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Objective:To investigate the role of adenosine diphosphate ribosylation factor 6 (Arf6) in the pathogenesis of endometriosis.Methods:Endometrial tissues were sampled from women who were hospitalized in the Affiliated Hospital of Medical School of Ningbo University and Ningbo Women and Children′s Hospital from November 2020 to May 2021 with endometriosis ( n=44, endometriosis group) and without endometriosis ( n=17, control group). The expression of Arf6 protein in the endometrial tissues was detected by western blot. Endometrial epithelial cells from both groups were primary cultured and the distribution of intracellular mitochondria was detected by immunofluorescence. The expression of Arf6 protein was down-regulated by small interference RNA (siRNA), the distribution of mitochondria in cells with decreased Arf6 protein expression was observed, and the expression of mitochondria-related proteins development and differentiation enhancing factor 1 (DDEF1, also called AMAP1), reactive oxygen species 1 (ROS1) and epithelial-mesenchymal transition (EMT)-related proteins E-cadherin, vimentin were detected. Transwell assay was used to detect the changes in the migration ability of the cells. Results:Compared with the control group, ectopic endometrial tissue of endometriosis group showed high expression of Arf6 protein (0.174±0.019 vs 0.423±0.033; t=29.630, P<0.01); and in ectopic endometrial epithelial cells, mitochondria were distributed near the edge of the cell membrane. While Arf6 expression was down-regulated by siRNA, the distribution of mitochondria in ectopic cells returned to natural, close to the control level. In addition, the expression levels of AMAP1 and ROS1 in ectopic cells after Arf6 protein knockdown were significantly decreased. Transwell assay results indicated that knockdown of Arf6 could reduce the migration ability of ectopic epithelial cells [migration cell count: (34.3±7.5) cells]; and immunofluorescence verified low expression of E-cadherin but high expression of vimentin in ectopic epithelial cells, whereas knockdown of Arf6 protein E-cadherin expression increased but vimentin expression decreased. Conclusions:High expression of Arf6 protein in ectopic endometrial epithelial cells leads to the distribution of mitochondria tending to membrane marginalization, while inducing EMT, which are involved in the mechanism of endoheterosis pathogenesis.
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Objective To investigate the protective effect of ADP-ribosylation factor 6 inhibitor on acute kidney injury induced by sepsis in mice.Methods In February 2018,thirty male BALB/c mice were divided into uninfected group (5 mice),fluconazole group (5 mice),ADP-ribosylation factor 6 inhibitor group (10 mice)(inhibitor group) and saline control group (10 mice)(control group) by random number table method.In fluconazole group,inhibitor group and control group,1 × 105 CFU of Candida albicans was injected via tail vein for modeling.The uninfected group was injected with equal volume of saline.After 3 hours,inhibitor group was injected with 1.032 mg ADP-ribosylation factor 6 inhibitor,and fluconazole group was injected with 51 μg fluconazole.The control group were injected with equal volume of saline as inhibitor group.After 24hours,serum creatinine,urea nitrogen were measured by kit method.The mice were clinically scored for sepsis severity according to signs and symptoms after treatment and histopathological changing of kidney tissue were observed and scored according to the damage area of renal cortical with hematoxylin-eosin staining.Results The clinical scores,serum creatinine,urea nitrogen and pathological scores of uninfected group were 0,(0.98 ± 0.38) μmol/L,(9.77 ± 0.36) mmol/L,(0.88 ± 0.30),respectively.The fluconazole group were (0.80 ± 0.84),(1.09 ± 0.51) μmol/L,(9.64 ± 0.17) mmol/L,(1.22 ± 0.270),respectively.The inhibitor group were (2.80 ± 1.32),(1.43 ± 0.50) μmol/L,(12.05 ± 1.20) mmol/L,(2.04 ± 0.55),respectively).The control group were (5.20 ± 1.87),(2.96 ± 1.55) μmol/L,(13.94 ± 1.94) mmoL/L,(2.67±0.55).The difference was statistically significant between inhibitor group and the control group both (P ＜ 0.05).Conclusions ADP-ribosylation factor 6 inhibitor reduce acute kidney injury induced by sepsis in mice.
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Objective To establish ovarian cancer cell line SKVO3 that can stably express human ADP ribosylation factor-4 (ARF4). Methods A eukaryotic expression vector pCDH-CMV-MCS-EF1-Puro/ARF4 was constructed and transfected into SKOV3 cells after verifying by DNA sequencing. The expression of ARF4 mRNA was verified by real-time quantitative PCR (qRT-PCR). Then, the recombinant plasmid with lentiviral packaging plasmids were co-transfected into SKOV3 cells for packaging. The recombinant lentiviral particles LV-ARF4 were collected and transfected into SKOV3 cells, and the stable transfected SKOV3 cell line was screening by culture with puromycin. The expression of ARF4 gene was detected by qRT-PCR and Western Blot. Results A eukaryotic expression vector pCDH-CMV-MCS-EF1-Puro/ARF4 was successfully constructed. The vector could significantly up-regulate the expression of ARF4 mRNA in SKOV3 cells and be successfully packaged into recombinant lentiviral particles in HEK-293T cells. Compared with the control group, the relative expression level of ARF4 mRNA and protein in SKOV3 cells was significantly increased after the infection with LV-ARF4 (all P<0.001). Conclusion The recombinant plasmid pCDH-CMV-MCS-EF1-Puro/ARF4 and lentiviral vector LV-ARF4 were successfully constructed. The establishment of stably infected SKOV3 cell line with LV-ARF4 provides an experimental foundation for further studies on the biological function of ARF4 in ovarian cancer.
