ABSTRACT
We evaluated the effect of the total macerate (TM) and seed oil (SO) of mature Carica candamarcensis fruits, on the release of Matrix metalloproteinase 9 (MMP9) and the phosphorylation of MAPK in neutrophils. The antioxidant capacity of these extracts was evaluated by ABTS assay. Neutrophils stimulated with different dilutions of TM or SO were analyzed for cytotoxicity, MMP9 release, and MAPK phosphorylation, using trypan blue exclusion assays, zymography, and immunoblotting, respectively. Both extracts show antioxidant activity, being higher in TM; none presented cytotoxic effect. The 5% and 2.5% dilutions of TM significantly reduced MMP9 release, and all decreased MAPK phosphorylation. SO significantly increased the release o f MMP9 and MAPK phosphorylation, the effect being greater when they were prestimulated with lipopolysaccharide.TM may have anti - inflammatory potential, while SO could have a priming effect that needs to be confirmed
Evaluamos el efecto del macerado total (MT) y aceite de semillas (AV) de frutos maduros de Carica candamarcensis , en la liberación de Matriz metaloproteinasa 9 (MMP9) y la fosfor ilación de MAPK en neutrófilos. La capacidad antioxidante de estos extractos se evaluó por ensayo ABTS. En neutrófilos estimulados con diferentes diluciones de MT o AV se analizó la citotoxicidad, liberación de MMP9 y fosforilación de MAPK, mediante ensayo s de exclusión con azul de tripano, zimografía e inmunotransferencia, respectivamente. Ambos extractos muestran actividad antioxidante, siendo mayor en MT; ninguno presentó efecto citotóxico. Las diluciones 5% y 2,5% de MT redujeron significativamente la l iberación de MMP9, y todas disminuyeron la fosforilación de MAPK. El AV incrementó significativamente la liberación de MMP9 y la fosforilación de MAPK, el efecto fue mayor cuando se preestimularon con lipopolisacárido. El MT puede tener potencial antiinfla matorio, mientras que el AV podría tener un efecto "priming" que necesita ser corroborado.
Subject(s)
Humans , Plant Extracts/pharmacology , Carica/enzymology , Neutrophils/drug effects , Phosphorylation , Mitogen-Activated Protein Kinase 1 , Matrix Metalloproteinase 9/metabolism , Latex/analysisABSTRACT
Abiotic stresses substantially affect the growth and development of plants. Plants have evolved multiple strategies to cope with the environmental stresses, among which transcription factors play an important role in regulating the tolerance to abiotic stresses. Basic leucine zipper transcription factors (bZIP) are one of the largest gene families. The stability and activity of bZIP transcription factors could be regulated by different post-translational modifications (PTMs) in response to various intracellular or extracellular stresses. This paper introduces the structural feature and classification of bZIP transcription factors, followed by summarizing the PTMs of bZIP transcription factors, such as phosphorylation, ubiquitination and small ubiquitin-like modifier (SUMO) modification, in response to abiotic stresses. In addition, future perspectives were prospected, which may facilitate cultivating excellent stress-resistant crop varieties by regulating the PTMs of bZIP transcription factors.
Subject(s)
Basic-Leucine Zipper Transcription Factors/genetics , Protein Processing, Post-Translational , Phosphorylation , Transcription Factors/genetics , Stress, Physiological/geneticsABSTRACT
Stigmasterol is a plant sterol with anti-apoptotic, anti-oxidative and anti-inflammatory effect through multiple mechanisms. In this study, we further assessed whether it exerts protective effect on human brain microvessel endothelial cells (HBMECs) against ischemia-reperfusion injury and explored the underlying mechanisms. HBMECs were used to establish an in vitro oxygen and glucose deprivation/reperfusion (OGD/R) model, while a middle cerebral artery occlusion (MCAO) model of rats were constructed. The interaction between stigmasterol and EPHA2 was detected by surface plasmon resonance (SPR) and cellular thermal shift assay (CETSA). The results showed that 10 μmol·L-1 stigmasterol significantly protected cell viability, alleviated the loss of tight junction proteins and attenuated the blood-brain barrier (BBB) damage induced by OGD/R in thein vitro model. Subsequent molecular docking showed that stigmasterol might interact with EPHA2 at multiple sites, including T692, a critical gatekeep residue of this receptor. Exogenous ephrin-A1 (an EPHA2 ligand) exacerbated OGD/R-induced EPHA2 phosphorylation at S897, facilitated ZO-1/claudin-5 loss, and promoted BBB leakage in vitro, which were significantly attenuated after stigmasterol treatment. The rat MCAO model confirmed these protective effects in vivo. In summary, these findings suggest that stigmasterol protects HBMECs against ischemia-reperfusion injury by maintaining cell viability, reducing the loss of tight junction proteins, and attenuating the BBB damage. These protective effects are at least meditated by its interaction with EPHA2 and inhibitory effect on EPHA2 phosphorylation.
