ObjectiveTo observe the effects of aquaporin 1 (AQP1) on the proliferation and migration of endothelial progenitor-endothelial progenitor cells (EPC).MethodsBone marrow cells of AQP1 wild-type (WT) (n=6) and knockout-type (KO) mice (n=6) were isolated and differentiated into EPC in vitro. Immunofluorescence was used to detect cell surface antigens to identify EPC. Live cell kinetic imaging and quantification technology, transwell migration assays, as well as scratch test were used to compare the function of EPC between AQP1 WT and KO mice.ResultsEPC culture showed that cells were initially suspended and gradually adhered to typical mesenchymal stem cells within 7 days. After cultured on special medium for endothelial cells they were adhered and differentiated, and fusiform or polygonal, paving stone-like EPC were observed around 14 days. When cultured by special medium of EPC, CD133 and CD31 were positively detected after 7 days, and CD34 and Flk-1 were positively detected after 14 days. Positive expression of AQP1 was only detected in EPC of AQP1 WT mice. Functional studies of EPC revealed there was no significant difference in the proliferation of EPC between AQP1 WT and KO group mice. Transwell assay showed that EPC migration ability of AQP1 KO mice was significantly weaker than that of WT mice. The scratch healing ability of EPC in AQP1 KO mice was significantly lower than that of WT mice.ConclusionsEPC initially shows the characteristics of stem cells and with the prolongation of culture time, EPC gradually shows the characteristics of endothelial cells. AQP1 affects the EPC migration rather than proliferation.
ObjectiveTo investigate the effect of saikosaponin a (SSa) on the levels of immune inflammation in rats with acute spinal cord injury and its possible mechanism.MethodsSeventy-two Sprague Dawley rats (weighing, 220-250 g) were randomly divided into sham operation group (group A), spinal cord injury group (group B), and SSa treatment group (group C) respectively, 24 rats in each group. The spinal cord injury model was induced by using the Allen’s method in groups B and C; the spinous process and vertebral plate at both sides were cut off by lamina excision to expose the spinal cord in group A. The rats were given intraperitoneal injection of 10 mg/kg SSa in group C and equal volume of normal saline in group B at immediate after injury. The spinal cord tissue was harvested from 18 rats of each group at 24 hours after operation to measure the levels of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) by ELISA, to detect the expressions of nuclear factor κB (NF-κB) P65, NF-κB P-P65, and aquaporin 4 (AQP4) by Western blot and to observe the morphology of spinal cord by HE staining. The motor function of the lower limbs was evaluated by BBB score and tiltboard experiment in 6 rats at 1, 3, 7, 14, 21, and 28 days after injury.ResultsThe BBB score and tiltboard experiment maximum angle were significantly higher in group A than groups B and C at each time point (P<0.05) and in group C than group B at 14, 21, and 28 days after operation (P<0.05). ELISA test showed that the concentrations of TNF-α and IL-6 were significantly lower in group A than groups B and C, and in group C than group B (P<0.05). Western blot results showed that the protein expression levels of NF-κB P65, NF-κB P-P65, and AQP4 were significantly lower in group A than groups B and C, and in group C than group B (P<0.05). HE staining demonstrated normal neurons of the spinal cord and no obvious lesion in group A; neuronal cells were observed in the injured area of group B, with hemorrhage, neutrophil infiltration, and nerve cell edema in the injured area; the neuronal cells were visible in the spinal cord of group C, with microglia mild hyperplasia, and the pathological changes were improved when compared with group B.ConclusionSSa has neuroprotective effects on acute spinal cord injury in rats by inhibiting NF-κB signaling pathway and AQP4 protein expression and reducing inflammation response and edema.
Objective To investigate the expression of aquaporin-1( AQP-1) in pulmonary tissues of asthma mice and the effects of acetazolamide( AZ) on AQP-1 expression. Methods Forty C57BL/6 mice were randomly divided into five groups. Group A was treated with phosphate buffer as a non-asthmatic group.The mice in group B, C, D, and E were sensitized with ovalbumin( OVA) and challenged with aerosol OVA to establish asthma model. The mice in group B, C, and D were interperitoneally injected with AZ at doses of 300, 200, 100 mg/kg, respectively during the challenge period. Results ①Wet/dry weight ratio of lung tissues in group E was significantly higher than that in group A( P lt;0. 05) , while it was lower in B, C and D groups than group E. ②The total number of cells, the number of eosinophils, and interleukin-5( IL-5) inBALF of group E were higher than those in group A( P lt;0. 05) , and interferon-γ( IFN-γ) level was lower in group E than in group A ( P lt; 0. 05) . After AZ treatment, the total number of cells, the number of eosinophils, neutrophils and lymphocytes were significantly decreased( P lt; 0. 05) , which were positively correlated with the dose of AZ. ③AQP-1 were expressed in tracheal epithelium, microvascular endothelial cell and bronchial peripheral vascular bed, and the expression in group E was significantly higher than that in group A( P lt;0. 01) . AQP-1 expression was significantly decreased after the intervention of AZ ( P lt;0. 05) .The decrease was positively correlated with the dose of AZ. The expression of AQP-1 mRNA showed no significant difference among these groups( P gt;0. 05) . Conclusions AQP-1 was over-expressed in the lung tissue of mice with asthma. AZ can inhibit the expression of AQP-1 and relieve lung inflammatory cells infiltrationin a dose-dependent manner. It is the protein expression of AQP-1 not the AQP-1 mRNA which were significantly different in different groups, suggesting that AZ affected AQP-1 in the post-transcriptional stage.
