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
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
An improved CBB staining with higher sensitivity than that of the typical CBB staining was reported.The main improvement was using a fixing step of 25% trichloroacetic acid(TCA) before CBB staining.For most proteins s...An improved CBB staining with higher sensitivity than that of the typical CBB staining was reported.The main improvement was using a fixing step of 25% trichloroacetic acid(TCA) before CBB staining.For most proteins studied,the sensitivity of the improved CBB staining was about twice as high as that of the typical method.For basic and low molecular weight proteins such as ribosomal proteins,the sensitivity of this improved staining method was about 3.5-28 times that of the typical method.It was speculated that the improved procedure would be suitable for exact quantitative analysis of proteins fractionated by SDS-PAGE,especially for basic and low molecular weight proteins.On the other hand,this new modified method might be also applied to multidisciplinary studies,such as biological researches and nuclear sciences.展开更多
Background Recent studies have shown that T helper type-2 （Th2） cells can induce the apoptosis of CD4＋CD25＋ Treg cells or resist the immunosuppressive effect of Treg cells.We hypothesize that an imbalance of Th2/T...Background Recent studies have shown that T helper type-2 （Th2） cells can induce the apoptosis of CD4＋CD25＋ Treg cells or resist the immunosuppressive effect of Treg cells.We hypothesize that an imbalance of Th2/Treg is present in patients with allergic asthma.Methods Twenty-two patients with mild asthma,17 patients with moderate to severe asthma,and 20 healthy donors were enrolled.All patients were allergic to house dust mites.The proportion of peripheral blood CD4＋CD25＋ Treg cells and Th2 cells were determined by flow cytometry.The concentration of interleukin （IL）-10,transforming growth factor （TGF）-β and IL-4 in plasma was determined by enzyme linked immunosorbent assay.In these subjects,peripheral blood mononuclear cells from 17 mild asthmatic patients,13 moderate to severe asthmatic patients and 14 healthy donors were acquired and expression of forkhead box P3 （Foxp3） and GATA-3 mRNA was detected by reverse-transcriptase polymerase chain reaction.Results Compared with healthy donors and patients with mild asthma,the percent of CD4＋CD25＋ Treg cells and plasma IL-10 levels were decreased in patients with moderate to severe asthma.There were no significant differences in Foxp3 mRNA expression among three groups,but a downward trend seen among patients with asthma.However,the percent of Th2 cells,IL-4 levels and expression of GATA-3 mRNA was markedly higher in patients with mild and moderate to severe asthma than in the control group.The ratio of Th2/Treg and their cytokines was increased in allergic asthma,especially for moderate to severe asthma.The ratio of GATA-3/Foxp3 mRNA was also increased in allergic asthma.In patients with moderate to severe asthma,the percentage of peripheral blood Treg cells was negatively correlated to the percentage of Th2 cells and IL-4 levels.Conclusions The decline of CD4＋CD25＋ Treg cells in patients with moderate to severe asthma may play an important role in progress of the disease.Furthermore,the deficiency of CD4＋CD25＋ Treg cells was associated with the overexpression of Th2 response.展开更多
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An improved CBB staining with higher sensitivity than that of the typical CBB staining was reported.The main improvement was using a fixing step of 25% trichloroacetic acid(TCA) before CBB staining.For most proteins studied,the sensitivity of the improved CBB staining was about twice as high as that of the typical method.For basic and low molecular weight proteins such as ribosomal proteins,the sensitivity of this improved staining method was about 3.5-28 times that of the typical method.It was speculated that the improved procedure would be suitable for exact quantitative analysis of proteins fractionated by SDS-PAGE,especially for basic and low molecular weight proteins.On the other hand,this new modified method might be also applied to multidisciplinary studies,such as biological researches and nuclear sciences.
文摘Background Recent studies have shown that T helper type-2 （Th2） cells can induce the apoptosis of CD4＋CD25＋ Treg cells or resist the immunosuppressive effect of Treg cells.We hypothesize that an imbalance of Th2/Treg is present in patients with allergic asthma.Methods Twenty-two patients with mild asthma,17 patients with moderate to severe asthma,and 20 healthy donors were enrolled.All patients were allergic to house dust mites.The proportion of peripheral blood CD4＋CD25＋ Treg cells and Th2 cells were determined by flow cytometry.The concentration of interleukin （IL）-10,transforming growth factor （TGF）-β and IL-4 in plasma was determined by enzyme linked immunosorbent assay.In these subjects,peripheral blood mononuclear cells from 17 mild asthmatic patients,13 moderate to severe asthmatic patients and 14 healthy donors were acquired and expression of forkhead box P3 （Foxp3） and GATA-3 mRNA was detected by reverse-transcriptase polymerase chain reaction.Results Compared with healthy donors and patients with mild asthma,the percent of CD4＋CD25＋ Treg cells and plasma IL-10 levels were decreased in patients with moderate to severe asthma.There were no significant differences in Foxp3 mRNA expression among three groups,but a downward trend seen among patients with asthma.However,the percent of Th2 cells,IL-4 levels and expression of GATA-3 mRNA was markedly higher in patients with mild and moderate to severe asthma than in the control group.The ratio of Th2/Treg and their cytokines was increased in allergic asthma,especially for moderate to severe asthma.The ratio of GATA-3/Foxp3 mRNA was also increased in allergic asthma.In patients with moderate to severe asthma,the percentage of peripheral blood Treg cells was negatively correlated to the percentage of Th2 cells and IL-4 levels.Conclusions The decline of CD4＋CD25＋ Treg cells in patients with moderate to severe asthma may play an important role in progress of the disease.Furthermore,the deficiency of CD4＋CD25＋ Treg cells was associated with the overexpression of Th2 response.
