Objective： The use of donor-derived immature dendritic cells （imDC） has become a promising approach to induce immune tolerance or immune hyporesponsiveness. However, donor-derived imDC needs to be harvested for a f...Objective： The use of donor-derived immature dendritic cells （imDC） has become a promising approach to induce immune tolerance or immune hyporesponsiveness. However, donor-derived imDC needs to be harvested for a few days and transfused into the recipient in 5-10 days before transplantation, which is practically impossible in a clinical setting where donor organs are mainly harvested from cadavers. Moreover, donor-derived imDC might be cleared by allogeneic reaction offsetting induced immune tolerance or immune hyporesponsiveness. In our study, we further explored the underlying mechanism of immune hyporesponsiveness induced by donor-antigen-unloaded recipient-derived imDC by transfusing these imDC into rats in 1 day before liver transplantation. This paper is to study the mechanism of immune hyporesponsiveness induced by donor-antigen-unloaded recipient-derived imDC and its protection of liver grafts in rats. Methods： 40 SD rats （donor） and 40 male Wistar rats （recipient） were randomly divided into 4 groups： control, cyclosporine A （CsA）, mature DC （mDC）, and imDC; with 10 SD rats and 10 Wistar rats for each group. Animal models of acute graft rejection were established with these rats. Corresponding treatments were given before or after transplantation. In the control group, Wistar rats received no treatment other than liver transplantation. In the CsA group, Wistar rats underwent liver transplantation plus CsA treatment （10 mg/kg·d） in the starting day 2 after transplantation. For the mDC group, recipient-derived mDC （1 × 10^6/rat） were infused intravenously via the dorsal vein of the penis to recipient rats. For the imDC group, imDC （1× 10^6/rat） were injected into recipient rats via the dorsal vein of the penis. In each group, 5 recipients were executed at 10 days after transplantation; the remaining five recipients were kept for the observation of survival time. Blood samples were collected for the measurement of ALT and TBIL; IL-2, IFN-γ, IL-4 and IL-10 and levels were measured with double-antibody sandwich ELISA. Liver tissue was harvested for HE staining and the observation of histological features. Acute rejection was evaluated with Banff classification. Expression levels of Fas-L/Fas in the grafts were detected by iminunohistochemieal staining; and western blot was used to detect the expression level of Scurfin. Results： The median survival times （MST） of the liver allografls in the CsA and imDC group were significantly longer than those in the control or mDC group （P〈0.05）. The serum levels of ALT and TBIL in the control and mDC groups were significantly higher than those of the CsA or imDC group （P〈0.05）. Compared with the CsA anti imDC group, the levels of IL-2 and IFN-γ were higher but the levels of IL-4 and IL-10 were lower than those of the control and mDC groups （P〈0.01）. Slight or no rejection reaction was found in the CsA anti imDC groups （P〈0.05）. The expression level of Scurfin protein in CD4^＋ CD25^＋ T cells of the imDC group was significantly higher than that of three other groups （P〈 0.05）. Conclusion： Donor-antigen-unloaded recipient- derived imDC is an effective treatment in inducing immune hyporesponsiveness by blocking indirect recognition in rat liver transplantation model. Survival span was significantly prolonged by its protective effect. The mechanism of immune hyporesponsiveness induced hy imDC transfusion may involve the preprocesses of T cell apoptosis induction, immune tolerance or hyporesponsiveness in T cells, induction of the shift in TH1/TH2 balance, selection activation of Th2 subset, or induction of regulatory T cell.展开更多
