Construction method of solar dermatitis guinea pig model and application of model

Abstract

The invention provides a construction method of a solar dermatitis guinea pig model and application of the model, and belongs to the technical field of animal models. The invention provides a construction method of a solar dermatitis guinea pig model, which utilizes 2-10J / cm < 2 > UVB dose irradiation to evaluate systems from multiple dimensions such as dynamic skin scoring, skin thickness monitoring, histopathology and the like, and determines that the method can utilize guinea pig back skin to establish an animal model with stable solar dermatitis phenotype. A reliable and normative standardized experimental platform is provided for in-depth study of pathogenesis of solar dermatitis, development of novel protection strategies and preclinical pharmacodynamic evaluation of therapeutic drugs.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of animal models, and particularly relates to a construction method of a guinea pig model of solar dermatitis and application of the model. BACKGROUND

[0002] Solar dermatitis (SD) is also called sunburn or sunburnt, which is an acute skin damage caused by ultraviolet radiation in sunlight. UVB (280-320 nm) participates in skin photodamage through mechanisms such as direct induction of DNA damage, activation of oxidative stress and release of pro-inflammatory factors. The typical clinical manifestations are redness, swelling, burning pain, blisters and desquamation on the exposed parts, which can be accompanied by fever, headache and other systemic symptoms.

[0003] At present, the pathological mechanism research and drug development of solar dermatitis are highly dependent on animal models. The existing technology mainly uses mice as modeling animals to construct solar dermatitis models by UVB irradiation. However, the mouse model has the following inherent limitations: (1) significant differences in skin structure from humans: mouse skin is thinner, the hair follicle density is high, and the barrier function is essentially different from human skin; (2) inconsistent photosensitivity: different strains of mice have large differences in sensitivity to UVB, resulting in high variability of experimental results; (3) lack of dose standardization: the UVB irradiation dose used in existing studies ranges widely (from 50 mJ / cm 2 to 1000 mJ / cm 2 ), and there is a lack of systematic dose-effect relationship research, which seriously affects the repeatability and comparability of the model; (4) incomplete pathological features: mouse models often show acute erythema, but it is difficult to simulate the pathological changes of human solar dermatitis in the middle and late stages, such as dermal inflammatory cell infiltration pattern and keratinocyte apoptosis characteristics. Guinea pigs are highly similar to humans in skin physiological structure: their epidermal thickness, melanin distribution pattern, vascular reactivity and immune response characteristics are superior to mice. Studies have shown that guinea pigs have a sensitivity to UVB that is closer to humans, and can produce typical erythema and delayed pigmentation. However, a standardized solar dermatitis guinea pig model has not yet been established, and there is a lack of a systematic dose exploration and model verification system, which seriously restricts the application of the model in photodermatosis research and drug evaluation. SUMMARY

[0004] The application provides a construction method of a solar dermatitis guinea pig model and application of the model, and the obtained solar dermatitis animal model is standardized, has good repeatability, complete pathological features and strong clinical relevance.

[0005] The application provides a construction method of a solar dermatitis guinea pig model, which comprises the following steps: irradiating guinea pigs with ultraviolet light, wherein the irradiation dose of the ultraviolet light is 2-10 J / cm 2 .

[0006] In one specific embodiment of the present invention, the irradiation dose of the ultraviolet light is 4~10 J / cm². 2 .

[0007] In one specific embodiment of the present invention, the ultraviolet radiation dose is 8~10 J / cm². 2 .

[0008] In one specific embodiment of the present invention, the ultraviolet radiation dose is 10 J / cm². 2 .

[0009] In one specific embodiment of the present invention, the irradiation time of the ultraviolet light is 50~300s.

[0010] In one specific embodiment of the present invention, the irradiation includes irradiating the modeling area on the back of the guinea pig with ultraviolet light.

[0011] In one specific embodiment of the present invention, the modeling site includes the back of the guinea pig being shaved and prepared as the modeling site.

[0012] In one specific embodiment of the present invention, the size of the molding part is 3cm × 2cm.

[0013] This invention also provides the application of the guinea pig model of photodermatitis constructed using the above-described method in the preparation of sunscreens, anti-inflammatory and repair drugs, and photoprotective products.

[0014] This invention also provides the application of the guinea pig model of photodermatitis constructed using the above-described method in the efficacy evaluation tool for preparing sunscreens, anti-inflammatory and repair drugs, and photoprotective products.

