BACKGROUND Acute pancreatitis(AP),the initially triggered inflammatory process in the pancreas,can be life-threatening.It has been reported that 15-lipoxygenase may promote the removal of damaged intracellular compone...BACKGROUND Acute pancreatitis(AP),the initially triggered inflammatory process in the pancreas,can be life-threatening.It has been reported that 15-lipoxygenase may promote the removal of damaged intracellular components,maintain intracellular homeostasis,and promote apoptosis by upregulating the activity of caspases.Despite an increased understanding of the lipoxygenase pathway in inflammation and immune diseases,the role of the Alox15 gene product in modulating the inflammatory changes during AP is not well defined.AIM To investigate the effect of Alox15 expression in cerulein-induced AP in rats.METHODS Model rats were transfected with Alox15 by injecting a recombinant lentivirus vector encoding Alox15 into the left gastric artery before inducing AP.The expression of Alox15 was then assessed at the mRNA and protein levels.RESULTS Our in vivo results showed that serum amylase activity and pancreatic tissue water content were significantly reduced in Alox15-transfected rats.Further,the mRNA expression levels of tumor necrosis factor alpha,interleukin(IL)-1β,IL-6,and monocyte chemoattractant protein-1,as well as the protein expression of nuclear factor kappa B in pancreatic tissue were reduced.Additionally,we observed an upregulation of cleaved caspase-3 that implies an induction of apoptosis in pancreatic cells.The transfection of Alox15 resulted in a lower number of autophagic vacuoles in AP.CONCLUSION Our findings demonstrate a regulatory role of Alox15 in apoptosis and autophagy,making it a potential therapeutic target for AP.展开更多
Objective:To evaluate the 15-lipoxygenase inhibitory activity of the methanol leaf extracts of Commelina benghalensis,Tradescantia fluminensis(T.fluminensis)and Tradescantia zebrina.Method:The inhibitory activity was ...Objective:To evaluate the 15-lipoxygenase inhibitory activity of the methanol leaf extracts of Commelina benghalensis,Tradescantia fluminensis(T.fluminensis)and Tradescantia zebrina.Method:The inhibitory activity was evaluated using a spectrophotometric assay by observing the increase in absorbance at 234 nm due to the formation of the product 13-hydroperoxyoctadecadienoic acid.The extracts were also tested for the presence of terpenoids,saponins,tannins,flavonoids,steroids,phenolic compounds,alkaloids and cardiac glycosides.Results:All the extracts inhibited the action of 15-lipoxygenase at a concentration of 0.2μg/mL.T.fluminensis and Tradescantia zebrina exhibited higher than 50%inhibition with T.fluminensis at 87.2%.T.fluminensis was partitioned with ethyl acetate and hexane and their IC_(50)values were determined at 8.72μg/mL and 98.04μg/mL,respectively.Conclusions:T.fluminensis is a potentially good source of 15-lipoxygenase inhibitors.展开更多
AIM: To investigate whether 15-Lipoxygenase-1 (15-LOX-1) plays an important role in the regulation of angiogenesis, inhibiting hypoxia-induced proliferation of retinal microvascular endothelial cells (RMVECs) and the ...AIM: To investigate whether 15-Lipoxygenase-1 (15-LOX-1) plays an important role in the regulation of angiogenesis, inhibiting hypoxia-induced proliferation of retinal microvascular endothelial cells (RMVECs) and the underlying mechanism. METHODS: Primary RMVECs were isolated from the retinas of C57/BL63 mice and identified by an evaluation for FITC-marked CD31. The hypoxia models were established with the Bio-bag and evaluated with a blood-gas analyzer. Experiments were performed using RMVECs treated with and without transfer. Ad-15-LOX-1 or Ad-vector both under hypoxia and normoxia condition at 12, 24, 48, 72 hours. The efficacy of the gene transfer was assessed by immunofluorescence staining. Cells proliferation was evaluated by the CCK-8 method. RNA and protein expressions of 15-LOX-1, VEGF-A, VEGFR-2, eNOs and PPAR-r were analyzed by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blot. RESULTS: Routine evaluation for FITC-marked CD31 showed that cells were pure. The results of blood-gas analysis showed that when the cultures were exposed to hypoxia for more than 2 hours, the Po2 was 4.5 to 5.4 Kpa. We verified RMVECs could be infected with Ad-LS-LOX-for Ad-vectorvia Fluorescence microscopy. CCK-8 analysis revealed that the proliferative capacities of RMVECs in hypoxic group were significantly higher at each time point than they were in normoxic group (P <0.05). In a hypoxic condition, the proliferative capacities