Bactericidal/permeability-increasing protein (BPI) is an endogenous antibiotic protein with activity against gram-negative bacteria. In the present study, we examined the expression of BPI in postnatal mouse testes ...Bactericidal/permeability-increasing protein (BPI) is an endogenous antibiotic protein with activity against gram-negative bacteria. In the present study, we examined the expression of BPI in postnatal mouse testes and epididymides as well as the subcellular localization within epididymal spermatozoa. Our results showed that, BPI mRNA was expressed in testis and epididymis independently. Throughout the epididymis, the BPI protein level gradually decreased in the epididymal epithelium in a spatial manner, specialized within the cytoplasm of clear cells in the cauda part. We detected BPI proteins in intact acrosome, implying its testicular origin; on the other hand, after the acrosome reaction, BPI proteins were observed dispersed across the entire sperm head, especially enriched at the equatorial segment. Our findings suggested a dual origin of the BPI that generated both in the testis and epididymis, and associated with mouse spermatozoa. BPI protein might be involved in the dynamics modification of the sperm plasma membrane and also the fertilization process.展开更多
objective: To investigate the protective effects of bactericidal/permeability-increa protein (BPIP) on rats after endotoxic shock as to provide more experimental evidence for studies on its clinical use. Methods:E. co...objective: To investigate the protective effects of bactericidal/permeability-increa protein (BPIP) on rats after endotoxic shock as to provide more experimental evidence for studies on its clinical use. Methods:E. coli 026:B6 LPS was injected at a dosage of 12. 5 mg/kg through the artery to reproduce endo toxic shock. BPIP at a dosage of 5 mg/kg (BPIP-treated group) or equal volume of normal saline (control group) were injected immediately after the injection of LPS. Results: ①Survival time of the shocked animals was prolonged and the 24 h survival rate was also significantly increased in BPIP-treated group as compared with the control group. ②The mean arterial pressure, left intraventricular systolic pressure, isovolemic ven tricular pressure and ±dp/dtmax. were significantly higher in BPIP-treated group than in control group. ③ Plasma levels of glutamic-pyruvic transaminase and urea nitrogen were markedly higher but those of endotox in and TNFα were lower in BPIP-treated group than in control group. Conclusion: BPIP can exert significant protective effects on cardiac, hepatic and renal functions in rats after endotoxic shock, indicating that BPIP might be a good choice in treatment of sepsis/septic shock.展开更多
Effects of bactericidal/permeability-increa protein(BPI, 1. 5 and 3. 5 rug/kg iv at the beginning of shock and resuscitation respectively) on the outcome of hemorrhagic shock was investigated in rats. Itwas found that...Effects of bactericidal/permeability-increa protein(BPI, 1. 5 and 3. 5 rug/kg iv at the beginning of shock and resuscitation respectively) on the outcome of hemorrhagic shock was investigated in rats. Itwas found that BPI administration could improve hepatic and renal functions after hemorrhagic shock, andenhance the survival rate of the rats with shock (BPI group: 81 % vs physiological saline group: 44 %, P <0.05). In BPI group, the plasma endotoxin level was not significantly changed (0. 20± 0. 04 at the end of resuscitation vs 0. 24± 0. 05 U/ml before shock). Tumor necrosis factor. and interleukin-6 levels in BPI group, although higher after shock and resuscitation, were significantly lower than those in physiologia saline group.It is suggested that BPI exerts a protective effects on rats with hernorrhagic shock, which might be due to itsaction against hemorrhage-induced endotoxin translocation and its inhibition of cytokine responses in shock,展开更多
Objective: To discuss the changes in the tight junction protein of intestinal epithelium and permeability of colonic mucosa and its possible mechanism by building the rat mode of inflammatory bowel disease at the chro...Objective: To discuss the changes in the tight junction protein of intestinal epithelium and permeability of colonic mucosa and its possible mechanism by building the rat mode of inflammatory bowel disease at the chronic recovery stage. Methods: A total of 36 SD rats were divided into the model group and control one according to the random number table, with 18 rats in each group. Rats in the model group were given the 3% dextran sulfate sodium solution by the way of drinking for 7 d to build the rat model of inflammatory bowel disease, while rats in the control group were given free drinking of water. Six rats were executed at day 7, 14 and 21 respectively. The colonic tissues were collected from rats to observe the pathological changes of colonic mucosa. The activity of myeloperoxidase was detected and the white blood count was performed for rats in each group. The Ussing chamber technique was employed to detect the transepithelial electrical resistance(TER) and short-circuit current(SC) of colonic mucosa of rats in