Regulatory role of circIGF2BP3 in autophagy in photoaged dermal fibroblasts / 中华皮肤科杂志

Objective:To preliminarily investigate the effect of circIGF2BP3 on autophagy in photoaged dermal fibroblasts.Methods:Human dermal fibroblasts were isolated from circumcised foreskin tissues from 6 children in the Department of Urological Surgery, Third Affiliated Hospital of Sun Yat-sen University. An ultraviolet A (UVA) -induced photoaged human dermal fibroblast model (UVA radiation group) was established by repeated UVA radiation at a dose of 10 J/cm 2 for 14 consecutive days, and human dermal fibroblasts receiving no treatment served as control group. The photoaged cell model was verified by β-galactosidase staining, Western blot analysis for determining P21 protein expression, and cell counting kit-8 (CCK8) assay for evaluating cell viability. Moreover, Western blot analysis was performed to determine the protein expression of autophagy-related proteins P62, microtubule-associated protein 1 light chain 3 (LC3) -Ⅰand LC3-Ⅱ in photoaged human dermal fibroblasts, and real-time quantitative RCR (qRT-PCR) to verify the differential expression of circIGF2BP3 between photoaged and normal human dermal fibroblasts. Furthermore, circIGF2BP3 was biologically annotated. Some cultured primary human dermal fibroblasts were divided into 4 groups: empty vector group transfected with an empty vector, UVA + empty vector group transfected with an empty vector followed by repeated UVA radiation, circIGF2BP3 group transfected with a circIGF2BP3-overexpressing lentiviral vector, UVA + circIGF2BP3 group transfected with a circIGF2BP3-overexpressing lentiviral vector followed by repeated UVA radiation. Western blot analysis was performed to determine the expression of autophagy-related proteins. Statistical analysis was carried out by using t test, one-way analysis of variance and least significant difference- t test. Results:Compared with the control group, the UVA radiation group showed significantly increased proportions of β-galactosidase-positive cells (61.33% ± 5.78% vs. 6.37% ± 0.32%, t = 9.49, P < 0.01) and P21 expression (1.25 ± 0.03 vs. 1.00 ± 0.05, t = 4.26, P < 0.05), but significantly decreased cell viability (74.33% ± 3.48% vs. 100%, t = 7.38, P < 0.01). Moreover, the P62 expression and LC3-Ⅱ/Ⅰ ratio were significantly higher in the UVA radiation group than in the control group (both P < 0.05). The relative expression of circIGF2BP3 was 0.72 ± 0.04 in the photoaged human dermal fibroblasts, which was significantly lower than that in the normal human dermal fibroblasts (1.00 ± 0.03, t = 5.46, P < 0.01). The P62 expression and LC3-Ⅱ/Ⅰ ratio were significantly lower in the circIGF2BP3 group (0.60 ± 0.01, 0.71 ± 0.01, respectively) than in the empty vector group (1.00 ± 0.02, 1.00 ± 0.01, t = 16.25, 2.75, P < 0.01, < 0.05, respectively), and lower in the UVA + circIGF2BP3 group (1.05 ± 0.02, 2.04 ± 0.05, respectively) than in the UVA + empty vector group (1.31 ± 0.02, 2.72 ± 0.14, t = 10.493, 6.472, respectively, both P < 0.01) . Conclusion:circIGF2BP3 can regulate autophagy in UVA-induced photoaged dermal fibroblasts, which provides a new potential therapeutic target for the prevention and treatment of skin photoaging.

Novel Point Mutation of EBSS Gene Coexisted with 1p36 Deletion

EBSS (epidermolysis bullosa simplex superficialis) is mainly caused by gene mutations which targeted protein as plakophilin-1, desmoplakin and keratins. 1p36 gene deleted could cause typical clinical manifestations and might also affect the expression of functional genes in other regions. Here we reported the first case of PKP1 gene and DSP gene mutation coexisted with 1p36 deletion presented as serious EBSS and 1p36 deletion syndromes and identified a new homozygous mutation in the PKP1 gene (chr1:201292246 c.1672 T＞C) and in the DSP gene (chr6:7580346 c.3923C＞T).

