Use of Fenofibrate in the Treatment of Fuchs Corneal Endothelial Dystrophy

Abstract

The present invention relates to the field of biomedical technologies, and particularly to the application of fenofibrate in the treatment of Fuchs endothelial corneal dystrophy. By using the fenofibrate drug, the present invention can effectively reduce the thickness of Descemet's membrane during the pathogenesis of FECD, reduce the decrease in corneal endothelial cell density, cell damage, etc., and ultimately improve corneal endothelial decompensation.

Description

Technical Field

[0001] The present invention relates to the field of biological medicine technology, and particularly to the application of fenofibrate in the treatment of Fuchs endothelial corneal dystrophy. Background Art

[0002] Fuchs endothelial corneal dystrophy (FECD), also known as keratoconus, is an age-related complex genetic disease, manifested as the formation of extracellular matrix deposition and apoptosis of corneal endothelial cells (CECs).

[0003] FECD is clinically divided into two categories: early-onset and late-onset. Among them, early-onset FECD is relatively rare and is caused by point mutations in the pathogenic gene Col8a2. Late-onset FECD has a higher incidence, mostly seen in people aged 50-60 years old. It is a degenerative disease caused by the combined action of gene mutations and environmental factors. The incidence in female population is 3-4 times that in male population, and the condition in female population is more severe. Late-onset FECD is clinically characterized by corneal guttae, thickening of Descemet's membrane, and progressive loss of corneal endothelial cells.

[0004] The formation of corneal guttae on Descemet's membrane (DM) is the earliest and most typical pathological feature of FECD. CECs attach to Descemet's membrane. Descemet's membrane consists of two layers. The layer close to the corneal stroma is formed during fetal period and is called the anterior banded layer (ABL) or fetal layer. The layer close to the endothelial surface is the posterior non-banded layer (PNBL) secreted by CECs, which thickens year by year with age. The thickness of Descemet's membrane in FECD patients is about 4 times that of normal people. The posterior non-banded layer becomes thinner or disappears and is replaced by an abnormally formed collagenous banded layer (CBL). In some patients, a loose fibrous layer will also form under the corneal endothelium, and corneal guttae attach to the collagenous banded layer or fibrous layer.

[0005] Human corneal endothelial cells are non-renewable cells. When the density of corneal endothelial cells is less than 500 cells / mm 2Symptoms such as corneal edema, painful subepithelial bullae, and corneal opacity may occur, and in severe cases, it may even lead to blindness. Delayed FECD is the most important disease leading to corneal endothelial decompensation. The traditional method is corneal endothelial transplantation. In recent years, it has been found that after removing the corneal endothelium in the area with corneal guttata in the central cornea, local combined application of ripasudil can promote corneal endothelial migration, but it cannot inhibit corneal endothelial damage. This is also the only effective drug currently used clinically to treat FECD.

[0006] The thickening of Descemet's membrane and the formation of corneal guttata are the primary links in the pathogenesis of FECD and the key factors leading to subsequent corneal endothelial damage, apoptosis, and decompensation. Currently, there is no research report on effective means to inhibit the abnormal hyperplasia of Descemet's membrane, nor is there a drug that treats FECD from the perspective of lipid metabolism. Summary of the Invention

[0007] The present invention discovers that there is a correlation between abnormal energy metabolism of corneal endothelium and extracellular matrix remodeling in FECD patients. By regulating the lipid metabolism of corneal endothelium, it is possible to effectively inhibit the thickening of corneal Descemet's membrane and thus achieve the effect of protecting corneal endothelial cells. Based on this, the present invention targets the regulation of the lipid metabolism process of corneal endothelium to treat corneal endothelial fibrosis and thickening of Descemet's membrane, thereby reducing the tendency of thickening of Descemet's membrane and reversing or reducing corneal endothelial apoptosis and exfoliation, so as to treat FECD from the source.