Objective: To study the effect of nitric oxide-induced tyrosine phosphorylation of large-conductance calcium-activated potassium (BK Ca) channel α subunit on vascular hyporesponsiveness in rats. Methods: A total of 4...Objective: To study the effect of nitric oxide-induced tyrosine phosphorylation of large-conductance calcium-activated potassium (BK Ca) channel α subunit on vascular hyporesponsiveness in rats. Methods: A total of 46 Wistar rats of either sex, weighing 250 g±20 g, were used in this study. Models of vascular hyporesponsiveness induced by hemorrhagic shock (30 mm Hg for 2 hours) in vivo and by L-arginine in vitro were established respectively. The vascular responsiveness of isolated superior mesenteric arteries to norepinephrine was observed. Tyrosine phosphorylation of BK Ca α subunit was evaluated with methods of immunoprecipitation and Western blotting. Results: In the smooth muscle cells of the superior mesenteric arteries, the expression of BK Ca α subunit tyrosine phosphorylation increased following hemorrhagic shock, and L-arginine could induce BK Ca channel α subunit tyrosine phosphorylation in a time- and dose-dependent manner. L-NAME (Nω-nitro-L-arginine-methyl-ester), a nitric oxide synthetase inhibitor, could partly restore the decreased vasoresponsiveness of the superior mesenteric arteries after hemorrhagic shock in rats. Down-regulating the protein tyrosine phosphorylation with genistein, a widely-used special protein tyrosine kinase inhibitor, could partly improve the decreased vasoresponsiveness of the superior mesenteric arteries induced by L-arginine in vitro, while up-regulating the protein tyrosine phosphorylation with Na3VO4, a protein tyrosine phosphatase inhibitor, could further decrease the nitric oxide-induced vascular hyporesponsiveness, which could be partly ameliorated by 0.1 mmol/L tetrabutylammonium chloride (TEA), a selective BK Ca inhibitor at this concentration. Conclusions: Nitric oxide can induce the tyrosine phosphorylation of BK Ca α subunit, which influences the vascular hyporesponsiveness in hemorrhagic shock rats or induced by L-arginine in vitro.展开更多
BACKGROUND Hyporesponsiveness to erythropoiesis-stimulating agents(ESAs)is a prevalent problem in patients with chronic kidney disease.It is associated with increased morbidity and mortality in patients who undergo di...BACKGROUND Hyporesponsiveness to erythropoiesis-stimulating agents(ESAs)is a prevalent problem in patients with chronic kidney disease.It is associated with increased morbidity and mortality in patients who undergo dialysis.A significant proportion of patients do not respond to iron supplementation and conventional ESAs.We report a case of severe ESA hyporesponsiveness-related anemia that was successfully treated with oral roxadustat.CASE SUMMARY A 59-year-old Chinese woman had high blood glucose for 25 years,maintenance hemodialysis for 7 years,and recurrent dizziness and fatigue for more than 2 years.Laboratory tests showed severe anemia(hemoglobin level of 54 g/L),though bone marrow biopsy,fluorescence in situ hybridization,and hemolysis tests were within normal ranges.We initially administered first-line therapies and other adjuvant treatments,such as blood transfusions,ESAs,and adequate dialysis,but the patient did not respond as anticipated.Her erythropoietinresistant anemia was probably not only due to chronic renal insufficiency.The patient received the hypoxia-inducible factor prolyl hydroxylase inhibitor roxadustat(100 mg,three times weekly).After 12 wk of treatment,the patient’s hemoglobin increased significantly,and her symptoms were alleviated.During the follow-up period,adverse drug reactions were controllable and tolerable.CONCLUSION Oral roxadustat is effective and tolerable for the treatment of ESA hyporesponsiveness-related anemia in patients undergoing hemodialysis.展开更多