Novel Point Mutation of EBSS Gene Coexisted with 1p36 Deletion

EBSS (epidermolysis bullosa simplex superficialis) is mainly caused by gene mutations which targeted protein as plakophilin-1, desmoplakin and keratins. 1p36 gene deleted could cause typical clinical manifestations and might also affect the expression of functional genes in other regions. Here we reported the first case of PKP1 gene and DSP gene mutation coexisted with 1p36 deletion presented as serious EBSS and 1p36 deletion syndromes and identified a new homozygous mutation in the PKP1 gene (chr1:201292246 c.1672 T＞C) and in the DSP gene (chr6:7580346 c.3923C＞T).

Regulatory role of cathepsin D in degradation of advanced glycation end products by human dermal fibroblasts / 中华皮肤科杂志

Objective To investigate the regulatory role of cathepsin D (CatD) in the degradation of intracellular advanced glycation end products (AGEs) endocytosed by human dermal fibroblasts (HDFs).Methods Cultured HDFs were treated with 1 μnol/L CA074Me (an inhibitor of CatB and CatL),75 μmol/L pepstatin A (an inhibitor of CatD) and 1 μmol/L MG-132 (an inhibitor of20S proteasome) separately for 4 hours,and then cell counting kit 8 (CCKS) assay and fluorometric assay were performed to determine the cellular viability and protease activity,respectively.The cells in the CA074Me group,pepstatin A group and MG-132 group were additionally treated with AGE-bovine serum albumin (BSA) for 8 hours,and the cells in the blank control group were treated with phosphate-buffered saline (PBS) alone.After 8-hour cultivation,the cells in the above groups were subsequently reincubated with fresh culture medium containing the corresponding inhibitors for 24 hours.Then,flow cytometry was performed to assess the mean fluorescence intensity of intracellular AGE-BSA at different time points.Some other HDFs were treated with 37.5,75 and 150 μmol/L pepstatin A and PBS separately for 4 hours,and then the cells in the 4 groups were treated with 200 mg/L AGE-BSA for 8 hours,followed by the removal of AGE-BSA from the medium and the treatment with 37.5,75 and 150 μmol/L pepstatin A and PBS respectively.Enzyme-linked immunosorbent assay (ELISA) was conducted to measure the mean concentration of intracellular AGE-BSA at different time points,and the degradation rate of AGE was calculated.Some HDFs were divided into 3 groups:blank control group receiving no treatment,NC group transfected with an empty vector,and CatD group transfected with a CatD-overexpressing lentiviral vector.Fluorescence microscopy was conducted to estimate the transfection efficiency.Reverse transcription-PCR,Western blot analysis and fluorometric assay were performed to determine the mRNA and protein expression,and activity of CatD respectively.Then,the cells in the above 3 groups were incubated with AGE-BSA for 8 hours,followed by the removal of AGE-BSA from the medium and the treatment with fresh culture medium.The detection methods were same as the above experiment,and the degradation rate was calculated.Results The cellular proliferative activity in the 1-μmol/L CA074Me group,75-μmnol/L pepstatin A group and 1-μ mol/L MG-132 group was more than 90％,and there was no significant difference between the 3 groups and the control group (100％,F =1.525,P ＞ 0.05).Twenty-four hours after the removal of AGE-BSA from the medium,the fluorescence intensities of intracellular AGE-BSA in the CA074Me + AGE-BSA group (275.00 ± 10.15) and MG-132 + AGE-BSA group (259.00 ± 11.14) significantly decreased compared with those at the 8-hour time point (295.00 ± 6.56 and 285.67±8.74 respectively;paired t test,t =4.778,6.154 respectively,both P ＜ 0.05),while no significant difference was observed in the fluorescence intensities of intracellular AGE-BSA in the pepstatin A + AGE-BSA group between the 8-hour time point and 32-hour time point (P ＞ 0.05).The degradation rates of intracellular AGE-BSA within 24 hours in the 37.5,75 and 150 μmol/L pepstatin A groups were 9.64％ ± 1.27％,5.62％ ± 0.47％ and 3.21％ ± 0.73％ respectively;there were significant differences among the 3 groups (F =45.876,P ＜ 0.05),and the degradation rate significantly decreased along with the increase of pepstatin A concentration (P ＜ 0.05).Fluorescence microscopy showed no fluorescent cells in the blank control group,while the NC group and CatD group both showed a high proportion (＞ 80％) of fluorescent cells.The mRNA and protein expression as well as the activity of CatD were significantly higher in the CatD group than in the blank control group and NC group (all P ＜ 0.05).The CatD + AGE-BSA group showed a significantly higher degradation rate of intracellular AGE-BSA within 24 hours compared with the AGE-BSA group and NC + AGE-BSA group (both P ＜ 0.05).Conclusion CatD can promote the degradation of intracellular AGE-BSA endocytosed by HDFs.