[0008] Therefore, the present invention provides the application of fenofibrate in the treatment of Fuchs corneal endothelial dystrophy. Specifically, by using fenofibrate to act on the PPARα target to regulate the lipid metabolism of corneal endothelium, the corneal endothelial fibrosis and thickening of Descemet's membrane in Fuchs corneal endothelial dystrophy can be treated. Experiments show that oral administration of fenofibrate can inhibit the thickening of Descemet's membrane after corneal endothelial decompensation, significantly reduce corneal endothelial damage, and inhibit corneal endothelial apoptosis, thereby treating Fuchs corneal endothelial dystrophy from the source.

[0009] To achieve the above invention objective, the technical solutions provided by the present invention are as follows:

[0010] The present invention provides the application of fenofibrate in the treatment of Fuchs corneal endothelial dystrophy.

[0011] In the present invention, the Fuchs corneal endothelial dystrophy is of the delayed type.

[0012] In the present invention, the application method is oral administration of fenofibrate.

[0013] In the present invention, the application method is to prepare an eye drop containing fenofibrate.

[0014] In the present invention, fenofibrate reduces the thickening of the posterior elastic lamina of the cornea and / or reduces the apoptosis and exfoliation of corneal endothelial cells by regulating lipid metabolism in corneal endothelial cells.

[0015] In the present invention, the target of fenofibrate in regulating lipid metabolism in corneal endothelial cells is PPARα.

[0016] The present invention also provides the use of PPARα as a target in screening or developing a treatment for Fuchs endothelial corneal dystrophy.

[0017] The present invention further provides a drug for treating Fuchs endothelial corneal dystrophy, characterized in that the drug contains a therapeutically effective amount of fenofibrate.

[0018] According to the present invention, fenofibrate drugs can inhibit the thickening of the posterior elastic lamina of the cornea and protect corneal endothelial cells by regulating lipid metabolism in corneal endothelium.

[0019] Specifically, by using fenofibrate drugs, the thickness of the posterior elastic lamina of the cornea during the onset of FECD can be effectively reduced, the decrease in corneal endothelial cell density and cell damage can be improved, and finally corneal endothelial cell decompensation can be improved. This method can treat Fuchs endothelial corneal dystrophy from the root cause without surgery or immunosuppression. Description of the Drawings

[0020] Figures 1A - 1C It is a diagram showing the corneal morphology and transparency of mice at different injury time points observed by slit lamp photography;

[0021] Figure 2 It is a statistical chart of corneal turbidity in mice;

[0022] Figures 3A - 3C It is an OCT schematic diagram of the corneal state of mice at different injury time points;

[0023] Figure 4 It is a statistical chart of corneal thickness detected by OCT in mice;

[0024] Figure 5 It is a diagram showing the morphology of corneal endothelial cells of mice at different injury time points observed by in vivo confocal microscopy;

[0025] Figures 6A - 6C It is the observation of corneal stromal morphology and posterior elastic lamina of the cornea by HE staining and PSR staining;

[0026] Figure 7 It is a diagram showing the morphology of the posterior elastic lamina of the cornea of mice observed by transmission electron microscopy experiment;

[0027] Figure 8It is a statistical chart of the thickness of the posterior elastic layer of the mouse cornea detected by transmission electron microscopy. Detailed implementation mode

[0028] Hereinafter, the present invention will be described in detail according to exemplary embodiments, but the present invention is not limited to these embodiments. The present invention is embodied in the following various forms, but should not be construed as limited to the exemplary embodiments set forth herein. Therefore, the detailed description and embodiments of the present invention will convey the scope of the present invention to those of ordinary skill in the art and be construed as falling within the scope of the present invention.

[0029] The present invention first discovers that fenofibrate drugs are used to regulate lipid metabolism in corneal endothelium, reduce the thickness of the posterior elastic layer of the cornea during the pathogenesis of FECD, and thereby improve the decrease in corneal endothelial cell density and cell damage, and finally improve corneal endothelial cell decompensation. Specifically, the target of the fenofibrate drug in regulating lipid metabolism in corneal endothelial cells is PPARa.

