H2O2 which itself is induced by insulin. In addition, our study confirmed the hypoglycemic efficacy being associated with guava leaf and found the most effective molecules reside in the aqueous partition which is also less cytotoxic to Chinese hamster ovary cells when compared to other less polar partitions. The guava leaf extract can modulate insulin activity through a redox regulation on PP1B enzymatic activity. It is speculated that a compound similar to gallocatechin in the aqueous partition can reduce an oxygen molecule to hydrogen peroxide which in turn oxidizes the catalytic residue Cys in PTP1B. Therefore, the guava leaf tea can serve as a functional hypoglycemic drink that is suitable for either healthy or diabetic subjects.
基金supported by the Zhejiang Province Traditional Chinese Medicine Health Science and Technology Program(2023ZL570).
文摘Objective:To determine the inhibitory effects of pachymic acid on lung adenocarcinoma(LUAD)cells and elucidate its underlying mechanism.Methods:CCK-8,wound healing,Transwell,Western blot,tube formation,and immunofluorescence assays were carried out to measure the effects of various concentrations of pachymic acid on LUAD cell proliferation,metastasis,angiogenesis as well as autophagy.Subsequently,molecular docking technology was used to detect the potential targeted binding association between pachymic acid and protein tyrosine phosphatase 1B(PTP1B).Moreover,PTP1B was overexpressed in A549 cells to detect the specific mechanisms of pachymic acid.Results:Pachymic acid suppressed LUAD cell viability,metastasis as well as angiogenesis while inducing cell autophagy.It also targeted PTP1B and lowered PTP1B expression.However,PTP1B overexpression reversed the effects of pachymic acid on metastasis,angiogenesis,and autophagy as well as the expression of Wnt3a andβ-catenin in LUAD cells.Conclusions:Pachymic acid inhibits metastasis and angiogenesis,and promotes autophagy in LUAD cells by modulating the Wnt/β-catenin signaling pathway via targeting PTP1B.
基金This study was supported by a grant from the youth dawn program of Wuhan (Grant No. 20025001028).
文摘Objective： To construct eukaryotic expression vector containing B7-1/GFP geneand study its expression in osteosarcoma cell line LM8. Methods： By using gene cloning technique, eukaxyotic expression vector pEGFP-C1 was used to construct the murine B7-1 recombinant plasmid （pEGFP-C1/B7）. Recombinant plasmid was transfected into LM8 cells with liposome and was confirmed by restriction endonuclease digestion and DNA sequencing. The expression of the fusion protein was detected using fluorescence microscope and Western blot analysis. Results： The recombinant eukaryotic expression plasmid pEGFP-C1/B7 was successfully constructed, which was confirmed by DNA sequencing, RT-PGR and restriction enzymes analysis. The green fluorescent protein could be detected in the transfected LM8 with fluorescence microscope. The expected B7-1 and green fluorescent protein （GFP） fusion protein was detected by RT-PCR and Western blot. Conclusion： The eukaryotic expression vector containing B7-1/GFP gene was constructed successfully, and it could be expressed in LM8 after transfection.
基金Supported by “Clinical medical+X” Project from Department of Medicine of Qingdao University
文摘AIM: To identify the novel mutation alleles in the CYP1B1 gene of primary congenital glaucoma(PCG) patients at Shandong Province of China, and investigate their correlation with glaucomatous features.METHODS: The DNA from the peripheral blood of 13 congenital glaucoma patients and 50 ethnically matched healthy controls from the affiliated hospital of Qingdao University were extracted. The coding region of the CYP1B1 gene was amplified by PCR and direct DNA sequencing was performed. Disease causing-variants were analyzed by comparing the sequences and the structures of wild type and mutant CYP1B1 proteins by PyMOL software.RESULTS: Two missense mutations, including A330 F caused by c.988 G>T&c.989 C>T, and R390H caused by c.1169 G>A, were identified in one of the 13 PCG patients analyzed in our study. A330F mutation was observed to be novel in the Chinese Han population, which dramatically altered the protein structure of CYP1B1 gene, including the changes in the ligand-binding pocket. Furthermore, R390H mutation caused the changes in heme-protein binding site of this gene. In addition, the clinical phenotype displayed by PCG patient with these mutations was more pronounced than other PCG patients without these mutations. Multiple surgeries and combined drug treatment were not effective in reducing the elevated intraocular pressure in this patient.CONCLUSION: A novel A330F mutation is identified in the CYP1B1 gene of Chinese PCG patient. Moreover, in combination with other mutation R390H, this PCG patient shows significant difference in the CYP1B1 protein structure, which may specifically contribute to severe glaucomatous phenotype.
基金Supported by the China Agriculture Research System of MOF and MARA(CARS-21)the Financial Fund of the Ministry of Agriculture and Rural Affairs,China(No.NFZX2021)the National Natural Science Foundation of China(No.81973568)。
文摘A new isochromanone,cladosporinisochromanone(1),accompanied by 15 known compounds(2–16)were obtained from secondary metabolites produced by marine-derived fungus Cladosporium sp.DLT-5.NMR and HRESIMS spectra elucidation determined the planar structure of 1.Subsequent electronic circular dichroism(ECD)experiment assigned the absolute configuration of 1.Compounds 1,2,4–6,and 10 displayed different degrees of neuroprotective activities on human neuroblastoma cells SH-SY5Y.Five compounds(1,3–5,and 13)emerged resistance to protein tyrosine phosphatase 1B(PTP1B),further kinetic analysis and molecular docking study indicated that the most potent compound 13(IC50value of 10.74±0.61μmol/L)was found as a noncompetitive inhibitor for PTP1B.Surface plasmon resonance(SPR)and molecular docking studies also demonstrated the interaction between compound 12 and Niemann-Pick C1 Like 1(NPC1L1),which has been identified as significant therapeutic target for hypercholesteremia.In addition,compounds 3,6,and 14 showed attractive inhibitory activity against the phytopathogenic fungi:Colletotrichum capsici.Therefore,library of Cladosporium metabolites is enriched and new active uses of known compounds are explored.
