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AIM: To establish a dry eye mouse model of iron overload by intraperitoneal injection of iron dextran and preliminarily explore its possible mechanism.METHODS: A total of 40 male C57BL/6 mice(taking the right eye as the experimental eye)were divided into 4 groups by random number table method: There were 10 mice in the control group, each time by intraperitoneal injection of 0.2mL of normal saline; Low-dose group, middle-dose group and high-dose iron group with 10 mice in each group were the model group. Each time, 0.2mL of iron dextran solution with concentrations of 12.5, 25, and 50 mg/mL was injected intraperitoneally. One injection 3d for a total of 28d. We observed the ocular surface inflammation index, corneal fluorescein staining, tear break-up time(BUT)and Schimer I test(SIt)on the 7, 14 and 28d after injection and evaluated the degree of dry eye and ocular surface inflammation. After 28d, the mice were sacrificed for cornea, conjunctiva and lacrimal glands tissue for HE staining, Prussian blue staining and tissue iron detection, to evaluate the inflammatory reaction and iron overload. The expression of inflammatory factors interleukin-1β(IL-1β), tumor necrosis factor-α(TNF-α)and matrix metallo proteinase-9(MMP-9)were detected by enzyme-linked immunosorbent assay(ELISA).RESULTS: Compared with the control group, the mice in the model group showed a series of dry eye symptoms, the inflammation index of ocular surface in mice were increased, the score of corneal fluorescein staining increased, the BUT shortened and the amount of tear secretion decreased(all P<0.05). The cornea, conjunctiva and lacrimal gland tissues of the mice were damaged to varying degrees, the iron deposition on the eye surface of the model group was more serious than that of the control group, and the iron content of the tissue was significantly increased than the control group(all P<0.01). The contents of inflammatory factors(IL-1β, TNF-α, MMP-9)in the cornea, conjunctiva and lacrimal gland tissue of the mice in the model group were significantly higher than those of the control group(all P<0.01). With the increase of injection time and concentration of iron dextran, the degree of dry eye and ocular surface inflammation in mice gradually increased. CONCLUSION: The mouse iron overload dry eye model was successfully established by intraperitoneal injection of iron dextran, the mechanism may be related to the ocular surface inflammation aggravated by iron overload.
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AIM: To explore whether efferocytosis impacts ocular surface inflammation in high-iron environment by regulating macrophage polarization. METHODS: A total of 50 healthy C57BL/6 male mice aged 6-8wk were randomly divided into normal control group, iron group, inhibitor group, enhancer group and solvent control group, with 10 mice in each group. The normal control group was injected intraperitoneally with 0.2mL of normal saline, and the other groups were injected intraperitoneally with 50mg/mL iron dextran of 0.2mL, once every 3d. From the 14d, the inhibitor group, the enhancer group and the solvent control group were injected intraperitoneally with the same volume(0.2mL)50mg/kg XMD8-92, 10mg/kg simvastatin and 50% DMSO solvent once a day, respectively. The anterior segment of the eyes was observed under slit lamp microscope on the 7, 14, 28d after intraperitoneal injection, and the ocular surface inflammation index and corneal fluorescein staining score were evaluated. The cornea, conjunctiva and lacrimal gland tissues were taken at 28d for the HE staining and immunofluorescence staining, and RT-PCR were used to detect the expression of macrophage polarization related indexes(CD86, CD206, iNOS, Arg-1); Western blot were used to detect the expression of efferocytosis related signal factors(Gas6, MerTK); ELISA was used to detect the expression of inflammatory factors(IL-1β, TNF-α, MMP-9).RESULTS: After injection for 28d, compared with the normal control group, the ocular surface inflammatory index and corneal fluorescein staining score were increased in the iron group and the solvent control group. HE staining showed incomplete corneal epithelium, reduced conjunctival goblet cells, unclear lacrimal gland structure and relatively disordered arrangement of cells. In all tissues, the expressions of polarization related indexes of M1 macrophages such as CD86 and iNOS were up-regulated, while those of M2 macrophages such as CD206 and Arg-1 were down-regulated, and the expressions of inflammatory factors such as IL-1β, TNF-α and MMP-9 were up-regulated(all P<0.05). Compared with the iron group and the solvent control group, the ocular surface inflammation index and corneal fluorescein staining score of the inhibitor group were further increased. HE staining showed obvious exfoliation of corneal epithelium, further decrease or even disappearance of conjunctival goblet cells, disorder of lacrimal gland structure and irregular arrangement of cells. In all tissues, the expression of signal factors related to efferocytosis such as Gas6 and MerTK was down-regulated(all P<0.05), the expression of polarization related indexes of M1 macrophages such as CD86 and iNOS and the expression of inflammatory factors such as IL-1β, TNF-α and MMP-9 were further up-regulated(all P<0.05). But the ocular surface inflammation index and corneal fluorescein staining score decreased in the enhancer group. HE staining showed the integrity of corneal epithelial, the increase of conjunctival goblet cells and the improvement of lacrimal gland structure and morphology. In all tissues, the expression of signal factors related to efferocytosis such as Gas6 and MerTK was up-regulated(all P<0.05), and the expression of polarization related indexes of M2 macrophages such as CD206 and Arg-1 was up-regulated, while the expression of inflammatory factors such as IL-1β, TNF-α and MMP-9 was down-regulated(all P<0.05). CONCLUSION: High-iron environment induces macrophages polarize to M1, which aggravates ocular surface inflammation and tissue damage. Efferocytosis by regulating the polarization of macrophages impact the occurrence of ocular surface inflammation in high-iron environment.