Subject(s)
Humans , Animals , Rats , Stigmasterol , Phosphorylation , Endothelial Cells , Molecular Docking Simulation , Reperfusion Injury , Blood-Brain Barrier , Glucose , Microvessels , OxygenABSTRACT
The present study aimed to investigate the protective effect of S-propargyl-cysteine (SPRC) on atherosclerosis progression in mice. A mouse model of vulnerable atherosclerotic plaque was created in ApoE-/- mice by carotid artery tandem stenosis (TS) combined with a Western diet. Macrophotography, lipid profiles, and inflammatory markers were measured to evaluate the antiatherosclerotic effects of SPRC compared to atorvastatin as a control. Histopathological analysis was performed to assess the plaque stability. To explore the protective mechanism of SPRC, human umbilical vein endothelial cells (HUVECs) were cultured in vitro and challenged with oxidized low-density lipoprotein (ox-LDL). Cell viability was determined with a Cell Counting Kit-8 (CCK-8). Endothelial nitric oxide synthase (eNOS) phosphorylation and mRNA expression were detected by Western blot and RT-qPCR respectively. The results showed that the lesion area quantified by en face photographs of the aortic arch and carotid artery was significantly less, plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were reduced, plaque collagen content was increased and matrix metalloproteinase-9 (MMP-9) was decreased in 80 mg/kg per day SPRC-treated mice compared with model mice. These findings support the role of SPRC in plaque stabilization. In vitro studies revealed that 100 μmol/L SPRC increased the cell viability and the phosphorylation level of eNOS after ox-LDL challenge. These results suggest that SPRC delays the progression of atherosclerosis and enhances plaque stability. The protective effect may be at least partially related to the increased phosphorylation of eNOS in endothelial cells.
Subject(s)
Animals , Humans , Mice , Atherosclerosis , Cholesterol/metabolism , Cysteine/pharmacology , Human Umbilical Vein Endothelial Cells/metabolism , Lipoproteins, LDL/pharmacology , Nitric Oxide Synthase Type III/metabolism , Phosphorylation , Plaque, Atherosclerotic/pathologyABSTRACT
Objective To investigate the neuroprotective effect of methylene blue on diabetic retinopathy in rats. Methods Thirty SD rats were randomly divided into blank, control and experimental groups. The control and experimental groups were induced with diabetes by streptozotocin (STZ) intraperitoneal injection. After 6 weeks of successful modeling, the experimental group received intravitreal injection of methylene blue at a dose of [0.2 mg/(kg.d)], while the control group received an equal amount of dimethyl sulfoxide (DMSO) intravitreal injection, both continuously injected for 7 days. ELISA was used to detect the levels of retinal superoxide dismutase (SOD), 8-iso-prostaglandin F2alpha (iPF2α) and interleukin-1β (IL-1β) in rats. Western blot analysis was used to detect the expression of retinal extracellular signal-regulated kinase 1/2 phosphorylation (p-ERK1/2) and phosphorylated protein kinase B (p-AKT), and PAS staining was used to detect retinal morphological changes. Results Compared with the blank group rats, the retinal SOD activity in the control and experimental group rats was significantly reduced. iPF2α, IL-1β and p-ERK1/2 level increased, while p-AKT level decreased. Compared with the control group, the SOD activity of the experimental group rats increased. iPF2α and IL-1β level went down, while p-ERK1/2 and p-AKT level went up significantly. The overall thickness of the retinal layer and the number of retinal ganglion cells were significantly reduced. Conclusion Methylene blue improves diabetic retinopathy in rats by reducing retinal oxidative stress and enhancing ERK1/2 and AKT phosphorylation.
Subject(s)
Rats , Animals , Diabetic Retinopathy/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , Interleukin-1beta/metabolism , Methylene Blue/pharmacology , Phosphorylation , Rats, Sprague-Dawley , MAP Kinase Signaling System , Diabetes Mellitus, Experimental/drug therapy , Superoxide Dismutase/metabolismABSTRACT
OBJECTIVES@#Endothelium-dependent vasodilation dysfunction is the pathological basis of diabetic macroangiopathy. The utilization and adaptation of endothelial cells to high glucose determine the functional status of endothelial cells. Glycolysis pathway is the major energy source for endothelial cells. Abnormal glycolysis plays an important role in endothelium-dependent vasodilation dysfunction induced by high glucose. Pyruvate kinase isozyme type M2 (PKM2) is one of key enzymes in glycolysis pathway, phosphorylation of PKM2 can reduce the activity of pyruvate kinase and affect the glycolysis process of glucose. TEPP-46 can stabilize PKM2 in its tetramer form, reducing its dimer formation and phosphorylation. Using TEPP-46 as a tool drug to inhibit PKM2 phosphorylation, this study aims to explore the impact and potential mechanism of phosphorylated PKM2 (p-PKM2) on endothelial dependent vasodilation function in high glucose, and to provide a theoretical basis for finding new intervention targets for diabetic macroangiopathy.@*METHODS@#The mice were divided into 3 groups: a wild-type (WT) group (a control group, C57BL/6 mice) and a db/db group (a diabetic group, db/db mice), which were treated with the sodium carboxymethyl cellulose solution (solvent) by gavage once a day, and a TEPP-46 group (a treatment group, db/db mice+TEPP-46), which was gavaged with TEPP-46 (30 mg/kg) and sodium carboxymethyl cellulose solution once a day. After 12 weeks of treatment, the levels of p-PKM2 and PKM2 protein in thoracic aortas, plasma nitric oxide (NO) level and endothelium-dependent vasodilation function of thoracic aortas were detected. High glucose (30 mmol/L) with or without TEPP-46 (10 μmol/L), mannitol incubating human umbilical vein endothelial cells (HUVECs) for 72 hours, respectively. The level of NO in supernatant, the content of NO in cells, and the levels of p-PKM2 and PKM2 protein were detected. Finally, the effect of TEPP-46 on endothelial nitric oxide synthase (eNOS) phosphorylation was detected at the cellular and animal levels.@*RESULTS@#Compared with the control group, the levels of p-PKM2 in thoracic aortas of the diabetic group increased (P<0.05). The responsiveness of thoracic aortas in the diabetic group to acetylcholine (ACh) was 47% lower than that in the control group (P<0.05), and that in TEPP-46 treatment group was 28% higher than that in the diabetic group (P<0.05), while there was no statistically significant difference in the responsiveness of thoracic aortas to sodium nitroprusside (SNP). Compared with the control group, the plasma NO level of mice decreased in the diabetic group, while compared with the diabetic group, the phosphorylation of PKM2 in thoracic aortas decreased and the plasma NO level increased in the TEPP-46 group (both P<0.05). High glucose instead of mannitol induced the increase of PKM2 phosphorylation in HUVECs and reduced the level of NO in supernatant (both P<0.05). HUVECs incubated with TEPP-46 and high glucose reversed the reduction of NO production and secretion induced by high glucose while inhibiting PKM2 phosphorylation (both P<0.05). At the cellular and animal levels, TEPP-46 reversed the decrease of eNOS (ser1177) phosphorylation induced by high glucose (both P<0.05).@*CONCLUSIONS@#p-PKM2 may be involved in the process of endothelium-dependent vasodilation dysfunction in Type 2 diabetes by inhibiting p-eNOS (ser1177)/NO pathway.
