ABSTRACT
Background It has been proved that as an important adhesion protein of extracellular matrix,osteopontion (OPN) can affect tumor neovascularization.Some new researches showed that anti-OPN antibody plays a role in regulating the neovascular vessel formation.Choroidal neovascularization (CNV) has the same structure with tumor neovascularization,but whether anti-OPN antibody restricts new vessel formation is unclear.Objective This study was to investigate the inhibitory effect of anti-OPN antibody on CNV.Methods Laser-induced CNV models were created in 40 eyes of 40 male SPF C57BL/6J mice by Argon laser photocoagulation of retinas,with the wavelength 514 nm.Thirty-six successful models were randomly divided into anti-OPN antibody group,mouse-IgG group and PBS group by the randomized number table.On the second day after photocoagulation,anti-OPN antibody of 400 μg was intraperitoneally injected in the anti-OPN antibody group,and the equivalent amount of mouse IgG and PBS were used in the same way in the mouse IgG group and PBS group.The CNV was evaluated by fundus fluorescein angiography (FFA) on the seventh days after photocoagulation.The mice were immediately sacrificed and the eyeballs were enucleated on the fourteenth day after photocoagulation,and 4 eyeballs in each group were used to observe the areas of CNV on the retinal pigmental epithelium-choroid-sclera fiat mounts,and the other 8 eyeballs of each groups were used to analyze the expression levels of OPN mRNA and vascular endothelial growth factor(VEGF) mRNA using quantitative fluorescence-PCR (QF-PCR).Results FFA showed fluorescein leakage areas around laser spots 7 days after photocoagulation,indicating that CNV appeared.The CNV areas were ([16.98±0.70] × 103) μm2,([27.13 ± 0.81] × 103) μm2 and ([35.39±2.14] ×103) μm2 respectively in the anti-OPN antibody group,mouse IgG group and PBS group,with a significant difference among the 3 groups (F =533.76,P =0.00),and the CNV area was significantly smaller in the anti-OPN antibody group compared with those of the mouse IgG group and PBS group (q =-3.95,-4.40,both at P＜0.05).No significant difference was found in the OPN mRNA expression between the antiOPN antibody group and mouse IgG group (t =-5.26,P =0.66).However,the expression of VEGF mRNA in choroidal tissue was significantly declined in the anti-OPN antibody group than that in the mouse IgG group (t =-6.74,P＜0.01).Conclusions Anti-OPN antibody suppresses the formation of CNV in laser-induced mouse model by down-regulating VEGF.
ABSTRACT
Background Minocycline possesses neuroprotective effect in a variety of animal models and clinical trials of central nervous system,but whether it works on optic nerve injury remains unclear.Objective This study aimed to observe the protective effects of minocycline on retinal ganglion cells (RGCs) in the early stage of optic nerve crush and explore its mechanism.Methods One hundred and thirty-six clean C57BL/6J mice were randomly divided into normal control group,normal saline solution group and minocycline group.The optic nerve crush injury models were induced in the left eyes of the mice in the normal saline solution group and minocycline group by a cross-action forceps for 3 seconds.Minocycline was injected intraperitoneally in the minocycline group firstly 45 mg/kg(0.4 ml) and followed by 22.5 mg/kg per day after 24 hours until sacrifice of the animals,and the equivalent volume of normal saline solution was injected in the same way in the normal saline solution group.The mice were euthanized at 4,7,11,14 days postoperatively and the left eyeballs were collected.Retinal flat mounts and DAPI staining was used to observe and compare the change of RGCs density among different groups and various time points.Apoptosis of mice RGCs were assessed by TdT-mediated dUTP nick end labeling (TUNEL).Real-time polymerase chain reaction (real-time PCR) was used to detect the expression of CD11b mRNA in retinal microglials.Results DAPI staining in retinal flat mounts showed that the average RGCs density was (77.50±2.38)/0.01 mm2 and (70.00±2.94) /0.01 mm2 in the 4th and 7th day after modeling in the normal saline solution group,and those in the minocycline group were (88.75 ± 2.36) /0.01 mm2 and (81.00 ± 3.92)/0.01 mm2,with significant differences between the two groups (t4d =-6.708,P＜0.01 ;t7d =--4.491,P＜0.01).The apoptotic RGCs were (12±1)/mm and (4±1)/mm in the normal saline solution,which were significantly more than (4±1)/mm and (1±0)/mm in the minocycline group (t4 d =12.832,P＜0.01 ; t7d =3.455,P =0.026).However,no significant difference was found in apoptotic RGCs in postoperative 11 days and 14 days between the normal saline solution group and the minocycline group (P =0.708,0.777).The expressing levels of CD11 b mRNA in the retinal microglials were significantly higher in the 4th and 7th day in the normal saline solution group than those in the minocycline group (t4 d =8.312,P＜0.01 ;t7d=5.407,P＜0.01),but were not significantly different in the 11st and 14th day after modeling between the two groups (P=0.055,0.170).Conclusions Minocycline can play a neuroprotective effect on RGCs in the early stage of optic nerve crush in mice by inhibiting microglia activation and decreasing RGCs apoptosis.
ABSTRACT
BACKGROUND: Although the efficacy of morphine in the neuropathic pain state is somewhat controversial, spinally administered morphine reversed the tactile allodynia in our previous animal study. Using a von Frey filament test, we examined the mechanism of action of intrathecal morphine by administration of the opioid receptor antagonist naloxone in a rat model of neuropathic pain induced by nerve ligation injury. METHODS: Male Sprague Dawley rats were prepared with tight ligation of the left lumbar 5th and 6th spinal nerves and a chronic lumbar intrathecal catheter. Intrathecal doses (0.3 and 1 microgram) of morphine were administered to attenuate the allodynic state. Naloxone was administered intrathecally (10 microgram) or intraperitoneally (30 and 150 microgram) in order to investigate the reversal of the antiallodynic effect of morphine. Allodynic thresholds for left hindpaw withdrawal to the von Frey hairs test were assessed and converted to %MPE. RESULTS: A reduced effect of tactile allodynia by intrathecal morphine was produced. Naloxone 10 microgram (IT) and 150 microgram (IP), but not naloxone 30 microgram (IP), reversed the antiallodynic effect of intrathecal morphine (P < 0.05). CONCLUSIONS: The results suggest that the mechanism of tactile antiallodynia induced by intrathecal morphine may include the opioid receptor system at the spinal and supraspinal level in a rat model of nerve ligation injury.