Interleukin-2 （IL）-2 signaling plays a pivotal role in the activation of immune responses, and drugs that block this pathway have been shown to be effective for the immunosuppression in patients with organ transplan...Interleukin-2 （IL）-2 signaling plays a pivotal role in the activation of immune responses, and drugs that block this pathway have been shown to be effective for the immunosuppression in patients with organ transplantation to alleviate/eliminate allograft rejection. The first humanized monoclonal antibody （mAb） daclizumab falls into this category and shows high specificity and affinity against a key component of the IL-2 receptor complex, namely IL-2Ra. To reveal the molecular mechanism of the inhibition of the IL-2 signaling pathway by dacllzumab, we determined the crystal structures of the daclizumab Fab in free form and in complex with the IL-2Ra ectodomain at 2.6 and 2.8 A resolution, respectively. The daclizumab Fab adopts a similar conformation in the presence or absence of the IL- 2Ra ectodomain. The antigen-binding site of daclizumab is mainly composed of live complementarity determining regions （CDRs） that form a large positively charged surface depression and two flanking patches that are generally hydrophobic. The conformational epitope consists of several discontinuous segments of the IL-2Ru ectodomain, a large portion of which overlaps with the regions that interact with IL-2, suggesting that the binding of daclizumab to IL-2Ra would prevent the IL-2 binding to IL-2Ra and the subsequent formation of the IL-2fIL-2Ra[~/c complex, and therefore block the IL-2 signaling pathway. These results also have implications for the design and development of improved mAb drugs targeting IL-2Ra.展开更多
AIM: To systematically investigate if cGMP/cGMP- dependent protein kinase G (PKG) signaling pathway may participate in dendroaspis natriuretic peptide (DNP)-induced relaxation of gastric circular smooth muscle. METHOD...AIM: To systematically investigate if cGMP/cGMP- dependent protein kinase G (PKG) signaling pathway may participate in dendroaspis natriuretic peptide (DNP)-induced relaxation of gastric circular smooth muscle. METHODS: The content of cGMP in guinea pig gastric antral smooth muscle tissue and perfusion solution were measured using radioimmunoassay; spontaneous contraction of gastric antral circular muscles recorded using a 4-channel physiograph; and Ca2+-activated K+ currents (IK(Ca)) and spontaneous transient outward currents (STOCs) in isolated gastric antral myocytes were recorded using the whole-cell patch clamp technique. RESULTS: DNP markedly enhanced cGMP levels in gastric antral smooth muscle tissue and in the perfusion medium. DNP induced relaxation in gastricantral circular smooth muscle, which was inhibited by KT5823, a cGMP-dependent PKG inhibitor. DNP increased IK(Ca). This effect was almost completely blocked by KT5823, and partially blocked by LY83583, an inhibitor of guanylate cyclase to change the production of cGMP. DNP also increased STOCs. The effect of DNP on STOCs was abolished in the presence of KT5823, but not affected by KT-5720, a PKA-specific inhibitor. CONCLUSION: DNP activates IK(Ca) and relaxes guinea-pig gastric antral circular smooth muscle via the cGMP/PKG-dependent singling axis instead of cAMP/ PKA pathway.展开更多
Herpes simplex viruses （HSV-1 and HSV-2） cause global morbidity and synergistically correlate with HIV infection. HSV exists life-long in a latent form in sensory neurons with intermittent reactivation, in despite o...Herpes simplex viruses （HSV-1 and HSV-2） cause global morbidity and synergistically correlate with HIV infection. HSV exists life-long in a latent form in sensory neurons with intermittent reactivation, in despite of host immune surveillatlce. While abundant evidence for HSV interfering with innate immune responses so as to favor the replication and propagation of the virus, several lines of evidence declare that HSV attenuates adaptive immunity by various mechanisms, including but not limited to the ablation of antigen presentation, induction of apoptosis, and interruption of cellular signaling. In this review, we will focus on the perturbative role of HSV in T cells signaling.展开更多