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AIM: To compare the effectiveness on 10g/L cyclopentolate and 10g/L atropine on cycloplegia in children before optometry. METHODS:Eighty eyes of 40 children among 4-12 years old with refractive error were recruited in this study. 10g/L cyclopentolate eye drops were topically administered once per 5min for 3 times and optometry was performed after 45min. Three days after that, 10g/L atropine sulfate eye gel then was used 3 times per day for consecutive 3d and again the refractive diopter was obtained at the 4th d. The differences of the results in retinoscopy refraction were compared between 10g/L cyclopentolate eye drops and 10g/L atropine sulfate eye gel. RESULTS: Therefraction results of those given 10g/L cyclopentolate eye drops and 10g/L atropine sulfate eye gel were no statistical different in both 4-8 years group and 9-12 years group with myopia (≤-3. 00D) (P=0. 411, 0. 924). The differences of refraction results of both the drugs were significant in 4 - 8 years group with low hypermetropia, medium hypermetropia and high hypermetropia (P=0. 007, 0. 007, 0. 009). No significant difference was found in 9 - 12 years group with low hypermetropia (P= 0. 592), given 10g/L cyclopentolate eye drops and 10g/L atropine sulfate eye gel, but the differences of refraction results of both the ophthalmic preparations above were significant in 9-12 years group with medium and high hypermetropia (P=0. 039, 0. 012). CONCLUSION:Both 10g/L cyclopentolate eye drops and 10g/L atropine sulfate eye gel have the cycloplegic effects, but their cycloplegic effects are significant different among hypermetropia children. Thus, the reasonable cycloplegic should be chosen according to the specific situation.
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Background Researches demonstrated that ciliary neurotrophic factor (CNTF) can enhance survival and promote differentiation of neutron.Meanwhile,CNTF also is thought to play an important role in the development of visual pathway.But,less studies are reported in the relationship of CNTF and form deprivation amblyopia.Objective This study was to investigate the expressions of CNTF in visual cortex area 17 in form deprivation amblyopia model.Methods Twelve 4-week-old cats were randomized into normal group and form deprivation amblyopia group.Monocular form deprivation amblyopic models were established in 6 cats by eyelids suture method.Pattern visual evoked potential(P-VEP) was recorded to evaluate the amblyopic models 16 weeks later following the eyelids suturing.Then,bilateral visual cortex tissue was incised at a vertical in sagittal axis fashion to prepare the section.Nissl staining was used to detect the morphologies of neurons.Expression of CNTF in Ⅰ-Ⅵ layers of visual cortex area 17 was located and quantified by immunochemistry.The positive cell number and gray scale for CNTF were calculated and compared between two groups.The use of the animals complied with Regulations for the Administration of Affairs Coucerning Experimental Animals by State Science and Technology Commission.Results Compared with the normal group,P-VEP amplitude was significantly reduced (6.11 ±1.56 μV vs.11.42±t.92 μV) and latency was significantly prolonged(75.77±9.83 ms vs.58.56±7.17 ms) in the form deprivation amblyopia group (t=5.272,3.464,P＜0.05).Nissl staining showed that the number of neurons in the form deprivation amblyopia group was less than that in the normal group.In the form deprivation amblyopia group,neurons became shrinkage and turned round,cytoplasmic processes get shortened,and the nucleus became small.The number of Nissl bodies was decreased.lmmunochemistry showed the positive neutrons for CNTF in Ⅰ-Ⅵ layers of visual cortex area 17 in hoth normal cats and model cats with the more positive cells in Ⅱ-Ⅳ layers.Compared with the normal group,the positive cell number for CNTF was significantly reduced in Ⅱ-Ⅳ layers of visual cortex area 17 in the form deprivation amblyopia group (Ⅱ layer:95.93±8.24 vs.116.25±6.52;I layer:102.65±7.45 vs.125.23±8.21;Ⅳ layer:l10.65±6.85 vs.139.54±4.26) (t=4.737,4.989,8.773,P＜0.05).In addition,the gray scale of CNTF positive cells was significantly lower in Ⅱ-Ⅳ layers of visual cortex area 17 in the form deprivation amblyopia group than that the normal group (Ⅱ layer:106.98 ± 8.86 vs.138.65 ± 6.38 ; Ⅲ layer:109.56 ± 8.69 vs.149.59 ±8.55;Ⅳ layer:l16.65 ±9.52 vs.155.76±9.87) (t=7.105,8.043,6.986,P＜0.05).Both CNTF positive cell number and gray scale in Ⅰ,Ⅴ,Ⅵ layers of visual cortex area 17 had no significant differences between two groups (P＞0.05).Conclusions Form deprivation in critical period of a new born animal may lead to distributing abnormality of CNTF in visual cortex,which maybe play a role in the development of form deprived amblyopia.