BACKGROUND： Prostacyclin has been shown to increase portal hypertension, but the mechanism is unclear. This study aimed to investigate whether the overproduction of prostacyclin（PGI2） in cirrhosis participates in t...BACKGROUND： Prostacyclin has been shown to increase portal hypertension, but the mechanism is unclear. This study aimed to investigate whether the overproduction of prostacyclin（PGI2） in cirrhosis participates in the splanchnic vascular hyporesponsiveness to vasoconstrictors in cirrhotic rats.METHODS： Cirrhotic model was created by subcutaneous injection of 60% carbon tetrachloride（CCl4） corn oil solution combined with intermittent drinking of 5% alcohol, and agematched rats served as controls. The isolated third-generation mesenteric arterioles were used to examine the contractile response to norepinephrine. The changes in vascular diameter were observed under a microscope imaging device. The plasma concentration of 6-ketone-prostaglandin F1α（6-keto-PGF1α, a stable metabolite of PGI2） was tested via enzyme immunoassays and the expression of cyclooxygenase（COX） in mesenteric arteries was detected by Western blotting.RESULTS： In parallel with the increase of plasma 6-ketoPGF1α, the contractile response of arterioles from cirrhotic rats to norepinephrine was significantly impaired compared with that from controls. Inhibition of PGI2 or protein kinase A with indomethacin or Rp-adenosine 3＇, 5＇-cyclic monophosphothioate（Rp-cAMPS） partially reversed the vascular hypo-contractile response to norepinephrine in arterioles from cirrhotic rats.Indomethacin significantly decreased the plasma 6-keto-PGF1α.Furthermore, indomethacin significantly attenuated the effect of Rp-cAMPS on arterioles from cirrhotic rats. COX-1 expression was up-regulated in mesenteric arteries from cirrhotic rats,whereas COX-2 was not detectable in the mesenteric arteries from both cirrhotic and control rats.CONCLUSION： Enhanced COX-1 expression in cirrhotic rats resulted in elevated PGI2 production which partially contributedto the splanchnic vascular hyporesponsiveness to a vasoconstrictor via the protein kinase A pathway.展开更多
Objective： To study the synergistic effect of ICOS-Ig combined with cyclosporine （CsA） on mouse heart transplantation and explore its therapeutic potential. Methods： ICOS-Ig fusion protein was generated by fusing ...Objective： To study the synergistic effect of ICOS-Ig combined with cyclosporine （CsA） on mouse heart transplantation and explore its therapeutic potential. Methods： ICOS-Ig fusion protein was generated by fusing the extraeellular portion of human ICOS and Fc portion of human IgG. To investigate the effect of ICOS-Ig on T-cell proliferation in vitro, ICOS-Ig or IgG was added to the primary MLR cultures （BALB/c spleen T cells as responder cells and irradiated C57BL/6 spleen cells as stimulator cells）. The cells responsiveness rates were detected by 3H-TdR methods. Then the T cells of each group in primary MLR were cultured as responder cells for secondary MLR, and irradiated C57BL/6 （donor） or C3H （third party） spleen cells as stimulator cells. To study the effect of ICOS-Ig on T-cell proliferation in vivo, CFSE-labeled C57BL/6 spleen cells were transferred to irradiated BALB/c mice. Mice were then treated with IgG, ICOS-Ig or CsA. Seventy two hours after transfer, the spleen cells of the mice were harvested for the detection of CD4^＋CFSE^＋ and CD8^＋CFSE^＋ by FACS. C57BL/6 mouse underwent transplantation of the hearts of BALB/c mouse and were then randomly divided into five equal groups： no treatment group, control lgG treated group （250 gg i.p. d2, 4, 6）, ICOS-Ig treated group （250 μg i.p. d2, 4, 6）, CsA treated group （10 mg/kg i.p. d0-6）, ICOS-Ig combined with CsA group. The cardiac allograft survival was monitored by daily palpation. Results： In primary MLR, ICOS-Ig inhibited T-cell proliferation, （inhibition ratio 58i8.2% in 50 μg/ml）. In secondary MLR, ICOS-Ig specifically inhibited donor spleen cells, which suggested ICOS-Ig could induce donor-specific hyporesponsiveness. In the CFSE dye assay, CD4^＋CFSE^＋ and CD8^＋CFSE^＋ in ICOS-Ig and CsA group was stronger than those in control group, which showed ICOS-Ig and CsA could inhibit the proliferation of allo-reactive T cells in vivo. In mouse heart transplantation model, survival was significantly prolonged in animals treated with ICOS-Ig or CsA as compared with controls. Moreover, ICOS-Ig combined with CsA group had even longer engraftment （〉100 d） than ICOS-Ig or CsA used alone. In histological examination, it was found that there were congestions and edemas in no treatment and IgG treated recipients, together with a lot of inflammatory cells infiltrated. Allogeneic hearts from ICOS-Ig and/or CsA immunized recipients revealed milder histological changes. It was revealed in mechanical analysis that splenic T cells from recipients also exhibited depressed mixed leukocyte reactions （MLR） and cytotoxic lymphocyte reactions （CTL）. Conclusion： These data suggest that ICOS-Ig combined with CsA induces a long-term survival of mouse cardiac allografts, whereas monotherapy is less effective in this regard. Thus, ICOS-Ig combined with CsA treatment may be a novel regimen to combat allograft rejection.展开更多