Subject(s)
Animals , Humans , Mice , Carboxymethylcellulose Sodium/pharmacology , Diabetes Mellitus, Type 2/metabolism , Endothelium, Vascular/metabolism , Glucose/metabolism , Human Umbilical Vein Endothelial Cells , Mice, Inbred C57BL , Nitric Oxide/metabolism , Nitric Oxide Synthase Type III/metabolism , Phosphorylation , Pyruvate Kinase/metabolism , VasodilationABSTRACT
Esophageal squamous cell carcinoma (ESCC) is one of the leading causes of cancer death worldwide. It is urgent to develop new drugs to improve the prognosis of ESCC patients. Here, we found benzydamine, a locally acting non-steroidal anti-inflammatory drug, had potent cytotoxic effect on ESCC cells. Benzydamine could suppress ESCC proliferation in vivo and in vitro. In terms of mechanism, CDK2 was identified as a target of benzydamine by molecular docking, pull-down assay and in vitro kinase assay. Specifically, benzydamine inhibited the growth of ESCC cells by inhibiting CDK2 activity and affecting downstream phosphorylation of MCM2, c-Myc and Rb, resulting in cell cycle arrest. Our study illustrates that benzydamine inhibits the growth of ESCC cells by downregulating the CDK2 pathway.
Subject(s)
Humans , Benzydamine , Esophageal Neoplasms/drug therapy , Esophageal Squamous Cell Carcinoma/drug therapy , Molecular Docking Simulation , Phosphorylation , Cell Proliferation , Cell Line, Tumor , Apoptosis , Cyclin-Dependent Kinase 2ABSTRACT
Melanoma is the most aggressive cutaneous tumor. Neuropilin and tolloid-like 2 (NETO2) is closely related to tumorigenesis. However, the functional significance of NETO2 in melanoma progression remains unclear. Herein, we found that NETO2 expression was augmented in melanoma clinical tissues and associated with poor prognosis in melanoma patients. Disrupting NETO2 expression markedly inhibited melanoma proliferation, malignant growth, migration, and invasion by downregulating the levels of calcium ions (Ca2+) and the expression of key genes involved in the calcium signaling pathway. By contrast, NETO2 overexpression had the opposite effects. Importantly, pharmacological inhibition of CaMKII/CREB activity with the CaMKII inhibitor KN93 suppressed NETO2-induced proliferation and melanoma metastasis. Overall, this study uncovered the crucial role of NETO2-mediated regulation in melanoma progression, indicating that targeting NETO2 may effectively improve melanoma treatment.
Subject(s)
Humans , Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism , Cell Line, Tumor , Cell Proliferation , Melanoma/genetics , Membrane Proteins/genetics , Phosphorylation , Signal TransductionABSTRACT
OBJECTIVE@#To explore the role of endoplasmic reticulum ryanodine receptor 1 (RyR1) expression and phosphorylation in sepsis- induced diaphragm dysfunction.@*METHODS@#Thirty SPF male SD rats were randomized equally into 5 groups, including a sham-operated group, 3 sepsis model groups observed at 6, 12, or 24 h following cecal ligation and perforation (CLP; CLP-6h, CLP-12h, and CLP-24h groups, respectively), and a CLP-24h group with a single intraperitoneal injection of KN- 93 immediately after the operation (CLP-24h+KN-93 group). At the indicated time points, diaphragm samples were collected for measurement of compound muscle action potential (CMAP), fatigue index of the isolated diaphragm and fitted frequencycontraction curves. The protein expression levels of CaMK Ⅱ, RyR1 and P-RyR1 in the diaphragm were detected using Western blotting.@*RESULTS@#In the rat models of sepsis, the amplitude of diaphragm CMAP decreased and its duration increased with time following CLP, and the changes were the most obvious at 24 h and significantly attenuated by KN-93 treatment (P < 0.05). The diaphragm fatigue index increased progressively following CLP (P < 0.05) irrespective of KN- 93 treatment (P>0.05). The frequency-contraction curve of the diaphragm muscle decreased progressively following CLP, and was significantly lower in CLP-24 h group than in CLP-24 h+KN-93 group (P < 0.05). Compared with that in the sham-operated group, RyR1 expression level in the diaphragm was significantly lowered at 24 h (P < 0.05) but not at 6 or 12 following CLP, irrespective of KN-93 treatment; The expression level of P-RyR1 increased gradually with time after CLP, and was significantly lowered by KN-93 treatment at 24 h following CLP (P < 0.05). The expression level of CaMKⅡ increased significantly at 24 h following CLP, and was obviously lowered by KN-93 treatment (P < 0.05).@*CONCLUSION@#Sepsis causes diaphragmatic dysfunction by enhancing CaMK Ⅱ expression and RyR1 receptor phosphorylation in the endoplasmic reticulum of the diaphragm.