[0030] The usage method of the fenofibrate drug in the present invention is to add fenofibrate to the feed of mice at a ratio of 0.2% (2 mg / kg), and the food intake of mice is calculated at 4.5 g per day. In some embodiments, fenofibrate can be used in the form of an eye drop preparation, and the single dose of fenofibrate is 0.1 g, three times a day.

[0031] Example 1 Effects of oral 0.2% fenofibrate on corneal endothelial cells of mice

[0032] 1 - 1 Experimental method

[0033] Prepare feed containing 0.2% fenofibrate, and divide the experimental mice into a normal feed group and a 0.2% fenofibrate feed group. Give 750 J / cm 2 UVA irradiation to the right eyes of the experimental mice. During the irradiation process, cover the left eyes. The left eyes are the control group, and the right eyes are the UVA injury group.

[0034] After the injury experiment is completed, the mice are further divided into a group fed with normal feed and a group fed with feed containing 0.2% fenofibrate.

[0035] After inducing chronic corneal endothelial injury, continuously observe for 1 week, 2 weeks, and 3 weeks, and regularly use a slit lamp to take pictures to observe the transparency of the mouse cornea. Then, 1 month after the injury, detect the corneal thickness of the mice by OCT, observe the corneal endothelial morphology by confocal microscopy, observe the corneal stromal thickness and the morphology of the posterior elastic layer of the cornea by HE staining, and observe the structures such as the posterior elastic layer of the mouse cornea by transmission electron microscopy.

[0036] 1 - 2 Experimental results

[0037] Appendix Figures 1A - 1CThe damage conditions of the corneas of mice in different experimental groups at one week, two weeks, and three weeks after UVA damage are respectively shown. The experimental results indicate that the degree of corneal damage in mice is relatively stable at three weeks after UVA damage. The degree of corneal opacity in the UVA irradiation group fed with normal diet is more severe than that in the UVA irradiation group fed with 0.2% fenofibrate.

[0038] Appendix Figure 2 The corneal turbidity conditions of different experimental groups at one month after UVA damage are also shown. The experimental results indicate that the degree of corneal opacity in the UVA irradiation group fed with normal diet is more severe than that in the UVA irradiation group fed with 0.2% fenofibrate.

[0039] Appendix Figures 3A - 3C The anterior segment OCT schematic diagrams of the corneas of mice in different experimental groups at one week, two weeks, and three weeks after UVA damage are respectively shown. The experimental results indicate that the degree of corneal edema in the group fed with 0.2% fenofibrate is significantly reduced compared with that in the normal diet group.

[0040] Appendix Figure 4 The corneal thickness conditions of different experimental groups at one month after UVA damage are shown. The experimental results indicate that the corneal thickness of the UVA irradiation group fed with normal diet is greater than that of the UVA irradiation group fed with 0.2% fenofibrate.

[0041] Appendix Figure 5 The in vivo confocal microscopy schematic diagrams of the corneas of mice at three weeks after UVA damage in different experimental groups are shown. In the UVA irradiation group fed with normal diet, the corneal endothelial cells become larger, the cell morphology is irregular, and the cell density in the same field of view decreases. While in the UVA irradiation group fed with 0.2% fenofibrate, the cell density does not decrease significantly and the cell sizes are uniform.

[0042] The above experimental results indicate that oral administration of 0.2% fenofibrate has a protective and therapeutic effect on corneal endothelial cells.

[0043] Example 2 Protection of fenofibrate against corneal damage

[0044] 2 - 1 Experimental method

[0045] Feed containing 0.2% fenofibrate was prepared, and the experimental mice were divided into a normal diet group and a 0.2% fenofibrate diet group. The right eyes of the experimental mice were irradiated with 750 J / cm 2 UVA, and the left eyes were shielded during the irradiation process. The left eyes were the control group, and the right eyes were the UVA damage group.

[0046] After the damage experiment was completed, the mice were further divided into a group fed with normal diet and a group fed with feed containing 0.2% fenofibrate.

[0047] At the time point of 1 month after UVA injury, the eyeballs of mice were taken to make paraffin sections for immunohistochemical staining, HE staining was used to observe cell damage, and Sirius (PSR) staining was used to observe collagen changes in the cornea.