ObjectiveTo observe the thickness of per-papillary retinal fiber layer (pRNFL) and structural changes of inner macular segmented layers in optic neuritis (ON) patients with positive aquaporin-4 antibody[AQP4-Ab(+)]. Methods60 ON patients (84 eyes) including 30 of AQP4-Ab(+) ON patients (42 eyes) and AQP4-Ab(-) ON patients (42 eyes), and 40 age-gender matched health controls(80 eyes) were recruited in present study. There was no statistical significance in gender (χ2=0.568) and age (χ2=1.472) between the three groups (P > 0.05). There was no statistical significance in the percentage of different course (χ2=0.000) and logMAR best corrected visual acuity (Z=-1.492) between AQP4-Ab(+)ON and AQP4-Ab(-)ON group (P=1.000, 0.136). All subjects were examined by Spectralis-OCT. The thickness of per-papillary, nasal, nasal lower, temporal lower, temporal, temporal upper, nasal upper and papillomacular bundle (PMB) were analyzed as well as nasal pRNFL/temporal pRNFL (N/T). The macular area was divided into three concentric circles which including central region with 1 mm diameter, inner area with > 1 mm but≤3 mm diameter, and outer ring area with > 3 mm but≤6 mm diameter. The macular volume in each partition and volume in macular RNFL (mRNFL), macular ganglion cell layer (mRGCL), macular inner plexiform layer (mIPL) and macular inner nuclear layer (mINL) were analyzed. ResultsCompared to HC group, the thickness of pRNFL, every quadrants and PMB were decreased significantly in ON group (P=0.000); the macular volume and the volume of mRNFL, mRGCL, mIPL were also decreased significantly in ON group (P=0.000); but there was no statistical difference in mINL volume between two groups (P=0.700). Compared to AQP4-Ab(-)ON group, the thickness of nasal and nasal lower were decreased significantly in AQP4-Ab(+)ON group (P=0.010, 0.000); the macular and mIPL volume were also decreased significantly in AQP4-Ab(+)ON group (P=0.038, 0.033); the thickness of inferior, superior and inferior mIPL in outer ring area and nasal mRNFL in inner area were decreased significantly in AQP4-Ab(+)ON group (P < 0.05). ConclusionsCompared to AQP4-Ab(-)ON patients, the pRNFL thickness and mIPL volume decreased in AQP4-Ab(+)ON patients. The thinner pRNFL area is mainly located in nasal, nasal lower quadrants, and inferior, superior mIPL.
Objective The changes of the aquaporins 1 (AQP-1) expression may be related to the chondrocyte apoptosis. To explore the correlation between the expression of AQP-1 and chondrocyte apoptosis by observing the expression of the AQP-1 and the Caspase-3, so as to provide experimental evidence for the further study in the pathogenesis of osteoarthritis (OA). Methods Seventy-two 8-week-old clean grade male Sprague Dawley rats, weighing 286-320 g (mean, 300 g), were randomly divided into the operated group (n=24), the sham-operated group (n=24), and the control group (n=24).OA models were made by amputating the anterior cruciate l igament and medial collateral l igament, and partial excision of medial meniscus in operated group; the articular cavity was exposed only in sham-operated group; and no treatment was given in control group. The general condition of the rat was observed after model was establ ished. At 1, 2, 4, and 8 weeks, the specimens of knee joints were harvested to perform the gross and histological observations; the mRNA expressions of AQP-1 and Caspase-3 were determined by real-time fluorescent quantitative PCR; and the activity of the Caspase-3 protease was detected. The correlations between the expression of AQP-1 mRNA and the expressions of Caspase-3 mRNA and protease were analyzed. Results Totally 6 rats died after operation, and the rats were suppl ied immediately; the other rats survived to the end of experiment. The appearance and structure of knee articular cartilage were normal in control group and sham-operated group. While in operated group, the cartilage had a rough surface with fissure and vegetation, and fibrosis and irregular cell arrangement were seen on the surface of cartilage. There were significant differences in the Mankin score between the operated group and sham-operated group, control group at 2, 4, and 8 weeks (P lt; 0.05). There was no significant difference in expressions of the AQP-1 mRNA and Caspase-3 mRNA, and the activity of the Caspase-3 protease among 3 groups at 1 week after operation (P gt; 0.05); while the expressions of the AQP-1 mRNA, Caspase-3 mRNA, and the activity of the Caspase-3 protease in operated group were significantly higher than those in sham-operated group and control group at 2, 4, and 8 weeks after operation (P lt; 0.05), andthere was an increased trend over time. There was significantly positive correlation (r=0.817, P=0.000) between the expressions of AQP-1 mRNA and Caspase-3 mRNA, and the regression equation was y=0.426 7x2+0.051 5x; meanwhile, there was also significantly positive correlation (r=0.945, P=0.000) between the expression of AQP-1 mRNA and the activity of Caspase-3 protease, and the regression equation was y=15.423 0x+4.392 8. Conclusion The up-regulation of AQP-1 expression in OA cartilage may be related to the chondrocyte apoptosis, and the changes of AQP-1 expression may involve in the pathogenesis of OA.
Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease of the central nervous system that primarily affects the optic nerves and spinal cord. Most patients have positive serum antibody of aquaporin-4 (AQP4), which targets the AQP4 protein expressed on the end-feet of astrocytes. Although the prevalence of NMOSD is limited, the recurrence rate is high. Repeated and severe immune-mediated attacks can quickly lead to blindness and paralysis if undiagnosed and untreated. While high-dose methylprednisolone and plasma exchange are used in the acute phase, the treatment for recurrent prevention is limited. In recent years, researchers developed several kinds of monoclonal antibodies targeting different nodes of immune pathogenic process, including satralizumab (an interleukin-6 receptor inhibitor), inebilizumab (an antibody against CD19+ B cells), and eculizumab (an antibody blocking the C5 component of complement). In several randomized controlled clinical trials, these monoclonal antibodies decreased the relapse rate significantly in NMOSD. These emerging treatments have greatly changed the treatment of NMOSD.
ObjectiveTo investigate the changes in the nerve fiber layer of the cornea in patients with demyelinating optic neuritis (DON) and its correlation with visual acuity. MethodsA cross-sectional study. From March 2021 to July 2022, 27 cases (39 eyes) of DON patients diagnosed in the Department of Neurology and Ophthalmology of Beijing Tongren Hospital Affiliated to Capital Medical University were enrolled in this study. According to the serological test results, the patients were divided into aquaporin 4 antibody associated optic neuritis (AQP4-ON group) and myelin oligodendrocyte glycoprotein antibody associated optic neuritis (MOG-ON group), with 15 cases (19 eyes) and 12 cases (20 eyes) respectively. According to previous history of glucocorticoid treatment, the patients were divided into glucocorticoid treated group and non-glucocorticoid treated group, with 17 cases (27 eyes) and 10 cases (12 eyes) respectively. Twenty healthy volunteers (20 eyes) with age- and gender-matched were selected as the control group. All eyes underwent best corrected visual acuity (BCVA) and in vivo confocal microscopy (IVCM) examinations. BCVA was performed using Snellen's standard logarithmic visual acuity chart, which was converted into logarithmic minimum angle resolution (logMAR) visual acuity during statistics. The corneal nerve fiber length (CNFL), corneal nerve fiber density (CNFD), corneal nerve fiber branch length (CNBL), corneal nerve fiber branch density (CNBD) and the density of corneal dendritic cells (DC) were detected by IVCM examination. Parameter comparison between groups by t-test and Kruskal-Wallis rank sum test. The correlation between logMAR BCVA and pamameters of corneal nerve fibers were analyzed using Spearman analysis. ResultsThe CNFL, CNFD, and CNBL of the DON group and the control group were (10.67±2.55) mm/mm2, (57.78±12.35) root/mm2, (3.27±1.34) mm/mm2, and (13.74±3.05) mm/mm2, (70.95±13.14) root/mm2, and (4.22±1.03) mm/mm2, respectively; the difference in CNFL, CNFD, and CNBL between the two groups were statistically significant (t=4.089, 3.795, 2.773; P＜0.05). The CNFL, CNBL, and CNBD of the affected eyes in the MOG-ON group and AQP4-ON group were (12.02±2.13) mm/mm2, (3.80±1.19) mm/mm2, (47.97±8.86) fibers/mm2, and (9.25±2.19) mm/mm2, (2.72±1.19) mm/mm2, (39.43±13.86) fibers/mm2, respectively; the differences in CNFL, CNBL, and CNBD between the two groups were statistically significant (t=－4.002, －2.706, －2.306; P＜0.05). The corneal DC density of the patients in the hormone treated group and the non-hormone treated group was (24.43±8.32) and (41.22±9.86) cells/mm2, respectively. The difference in corneal DC density between the two subgroups was statistically significant (P＜0.001). Correlation analysis showed that there was a significant negative correlation between logMAR BCVA and CNBL and CNFL in patients with DON (r=－0.422, －0.456; P＜0.05). ConclusionsThere are different degrees of corneal nerve fiber damage in patients with different types of DON. There was a negative correlation between BCVA and the length of corneal nerve fibers.