different time intervals; the quantum dots labeling technique was employed to detect the expression level of claudin-1 and claudin-2 in the colonic tissues. Results: After the successful modeling, the weight of rats in the model group was significantly reduced, while the disease activity index score was increased. The weight was at the lowest level at day 14 and then it began to increase afterwards. The disease activity index score was at the highest level at day 12 and then it began to decrease gradually. The activity of myeloperoxidase and WBC for rats in the model group all reached the peak value at day 14 and then decreased gradually. There was no significant difference in the changes of TER and SC in different time intervals for rats in the control group(P>0.05). TER of model group was at the lowest level at day 14 and then increased gradually; SC was at the highest level at day 14 and then decreased gradually. TER of model group at day 7, 14 and 21 was significantly lower than that of control group, while SC of model group was significantly higher than that of control group(P<0.05). There was no significant difference in the change of mean fluorescence intensity of claudin-1 and claudin-2 in different time intervals for rats in the control group(P>0.05). The claudin-1 and claudin-2 for rats in the model group reached the highest level at day 14 and then decreased gradually. The claudin-1 and claudin-2 of model group at day 7, 14 and 21 was significantly higher than that of control group(P<0.05). Conclusions: After the acute stage, the inflammatory bowel disease is then in the chronic recovery stage; the increased permeability of colonic mucosa and increased expression of tight junction protein of intestinal epithelium are closely related to the pathogenesis and development of disease. The tight junction protein plays a key role in the pathogenesis of injured colonic barrier of inflammatory bowel disease.展开更多
Gelatinases matrix metalloproteinase-2 and matrix metalloproteinase-9 have been shown to mediate claudin-5 and occludin degradation, and play an important regulatory role in blood-brain barrier permeability. This stud...Gelatinases matrix metalloproteinase-2 and matrix metalloproteinase-9 have been shown to mediate claudin-5 and occludin degradation, and play an important regulatory role in blood-brain barrier permeability. This study established a rat model of 1.5-hour middle cerebral artery occlusion with reperfusion. Protein expression levels of claudin-5 and occludin gradually decreased in the early stage of reperfusion, which corresponded to the increase of the gelatinolytic activity of matrix metalloproteinase-2 and matrix metalloproteinase-9. In addition, rats that received treatment with matrix metalloproteinase inhibitor N-[(2R)-2-(hydroxamidocarbonylmethyl)-4-methylpenthanoyl]-L- tryptophan methylamide (GM6001) showed a significant reduction in Evans blue leakage and an inhibition of claudin-5 and occludin protein degradation in striatal tissue. These data indicate that matrix metalloproteinase-2 and matrix metalloproteinase-9-mediated claudin-5 and occludin degradation is an important reason for blood-brain barrier leakage in the early stage of reperfusion. The leakage of the blood-brain barrier was present due to gelatinases-mediated degradation of claudin-5 and occludin proteins. We hypothesized that the timely closure of the structural component of the blood-brain barrier (tight junction proteins) is of importance.展开更多
The bone morphogenetic protein(BMP)family of proteins has a multitude of roles throughout the body.It plays important roles in development and in the adult vascular endothelium,by modulating the angiogenic response.Th...The bone morphogenetic protein(BMP)family of proteins has a multitude of roles throughout the body.It plays important roles in development and in the adult vascular endothelium,by modulating the angiogenic response.The endothelial-specific receptor BMP receptor Alk1 is of particular importance in the proper remodeling of the vasculature and its ligand BMP9 has been shown to be a potent inhibitor of neovascularization.Dysregulated BMP signaling has been linked to multiple vascular diseases and can lead to the abnormal angiogenesis.We therefore investigated the role of BMP9/Alk1 signaling in retinal angiogenesis,and its therapeutic implications for vascular pathologies of the eye.展开更多