文摘Objective： The use of donor-derived immature dendritic cells （imDC） has become a promising approach to induce immune tolerance or immune hyporesponsiveness. However, donor-derived imDC needs to be harvested for a few days and transfused into the recipient in 5-10 days before transplantation, which is practically impossible in a clinical setting where donor organs are mainly harvested from cadavers. Moreover, donor-derived imDC might be cleared by allogeneic reaction offsetting induced immune tolerance or immune hyporesponsiveness. In our study, we further explored the underlying mechanism of immune hyporesponsiveness induced by donor-antigen-unloaded recipient-derived imDC by transfusing these imDC into rats in 1 day before liver transplantation. This paper is to study the mechanism of immune hyporesponsiveness induced by donor-antigen-unloaded recipient-derived imDC and its protection of liver grafts in rats. Methods： 40 SD rats （donor） and 40 male Wistar rats （recipient） were randomly divided into 4 groups： control, cyclosporine A （CsA）, mature DC （mDC）, and imDC; with 10 SD rats and 10 Wistar rats for each group. Animal models of acute graft rejection were established with these rats. Corresponding treatments were given before or after transplantation. In the control group, Wistar rats received no treatment other than liver transplantation. In the CsA group, Wistar rats underwent liver transplantation plus CsA treatment （10 mg/kg·d） in the starting day 2 after transplantation. For the mDC group, recipient-derived mDC （1 × 10^6/rat） were infused intravenously via the dorsal vein of the penis to recipient rats. For the imDC group, imDC （1× 10^6/rat） were injected into recipient rats via the dorsal vein of the penis. In each group, 5 recipients were executed at 10 days after transplantation; the remaining five recipients were kept for the observation of survival time. Blood samples were collected for the measurement of ALT and TBIL; IL-2, IFN-γ, IL-4 and IL-10 and levels were measured with double-antibody sandwich ELISA. Liver tissue was harvested for HE staining and the observation of histological features. Acute rejection was evaluated with Banff classification. Expression levels of Fas-L/Fas in the grafts were detected by iminunohistochemieal staining; and western blot was used to detect the expression level of Scurfin. Results： The median survival times （MST） of the liver allografls in the CsA and imDC group were significantly longer than those in the control or mDC group （P〈0.05）. The serum levels of ALT and TBIL in the control and mDC groups were significantly higher than those of the CsA or imDC group （P〈0.05）. Compared with the CsA anti imDC group, the levels of IL-2 and IFN-γ were higher but the levels of IL-4 and IL-10 were lower than those of the control and mDC groups （P〈0.01）. Slight or no rejection reaction was found in the CsA anti imDC groups （P〈0.05）. The expression level of Scurfin protein in CD4^＋ CD25^＋ T cells of the imDC group was significantly higher than that of three other groups （P〈 0.05）. Conclusion： Donor-antigen-unloaded recipient- derived imDC is an effective treatment in inducing immune hyporesponsiveness by blocking indirect recognition in rat liver transplantation model. Survival span was significantly prolonged by its protective effect. The mechanism of immune hyporesponsiveness induced hy imDC transfusion may involve the preprocesses of T cell apoptosis induction, immune tolerance or hyporesponsiveness in T cells, induction of the shift in TH1/TH2 balance, selection activation of Th2 subset, or induction of regulatory T cell.