Subject(s)
Rats , Male , Animals , Diaphragm/metabolism , Ryanodine Receptor Calcium Release Channel/metabolism , Rats, Sprague-Dawley , Phosphorylation , Muscle Contraction/physiology , Endoplasmic Reticulum , Sepsis/metabolismABSTRACT
Objective: To investigate the molecular mechanism of how lactate induces high mobility group box 1 (HMGB1) release. Methods: Gastric cancer HGC-27 cells were divided into the control group and the lactate group (The cells were treated with lactate for 6 h). The level of HMGB1 in the cell culture medium was detected by enzyme-linked immunosorbent assay (ELISA), the localization of HMGB1 was detected using laser confocal microscopy, and the nuclear translocation of HMGB1 was detected using the nucleoplasmic separation assay. The phosphorylation and acetylation levels of HMGB1 were determined by co-immunoprecipitation, and Western blot was used to measure the phosphorylation of Akt and protein kinase C (PKC). HGC-27 cells were first treated with lactate and LY294002, the inhibitor of Akt, and then the phosphorylation of HMGB1 and Akt was analyzed by co-immunoprecipitation and Western blot, respectively. The localization of HMGB1 in cells was detected by laser confocal microscopy. EdU and Transwell assays were used to detect the proliferation and migration abilities of HGC-27 cells, respectively. HGC-27 cells were then injected into the BALB/C null mice for subcutaneous tumor implantation. Mice in the lactate group were intraperitoneally injected with lactate (0.2 g/kg/2 d), while those in the control group were intraperitoneally injected with an equal amount of PBS for 20 consecutive days. ELISA was used to detect the HMGB1 levels in the blood samples taken from the medial canthus vein of the mice, while co-immunoprecipitation and Western blot were used to detect the phosphorylation of HMGB1 and Akt in tumor tissue proteins, respectively. Results: The release levels of HMGB1 in the lactate group were (2 995.00±660.91) pg/ml and (696.33±22.03) pg/ml, after lactate treatment for 6 h and 12 h, respectively, both higher than those in the control group (485.00±105.83) pg/ml (P<0.001 and P=0.028, respectively). After lactate treatment for 6 h, the relative expression of HMGB1 protein in the cytoplasm of HGC-27 cells was 1.13±0.09, higher than that of the control group (0.83±0.07, P=0.001), while the relative expression of HMGB1 in the nucleus was 0.79±0.06, lower than that of the control group (1.07±0.06, P=0.007). The phosphorylation level of HMGB1 reached 1.41±0.09, which was higher than that of the control group (0.97±0.10, P=0.031). The phosphorylation level of Akt was 11.16±0.06, higher than that of the control group (0.91±0.022, P=0.002). The phosphorylation level and nuclear translocation of HMGB1 induced by lactate decreased obviously after Akt inhibition; the proliferation and migration abilities induced by lactate were also obviously inhibited after Akt inhibition. In vivo, the HMGB1 level in the peripheral blood was (1 280.70±389.66) pg/ml in the lactate group, which was obviously higher than that in the control group (595.11±44.75) pg/ml (P=0.008), and the phosphorylation levels of HMGB1 and Akt in tumor tissues in the lactate group were obviously enhanced compared with the control group. Conclusion: Lactate induces HMGB1 release through enhancing HMGB1 phosphorylation via the Akt signaling pathway.
Subject(s)
Mice , Animals , Stomach Neoplasms/pathology , Proto-Oncogene Proteins c-akt/metabolism , HMGB1 Protein/metabolism , Phosphorylation , Lactic Acid , Mice, Inbred BALB C , Signal TransductionABSTRACT
Objective: To investigate the molecular mechanism of how lactate induces high mobility group box 1 (HMGB1) release. Methods: Gastric cancer HGC-27 cells were divided into the control group and the lactate group (The cells were treated with lactate for 6 h). The level of HMGB1 in the cell culture medium was detected by enzyme-linked immunosorbent assay (ELISA), the localization of HMGB1 was detected using laser confocal microscopy, and the nuclear translocation of HMGB1 was detected using the nucleoplasmic separation assay. The phosphorylation and acetylation levels of HMGB1 were determined by co-immunoprecipitation, and Western blot was used to measure the phosphorylation of Akt and protein kinase C (PKC). HGC-27 cells were first treated with lactate and LY294002, the inhibitor of Akt, and then the phosphorylation of HMGB1 and Akt was analyzed by co-immunoprecipitation and Western blot, respectively. The localization of HMGB1 in cells was detected by laser confocal microscopy. EdU and Transwell assays were used to detect the proliferation and migration abilities of HGC-27 cells, respectively. HGC-27 cells were then injected into the BALB/C null mice for subcutaneous tumor implantation. Mice in the lactate group were intraperitoneally injected with lactate (0.2 g/kg/2 d), while those in the control group were intraperitoneally injected with an equal amount of PBS for 20 consecutive days. ELISA was used to detect the HMGB1 levels in the blood samples taken from the medial canthus vein of the mice, while co-immunoprecipitation and Western blot were used to detect the phosphorylation of HMGB1 and Akt in tumor tissue proteins, respectively. Results: The release levels of HMGB1 in the lactate group were (2 995.00±660.91) pg/ml and (696.33±22.03) pg/ml, after lactate treatment for 6 h and 12 h, respectively, both higher than those in the control group (485.00±105.83) pg/ml (P<0.001 and P=0.028, respectively). After lactate treatment for 6 h, the relative expression of HMGB1 protein in the cytoplasm of HGC-27 cells was 1.13±0.09, higher than that of the control group (0.83±0.07, P=0.001), while the relative expression of HMGB1 in the nucleus was 0.79±0.06, lower than that of the control group (1.07±0.06, P=0.007). The phosphorylation level of HMGB1 reached 1.41±0.09, which was higher than that of the control group (0.97±0.10, P=0.031). The phosphorylation level of Akt was 11.16±0.06, higher than that of the control group (0.91±0.022, P=0.002). The phosphorylation level and nuclear translocation of HMGB1 induced by lactate decreased obviously after Akt inhibition; the proliferation and migration abilities induced by lactate were also obviously inhibited after Akt inhibition. In vivo, the HMGB1 level in the peripheral blood was (1 280.70±389.66) pg/ml in the lactate group, which was obviously higher than that in the control group (595.11±44.75) pg/ml (P=0.008), and the phosphorylation levels of HMGB1 and Akt in tumor tissues in the lactate group were obviously enhanced compared with the control group. Conclusion: Lactate induces HMGB1 release through enhancing HMGB1 phosphorylation via the Akt signaling pathway.