Correlation analysis between the expression of cathepsin D and the accumulation of advanced glycation end products in skin tissues / 中华皮肤科杂志

Objective To determine the expression of cathepsin D and advanced glycation end products (AGEs)in skin tissues from patients of different ages or skin tissues with different degrees of sun exposure,to evaluate their correlation,and to preliminarily investigate the role of cathepsin D in the degradation and accumulation of AGEs in photoaged skin.Methods Skin tissues were collected from sunexposed and sun-protected body sites in patients aged 15-20 years,35-40 years,55-60 years or 75-80 years.These skin tissues were divided into 8 groups according to age of patients and degrees of sun exposure,and there were 6 specimens in each group.Immunohistochemical and immunofluorescent methods were used to measure the expression of cathepsin D and AGEs in the skin tissues.Statistical analysis was carried out by factorial design analysis of variance,Wilcoxon rank sum test and Kruskal-Wallis rank sum test for analyzing associations of the expression of cathepsin D and AGEs with age and sun exposure,as well as by Pearson correlation analysis for assessing the correlation between cathepsin D expression and AGEs expression.Results Immunohistochemical study showed that the expression of cathepsin D markedly decreased along with the increase of age,but the accumulation of AGEs gradually increased along with the increase of age.In the same age group,the cathepsin D expression was lower in the sun-exposed skin tissues than in the sun-protected skin tissues,while the accumulation of AGEs was more in the sun-exposed skin tissues than in the sun-protected skin tissues.Factorial design analysis of variance showed that sun exposure could decrease the expression of cathepsin D (F =58.70,P ＜ 0.001),but increase the accumulation of AGEs (F =158.18,P ＜ 0.001).Moreover,the increase of age could lead to decreased expression of cathepsin D (F =79.49,P ＜ 0.001),and increased expression of AGEs (F =106.06,P ＜0.001).Compared with the sun-protected skin tissues,the sun-exposed skin tissues in all the age groups showed significantly lower absorbance value of cathepsin D (35-40 years:0.020 ± 0.005 vs.0.032 ± 0.005;55-60 years:0.012 ± 0.004 vs.0.026 ± 0.002;75-80 years:0.002 ± 0.001 vs.0.013 ± 0.004;all P ＜0.001),but higher absorbance value of AGEs (35-40 years:0.030 ± 0.008 vs.0.010 ± 0.003;55-60years:0.066 ± 0.010 vs.0.021 ± 0.004;75-80 years:0.085 ± 0.015 vs.0.035 ± 0.009;all P ＜ 0.001)except the age group of 15-20 years.No matter whether the skin tissues were sun-exposed or sunprotected,there were significant differences in the expression of cathepsin D and AGEs among different age groups (all P ＜ 0.001).The results of double immunofluorescence staining were similar to those of immunohistochemical study.Pearson correlation analysis showed that the expression of cathepsin D in the sun-exposed skin tissues was highly negatively correlated with the accumulation of AGEs (r =-0.915,P ＜0.05),while they were moderately negatively correlated in the sun-protected skin tissues (r =-0.730,P ＜0.05).Conclusions Along with the increase of age,the expression of cathepsin D in skin tissues decreased,but the expression of AGEs increased.In the sun-protected skin tissues,the expression of cathepsin D was moderately negatively correlated with the expression of AGEs,while they were highly negatively correlated in the sun-exposed skin tissues,suggesting that cathepsin D may play an important role in the degradation and accumulation of AGEs in photoaged skin.