[0015] Beneficial effects: This invention provides a method for constructing a guinea pig model of photodermatitis, by utilizing 2~10 J / cm 2 The method described in this invention, through a multi-dimensional evaluation system including dynamic skin scoring, skin thickness monitoring, and histopathology, clearly demonstrates that it can establish a stable animal model of photodermatitis phenotype using guinea pig dorsal skin. This provides a reliable and standardized experimental platform for in-depth research on the pathogenesis of photodermatitis, the development of novel protective strategies, and the preclinical pharmacodynamic evaluation of therapeutic drugs. Attached Figure Description

[0016] Figure 1 Image of the modeling area, A in the image: 0J / cm 2 Dosage; B: 2J / cm 2 Dosage; C: 4J / cm 2 Dosage; D: 6 J / cm 2Dosage; E: 8 J / cm 2 Dosage; F: 10 J / cm 2 dose; Figure 2 0J / cm 2 HE staining results of light dose group A♂1 (100×), no obvious abnormalities were observed in the tissue structure, and the epidermal cells were arranged neatly; Figure 3 2J / cm 2 HE staining results (100×) of B♀4 in the light dose group, showing epidermal cell proliferation; Figure 4 4J / cm 2 HE staining results of C♂1 in the light dose group (100×), showing epidermal cell proliferation; Figure 5 6J / cm 2 HE staining results of D♀3 in the light dose group (100×), showing epidermal cell proliferation; Figure 6 8J / cm 2 HE staining results of E♂2 in the light dose group (100×), showing epidermal cell proliferation; Figure 7 8J / cm 2 HE staining results of E♂4 in the light dose group (100×), showing epidermal cell proliferation and parakeratosis; Figure 8 10 J / cm 2 HE staining results (100×) of F♀4 in the light dose group show epidermal cell proliferation, parakeratosis, and crusting. Detailed Implementation

[0017] This invention provides a method for constructing a guinea pig model of photodermatitis, comprising the following steps: irradiating guinea pigs with ultraviolet light, wherein the irradiation dose of the ultraviolet light is 2~10 J / cm². 2 .

[0018] This invention uses guinea pigs as the animal model. Compared with mice, guinea pig skin is closer to the physiological characteristics of human skin in terms of epidermal thickness, dermal structure, melanin distribution and vascular reactivity. This allows the erythema reaction, inflammatory process and tissue repair pattern produced by guinea pigs after UVB irradiation to more realistically simulate the clinical and pathological manifestations of human photodermatitis.

[0019] This invention involves irradiating the modeling sites of guinea pigs with UVB. Before irradiation, the back of the modeling site needs to be dehaired and prepared. For example, in one embodiment, a 6% sodium sulfide solution is used for dehairing and preparation, and a modeling site with a size of 3cm×2cm is selected.

[0020] The UVB irradiation dose described in this invention is 2~10 J / cm². 2 The irradiation time is 24 hours. Under the conditions of this embodiment of the invention, the irradiation intensity is 2~10 J / cm². 2 Under UVB irradiation, guinea pigs all showed varying degrees of inflammatory reactions in their skin; among them, 4~10 J / cm 2 The dose group consistently exhibited skin redness, thickening, and histopathological changes during the 7-day observation period, confirming that this dose range could establish a stable inflammatory phenotype of photodermatitis. Skin thickness increased significantly from 4 hours after irradiation, and the increase was positively correlated with the irradiation dose, ranging from 4 to 10 J / cm². 2 The thickening effect persisted until day 7 in all dose groups, showing a statistically significant difference. Histopathological examination revealed epidermal hyperplasia and parakeratosis in all dose groups, with the severity of the lesions increasing with increasing dose; especially in the 8–10 J / cm² range. 2 In the dosage group, skin lesions, crusting, and typical sunburn cells were observed, corresponding to the pathological manifestations of severe photodermatitis in clinical practice. Based on the above multi-dimensional evaluation results, 4~10 J / cm² 2 The effective dose range for establishing a guinea pig model of photodermatitis is 8–10 J / cm³. 2 Ulceration symptoms appeared at the specified dosage; based on comprehensive considerations of model stability, pathological typicality, and animal experimental ethics, 10J / cm 2 This is the optimal dose.

[0021] This invention also provides the application of the guinea pig model of photodermatitis constructed using the above-described method in the preparation of sunscreens, anti-inflammatory and repair drugs, and photoprotective products.

[0022] The model described in this invention operates at higher doses (8~10 J / cm²). 2 This model can simulate acute-phase symptoms such as erythema and edema, as well as the appearance of sunburned cells. Evaluation and testing using multi-dimensional indicators such as dynamic skin scoring, skin thickness monitoring, and histopathological grading demonstrate that the model described in this invention has high standardization, good reproducibility, complete pathological features, and strong clinical relevance. It is not only suitable for systematic research on the pathogenesis of photodermatitis, but also provides a stable and reliable preclinical experimental platform for evaluating the efficacy of sunscreens, anti-inflammatory and repairing drugs, and photoprotective products, possessing significant scientific research and translational application value.