Subject(s)
Mice , Animals , Stomach Neoplasms/pathology , Proto-Oncogene Proteins c-akt/metabolism , HMGB1 Protein/metabolism , Phosphorylation , Lactic Acid , Mice, Inbred BALB C , Signal TransductionABSTRACT
BACKGROUND: The biological tube is a basal biology structure distributed in all multicellular animals, from worms to humans, and has diverse biological functions. Formation of tubular system is crucial for embryogenesis and adult metabolism. Ascidian Ciona notochord lumen is an excellent in vivo model for tubulogenesis. Exocytosis has been known to be essential for tubular lumen formation and expansion. The roles of endocytosis in tubular lumen expansion remain largely unclear. RESULTS: In this study, we first identified a dual specificity tyrosine-phosphorylation-regulated kinase 1 (DYRK1), the protein kinase, which was upregulated and required for ascidian notochord extracellular lumen expansion. We demonstrated that DYRK1 interacted with and phosphorylated one of the endocytic components endophilin at Ser263 that was essential for notochord lumen expansion. Moreover, through phosphoproteomic sequencing, we revealed that in addition to endophilin, the phosphorylation of other endocytic components was also regulated by DYRK1. The loss of function of DYRK1 disturbed endocytosis. Then, we demonstrated that clathrin-mediated endocytosis existed and was required for notochord lumen expansion. In the meantime, the results showed that the secretion of noto-chord cells is vigorous in the apical membrane. CONCLUSIONS: We found the co-existence of endocytosis and exocytosis activities in apical membrane during lumen formation and expansion in Ciona notochord. A novel signaling pathway is revealed that DYRK1 regulates the endocytosis by phosphorylation that is required for lumen expansion. Our finding thus indicates a dynamic balance between endocytosis and exocytosis is crucial to maintain apical membrane homeostasis that is essential for lumen growth and expansion in tubular organogenesis.
Subject(s)
Humans , Animals , Ciona intestinalis/metabolism , Phosphorylation , Embryonic Development , Morphogenesis , Notochord/metabolismABSTRACT
Objective: To investigate the effects and mechanism of negative pressure microenvironment on the neogenesis of human umbilical vein endothelial cells (HUVECs). Methods: The experimental research methods were adopted. The third to the fifth passage of HUVECs in the logarithmic growth stage were used for the subsequent experiments. Three batches of cells were taken, with each batch of cells being divided into normal control group and negative pressure treatment alone group (both routinely cultured for 24 h), and 17-allylamino-17-demethoxy-geldanamycin (17-AAG) alone group and 17-AAG+negative pressure treatment group (both cultured with 17-AAG for 24 h). In addition, the intermittent negative pressure suction, with the negative pressure value of -5.33 kPa (suction for 30 s, pause for 10 s) was continuously applied for 8 h on cells in the two negative pressure treatment groups using an automatic three-dimensional cell gradient negative pressure loading device designed and developed by ourselves. After the treatment of the first batch of cells, the cell proliferation level was detected by cell counting kit 8 method at 0 (immediately), 24, 48, and 72 h of culture, with the number of samples being 6. After the treatment of the second batch of cells, the scratch experiment was performed. At 12 h after scratching, the cell migration was observed under an inverted phase contrast microscope and the cell migration rate was calculated, with the number of samples being 3. After the treatment of the third batch of cells, the tubule formation experiment was conducted. After 6 h of culture, the tubulogenesis was observed under an inverted phase contrast microscope and the total tubule length and the number of branch nodes of cells were calculated, with the number of samples being 3. The cells were taken and divided into normal control group, negative pressure treatment alone group, and 17-AAG+negative pressure treatment group. The cells were treated the same as in the previous corresponding group. After the treatment, Western blotting was used to detect the protein expressions of heat shock protein 90 (HSP90), caveolin 1, endothelial nitric oxide synthase (eNOS), and eNOS phosphorylation site 1177 in the cells, and the eNOS phosphorylation site 1177/eNOS ratio was calculated, with the number of samples being 3; co-immunoprecipitation (co-precipitating HSP90 and caveolin 1, caveolin 1 and eNOS) and Western blotting were used to detect the protein expressions of caveolin 1 and eNOS in the cells, with the number of samples being 3; the protein co-localization of HSP90 and caveolin 1 and that of caveolin 1 and eNOS in the cells was assessed by immunofluorescence double staining. The molecular docking prediction of caveolin 1 and eNOS was processed by HADDOCK 2.4 protein-protein docking program. Data were statistically analyzed with analysis of variance for factorial design, one-way analysis of variance, and least significant difference method. Results: Compared with that in normal control group, the cell proliferation level in 17-AAG alone group was significantly decreased at culture hour of 24, 48, and 72 after the treatment (P<0.01), while the cell proliferation level in negative pressure treatment alone group was significantly increased at culture hour of 24, 48, and 72 after the treatment (P<0.01). Compared with that in 17-AAG alone group, the cell proliferation level in 17-AAG+negative pressure treatment group was significantly increased at culture hour of 48 and 72 after the treatment (P<0.05 or P<0.01). Compared with that in negative pressure treatment alone group, the cell proliferation level in 17-AAG+negative