文摘Objective: To study the effect of nitric oxide-induced tyrosine phosphorylation of large-conductance calcium-activated potassium (BK Ca) channel α subunit on vascular hyporesponsiveness in rats. Methods: A total of 46 Wistar rats of either sex, weighing 250 g±20 g, were used in this study. Models of vascular hyporesponsiveness induced by hemorrhagic shock (30 mm Hg for 2 hours) in vivo and by L-arginine in vitro were established respectively. The vascular responsiveness of isolated superior mesenteric arteries to norepinephrine was observed. Tyrosine phosphorylation of BK Ca α subunit was evaluated with methods of immunoprecipitation and Western blotting. Results: In the smooth muscle cells of the superior mesenteric arteries, the expression of BK Ca α subunit tyrosine phosphorylation increased following hemorrhagic shock, and L-arginine could induce BK Ca channel α subunit tyrosine phosphorylation in a time- and dose-dependent manner. L-NAME (Nω-nitro-L-arginine-methyl-ester), a nitric oxide synthetase inhibitor, could partly restore the decreased vasoresponsiveness of the superior mesenteric arteries after hemorrhagic shock in rats. Down-regulating the protein tyrosine phosphorylation with genistein, a widely-used special protein tyrosine kinase inhibitor, could partly improve the decreased vasoresponsiveness of the superior mesenteric arteries induced by L-arginine in vitro, while up-regulating the protein tyrosine phosphorylation with Na3VO4, a protein tyrosine phosphatase inhibitor, could further decrease the nitric oxide-induced vascular hyporesponsiveness, which could be partly ameliorated by 0.1 mmol/L tetrabutylammonium chloride (TEA), a selective BK Ca inhibitor at this concentration. Conclusions: Nitric oxide can induce the tyrosine phosphorylation of BK Ca α subunit, which influences the vascular hyporesponsiveness in hemorrhagic shock rats or induced by L-arginine in vitro.
基金Supported by the National Natural Science Foundation of China,No.81770730and the Hunan Provincial Natural Science Fund,No.2017JJ2352.
文摘BACKGROUND Hyporesponsiveness to erythropoiesis-stimulating agents(ESAs)is a prevalent problem in patients with chronic kidney disease.It is associated with increased morbidity and mortality in patients who undergo dialysis.A significant proportion of patients do not respond to iron supplementation and conventional ESAs.We report a case of severe ESA hyporesponsiveness-related anemia that was successfully treated with oral roxadustat.CASE SUMMARY A 59-year-old Chinese woman had high blood glucose for 25 years,maintenance hemodialysis for 7 years,and recurrent dizziness and fatigue for more than 2 years.Laboratory tests showed severe anemia(hemoglobin level of 54 g/L),though bone marrow biopsy,fluorescence in situ hybridization,and hemolysis tests were within normal ranges.We initially administered first-line therapies and other adjuvant treatments,such as blood transfusions,ESAs,and adequate dialysis,but the patient did not respond as anticipated.Her erythropoietinresistant anemia was probably not only due to chronic renal insufficiency.The patient received the hypoxia-inducible factor prolyl hydroxylase inhibitor roxadustat(100 mg,three times weekly).After 12 wk of treatment,the patient’s hemoglobin increased significantly,and her symptoms were alleviated.During the follow-up period,adverse drug reactions were controllable and tolerable.CONCLUSION Oral roxadustat is effective and tolerable for the treatment of ESA hyporesponsiveness-related anemia in patients undergoing hemodialysis.
基金supported by a grant from the Shanghai Science and Technology Commission(10411965200)
文摘BACKGROUND： Prostacyclin has been shown to increase portal hypertension, but the mechanism is unclear. This study aimed to investigate whether the overproduction of prostacyclin（PGI2） in cirrhosis participates in the splanchnic vascular hyporesponsiveness to vasoconstrictors in cirrhotic rats.METHODS： Cirrhotic model was created by subcutaneous injection of 60% carbon tetrachloride（CCl4） corn oil solution combined with intermittent drinking of 5% alcohol, and agematched rats served as controls. The isolated third-generation mesenteric arterioles were used to examine the contractile response to norepinephrine. The changes in vascular diameter were observed under a microscope imaging device. The plasma concentration of 6-ketone-prostaglandin F1α（6-keto-PGF1α, a stable metabolite of PGI2） was tested via enzyme immunoassays and the expression of cyclooxygenase（COX） in mesenteric arteries was detected by Western blotting.RESULTS： In parallel with the increase of plasma 6-ketoPGF1α, the contractile response of arterioles from cirrhotic rats to norepinephrine was significantly impaired compared with that from controls. Inhibition of PGI2 or protein kinase A with indomethacin or Rp-adenosine 3＇, 5＇-cyclic monophosphothioate（Rp-cAMPS） partially reversed the vascular hypo-contractile response to norepinephrine in arterioles from cirrhotic rats.Indomethacin significantly decreased the plasma 6-keto-PGF1α.Furthermore, indomethacin significantly attenuated the effect of Rp-cAMPS on arterioles from cirrhotic rats. COX-1 expression was up-regulated in mesenteric arteries from cirrhotic rats,whereas COX-2 was not detectable in the mesenteric arteries from both cirrhotic and control rats.CONCLUSION： Enhanced COX-1 expression in cirrhotic rats resulted in elevated PGI2 production which partially contributedto the splanchnic vascular hyporesponsiveness to a vasoconstrictor via the protein kinase A pathway.