The APCDDI （adenomatosis polyposis coli down-regulated 1） gene is an inhibitor of the Wnt signaling pathway, and a rare mutation of this gene has been associated with hereditary hypotrichosis simplex. In this study,...The APCDDI （adenomatosis polyposis coli down-regulated 1） gene is an inhibitor of the Wnt signaling pathway, and a rare mutation of this gene has been associated with hereditary hypotrichosis simplex. In this study, the authors aimed to investigate whether common APCDD1 gene polymorphisms contribute to the development of androgenic alopecia. Patients （n = 210） with androgenic alopecia and 98 controls were investigated. SNPs （Single nucleotide polymorphisms） in the coding region of the gene were sequenced. A significant difference in genotype distribution was found for the c. 1781C/T, p.L476L SNP （rs3185480） of the APCDD1 gene. This SNP is located in exon 5 and is associated with a 3.5- and a 2.8-fold increase in risk for the development of androgenic alopecia for homozygote （CI 0.933-13.125; nominal regression P = 0.063） and heterozygote （CI 1.086-7.217; nominal regression P = 0.033） carriers, respectively. These data suggest that the rs3185480 polymorphism contributes to the development of androgenic alopecia. Protein expression experiments revealed that the polymorphism is associated with reduced APCDDI protein abundance. This reduction is likely due to altered codon usage for leucine from a preferred codon （CTC） to a rare codon （CTT）, which might influence translation efficiency and, thus, APCDDI protein level.展开更多
Objective： To assess the effects of penehyclidine hydrochloride on patients with acute lung injury （ALI）, to observe the expression of Toll-like receptor 4 （TLR4） on the peripheral monocytes of ALI patients and c...Objective： To assess the effects of penehyclidine hydrochloride on patients with acute lung injury （ALI）, to observe the expression of Toll-like receptor 4 （TLR4） on the peripheral monocytes of ALI patients and changes of inflammatory ＆ anti-inflammatory cytokines and to investigate the mechanism of TLR4 in ALI.Methods： Forty-five patients with ALI were randomly divided into penehyclidine hydrochloride treatment group （P group, n=21） and conventional treatment group （control group, C group, n=24）. Patients in both groups received conventional treatment, including active treatment of the primary disease, respiratory support, nutritional support and fluid management therapy, while those in P group were given penehyclidine hydrochloride （1 mg, im, q. 12 h） in addition.The TLR4 expression of 20 healthy volunteers were detected.The clinical effect, average length of stay in ICU and hospital,values of PaO2 and PaO2/FiO2, expression of TLR4 on the surface of peripheral blood mononuclear cells and some serum cytokines were evaluated for 48 h.Results： The general conditions of the two groups were improved gradually and PaO2 increased progressively.Compared with 0 h, PaO2 and PaO2/FiO2 at 6, 12, 24 and 48 h after treatment were significantly increased （P＜0.05）. The improvement in P group was obviously greater than that in C group （P＜0.05）. The average length of hospitalization showed no difference between the two groups, but penehyclidine hydrochloride significantly decreased the average length of stay in ICU （t=3.485, P＜0.01）. The expression of TLR4 in two groups were both obviously higher than that of healthy volunteers （P＜0.01）. It decreased significantly at 24 h （t=2.032, P＜0.05） and 48 h （t=3.620, P＜0.01）and was lower in P group than in C group. The patients who showed a higher level of TLR4 expression in early stage had a worse prognosis and most of them developed acute respiratory distress syndrome （ARDS）. The incidence of ARDS was 23.8% in P group and 29.17% in C group at 24 h.Until148 h, there were other two patients developing ARDS in control group. Serum IL-l, IL-8 and TNF-α expressions reduced after 24 h in both groups. The reduction in P group was more obvious than that in C group （P＜0.05）. IL-13 increased gradually from 0 h to 24 h, and decreased slightly at 48 h, which showed no difference between two groups （t=1.028, P＞0.05）.Conclusions： Penehyclidine hydrochloride improves the arterial oxygen pressure, down-regulates the expression of TLR4 and restrains the inflammatory cytokines in the downstream of TLR4 signaling pathway. It prevents the development of ALI and can be considered as an important drug in ALI treatment.展开更多
基金Acknowledgments We are grateful to the staff members at Shanghai Synchrotron Radiation Facility for support in diffraction data collection and other members of our group for helpful discussion. This work was supported by grants from the Ministry of Science and Technology of China （2010CB833601, 2006AA02A313, and 2009ZX09503- 009）, the National Natural Science Foundation of China （30730028 and 90713046）, and the Chinese Academy of Sciences （KSCX2-YW-R- 107 and SIBS2008002）.