Effect of photoaging on the degradation of advanced glycation end products by human dermal fibroblasts / 中华皮肤科杂志

Objective To evaluate the effect of photoaging on the degradation of advanced glycation end products (AGEs) by human dermal fibroblasts.Methods Some cultured human dermal fibroblasts were subjected to repetitive ultraviolet A (UVA) radiation (UVA radiation group) to establish a photoaging cell model,which was then evaluated by cell counting kit 8 (CCK-8) assay,senescenceassociated β-galactosidase staining and detection of apoptosis rate.Moreover,fibroblasts receiving no treatment served as control group.Some other primary fibroblasts were divided into 4 groups:photoaged group receiving UVA radiation,non-photoaged group receiving no treatment,AGE-treated photoaged group treated with UVA radiation followed by the treatment with 200 mg/L AGE-bovine serum albumin (BSA),and AGE-treated non-photoaged group treated with 200 mg/L AGE-BSA alone.After the treatment with AGE-BSA for 4-72 hours,flow cytometry was performed to determine the fluorescence intensity of AGE-BSA in fibroblasts of the above groups.After 8-hour treatment with AGE-BSA,confocal laser scanning microscopy was performed to localize and semiquantitatively detect AGE-BSA in fibroblasts,and enzymelinked immunosorbent assay (ELISA) was conducted to detect AGE-BSA levels in fibroblasts,as well as changes in the intracellular AGE-BSA level within 24 hours after the removal of AGE-BSA.Results Compared with the control group,the UVA radiation group showed significantly decreased cellular proliferative activity (t =7.559,P ＜ 0.05),but significantly increased apoptosis rate and percentage of β-galactosidase-positive fibroblasts (t =14.075,43.524 respectively,both P ＜ 0.05).Flow cytometry revealed that the average fluorescence intensities of AGE-BSA after 4-,8-,16-,24-,48-and 72-hour treatment with AGE-BSA were significantly higher in the AGE-treated photoaged group (293.00 ± 8.19,359.67 ± 11.59,347.00 ± 12.29,338.00 ± 12.77,334.67 ± 14.22 and 336.30 ± 10.21,respectively) than in the photoaged group (all P ＜ 0.05),as well as in the AGE-treated non-photoaged group (222.33 ± 8.74,276.33 ± 6.11,256.33 ± 5.51,243.00 ± 10.15,236.33 ± 1.53 and 240.33 ± 1.52,respectively) than in the non-photoaged group (all P ＜ 0.05).Moreover,the average fluorescence intensities of AGE-BSA at different time points were all significantly higher in the AGE-treated photoaged group than in the AGE-treated non-photoaged group (all P ＜ 0.05).Confocal laser scanning microscopy showed that AGE-BSA was mainly localized in lysosomes after endocytic uptake into the fibroblasts,and the AGE-treated photoaged group showed significantly increased fluorescence intensity of AGE-BSA compared with the AGE-treated non-photoaged group (P ＜ 0.05).ELISA revealed that the intracellular AGE level in the AGE-treated non-photoaged group at 24 hours after the removal of AGE-BSA was decreased by (14.6 ± 1.2)％ compared with that before the removal,and the degradation rate of AGE-BSA was significantly higher in the AGE-treated non-photoaged group than in the AGE-treated photoaged group (7.6％ ± 1.4％,t =6.604,P ＜ 0.05).Conclusion The internalized AGE-degradating ability decreases in photoaged fibroblasts,which may induce the accumulation of AGEs in photoaged skin.