Objective To investgate the expression of p38 mitogen-activated protein kinase （p38MAPK） in lung tissue of rats with severe acute pancreatitis （SAP）， and to explore the relationship between p38MAPK and pulmonary capillary barrier injury. Methods Forty male and healthy Sprague-Dawley （SD） rats were randomly （random number method） divided into sham operation （SO） group and SAP group， then rats of SAP group were sub-divided into 3， 6， 12， and 24 h group， each group enrolled 8 rats， respectively. SAP model rats were established by injecting 5% sodium taurocholate solution retrograde into the biliopancreatic duct. ELISA method was used to test the serum tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β）， and pathological changes in lung and pancreas tissues were observed by HE staining. Immunohischemistry method was used to detect phosphorylated p38 （p-p38） protein and aquaporin 1 （AQP1） protein of lung tissues. The expression level of AQP1 mRNA was measured by quantitative real-time PCR. Results Hyperemia， edema， and inflammatory cell infiltration were observed in lung tissues， abundance of necrosis， part gland structure fuzzy or even disappear were observed in pancreas tissues of all 4 time point groups. Compared with SO group， levels of serum TNF-α and IL-1β were significantly higher in 4 time point groups （P＜0.05）. Lower expression level of p-p38 protein was detected in lung tissues of SO group， while in the early stage of SAP （SAP 3 h group）， the expression level of p-p38 protein significantly increased， which peaked in 6 h group and was still higher than SO group in 24 h group （P＜0.05）. Compared with SO group， the expression levels of AQP1 mRNA and protein were significantly lower in all 4 time point groups （P＜0.05）， which had negative correlation with the levels of serum TNF-α，IL-1β， and the expression level of p-p38 protein （r=-0.87， P＜0.05；r=-0.88， P＜0.05；r=-0.78， P＜0.05）. Conclusion The decrease of AQP1 protein in lung tissue is one of the vital causes for pulmonary capillary barrier injury in SAP， which probably works by the activation of p38MAPK and the excessive release of inflammatory cytokines.
Objective Aminoguanidine (AG) can reduce brain edema and increase the recovery of neuron functions in surgical brain injury and stroke. To investigate the effect of AG on spinal cord injury (SCI) in rats and its mechanism. Methods A total of 150 adult male Sprague Dawley rats (weighing, 230-255 g) were divided into control group (group A, 25 rats without treatment), the sham-operated group (group B, 25 rats undergoing laminectomy), SCI group (group C, 25 SCI rats with injection of 5%DMSO), SCI + AG groups (groups D, E, and F, 25 SCI rats and AG injection of 75, 150, and 300 mg/kg, respectively). The optimal dosage of AG was screened by dry-wet weight method with the percentage of water content at 0, 12, 24, and 48 hours after injury. The blood-spinal cord barriar permeability was further detected by Evans blue (EB) method, aquaporins 4 (AQP4) mRNA expression by RT-PCR, AQP4 protein expression by immunohistochemistry and Western blot. Results AG injection at dosage of 150 mg/kg can significantly reduce edema of spinal cords at 12, 24, and 48 hours after SCI (P lt; 0.05), so 150 mg/kg was the optimal dosage. The EB content in group E was significantly lower than that in group C at 12, 24, and 48 hours after SCI, and the permeability of blood-spinal cord barrier was significantly decreased compared with group C (P lt; 0.05). The AQP4 mRNA expressions in groups B and E were significantly lower than that in group C at 12, 24, and 48 hours after SCI (P lt; 0.05). AQP4 protein expressions in groups B and E were significantly lower than that in group C at 24 and 48 hours after SCI (P lt; 0.05) by Western blot. Immunohistochemical staining revealed that AQP4 protein expression in group C was significantly higher than that in groups B and E (P lt; 0.05) at 48 hours after SCI, but no significant difference was found between group B and group E (P gt; 0.05). Conclusion AG injection at dosage of 150 mg/kg can induce spinal cord edema and injury in rats, which could be correlated with the down-regulation of AQP4 expression.