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Background Researches showed that ADP-ribosylation factor (ARF) promotes intracorneal secretion of multiple angiogenesis-related factors,such as vascular endothelial growth factor (VEGF) and nitricoxide synthase (NOS) etc., and therefore results in corneal neovascularization.However, whether ARF affects the tube formation of human retinal endothelial cells(HRECs) is unelucidated.Understanding the effect of ARF tube formation of HRECs is important for the target treatment of retinal vascular diseases.Objective The aim of this study was to explore the effect and mechanism of ARF inhibitor on tube formation of HRECs in vitro.Methods HRECs (HREC line) were cultured and passaged.The growth-well cells were harvested and divided into two groups.The cells were regularly cultured in the control group,and ARF antagonist (lml) was added in the culture medium in the ARF antagonist group.The expression levels of ARFmRNA and protein in the cells were examined by reverse transcription (RT)-PCR and Western blot.The morphology and number of HREC tube formation were detected by using three-dimensional Matrigel assay.The relative expression levels of VEGF, NOS, focal adhesion kinase (FAK) and heat shock protein 90 (HSP90) at gene level and protein level were examined by RT-PCR and Western blot in vitro.Results The relative expression levels of ARFmRNA in the cells were 0.65 ±0.14 and 0.32±0.10, and those of ARF protein were 0.85±0.15 and 0.24±0.17 in the control group and ARF antagonist group,showing significant differnces between the two groups (t =7.32, P =0.00;t =5.15, P =0.00).The number of HREC tube formation was (34.66±8.57)/field in the ARF antagonist group, which was significantly lower than (51.46±7.12)/field in the control group (t=2.99 ,P=0.04).The relative expression levels of VEGF mRNA, NOSmRNA and their proteins in the cells were significantly lower than those of the control group (t =3.02, P =0.04;t =3.68, P =0.02;t =3.33,P=0.03;t=2.89 ,P=0.04).The relative expression levels of FAKmRNA and HSP90mRNA in the ARF antagonist group were 0.65±0.18 and 0.28±0.05 ,which were significantly lower than 0.76±0.25 and 0.46±0.09 in the control group (all at P＜0.05).Conclusions ARF antagonist appears to have an inhibitory effect on the tube formation ability of HRECs propably by down-regulating the expressions of VEGF, NOS and the downstream signal transduction factors FAK and HSP90 in HRECs in vitro.
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Background Corneal neovascularization (CNV) is one of the causes of corneal blindness.Studies showed that ADP-ribosylation factor (ARF) can regulate the growth of tumor cells,and inhibiting ARF will decrease angiogenesis.However,whether ARF antagonist plays an action on CNV is unclear.Objective The aim of this study was to explore the effect and mechanism of ARF inhibitor on alkali-burn induced CNV.Methods Sixty clean male BABL/c mice aged 7-8 weeks were divided into PBS group and ARF antagonist group according to randomized number table.CNV models were induced by NaOH burn method in all the mice.ARF at the concentration of 0.5 g/L(0.5 ml) was intraperitoneally injected 3 times per week for 1 week followed the induction of CNV in the ARF antagonist group,and 0.5 ml PBS was used in the PBS group.CNV was examined 2,4,7,14 days after injection by the slit lamp microscope and the CNV related area in the cornea was calculated.Betore modeling(0 day) and 4,7,14 days after modeling,real-time PCR and Western blot were used to analyze the expressions of ARF mRNA and protein in the corneas.Forteen days after modeling,the expression of the CD31 in the CNV was detected using immnofluorescence of corneal whole mount;the expression of vascular endothelial growth factor(VEGF) in the cornea was assayed by Western blot.Cellular wound scratch test was employed to evaluate the effects of ARF antagonist on proliferation and migration of human retinal vascular endothelial cells (RECs).All animal experiments were done in accordance with the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research and Guideline for the Care and Use of Laboratory Animals on the the Soochow University Animal Care Committee.Results ARF mRNA and protein were expressed in the mice corneas in both the PBS group and the ARF antagonist group at various time points.The expression of ARF mRNA in mice corneas was enhanced with the lapse of the time (Ftime =65.17,P =0.00),but no significant difference was found among the groups (Fsroup =1.98,P=0.18).There was also significant difference in the expression of ARF protein in mice corneas at different time points in the ARF antagonist group (F =10.77,P =0.00).The related CNV area was 0.45±0.05 in the ARF antagonist group,and that in the PBS group was 0.72±0.11,with significant difference between them (t =-3.87,P ＜ 0.05).The green fluorescence area of C D31 expression in the cornea was smaller in the ARF antagonist group than that of the PBS group.Expression level of VEGF in the ARF antagonist group was 1.20±0.21,and that in the PBS group was 2.47±0.33,showing a significant difference (t =-5.62,P ＜ 0.05).As the increase of ARF antagonist concentration,the inhibiting rate of cell proliferation was reinforced among 10,100 and 1 000 μg/L ARF antagonist groups (F=8.47,P =0.02).Twenty-four hours after scratch test,the migrating distance of human RECs was (5.46±1.32) μm and (5.04±1.68) μm in the 100 μg/L and 1 000 μg/L ARF antagonist groups,respectively,which were shorter than (8.49± 1.18) μm of the PBS group (t=-2.94,-2.91,both at P＜0.05).Conclusions ARF inhibitor can reduce CNV by down-regulating the expression of VEGF in alkaline burn cornea and inhibiting the proliferation and migration of vascular endothelial cells.