Effects of miRNA-29c-3p on the expression of collagen type Ⅰ α1 and collagen type Ⅲ α1 genes and the synthesis of collagen Ⅰ and Ⅲ in chronically photodamaged human dermal fibroblasts in vitro / 中华皮肤科杂志

Objective To evaluate the effect of miRNA-29 (miR-29) family on the synthesis of collagen Ⅰ and Ⅲ in chronically photodamaged (photoaged) skin.Methods Some cultured human dermal fibroblasts (HDFs) were divided into 2 groups:non-irradiated group receiving no treatment,and chronic photodamage group treated with repetitive ultraviolet A (UVA) radiation,which served as a chronically photodamaged cell model and was verified by flow cytometry and β-galactosidase staining.Western blot analysis was performed to determine the protein expression of collagen Ⅰ and Ⅲ,and real-time fluorescence-based quantitative PCR (qRT-PCR) to measure expression of 3 members of the miR-29 family (miR-29a-3p,miR-29b-3p and miR-29c-3p) in the above 2 groups.The differentially expressed miR-29c-3p between the above 2 groups was chosen for further functional tests.Some HDFs were divided into 4 groups to be transfected with fluorescein-labelled miR-29c-3p mimics (overexpression group),inhibitors (inhibition group),and their control RNA oligonucleotides (negative control group and inhibitor control group) respectively.The transfection efficiency was evaluated by the proportion of fluorescent cells,and the relative expression of miR-29c-3p in the above 4 groups was measured by qRT-PCR for evaluating the RNA interference efficiency,qRT-PCR was conducted to determine the mRNA expression of collagen type Ⅰ α1 (COL1A1) and collagen type Ⅲ α1 (COL3A1) genes,and Western blot analysis to measure the protein expression of collagen Ⅰ and Ⅲ.Results Compared with the non-irradiated group,the chronic photodamage group showed significantly increased proportion of senescent cells (36.47％ ± 3.20％ vs.12.56％ ± 1.46％,P ＜ 0.01) and G1-phase cells (71.70％ ± 2.43％ vs.41.89％ ± 1.86％,P ＜ 0.01),but significantly decreased proportion of S-phase cells (10.63％ ± 0.36％ vs.36.48％ ± 1.31％,P ＜ 0.01),which indicated that the chronically photodamaged cell model was established successfully.The protein expression of collagen Ⅰ and Ⅲ was significantly lower in the chronic photodamage group (0.40 ± 0.19 and 0.52 ± 0.10) than in the non-irradiated group (1.00 ± 0.12 and 1.00 ± 0.10,respectively,both P ＜ 0.01).The expression of miR-29c-3p was significantly higher in the chronic photodamage group than in the non-irradiated group (4.42 ± 2.05 vs.0.89± 0.10,P ＜ 0.05),while there were no significant differences in the expression of miR-29a-3p or miR-29b-3p between the 2 groups (both P ＞ 0.05).Twenty-four hours after transfection,the overexpression group and inhibition group both showed more than 90％ transfection efficiency which met the interference requirements.The expression of miR-29c-3p was significantly higher in the overexpression group than in the negative control group (224.17 ± 2.00 vs.2.45 ± 0.34,P ＜ 0.01),but significantly lower in the inhibition group than in the inhibitor control group (0.20 ± 0.08 vs.2.24± 0.14,P ＜ 0.01),suggesting that a RNA interference model was successfully established.The mRNA expression of COL1A1 and COL3A1 and the protein expression of collagen Ⅰ and Ⅲ were significantly lower in the overexpression group than in the negative control group and inhibition group (all P ＜ 0.05),and significantly higher in the inhibition group than in the inhibitor control group (all P ＜ 0.01).Conclusion The expression of miR-29c-3p is up-regulated in chronically photodamaged HDFs,likely by regulating the mRNA expression of COL1A1 and COL3A1 and the protein expression of collagen Ⅰ and Ⅲ.