[0023] This invention also provides the application of the guinea pig model of photodermatitis constructed using the above-described method in the efficacy evaluation tool for preparing sunscreens, anti-inflammatory and repair drugs, and photoprotective products.

[0024] To further illustrate the present invention, the construction method of a guinea pig model for solar dermatitis and the uses of the model provided by the present invention will be described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0025] Example 1 1. Animal strain: SPF-level Hartley guinea pigs; Quantity: 12; Age: 4 - 6 months old; Weight range: 492 - 575 g; Gender: Half male and half female; Purchased from Beijing Vital River Laboratory Animal Technology Co., Ltd. [SCXK (Beijing) 2021 - 0011]; Housed in the animal house of Guangdong Rhein Medical Research Institute Co., Ltd. [SYXK (Guangdong) 2022 - 0146], temperature (24 ± 2) °C, relative humidity (50 ± 20)%, 12h / 12h light and dark alternation, free drinking water and eating during the feeding period.

[0026] 2. Main detection instruments: Electronic balance (BCE2201 - 1CCN, BSA2202S, Sartorius Scientific Instruments (Beijing) Co., Ltd.); Ultraviolet phototherapy instrument (SQ1DJF, Shanghai Sigma High-Tech Co., Ltd.); Digital micrometer (0 - 25 mm, Mitutoyo).

[0027] 3. Main reagents: Hair removal reagent (sodium sulfide nonahydrate, C13880113, Shanghai Macklin Biochemical Co., Ltd.).

[0028] 4. Main detection process: ① Grouping and model establishment Select 12 guinea pigs with qualified adaptability, half male and half female. Take an area of about 6 cm × 3 cm on the back of the guinea pigs for hair removal and skin preparation with 6% sodium sulfide solution. Take about 3 cm × 2 cm as a model establishment site for each guinea pig, and 2 model establishment sites for each guinea pig, and investigate 2 model establishment irradiation doses. Set the model establishment dose groups as follows: 0, 2, 4, 6, 8, 10 J / cm 2 , and each dose group has 2 male and 2 female animals. On the day after skin preparation, irradiate the skin preparation area of the animals with a phototherapy instrument for model establishment, and only model for one day.

[0029] Table 1 Details of model establishment conditions at different doses

[0030] ② Skin scoring and photography Observe the skin redness, ulceration, etc. of the animals 4 h, 1 d, 2 d, 3 d, 4 d, 5 d, 6 d, 7 d after the first model establishment, take pictures and record, and perform skin scoring on the model establishment sites.

[0031] Table 2 Details of scoring criteria

[0032] ③ Skin thickness detection at the modeling site After the initial modeling, the skin thickness in the modeling area was checked using a digital micrometer at 4h, 1d, 2d, 3d, 4d, 5d, 6d, and 7d.

[0033] ④ Examination of skin histopathological changes On day 7, skin tissue with visible wounds was collected from some animals in each group after euthanasia. The tissue was fixed in 10% formalin, routinely dehydrated, embedded in paraffin, and then sectioned. HE staining was performed to observe the histopathological examination of the skin tissue.

[0034] Table 3 Interpretation of Pathological Diagnosis and Lesion Degree

[0035] 5. Main test results: ① The result is as follows Figure 1 As shown in Table 4, the skin redness, swelling, and ulceration of animals were observed at 4h, 1d, 2d, 3d, 4d, 5d, 6d, and 7d after the first modeling, and the skin at the modeling site was scored. (2~10 J / cm) 2 The guinea pig developed red and swollen skin on its back, with a concentration of 8-10 J / cm². 2 Ulceration symptoms appeared at the specified dose; 2J / cm 2 In the light-induced modeling group, skin inflammation began to appear on day 1 and gradually subsided starting on day 3; 4~10 J / cm² 2 Stable skin inflammatory response was observed in the light dose group 1-7 days after modeling.