pressure treatment group was significantly decreased at culture hour of 24, 48, and 72 after the treatment (P<0.01). At 12 h after scratching, compared with (39.9±2.7)% in normal control group, the cell migration rate in 17-AAG alone group was significantly decreased ((10.7±2.7)%, P<0.01), while the cell migration rate in negative pressure treatment alone group was significantly increased ((61.9±2.4)%, P<0.01). Compared with those in 17-AAG alone group, the cell migration rate in 17-AAG+negative pressure treatment group was significantly increased ((37.7±3.7)%, P<0.01). Compared with that in negative pressure treatment alone group, the cell migration rate in 17-AAG+negative pressure treatment group was significantly decreased (P<0.01). At culture hour of 6 after the treatment, compared with those in normal control group, the total length of the tube formed by the cells in 17-AAG alone group was significantly shortened (P<0.05) and the number of branch nodes was significantly reduced (P<0.05), while the total length of the tube formed by the cells in negative pressure treatment alone group was significantly prolonged (P<0.01) and the number of branch nodes was dramatically increased (P<0.01). Compared with that in 17-AAG alone group, the number of branch nodes of the tube formed by the cells was significantly increased in 17-AAG+negative pressure treatment group (P<0.05). Compared with those in negative pressure treatment alone group, the total length of the tube formed by the cells in 17-AAG+negative pressure treatment group was significantly shortened (P<0.01) and the number of branch nodes was significantly reduced (P<0.01). Western blotting detection showed that after treatment, the overall comparison of eNOS and caveolin 1 protein expressions among the three groups of cells showed no statistically significant differences (P>0.05). The expression of HSP90 protein and the eNOS phosphorylation site 1177/eNOS ratio in the cells of negative pressure treatment alone group were significantly increased (P<0.01) compared with those in normal control group. Compared with those in negative pressure treatment alone group, the HSP90 protein expression and the eNOS phosphorylation site 1177/eNOS ratio in the cells of 17-AAG+negative pressure treatment group were significantly decreased (P<0.01). Co-immunoprecipitation and Western blotting detection after the treatment showed that compared with those in normal control group, the expression of caveolin 1 protein in the cells of negative pressure treatment alone group was significantly increased (P<0.01), while the protein expression of eNOS was significantly decreased (P<0.05). Compared with those in negative pressure treatment alone group, the expression of caveolin 1 protein in the cells of 17-AAG+negative pressure treatment group was significantly decreased (P<0.01), while the protein expression of eNOS was significantly increased (P<0.01). After the treatment, compared with those in normal control group, the co-localization of HSP90 and caveolin 1 protein in the cells of negative pressure treatment alone group was significantly increased, while the co-localization of caveolin 1 and eNOS protein was significantly decreased. Compared with those in negative pressure treatment alone group, the co-localization of HSP90 and caveolin 1 protein in the cells of 17-AAG+negative pressure treatment group was significantly decreased, while the co-localization of caveolin 1 and eNOS protein was significantly increased. Molecular docking prediction suggested that caveolin 1 interacted strongly with eNOS and inhibited the 1177 site phosphorylation of eNOS. Conclusions: The negative pressure microenvironment may inhibit the binding of caveolin 1 to eNOS by promoting the binding of HSP90 to caveolin 1 in HUVECs, so as to relieve the inhibition of 1177 site phosphorylation of eNOS by caveolin 1, thereby promoting the proliferation, migration, and tubulogenesis of HUVECs, and ultimately promoting the neogenesis of HUVECs.
Subject(s)
Humans , Caveolin 1/metabolism , Cells, Cultured , HSP90 Heat-Shock Proteins/metabolism , Human Umbilical Vein Endothelial Cells/metabolism , Molecular Docking Simulation , PhosphorylationABSTRACT
Hypertension is one of the strongest risk factors for cardiovascular diseases, cerebral stroke, and kidney failure. Lifestyle and nutrition are important factors that modulate blood pressure. Hypertension can be controlled by increasing physical activity, decreasing alcohol and sodium intake, and stopping tobacco smoking. Chronic kidney disease patients often have increased blood pressure, which indicates that kidney is one of the major organs responsible for blood pressure homeostasis. The decrease of renal sodium reabsorption and increase of diuresis induced by high potassium intake is critical for the blood pressure reduction. The beneficial effect of a high potassium diet on hypertension could be explained by decreased salt reabsorption by sodium-chloride cotransporter (NCC) in the distal convoluted tubule (DCT). In DCT cells, NCC activity is controlled by with-no-lysine kinases (WNKs) and its down-stream target kinases, Ste20-related proline-alanine-rich kinase (SPAK) and oxidative stress-responsive 1 (OSR1). The kinase activity of WNKs is inhibited by intracellular chloride ([Cl-]i) and WNK4 is known to be the major WNK positively regulating NCC. Based on our previous studies, high potassium intake reduces the basolateral potassium conductance, decreases the negativity of DCT basolateral membrane (depolarization), and increases [Cl-]i. High [Cl-]i inhibits WNK4-SPAK/OSR1 pathway, and thereby decreases NCC phosphorylation. In this review, we discuss the role of DCT in the blood pressure regulation by dietary potassium intake, which is the mechanism that has been best dissected so far.