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As glucose is known to induce insulin secretion in pancreatic beta cells, this study investigated the role of a phospholipase D (PLD)-related signaling pathway in insulin secretion caused by high glucose in the pancreatic beta-cell line MIN6N8. It was found that the PLD activity and PLD1 expression were both increased by high glucose (33.3 mM) treatment. The dominant negative PLD1 inhibited glucose-induced Beta2 expression, and glucose-induced insulin secretion was blocked by treatment with 1-butanol or PLD1-siRNA. These results suggest that high glucose increased insulin secretion through a PLD1-related pathway. High glucose induced the binding of Arf6 to PLD1. Pretreatment with brefeldin A (BFA), an Arf inhibitor, decreased the PLD activity as well as the insulin secretion. Furthermore, BFA blocked the glucose-induced mTOR and p70S6K activation, while mTOR inhibition with rapamycin attenuated the glucose induced Beta2 expression and insulin secretion. Thus, when taken together, PLD1 would appear to be an important regulator of glucose-induced insulin secretion through an Arf6/PLD1/mTOR/p70S6K/Beta2 pathway in MIN6N8 cells.
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Animals , Mice , ADP-Ribosylation Factors/metabolism , Basic Helix-Loop-Helix Transcription Factors/metabolism , Cells, Cultured , Gene Expression Regulation, Enzymologic/drug effects , Glucose/pharmacology , Insulin/metabolism , Insulin-Secreting Cells/drug effects , Intracellular Signaling Peptides and Proteins/metabolism , Models, Biological , Oligodeoxyribonucleotides, Antisense/pharmacology , Phospholipase D/antagonists & inhibitors , Protein Serine-Threonine Kinases/metabolism , Ribosomal Protein S6 Kinases, 70-kDa/metabolism , Signal Transduction/drug effectsABSTRACT
In 1982, ADP-ribosylation factors (ARFs), a family of GTP-binding proteins associated with Golgi complexes, were initially recognized based on their ability to stimulate the ADP-ribosyltransferase activity of cholera toxin in vitro, and named so. In fact, this pathophysiologic activity has been useful for functionally defining members of the ARF family. However, during last decade, genetic and biochemical studies have shown the physiologic role of ARFs that also play an essential role in intracellular vesicular transport, particularly in Golgi complexes, activate phospholipase D activity as a nod of signal transduction of cells. Moreover, their more functions were revealed continuously recently. Especially, human ARF1 was found earliest, and studied profoundly in human body cell. Therefore, in this article, there is a comprehensive review about its regulators and effectors, functions and its possibilities involved in tumorigenesis, development of tumors.
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GTPrS-dependent phospholipase D activity in human neutrophils was investigated using exogenous phospholipid as a substrate. Both cytosolic and membrane- associated phospholipase D activities were identified. The previously described 50 kDa cytosolic activating factor was resolved chromatographically from the cytosolic phospholipase D. Using exogenous phospholipid as substrate along with chromatographically resolved 50 kDa factor and recombinant ADP-ribosylation factor 1, plasma membrane was required for activity, indicating that the activity which was previously seen using endogenous phospholipid substrate was due to a phospholipase D located in the plasma membrane. In addition, ADP-ribosylation factor and the 50 kDa factor activated synergistically. Using neutrophil plasma membranes, a third regulator of neutrophil membrane phospholipase D was identified from bovine brain cytosol. This factor was resolved from ADP-ribosylation factor and Rho A by successive column chromatographies. The brain factor showed a synergistic effect with the 50 kDa neutrophil activator but an additive effect with recombinant ADP- ribosylation factor. Whether or not ADP-ribosylation factor or the brain factor were present, high activities were seen only when the 50 kDa factor was present, indicating that the 50 kDa cytosolic factor is a major activating factor for the neutrophil plasma membrane phospholipase D.