[0036] Table 4. Statistical table of skin scores at the modeling site ( ±S, n =4)

[0037] ② Skin thickness was measured at the guinea pig modeling site at 4h, 1d, 2d, 3d, 4d, 5d, 6d, and 7d after the initial modeling, and the increase in skin thickness was statistically analyzed. The results are shown in Tables 5 and 6, and are related to 0J / cm². 2 Compared to the skin increase value, 2J / cm 2 In the light dose group, skin thickening began 4 hours after modeling, and skin thickness increased significantly on days 1 and 2 after modeling. P <0.01), then gradually receded to normal levels; 4~10 J / cm 2 The skin thickness of the light dose group increased significantly from 4 hours to 7 days after modeling. P <0.05 or P <0.01), the higher the light dose, the more obvious the skin thickening.

[0038] Table 5. Statistics on skin thickness at the modeling site ( ±S, n =4)

[0039] Compared with the negative control group, # P <0.05, ## P <0.01.

[0040] Table 6. Statistics on skin thickening at the modeling site ( ±S, n =4)

[0041] Compared with the negative control group, # P <0.05, ## P <0.01.

[0042] ③ On day 7 of the experiment, the animals underwent their final treatment, and HE staining was used to detect pathological changes in the skin tissue. The results are as follows: Figures 2-8 As shown in Table 7, except for 0J / cm 2 In addition to the light dose group, significant skin lesions were observed in all different dose groups; a comparison of the degree of epidermal cell growth among the groups showed that at 10 J / cm²... 2 Light dose group > 8 J / cm 2 Light dose group > 6 J / cm 2 Light dose group > 4 J / cm 2 Light dose group >2J / cm 2 Light dose group; comparison of the degree of incomplete keratosis among groups, 10J / cm 2 Light dose group = 8J / cm 2 Light dose group > 6 J / cm 2 Light dose group = 4J / cm 2 Light dose group = 2J / cm 2 Light dose group.

[0043] Table 7. Statistical table of histological examination results of skin of various animals ( ±S, n =4)

[0044] In Table 7, the degree of histological changes is represented by -, ±, +, ++, and +++ to indicate normal, slight, mild, moderate, and severe.

[0045] In summary, this invention clarifies the key dosage parameters for constructing an animal model of photodermatitis, which are 2–10 J / cm³. 2 Under UVB irradiation, guinea pigs all showed varying degrees of inflammatory reactions in their skin; among them, 4~10 J / cm 2The dose group consistently exhibited skin redness, thickening, and histopathological changes during the 7-day observation period, confirming that this dose range could establish a stable inflammatory phenotype of photodermatitis. Further analysis showed that skin thickness increased significantly from 4 hours after irradiation, and the increase was positively correlated with the irradiation dose, ranging from 4 to 10 J / cm². 2 The thickening effect persisted until day 7 in all dose groups, showing a statistically significant difference. Histopathological examination further confirmed the pathological features of the model: epidermal hyperplasia and parakeratosis were observed in all dose groups, and the severity of the lesions increased with increasing dose; especially in the 8–10 J / cm² range. 2 In the dosage group, skin lesions, crusting, and typical sunburn cells were observed, corresponding to the pathological manifestations of severe photodermatitis in clinical practice. Based on the above multi-dimensional evaluation results, 4~10 J / cm² 2 To establish an effective dose range for a guinea pig model of photodermatitis; considering model stability, pathological typicality, and animal experimental ethics, 10 J / cm² was selected. 2 This is the optimal dose range.

[0046] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for constructing a guinea pig model of photodermatitis, characterized in that, Includes the following steps: Guinea pigs were irradiated with ultraviolet light at a dose of 2-10 J / cm². 2 .

2. The construction method according to claim 1, characterized in that, The ultraviolet radiation dose is 4~10 J / cm. 2 .

3. The construction method according to claim 1 or 2, characterized in that, The ultraviolet radiation dose is 8~10 J / cm. 2 .

4. The construction method according to claim 3, characterized in that, The ultraviolet radiation dose is 10 J / cm². 2 .

5. The construction method according to claim 1, characterized in that, The irradiation time of the ultraviolet light is 50~300s.

6. The construction method according to claim 1, characterized in that, The irradiation involved irradiating the modeled area on the back of the guinea pig with ultraviolet light.

7. The construction method according to claim 6, characterized in that, The modeling site includes the back of the guinea pig where hair has been removed and the skin prepared, serving as the modeling site.

8. The construction method according to claim 6 or 7, characterized in that, The size of the molded part is 3cm × 2cm.

9. The application of the guinea pig model of photodermatitis constructed using the construction method described in any one of claims 1 to 8 in the preparation of sunscreens, anti-inflammatory and repair drugs, and photoprotective products.

10. The application of the guinea pig model of photodermatitis constructed using the construction method described in any one of claims 1 to 8 in the efficacy evaluation tool for preparing sunscreens, anti-inflammatory and repair drugs, and photoprotective products.

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