Subject(s)
Humans , Blood Pressure , Diet , Kidney/metabolism , Kidney Tubules, Distal/metabolism , Phosphorylation , Potassium/pharmacology , Protein Serine-Threonine Kinases , Solute Carrier Family 12, Member 3/metabolismABSTRACT
Accidents with venomous animals are a public health issue worldwide. Among the species involved in these accidents are scorpions, spiders, bees, wasps, and other members of the phylum Arthropoda. The knowledge of the function of proteins present in these venoms is important to guide diagnosis, therapeutics, besides being a source of a large variety of biotechnological active molecules. Although our understanding about the characteristics and function of arthropod venoms has been evolving in the last decades, a major aspect crucial for the function of these proteins remains poorly studied, the posttranslational modifications (PTMs). Comprehension of such modifications can contribute to better understanding the basis of envenomation, leading to improvements in the specificities of potential therapeutic toxins. Therefore, in this review, we bring to light protein/toxin PTMs in arthropod venoms by accessing the information present in the UniProtKB/Swiss-Prot database, including experimental and putative inferences. Then, we concentrate our discussion on the current knowledge on protein phosphorylation and glycosylation, highlighting the potential functionality of these modifications in arthropod venom. We also briefly describe general approaches to study "PTM-functional-venomics", herein referred to the integration of PTM-venomics with a functional investigation of PTM impact on venom biology. Furthermore, we discuss the bottlenecks in toxinology studies covering PTM investigation. In conclusion, through the mining of PTMs in arthropod venoms, we observed a large gap in this field that limits our understanding on the biology of these venoms, affecting the diagnosis and therapeutics development. Hence, we encourage community efforts to draw attention to a better understanding of PTM in arthropod venom toxins.(AU)
Subject(s)
Animals , Arthropod Venoms/toxicity , Protein Processing, Post-Translational , Phosphorylation , Scorpions , Mass Spectrometry/methods , Spiders , Wasps , Bees , GlycosylationABSTRACT
Resumo Fundamento As células progenitoras endoteliais (CPEs) desempenham um papel importante na manutenção da função endotelial. A síndrome metabólica (SM) está associada à disfunção das CPEs. Embora o exercício físico tenha um impacto benéfico na atividade das CPEs, seu mecanismo ainda não está completamente esclarecido. Objetivo O objetivo deste estudo é investigar os efeitos do exercício físico nas funções das CPEs e os mecanismos subjacentes em pacientes com SM. Métodos Os voluntários com SM foram divididos em grupo exercício (n=15) e grupo controle (n=15). Antes e após 8 semanas de treinamento físico, as CPEs foram isoladas do sangue periférico. Foram feitos o ensaio de unidades formadoras de colônias (UFC), o ensaio de formação de tubos, a expressão proteica do óxido nítrico sintase endotelial (eNOS), da fosfatidilinositol-3-quinase (PI3-K) e da proteína quinase B (AKT). Considerou-se um valor de probabilidade <0,05 para indicar significância estatística. Resultados Após 8 semanas, o número de UFCs aumentou significativamente no grupo exercício em comparação com o grupo controle (p<0,05). Além disso, observamos uma diminuição significativa do modelo de avaliação da homeostase da resistência à insulina (HOMA-IR), endotelina-1, proteína C reativa de alta sensibilidade e dos níveis de homocisteína no grupo exercício. A intervenção com exercícios também pode aumentar a capacidade de formação de tubos de CPEs e aumentar o nível de fosforilação de eNOS, PI3-K e AKT. Conclusão O exercício físico aprimorou as funções das CPEs. O mecanismo pode estar relacionado ao exercício, ativando a via PI3-K/AKT/eNOS.
Abstract Background Endothelial progenitor cells (EPCs) play an important role in maintaining endothelial function. Metabolic syndrome (MetS) is associated with EPC dysfunction. Although physical exercise has a beneficial impact on EPC activity, its mechanism is not completely clear yet. Objective The purpose of this study is to investigate the effects of physical exercise on the functions of EPCs and the underlying mechanisms in patients with MetS. Methods Volunteers with MetS were divided into exercise group (n=15) and control group (n=15). Before and after 8 weeks exercise training, EPCs were isolated from peripheral blood. Colony forming unit (CFU) assay, tube-formation assay, the protein expression of endothelial nitric oxide synthase (eNOS), phosphatidylinositol-3-kinase (PI3-K) and protein kinase B (AKT) were determined. A probability value <0.05 was considered to indicate statistical significance. Results After 8 weeks, the number of CFUs was significantly increased in the exercise group compared to the control group (p<0.05). In addition, we observed a significant decrease of homeostasis model assessment for insulin resistance (HOMA-IR), endothelin-1, high-sensitive C-reactive protein, and homocysteine levels in the exercise group. Exercise intervention could also enhance tube-formation capacity of EPCs and increase phosphorylation level of eNOS, PI3-K and AKT. Conclusion Physical exercise enhanced the functions of EPCs. The mechanism may be related to exercise, activating the PI3-K/AKT/eNOS pathway.
Subject(s)
Humans , Metabolic Syndrome/therapy , Endothelial Progenitor Cells , Phosphorylation , Exercise , Cells, Cultured , Nitric Oxide Synthase Type III/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Nitric OxideABSTRACT
BACKGROUND@#The Nuclear Dbf2-related (NDR1) kinase is a member of the NDR/LATS family, which was a supplementary of Hippo pathway. However, whether NDR1 could inhibit glioblastoma (GBM) growth by phosphorylating Yes-associated protein (YAP) remains unknown. Meanwhile, the role of NDR1 in GBM was not clear. This study aimed to investigate the role of NDR1-YAP pathway in GBM.@*METHODS@#Bioinformation analysis and immunohistochemistry (IHC) were performed to identify the expression of NDR1 in GBM. The effect of NDR1 on cell proliferation and cell cycle was analyzed utilizing CCK-8, clone formation, immunofluorescence and flow cytometry, respectively. In addition, the xenograft tumor model was established as well. Protein interaction was examined by Co-immunoprecipitation and immunofluorescence to observe co-localization.@*RESULTS@#Bioinformation analysis and IHC of our patients' tumor tissues showed that expression of NDR1 in tumor tissue was relatively lower than that in normal tissues and was positively related to a lower survival rate. NDR1 could markedly reduce the proliferation and colony formation of U87 and U251. Furthermore, the results of flow cytometry showed that NDR1 led to cell cycle arrest at the G1 phase. Tumor growth was also inhibited in xenograft nude mouse models in NDR1-overexpression group. Western blotting and immunofluorescence showed that NDR1 could integrate with and phosphorylate YAP at S127 site. Meanwhile, NDR1 could mediate apoptosis process.@*CONCLUSION@#In summary, our findings point out that NDR1 functions as a tumor suppressor in GBM. NDR1 is identified as a novel regulator of YAP, which gives us an in-depth comprehension of the Hippo signaling pathway.