文摘Interleukin-2 （IL）-2 signaling plays a pivotal role in the activation of immune responses, and drugs that block this pathway have been shown to be effective for the immunosuppression in patients with organ transplantation to alleviate/eliminate allograft rejection. The first humanized monoclonal antibody （mAb） daclizumab falls into this category and shows high specificity and affinity against a key component of the IL-2 receptor complex, namely IL-2Ra. To reveal the molecular mechanism of the inhibition of the IL-2 signaling pathway by dacllzumab, we determined the crystal structures of the daclizumab Fab in free form and in complex with the IL-2Ra ectodomain at 2.6 and 2.8 A resolution, respectively. The daclizumab Fab adopts a similar conformation in the presence or absence of the IL- 2Ra ectodomain. The antigen-binding site of daclizumab is mainly composed of live complementarity determining regions （CDRs） that form a large positively charged surface depression and two flanking patches that are generally hydrophobic. The conformational epitope consists of several discontinuous segments of the IL-2Ru ectodomain, a large portion of which overlaps with the regions that interact with IL-2, suggesting that the binding of daclizumab to IL-2Ra would prevent the IL-2 binding to IL-2Ra and the subsequent formation of the IL-2fIL-2Ra[~/c complex, and therefore block the IL-2 signaling pathway. These results also have implications for the design and development of improved mAb drugs targeting IL-2Ra.
基金The National Natural Science Foundation of China, No. 30800382the Youth Science Foundation of Dalian to Professor Hui-Shu Guo, No. 2006B3NS218
文摘AIM: To systematically investigate if cGMP/cGMP- dependent protein kinase G (PKG) signaling pathway may participate in dendroaspis natriuretic peptide (DNP)-induced relaxation of gastric circular smooth muscle. METHODS: The content of cGMP in guinea pig gastric antral smooth muscle tissue and perfusion solution were measured using radioimmunoassay; spontaneous contraction of gastric antral circular muscles recorded using a 4-channel physiograph; and Ca2+-activated K+ currents (IK(Ca)) and spontaneous transient outward currents (STOCs) in isolated gastric antral myocytes were recorded using the whole-cell patch clamp technique. RESULTS: DNP markedly enhanced cGMP levels in gastric antral smooth muscle tissue and in the perfusion medium. DNP induced relaxation in gastricantral circular smooth muscle, which was inhibited by KT5823, a cGMP-dependent PKG inhibitor. DNP increased IK(Ca). This effect was almost completely blocked by KT5823, and partially blocked by LY83583, an inhibitor of guanylate cyclase to change the production of cGMP. DNP also increased STOCs. The effect of DNP on STOCs was abolished in the presence of KT5823, but not affected by KT-5720, a PKA-specific inhibitor. CONCLUSION: DNP activates IK(Ca) and relaxes guinea-pig gastric antral circular smooth muscle via the cGMP/PKG-dependent singling axis instead of cAMP/ PKA pathway.
基金National Natural Science Foundation of China (30670080)Ministry of Science and Technology of China (2007CB914800,2006CB910103)
文摘Herpes simplex viruses （HSV-1 and HSV-2） cause global morbidity and synergistically correlate with HIV infection. HSV exists life-long in a latent form in sensory neurons with intermittent reactivation, in despite of host immune surveillatlce. While abundant evidence for HSV interfering with innate immune responses so as to favor the replication and propagation of the virus, several lines of evidence declare that HSV attenuates adaptive immunity by various mechanisms, including but not limited to the ablation of antigen presentation, induction of apoptosis, and interruption of cellular signaling. In this review, we will focus on the perturbative role of HSV in T cells signaling.