of RMVECs in 15-LOX-1 group were significantly inhibited (P<0.05). Real-time RT-PCR analysis revealed that the expressions of VEGF-A, VEGF-R2 and eNOs mRNA increased in hypoxia group compared with normoxia group (P<0.01). However, the expressions of 15-LOX-1, PPAR-r mRNA decreased in hypoxia group compared with normoxia group (P<0.01). It also showed that in a hypoxic condition, the expressions of VEGF-A, VEGF-R2 and eNOs mRNA decreased significantly in 15-LOX-1 group compared with hypoxia group (P<0.01). However, 15-LOX-1 and PPAR-r mRNA increased significantly in 15-LOX-1 group compared with hypoxia group (P<0.01). There was no significant difference of the mRNA expressions between vector group and hypoxia group (P>0.05). Western blot analysis revealed that the expressions of relative proteins were also ranked in that order. CONCLUSION: Our results suggested that 15-LOX-1 and PPAR-r might act as a negative regulator of retinal angiogenesis. And the effect of 15-LOX-1 overexpression is an anti-angiogenic factor in hypoxia-induced retinal neovascularization (RNV). Overexpression 15-LOX-1 on RMVECs of hypoxia-induced RNV blocked signaling cascades by inhibiting hypoxia-induced increases in VEGF family. PPAR-r effect on VEGFR(2) could be an additional mechanism whereby 15-LOX-1 inhibited the hypoxia-induced RNV.展开更多
It has been found that expression of 15-lipoxygenasc-1(15-LOX-1) and its main product,13-C-hydroxyoctadecadienoic acid (13-S-HODE),are decreased in human colorectal and esophageal cancers and that nonsteroidal anti-in...It has been found that expression of 15-lipoxygenasc-1(15-LOX-1) and its main product,13-C-hydroxyoctadecadienoic acid (13-S-HODE),are decreased in human colorectal and esophageal cancers and that nonsteroidal anti-inflammatory drugs(NSAIDs) can therspeutically induce 15-LOC-1 expression to trigger apoptosis in those cancer cells independently COX-2.We found that a specific COX-2 inhibitor SC-236 similarly induce apoptosis in gastric cancer cells,although the mechanisms of these effects remain to be defined.In the present study,we tested whether SC-236 induced apoptosis through up-regulation of 15-LOX-1 in gastric cancer cells.We found that,(a) SC-236 inhibited growth of gastric cancer cells mainly by apoptosis induced;(b) SC-236 induced 15-LOX-1 expression and increased endogenous 13-S-HODE product,instead of 15-S-HETE during apoptosis in gastric cancer cells without 15-LOX-1 expression before treatment by SC-236;(c)sc-236 didn't effect expression of COX-1,COX-2,5-LOX and 12-LOX;and (d)15-LOX-1 inhibition suppressed SC-236 induced apoptosis.These findings demonstrated that SC-236 induced apoptosis in gastric cancer cells via up-regulation of 25-LOX-1.They also support the concept that the loss of the proapopotic role of 15-LOX-1 in epithelial cancers is not limited to human colorectal and esophageal cancers.展开更多
基金National Health Commission Research Fund,No.WKJ-ZJ-2342National Natural Science Foundation of China,No.81900583Science and Technology Plan Project of Wenzhou,No.Y20180103.
文摘BACKGROUND Acute pancreatitis(AP),the initially triggered inflammatory process in the pancreas,can be life-threatening.It has been reported that 15-lipoxygenase may promote the removal of damaged intracellular components,maintain intracellular homeostasis,and promote apoptosis by upregulating the activity of caspases.Despite an increased understanding of the lipoxygenase pathway in inflammation and immune diseases,the role of the Alox15 gene product in modulating the inflammatory changes during AP is not well defined.AIM To investigate the effect of Alox15 expression in cerulein-induced AP in rats.METHODS Model rats were transfected with Alox15 by injecting a recombinant lentivirus vector encoding Alox15 into the left gastric artery before inducing AP.The expression of Alox15 was then assessed at the mRNA and protein levels.RESULTS Our in vivo results showed that serum amylase activity and pancreatic tissue water content were significantly reduced in Alox15-transfected rats.Further,the mRNA expression levels of tumor necrosis factor alpha,interleukin(IL)-1β,IL-6,and monocyte chemoattractant protein-1,as well as the protein expression of nuclear factor kappa B in pancreatic tissue were reduced.Additionally,we observed an upregulation of cleaved caspase-3 that implies an induction of apoptosis in pancreatic cells.The transfection of Alox15 resulted in a lower number of autophagic vacuoles in AP.CONCLUSION Our findings demonstrate a regulatory role of Alox15 in apoptosis and autophagy,making it a potential therapeutic target for AP.