Subject(s)
Animals , Humans , Mice , Cell Nucleus/metabolism , Cell Proliferation , Glioblastoma , Phosphorylation , Protein Serine-Threonine Kinases/metabolism , Signal TransductionABSTRACT
Objective@#To investigate the molecular mechanism of high phosphorylation levels of cofilin-1 (p-CFL-1) associated with paclitaxel resistance in epithelial ovarian cancer (EOC) cells.@*Methods@#Cells displaying varying levels of p-CFL-1 and CFL-1 were created by plasmid transfection and shRNA interference. Cell inhibition rate indicating paclitaxel efficacy was assessed by Cell Counting Kit-8 (CCK-8) assay. Apoptosis was assessed by flow cytometry and protein levels were detected by western blotting. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the expression levels of phosphokinases and phosphatases of CFL-1. Survival analysis evaluated the correlation between the prognosis of EOC patients and the levels of p-CFL-1 and slingshot-1 (SSH-1).@*Results@#High levels of p-CFL-1 were observed in EOC cells that survived treatment with high doses of paclitaxel. SKOV3 cell mutants with upregulated p-CFL-1 showed impaired paclitaxel efficacy, as well as decreased apoptosis rates and pro-survival patterns of apoptosis-specific protein expression. Cytoplasmic accumulation of p-CFL-1 inhibited paclitaxel-induced mitochondrial apoptosis. SSH-1 silencing mediated CFL-1 phosphorylation in paclitaxel-resistant SKOV3 cells. Clinically, the high level of p-CFL-1 and the low level of SSH-1 in EOC tissues were closely related to chemotherapy resistance and poor prognosis in EOC patients.@*Conclusion@#The SSH-1/p-CFL-1 signaling pathway mediates paclitaxel resistance by apoptosis inhibition in EOC and is expected to be a potential prognostic predictor.
Subject(s)
Female , Humans , Antineoplastic Agents, Phytogenic/therapeutic use , Apoptosis , Carcinoma, Ovarian Epithelial/metabolism , Cell Line, Tumor , Cofilin 1/metabolism , Drug Resistance, Neoplasm , Ovarian Neoplasms/metabolism , Paclitaxel/therapeutic use , Phosphoprotein Phosphatases/metabolism , PhosphorylationABSTRACT
Tyrosine phosphorylation is one of the important protein phosphorylations in eukaryotes responsible for a variety of biological processes including cell signaling transduction, cell migration, and apoptosis. In the study of phosphoproteomics, due to the low stoichiometry of tyrosine phosphorylation (pTyr) proteins and sometimes limited initial sample, traditional phosphoproteomics enrichment technology is inefficient for the enrichment of pTyr peptides. Here, we review the substantial progress in tyrosine phosphoproteomics by preparation of limited amount sample and the newly introduced SH2 superbinder.
Subject(s)
Cell Movement , Peptides , Phosphorylation , Technology , Tyrosine/metabolismABSTRACT
OBJECTIVE@#To investigate the effect of CDK1 interference regulation of PLK1, Aurora B and TRF1 on the proliferation of leukemia cells.@*METHODS@#The human myelogenous leukemia cell line HL-60 was selected as the research object, and the effect of TRF1 expression and its changes on cell proliferation and cycle was investigated by regulating intracellular CDK1 expression. The objects were divided into 5 groups, including control group, shRNA-NC group, CDK1-shRNA group, pcDNA group and pcDNA-CDK1 group. RT-PCR was used to detect the CDK1 expression of cells in each group; colony formation was used to detect the proliferation of the cells. Western blot was used to detect the expression of CDK1, PLK1, Aurora B, TRF1, and cyclin p53, p27, cyclinA.@*RESULTS@#The phosphorylation level of PLK1, Aurora B and the expression of TRF1 in the CDK1-shRNA group were significantly down-regulated as compared with those in the control group (P<0.05). Compared with the control group, the cells in CDK1-shRNA group showed lower clone formation rate, the increasing of cycle-associated proteins p53 and p27 and the decreasing of cyclinA expression (P<0.05). It was shown that interfered CDK1 expression could inhibit the proliferation of HL-60 cells and prolong the time that they enter mitosis, thereby extending the cell cycle. Compared with the control group, the overexpressed CDK1 in the pcDNA-CDK1 group made the phosphorylation level of PLK1, Aurora B, and TRF1 expression increase significantly (P<0.05), also the colony formation rate (P<0.05). The cycle-related proteins p53 and p27 was down-regulated, while cyclinA expression was up-regulate significantly (P<0.05). The results indicted that overexpressed CDK1 could stimulate adverse reactions, thereby promoting the proliferation of HL-60 cells and shortening the cell cycle.@*CONCLUSION@#Knocking out CDK1 can inhibit the phosphorylation of PLK1 and Aurora B and negatively regulate TRF1, thereby inhibiting the proliferation of leukemia cells.