Effects of advanced glycation end products on the expressions and activity of cathepsin D in ultraviolet A- irradiated human dermal fibroblasts / 中华皮肤科杂志

Objective To investigate the effects of advanced glycation end products(AGE)on the expressions and activity of cathepsin D(CatD)in ultraviolet A(UVA)?irradiated human dermal fibroblasts. Methods Human dermal fibroblasts were isolated and harvested from the circumcised foreskin of children, and subjected to a primary culture. CCK?8 assay was performed to screen non?cytotoxic concentrations of AGE?bovine serum albumin (BSA). Some fibroblasts were incubated with 50, 100 and 300 mg/L AGE?BSA separately for 24 hours, with untreated cells as the control group. Then, reverse transcription(RT)?PCR, Western?blot analysis and a fluorimetric assay were performed to measure the mRNA and protein expressions as well as activity of CatD, respectively. Some fibroblasts were classified into six groups: control group receiving no treatment, AGE?BSA group and BSA group treated with the highest non?cytotoxic concentration of AGE?BSA and the same concentration of BSA respectively for 24 hours, UVA group irradiated by 10 J/cm2 UVA, UVA?AGE?BSA group and UVA?BSA group treated with AGE?BSA and BSA at the above non?cytotoxic concentration respectively for 24 hours both before and after UVA radiation at 10 J/cm2. After the treatments, RT?PCR, Western?blot analysis and a fluorimetric assay were conducted to detect mRNA and protein expressions and activity of CatD respectively. Results AGE?BSA of 50- 200 mg/L exhibited no obvious influence on cellular proliferation of fibroblasts. The fibroblasts incubated with AGE?BSA of 50, 100 and 200 mg/L showed a significant increase in the mRNA expression(0.267 ± 0.007, 0.348 ± 0.007, and 0.418 ± 0.006 respectively), protein expression (1.403 ± 0.181, 2.233 ± 0.090 and 2.477 ± 0.111 respectively), and activity(1.760 ± 0.080, 2.330 ± 0.060 and 2.890 ± 0.080 respectively)of CatD compared with the control group(mRNA:0.161 ± 0.006;protein:0.903 ± 0.200;activity:1.100 ± 0.090, all P < 0.05). AGE?BSA increased CatD expressions and activity in a dose?dependent manner. The mRNA and protein expressions as well as activity of CatD were significantly higher in the UVA group than in the control group (mRNA expression: 0.480 ± 0.005 vs. 0.155 ± 0.005; protein expression: 2.583 ± 0.199 vs. 0.920 ± 0.235;activity:2.970 ± 0.110 vs. 1.110 ± 0.040, all P<0.05), but significantly lower in the UVA?AGE?BSA group than in the UVA group(mRNA expression:0.394 ± 0.008 vs. 0.480 ± 0.005;protein expression:2.070 ± 0.125 vs. 2.583 ± 0.199;activity: 2.560 ± 0.060 vs. 2.970 ± 0.110, all P < 0.05). Conclusion AGEs could increase CatD expressions and activity in human dermal fibroblasts not receiving UVA irradiation, but inhibit their increase in UVA?induced human dermal fibroblasts.

Performance of transfection with a complex plasmid encoding green fluorescent protein tagged cathepsin D in researches on chronic photodamaged fibroblasts / 中华皮肤科杂志