Background Ischemia/reperfusion injury (IRI) is an inflammatory response that occurs when tissue is reperfused following a prolonged period of ischemia. Several studies have indicated that C-reactive protein (CRP)...Background Ischemia/reperfusion injury (IRI) is an inflammatory response that occurs when tissue is reperfused following a prolonged period of ischemia. Several studies have indicated that C-reactive protein (CRP) might play an important role in inducing IRI. However, the effects of CRP on myocardial IRI and the underlying mechanisms have not been fully elucidated. This study aimed to investigate the association between CRP and myocardial IRI and the underlying mechanisms. Methods We simulated ischemia/reperfusion using oxygen-glucose deprivation/ reoxygenation (OGD/R) in neonatal Sprague-Dawley rat cardiomyocytes; reperfusion injury was induced by three hours of hypoxia with glucose and serum deprivation followed by one hour of reperfusion. Cell viability was tested with MTS assays, and cardiomyocyte damage was evaluated by lactate dehydrogenase (LDH) leakage. Mitochondrial membrane potential was measured using tetramethylrhodamine ethyl ester (TMRE) and mitochondrial permeability transition pore (mPTP) opening was measured using calcein/AM; both TMRE and caocein/AM were visualized with laser scanning confocal microscopy. In addition, we studied the signaling pathways underlying CRP-mediated ischemia/reperfusion injury via Western blot analysis. Results Compared with the simple OGD/R group, after intervention with 10 pg/mL CRP, cell viability decreased markedly (82.36 % ± 6.18% vs. 64.84% ± 4.06%, P = 0.0007), and the LDH leakage significantly increased (145.3 U/L ± 16.06 U/L vs. 208.2 U/L ± 19.23 U/L, P = 0.0122). CRP also activated mPTP opening and reduced mitochondrial membrane potential during myocardial ischemia/reperfusion. Pretreatment with 1 pM atorvastatin (Ator) before CRP intervention protected cardiomyocytes from IRI. Mitochondrial KATP channel opener diazoxide and mPTP inhibitor cyclosporin A also offset the effects of CRP in this process. The level of phosphorylated extracellular-signal-regulated kinase (ERK) 1/2 was significantly higher after pre-treatment with CRP compared with the OGD/R group (170.4% ± 3.00% v.v. 93.53% ± 1.94%, P 〈 0.0001). Western blot analysis revealed that Akt expression was markedly activated (184.2% ± 6.96% vs. 122.7% ± 5.30%, P = 0.0003) and ERK 1/2 phosphorylation significantly reduced after co-treatment with Ator and CRP compared with the level after CRP pretreatment alone. Conclusions Our results suggested that CRP directly aggravates myocardial IRI in myocardial cells and that this effect is primarily mediated by inhibiting mitochondrial ATP- sensitive potassium (mitoKATp) channels and promoting mPTP opening. Ator counteracts these effects and can reduce CRP-induced IRI. One of the mechanisms of CRP-induced IRI may be related to the sustained activation of the ERK signaling pathway.展开更多
The fusion gene of BPI 23 and human Fcγ1 was obtained by PCR method,and the expression plasmid was constructed to express recombinant BPI 23 \|Fcγ1 fusion protein in CHO cells.After transfection with the plasmid and...The fusion gene of BPI 23 and human Fcγ1 was obtained by PCR method,and the expression plasmid was constructed to express recombinant BPI 23 \|Fcγ1 fusion protein in CHO cells.After transfection with the plasmid and selection by methotrexate,the cell lines expressing the fusion protein were obtained.The recombinant protein was purified using cation\|exchange chromatography and its bioactivity was proved with bactericidal assays.展开更多
文摘Bactericidal/permeability-increasing protein (BPI) is an endogenous antibiotic protein with activity against gram-negative bacteria. In the present study, we examined the expression of BPI in postnatal mouse testes and epididymides as well as the subcellular localization within epididymal spermatozoa. Our results showed that, BPI mRNA was expressed in testis and epididymis independently. Throughout the epididymis, the BPI protein level gradually decreased in the epididymal epithelium in a spatial manner, specialized within the cytoplasm of clear cells in the cauda part. We detected BPI proteins in intact acrosome, implying its testicular origin; on the other hand, after the acrosome reaction, BPI proteins were observed dispersed across the entire sperm head, especially enriched at the equatorial segment. Our findings suggested a dual origin of the BPI that generated both in the testis and epididymis, and associated with mouse spermatozoa. BPI protein might be involved in the dynamics modification of the sperm plasma membrane and also the fertilization process.
文摘objective: To investigate the protective effects of bactericidal/permeability-increa protein (BPIP) on rats after endotoxic shock as to provide more experimental evidence for studies on its clinical use. Methods:E. coli 026:B6 LPS was injected at a dosage of 12. 5 mg/kg through the artery to reproduce endo toxic shock. BPIP at a dosage of 5 mg/kg (BPIP-treated group) or equal volume of normal saline (control group) were injected immediately after the injection of LPS. Results: ①Survival time of the shocked animals was prolonged and the 24 h survival rate was also significantly increased in BPIP-treated group as compared with the control group. ②The mean arterial pressure, left intraventricular systolic pressure, isovolemic ven tricular pressure and ±dp/dtmax. were significantly higher in BPIP-treated group than in control group. ③ Plasma levels of glutamic-pyruvic transaminase and urea nitrogen were markedly higher but those of endotox in and TNFα were lower in BPIP-treated group than in control group. Conclusion: BPIP can exert significant protective effects on cardiac, hepatic and renal functions in rats after endotoxic shock, indicating that BPIP might be a good choice in treatment of sepsis/septic shock.