基金Supported by Research Grants from the Ministry of Science and Technology of People’s Republic of China (National 863 Plan, 2002AA214091)the NationalScience Foundation for Young Scholars of China (30500501)
文摘Objective： To study the synergistic effect of ICOS-Ig combined with cyclosporine （CsA） on mouse heart transplantation and explore its therapeutic potential. Methods： ICOS-Ig fusion protein was generated by fusing the extraeellular portion of human ICOS and Fc portion of human IgG. To investigate the effect of ICOS-Ig on T-cell proliferation in vitro, ICOS-Ig or IgG was added to the primary MLR cultures （BALB/c spleen T cells as responder cells and irradiated C57BL/6 spleen cells as stimulator cells）. The cells responsiveness rates were detected by 3H-TdR methods. Then the T cells of each group in primary MLR were cultured as responder cells for secondary MLR, and irradiated C57BL/6 （donor） or C3H （third party） spleen cells as stimulator cells. To study the effect of ICOS-Ig on T-cell proliferation in vivo, CFSE-labeled C57BL/6 spleen cells were transferred to irradiated BALB/c mice. Mice were then treated with IgG, ICOS-Ig or CsA. Seventy two hours after transfer, the spleen cells of the mice were harvested for the detection of CD4^＋CFSE^＋ and CD8^＋CFSE^＋ by FACS. C57BL/6 mouse underwent transplantation of the hearts of BALB/c mouse and were then randomly divided into five equal groups： no treatment group, control lgG treated group （250 gg i.p. d2, 4, 6）, ICOS-Ig treated group （250 μg i.p. d2, 4, 6）, CsA treated group （10 mg/kg i.p. d0-6）, ICOS-Ig combined with CsA group. The cardiac allograft survival was monitored by daily palpation. Results： In primary MLR, ICOS-Ig inhibited T-cell proliferation, （inhibition ratio 58i8.2% in 50 μg/ml）. In secondary MLR, ICOS-Ig specifically inhibited donor spleen cells, which suggested ICOS-Ig could induce donor-specific hyporesponsiveness. In the CFSE dye assay, CD4^＋CFSE^＋ and CD8^＋CFSE^＋ in ICOS-Ig and CsA group was stronger than those in control group, which showed ICOS-Ig and CsA could inhibit the proliferation of allo-reactive T cells in vivo. In mouse heart transplantation model, survival was significantly prolonged in animals treated with ICOS-Ig or CsA as compared with controls. Moreover, ICOS-Ig combined with CsA group had even longer engraftment （〉100 d） than ICOS-Ig or CsA used alone. In histological examination, it was found that there were congestions and edemas in no treatment and IgG treated recipients, together with a lot of inflammatory cells infiltrated. Allogeneic hearts from ICOS-Ig and/or CsA immunized recipients revealed milder histological changes. It was revealed in mechanical analysis that splenic T cells from recipients also exhibited depressed mixed leukocyte reactions （MLR） and cytotoxic lymphocyte reactions （CTL）. Conclusion： These data suggest that ICOS-Ig combined with CsA induces a long-term survival of mouse cardiac allografts, whereas monotherapy is less effective in this regard. Thus, ICOS-Ig combined with CsA treatment may be a novel regimen to combat allograft rejection.