Objective To evaluate the performance of transfection with a complex plasmid encoding green fluorescent protein tagged CatD (GFP-CatD)in researches on chronic photodamaged fibroblasts. Methods Human dermal fibroblasts (HSFs)were irradiated with ultraviolet A (UVA)at 25 J/cm2 once a day for 21 consecutive days to establish a chronic photodamaged cell model. A plasmid encoding GFP-CatD was constructed and transfected into some chronic photodamaged fibroblasts (experimental group). The photodamaged HSFs receiving no treatment served as the blank control group, and those transfected with the negative plasmid encoding GFP only as the negative control group. After additional culture, fluorescence microscopy and Western-blot analysis were performed to observe and measure the expression of GFP-CatD in HSFs respectively, flow cytometry and methyl thiazolyl tetrazolium (MTT)assay to evaluate the apoptosis and proliferation of chronic photodamaged fibroblasts respectively. Results Fluorescence microscopy showed the expression of GFP-CatD in cytoplasm of chronic photodamaged fibroblasts at 96 hours after transfection with the GFP-CatD-encoding plasmid. Western-blot analysis revealed that the expression of CatD in the experimental group was 1.28 times that in the blank control group. There were no significant differences in the apoptosis rate(4.29% ± 1.30%vs. 3.03% ± 1.70% , P > 0.05)or proliferative rate (45.20% ± 4.70% vs. 43.60 ± 3.90% , P > 0.05)between the experimental group and blank control group. Conclusion CatD could be traced in chronic photodamaged fibroblasts with no changes in biological activity or cell cycle after transfection with the GFP-CatD-encoding complex plasmid.

Effects of repetitive ultraviolet A radiation on the endocytosis and degradation of elastin by human skin fibroblasts / 中华皮肤科杂志

Objective To investigate the effects of repetitive ultraviolet A(UVA) radiation on the endocytosis and intracellular degradation of extracellular elastin by human dermal fibroblasts(HDFs), and to explore the mechanism responsible for elastin accumulation in photoaging skin. Methods Cultured HDFs were divided into two groups:repetitive UVA radiation group treated with UVA radiation(9.9 J/cm2)once a day for seven consecutive days to establish a chronic photodamage model, and blank control group receiving no treatment. For the verification of the model, flow cytometry was performed to detect cell cycle, and senescence-associated β-galactosidase staining to determine the degree of cell senescence. Fluorescent tracer technique and conjugated polymer-based fluorescence quenching technique were conducted to observe the endocytosis and intracellular degradation of extracellular elastin in culture media by HDFs in these groups. Results Compared with the blank control group, the repetitive UVA radiation group showed increased proportions of G1-phase cells and senescent cells, which confirmed the successful establishment of chronic photodamage model in the repetitive UVA radiation group. After coculture with elastin for 24, 48 and 72 hours, the endocytosis rate of elastin was 10.0% ± 1.4%, 27.8% ± 4.2% and 39.9% ± 4.1% respectively in the blank control group, 9.9% ± 1.6%, 28.3% ± 5.1% and 42.0% ± 5.7% respectively in the repetitive UVA radiation group, with no significant difference between the two groups at the three time points (all P > 0.05). The percentage of cells showing intracellular degradation of extracellular elastin was significantly lower in the repetitive UVA radiation group than in the blank control group (4.2% ± 1.1% vs. 7.7% ± 0.9% at 24 hours, 16.5% ± 2.4% vs. 22.8% ± 1.8% at 48 hours, 26.7% ± 2.6% vs. 33.9% ± 3.1% at 72 hours, all P < 0.05). Conclusions UVA radiation at 9.9 J/cm2 for 7 consecutive days can decrease the intracellular degradation of extracellular elastin by HDFs, but has no obvious effect on endocytosis of elastin.

Expression of cathepsin B in acutely photodamaged fibroblasts and its significance / 中华皮肤科杂志