文摘Effects of bactericidal/permeability-increa protein(BPI, 1. 5 and 3. 5 rug/kg iv at the beginning of shock and resuscitation respectively) on the outcome of hemorrhagic shock was investigated in rats. Itwas found that BPI administration could improve hepatic and renal functions after hemorrhagic shock, andenhance the survival rate of the rats with shock (BPI group: 81 % vs physiological saline group: 44 %, P <0.05). In BPI group, the plasma endotoxin level was not significantly changed (0. 20± 0. 04 at the end of resuscitation vs 0. 24± 0. 05 U/ml before shock). Tumor necrosis factor. and interleukin-6 levels in BPI group, although higher after shock and resuscitation, were significantly lower than those in physiologia saline group.It is suggested that BPI exerts a protective effects on rats with hernorrhagic shock, which might be due to itsaction against hemorrhage-induced endotoxin translocation and its inhibition of cytokine responses in shock,
基金supported by Project of Science and Technology Development of Hubei Province(No.2013HBF21825)
文摘Objective: To discuss the changes in the tight junction protein of intestinal epithelium and permeability of colonic mucosa and its possible mechanism by building the rat mode of inflammatory bowel disease at the chronic recovery stage. Methods: A total of 36 SD rats were divided into the model group and control one according to the random number table, with 18 rats in each group. Rats in the model group were given the 3% dextran sulfate sodium solution by the way of drinking for 7 d to build the rat model of inflammatory bowel disease, while rats in the control group were given free drinking of water. Six rats were executed at day 7, 14 and 21 respectively. The colonic tissues were collected from rats to observe the pathological changes of colonic mucosa. The activity of myeloperoxidase was detected and the white blood count was performed for rats in each group. The Ussing chamber technique was employed to detect the transepithelial electrical resistance(TER) and short-circuit current(SC) of colonic mucosa of rats in different time intervals; the quantum dots labeling technique was employed to detect the expression level of claudin-1 and claudin-2 in the colonic tissues. Results: After the successful modeling, the weight of rats in the model group was significantly reduced, while the disease activity index score was increased. The weight was at the lowest level at day 14 and then it began to increase afterwards. The disease activity index score was at the highest level at day 12 and then it began to decrease gradually. The activity of myeloperoxidase and WBC for rats in the model group all reached the peak value at day 14 and then decreased gradually. There was no significant difference in the changes of TER and SC in different time intervals for rats in the control group(P>0.05). TER of model group was at the lowest level at day 14 and then increased gradually; SC was at the highest level at day 14 and then decreased gradually. TER of model group at day 7, 14 and 21 was significantly lower than that of control group, while SC of model group was significantly higher than that of control group(P<0.05). There was no significant difference in the change of mean fluorescence intensity of claudin-1 and claudin-2 in different time intervals for rats in the control group(P>0.05). The claudin-1 and claudin-2 for rats in the model group reached the highest level at day 14 and then decreased gradually. The claudin-1 and claudin-2 of model group at day 7, 14 and 21 was significantly higher than that of control group(P<0.05). Conclusions: After the acute stage, the inflammatory bowel disease is then in the chronic recovery stage; the increased permeability of colonic mucosa and increased expression of tight junction protein of intestinal epithelium are closely related to the pathogenesis and development of disease. The tight junction protein plays a key role in the pathogenesis of injured colonic barrier of inflammatory bowel disease.