基金Supported by the University of the Philippines Diliman through the Natural Sciences Research Institute(Grant No.CHE-09-2-02)
文摘Objective:To evaluate the 15-lipoxygenase inhibitory activity of the methanol leaf extracts of Commelina benghalensis,Tradescantia fluminensis(T.fluminensis)and Tradescantia zebrina.Method:The inhibitory activity was evaluated using a spectrophotometric assay by observing the increase in absorbance at 234 nm due to the formation of the product 13-hydroperoxyoctadecadienoic acid.The extracts were also tested for the presence of terpenoids,saponins,tannins,flavonoids,steroids,phenolic compounds,alkaloids and cardiac glycosides.Results:All the extracts inhibited the action of 15-lipoxygenase at a concentration of 0.2μg/mL.T.fluminensis and Tradescantia zebrina exhibited higher than 50%inhibition with T.fluminensis at 87.2%.T.fluminensis was partitioned with ethyl acetate and hexane and their IC_(50)values were determined at 8.72μg/mL and 98.04μg/mL,respectively.Conclusions:T.fluminensis is a potentially good source of 15-lipoxygenase inhibitors.
基金National Natural Science Foundation of China (No. 81000393)
文摘AIM: To investigate whether 15-Lipoxygenase-1 (15-LOX-1) plays an important role in the regulation of angiogenesis, inhibiting hypoxia-induced proliferation of retinal microvascular endothelial cells (RMVECs) and the underlying mechanism. METHODS: Primary RMVECs were isolated from the retinas of C57/BL63 mice and identified by an evaluation for FITC-marked CD31. The hypoxia models were established with the Bio-bag and evaluated with a blood-gas analyzer. Experiments were performed using RMVECs treated with and without transfer. Ad-15-LOX-1 or Ad-vector both under hypoxia and normoxia condition at 12, 24, 48, 72 hours. The efficacy of the gene transfer was assessed by immunofluorescence staining. Cells proliferation was evaluated by the CCK-8 method. RNA and protein expressions of 15-LOX-1, VEGF-A, VEGFR-2, eNOs and PPAR-r were analyzed by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blot. RESULTS: Routine evaluation for FITC-marked CD31 showed that cells were pure. The results of blood-gas analysis showed that when the cultures were exposed to hypoxia for more than 2 hours, the Po2 was 4.5 to 5.4 Kpa. We verified RMVECs could be infected with Ad-LS-LOX-for Ad-vectorvia Fluorescence microscopy. CCK-8 analysis revealed that the proliferative capacities of RMVECs in hypoxic group were significantly higher at each time point than they were in normoxic group (P <0.05). In a hypoxic condition, the proliferative capacities of RMVECs in 15-LOX-1 group were significantly inhibited (P<0.05). Real-time RT-PCR analysis revealed that the expressions of VEGF-A, VEGF-R2 and eNOs mRNA increased in hypoxia group compared with normoxia group (P<0.01). However, the expressions of 15-LOX-1, PPAR-r mRNA decreased in hypoxia group compared with normoxia group (P<0.01). It also showed that in a hypoxic condition, the expressions of VEGF-A, VEGF-R2 and eNOs mRNA decreased significantly in 15-LOX-1 group compared with hypoxia group (P<0.01). However, 15-LOX-1 and PPAR-r mRNA increased significantly in 15-LOX-1 group compared with hypoxia group (P<0.01). There was no significant difference of the mRNA expressions between vector group and hypoxia group (P>0.05). Western blot analysis revealed that the expressions of relative proteins were also ranked in that order. CONCLUSION: Our results suggested that 15-LOX-1 and PPAR-r might act as a negative regulator of retinal angiogenesis. And the effect of 15-LOX-1 overexpression is an anti-angiogenic factor in hypoxia-induced retinal neovascularization (RNV). Overexpression 15-LOX-1 on RMVECs of hypoxia-induced RNV blocked signaling cascades by inhibiting hypoxia-induced increases in VEGF family. PPAR-r effect on VEGFR(2) could be an additional mechanism whereby 15-LOX-1 inhibited the hypoxia-induced RNV.
文摘It has been found that expression of 15-lipoxygenasc-1(15-LOX-1) and its main product,13-C-hydroxyoctadecadienoic acid (13-S-HODE),are decreased in human colorectal and esophageal cancers and that nonsteroidal anti-inflammatory drugs(NSAIDs) can therspeutically induce 15-LOC-1 expression to trigger apoptosis in those cancer cells independently COX-2.We found that a specific COX-2 inhibitor SC-236 similarly induce apoptosis in gastric cancer cells,although the mechanisms of these effects remain to be defined.In the present study,we tested whether SC-236 induced apoptosis through up-regulation of 15-LOX-1 in gastric cancer cells.We found that,(a) SC-236 inhibited growth of gastric cancer cells mainly by apoptosis induced;(b) SC-236 induced 15-LOX-1 expression and increased endogenous 13-S-HODE product,instead of 15-S-HETE during apoptosis in gastric cancer cells without 15-LOX-1 expression before treatment by SC-236;(c)sc-236 didn't effect expression of COX-1,COX-2,5-LOX and 12-LOX;and (d)15-LOX-1 inhibition suppressed SC-236 induced apoptosis.These findings demonstrated that SC-236 induced apoptosis in gastric cancer cells via up-regulation of 25-LOX-1.They also support the concept that the loss of the proapopotic role of 15-LOX-1 in epithelial cancers is not limited to human colorectal and esophageal cancers.