文摘The APCDDI （adenomatosis polyposis coli down-regulated 1） gene is an inhibitor of the Wnt signaling pathway, and a rare mutation of this gene has been associated with hereditary hypotrichosis simplex. In this study, the authors aimed to investigate whether common APCDD1 gene polymorphisms contribute to the development of androgenic alopecia. Patients （n = 210） with androgenic alopecia and 98 controls were investigated. SNPs （Single nucleotide polymorphisms） in the coding region of the gene were sequenced. A significant difference in genotype distribution was found for the c. 1781C/T, p.L476L SNP （rs3185480） of the APCDD1 gene. This SNP is located in exon 5 and is associated with a 3.5- and a 2.8-fold increase in risk for the development of androgenic alopecia for homozygote （CI 0.933-13.125; nominal regression P = 0.063） and heterozygote （CI 1.086-7.217; nominal regression P = 0.033） carriers, respectively. These data suggest that the rs3185480 polymorphism contributes to the development of androgenic alopecia. Protein expression experiments revealed that the polymorphism is associated with reduced APCDDI protein abundance. This reduction is likely due to altered codon usage for leucine from a preferred codon （CTC） to a rare codon （CTT）, which might influence translation efficiency and, thus, APCDDI protein level.
文摘Objective： To assess the effects of penehyclidine hydrochloride on patients with acute lung injury （ALI）, to observe the expression of Toll-like receptor 4 （TLR4） on the peripheral monocytes of ALI patients and changes of inflammatory ＆ anti-inflammatory cytokines and to investigate the mechanism of TLR4 in ALI.Methods： Forty-five patients with ALI were randomly divided into penehyclidine hydrochloride treatment group （P group, n=21） and conventional treatment group （control group, C group, n=24）. Patients in both groups received conventional treatment, including active treatment of the primary disease, respiratory support, nutritional support and fluid management therapy, while those in P group were given penehyclidine hydrochloride （1 mg, im, q. 12 h） in addition.The TLR4 expression of 20 healthy volunteers were detected.The clinical effect, average length of stay in ICU and hospital,values of PaO2 and PaO2/FiO2, expression of TLR4 on the surface of peripheral blood mononuclear cells and some serum cytokines were evaluated for 48 h.Results： The general conditions of the two groups were improved gradually and PaO2 increased progressively.Compared with 0 h, PaO2 and PaO2/FiO2 at 6, 12, 24 and 48 h after treatment were significantly increased （P＜0.05）. The improvement in P group was obviously greater than that in C group （P＜0.05）. The average length of hospitalization showed no difference between the two groups, but penehyclidine hydrochloride significantly decreased the average length of stay in ICU （t=3.485, P＜0.01）. The expression of TLR4 in two groups were both obviously higher than that of healthy volunteers （P＜0.01）. It decreased significantly at 24 h （t=2.032, P＜0.05） and 48 h （t=3.620, P＜0.01）and was lower in P group than in C group. The patients who showed a higher level of TLR4 expression in early stage had a worse prognosis and most of them developed acute respiratory distress syndrome （ARDS）. The incidence of ARDS was 23.8% in P group and 29.17% in C group at 24 h.Until148 h, there were other two patients developing ARDS in control group. Serum IL-l, IL-8 and TNF-α expressions reduced after 24 h in both groups. The reduction in P group was more obvious than that in C group （P＜0.05）. IL-13 increased gradually from 0 h to 24 h, and decreased slightly at 48 h, which showed no difference between two groups （t=1.028, P＞0.05）.Conclusions： Penehyclidine hydrochloride improves the arterial oxygen pressure, down-regulates the expression of TLR4 and restrains the inflammatory cytokines in the downstream of TLR4 signaling pathway. It prevents the development of ALI and can be considered as an important drug in ALI treatment.