文摘Gelatinases matrix metalloproteinase-2 and matrix metalloproteinase-9 have been shown to mediate claudin-5 and occludin degradation, and play an important regulatory role in blood-brain barrier permeability. This study established a rat model of 1.5-hour middle cerebral artery occlusion with reperfusion. Protein expression levels of claudin-5 and occludin gradually decreased in the early stage of reperfusion, which corresponded to the increase of the gelatinolytic activity of matrix metalloproteinase-2 and matrix metalloproteinase-9. In addition, rats that received treatment with matrix metalloproteinase inhibitor N-[(2R)-2-(hydroxamidocarbonylmethyl)-4-methylpenthanoyl]-L- tryptophan methylamide (GM6001) showed a significant reduction in Evans blue leakage and an inhibition of claudin-5 and occludin protein degradation in striatal tissue. These data indicate that matrix metalloproteinase-2 and matrix metalloproteinase-9-mediated claudin-5 and occludin degradation is an important reason for blood-brain barrier leakage in the early stage of reperfusion. The leakage of the blood-brain barrier was present due to gelatinases-mediated degradation of claudin-5 and occludin proteins. We hypothesized that the timely closure of the structural component of the blood-brain barrier (tight junction proteins) is of importance.
文摘The bone morphogenetic protein(BMP)family of proteins has a multitude of roles throughout the body.It plays important roles in development and in the adult vascular endothelium,by modulating the angiogenic response.The endothelial-specific receptor BMP receptor Alk1 is of particular importance in the proper remodeling of the vasculature and its ligand BMP9 has been shown to be a potent inhibitor of neovascularization.Dysregulated BMP signaling has been linked to multiple vascular diseases and can lead to the abnormal angiogenesis.We therefore investigated the role of BMP9/Alk1 signaling in retinal angiogenesis,and its therapeutic implications for vascular pathologies of the eye.
文摘Background Ischemia/reperfusion injury (IRI) is an inflammatory response that occurs when tissue is reperfused following a prolonged period of ischemia. Several studies have indicated that C-reactive protein (CRP) might play an important role in inducing IRI. However, the effects of CRP on myocardial IRI and the underlying mechanisms have not been fully elucidated. This study aimed to investigate the association between CRP and myocardial IRI and the underlying mechanisms. Methods We simulated ischemia/reperfusion using oxygen-glucose deprivation/ reoxygenation (OGD/R) in neonatal Sprague-Dawley rat cardiomyocytes; reperfusion injury was induced by three hours of hypoxia with glucose and serum deprivation followed by one hour of reperfusion. Cell viability was tested with MTS assays, and cardiomyocyte damage was evaluated by lactate dehydrogenase (LDH) leakage. Mitochondrial membrane potential was measured using tetramethylrhodamine ethyl ester (TMRE) and mitochondrial permeability transition pore (mPTP) opening was measured using calcein/AM; both TMRE and caocein/AM were visualized with laser scanning confocal microscopy. In addition, we studied the signaling pathways underlying CRP-mediated ischemia/reperfusion injury via Western blot analysis. Results Compared with the simple OGD/R group, after intervention with 10 pg/mL CRP, cell viability decreased markedly (82.36 % ± 6.18% vs. 64.84% ± 4.06%, P = 0.0007), and the LDH leakage significantly increased (145.3 U/L ± 16.06 U/L vs. 208.2 U/L ± 19.23 U/L, P = 0.0122). CRP also activated mPTP opening and reduced mitochondrial membrane potential during myocardial ischemia/reperfusion. Pretreatment with 1 pM atorvastatin (Ator) before CRP intervention protected cardiomyocytes from IRI. Mitochondrial KATP channel opener diazoxide and mPTP inhibitor cyclosporin A also offset the effects of CRP in this process. The level of phosphorylated extracellular-signal-regulated kinase (ERK) 1/2 was significantly higher after pre-treatment with CRP compared with the OGD/R group (170.4% ± 3.00% v.v. 93.53% ± 1.94%, P 〈 0.0001). Western blot analysis revealed that Akt expression was markedly activated (184.2% ± 6.96% vs. 122.7% ± 5.30%, P = 0.0003) and ERK 1/2 phosphorylation significantly reduced after co-treatment with Ator and CRP compared with the level after CRP pretreatment alone. Conclusions Our results suggested that CRP directly aggravates myocardial IRI in myocardial cells and that this effect is primarily mediated by inhibiting mitochondrial ATP- sensitive potassium (mitoKATp) channels and promoting mPTP opening. Ator counteracts these effects and can reduce CRP-induced IRI. One of the mechanisms of CRP-induced IRI may be related to the sustained activation of the ERK signaling pathway.
文摘The fusion gene of BPI 23 and human Fcγ1 was obtained by PCR method,and the expression plasmid was constructed to express recombinant BPI 23 \|Fcγ1 fusion protein in CHO cells.After transfection with the plasmid and selection by methotrexate,the cell lines expressing the fusion protein were obtained.The recombinant protein was purified using cation\|exchange chromatography and its bioactivity was proved with bactericidal assays.