[0048] At the time point of 1 month after UVA injury, a transmission electron microscopy experiment was conducted to observe the changes in Descemet's membrane.

[0049] 2 - 2 Experimental results

[0050] Appendix Figure 6A Shows the morphological changes of the corneal stroma and Descemet's membrane of mice in different experimental groups at 1 month after UVA injury.

[0051] Among them, the experimental results of HE staining showed that after UVA injury, the corneal epithelium of mice became thinner (p < 0.001), the thickness of corneal endothelial cells became thinner, the density decreased, the nuclear staining deepened, and the stromal layer was significantly thickened, from about 60 μm to about 90 μm (p < 0.001), far exceeding the corneal thickening caused by technical factors such as section preparation.

[0052] The experimental results of HE staining also showed that the corneal epithelium of mice fed with 0.2% fenofibrate was thinner than that of the normal group, but there was no difference in the degree of corneal epithelium thinning in this group of mice before and after UVA irradiation. This may be related to factors such as weight loss caused by feeding fenofibrate, rather than UVA irradiation injury factors. Compared with the UVA irradiation group fed with ordinary feed, the corneal endothelial thickness of the UVA irradiation group fed with 0.2% fenofibrate was retained more (p < 0.001), and there was no obvious pyknosis of corneal endothelial cell nuclei, the thickness of the corneal endothelial cell layer was acceptable, and the corneal stromal thickness was greatly reduced (p < 0.001), indicating that the degree of corneal stromal edema was reduced. (See Figure 6B 、 6C ).

[0053] In addition, the HE staining results also showed that the UVA irradiation group fed with ordinary feed was different from other groups in having a relatively obvious Descemet's membrane staining, which was very likely related to the thickening of Descemet's membrane thickness. At the same time, after Sirius staining, we were able to observe that the Descemet's membrane staining of the UVA irradiation group fed with ordinary feed was deepened and thickened after injury, but limited by the microscope magnification, the thickness of Descemet's membrane could not be statistically analyzed.

[0054] To further observe the changes in Descemet's membrane, a transmission electron microscopy experiment was conducted. The experimental results are shown in Appendix Figure 7 、Appendix Figure 8 As shown, the thickness of the Descemet's membrane of the cornea of mice in the UVA irradiation group fed with 0.2% fenofibrate did not change significantly compared with the normal group (about 2 μm), while the thickness of the Descemet's membrane of the UVA irradiation group fed with ordinary feed increased by about 1 / 2 (about 3.0 μm).

[0055] The above experimental results show that oral administration of fenofibrate can significantly inhibit the thickening of the posterior elastic lamina of the cornea.

[0056] As determined in the above results, the present invention can effectively reduce the thickness of the posterior elastic lamina of the cornea during the pathogenesis of FECD by using fenofibrate drugs, improve the decrease in corneal endothelial cell density and cell damage, and ultimately improve corneal endothelial cell decompensation. This method can treat Fuchs corneal endothelial dystrophy from the root cause without surgery or immunosuppression.

[0057] It should be understood that the exemplary embodiments described herein should be considered only in a descriptive sense and not for purposes of limitation. The description of features or aspects in each embodiment should generally be considered as also being applicable to similar features or aspects in other embodiments.

Claims

1. Application of fenofibrate in the preparation of drugs for the treatment of Fuchs' corneal endothelial dystrophy.

2. The use according to claim 1, characterized in that: The Fuchs corneal endothelial dystrophy is a late-onset disease.

3. The use according to claim 2, characterized in that: The application method is oral administration of fenofibrate.

4. The use according to claim 2, characterized in that: The application method is to prepare an eye drops preparation containing fenofibrate.

5. The use according to claim 2, characterized in that: The fenofibrate reduces the thickening of the corneal Descemet's membrane and / or reduces the apoptosis and shedding of the corneal endothelium by regulating the lipid metabolism of the corneal endothelial cells.

6. The use according to claim 5, characterized in that: The target of fenofibrate in regulating lipid metabolism of corneal endothelial cells is PPARa.

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