Objective To investigate the changes in cathepsin B (CatB) expression in acutely photodamaged human dermal fibroblasts (HDFs) and their significance.Methods HDFs were isolated from the foreskin of children,and subjected to primary culture and subculture.The fourth-to eighth-passage HDFs were used in the following experiment.HDFs were divided into two groups to receive irradiation with different doses of ultraviolet A (UVA) for different durations (acutely photodamaged group) or remain unirradiated (control group).Cell counting kit-8 (CCK8) assay was conducted to evaluate the proliferative activity of HDFs after irradiation with UVA at 5,10,15,20 and 25 J/cm2 respectively.Western blot and quantitative real-time reverse transcription PCR were performed to measure the protein and mRNA expressions of CatB respectively in HDFs at 24,48 and 72 hours after exposure to UVA at 10 J/cm2,and at 48 hours after exposure to UVA at 10,15,20 and 25 J/cm2.Statistical analysis was carried out by analysis of variance and least significant difference (LSD) test using the SPSS 13.0 software.Results UVA radiation induced a decrease in the proliferative activity of HDFs.When the dose of UVA was ≤ 10 J/cm2,the survival rate of HDFs maintained higher than 85％,and significant differences were observed in cell survival rate between unirradiated and irradiated HDFs at 24,48 and 72 hours (all P ＜ 0.05).Western blot showed that the gray value of CatB protein in the acutely photodamaged group irradiated with 10 J/cm2 UVA was significantly higher than that in the control group at 24 hours (0.76 ± 0.14 vs.0.35 ± 0.01,P ＜ 0.05),48 hours (1.34 ± 0.38 vs.0.45 ± 0.12,P＜ 0.05) and 72 hours (0.82 ± 0.09 vs.0.61 ± 0.06,P＜ 0.05).Increased mRNA expressions of CatB were also observed in the acutely photodamaged group compared with the control group at 24 hours (0.149 ± 0.009 vs.0.089 ± 0.015,P ＜ 0.05),48 hous (0.173 ± 0.009 vs.0.091 ± 0.010,P ＜ 0.05) and 72 hours (0.185 ± 0.158 vs.0.111 ± 0.017,P ＜ 0.05) after UVA radiation at 10 J/cm2.The gray value of CatB protein was 0.99 ± 0.07,1.49 ± 0.14,1.89 ± 0.08,2.07 ± 0.06 in HDFs at 48 hours after exposure to UVA of 10,15,20 and 25 J/cm2,respectively,significantly higher than that in the control group (0.60 ± 0.05,all P ＜ 0.05).Similarly,the mRNA expression of CatB was up-regulated in HDFs at 48 hours after UVA radiation at 10,15,20 and 25 J/cm2 compared with the unirradiated HDFs.Conclusion The protein and mRNA expressions of CatB are up-regulated in acutely photodamaged HDFs induced by UVA radiation.

Effect of ultraviolet A radiation on the expression and secretion of cathepsin G by human dermal fibroblasts / 中华皮肤科杂志

Objective To investigate the effect of ultraviolet A (UVA) radiation on the expression and secretion of cathepsin G (CatG) by human dermal fibroblasts.Methods Dermal fibroblasts were isolated from the foreskins of boys,and subjected to primary culture and subculture.After 10 or less passages,the fibroblasts were collected and divided into several groups to be irradiated with 10 J/cm2 UVA followed by 24,48 and 72 hours of additional culture,or be irradiated with 10,20 and 30 J/cm2 UVA followed by 24 hours of additional culture,with those receiving no treatment serving as the control group.Subsequently,cells and culture supernatant were collected,real time PCR and Western blot were performed to detect the expressions of CatG mRNA and protein respectively in these cells,and enzyme-linked immunosorbent assay (ELISA) was conducted to measure the expression of CatG protein in the culture supernatant of these cells.Results Compared with the control group,the fibroblasts irradiated with 10 J/cm2 UVA showed a significant increase at 24,48 and 72 hours in the expressions of CatG mRNA (0.376 ± 0.014 vs.0.183 ± 0.003,0.308 ± 0.022 vs.0.185 ± 0.005,0.296 ± 0.032 vs.0.182 ± 0.004,respectively,all P＜ 0.05) and protein (1.80 ± 0.12 vs.0.96 ± 0.06,1.41 ± 0.17 vs.0.95 ± 0.22,1.27 ± 0.09 vs.1.00 ± 0.14,respectively,all P ＜ 0.05),as well as in the supernatant level of CatG protein ((161.35 ± 7.55) vs.(122.45 ± 6.46) ng/L,(141.76 ± 2.95) vs.(124.17 ± 6.15) ng/L,(139.63 ± 3.04) vs.(121.72 ± 3.17) ng/L respectively,all P ＜0.05),with the strongest increase observed at 24 hours.At 24 hours after 10,20 and 30 J/cm2 of UVA radiation,the expression of CatG mRNA in irradiated fibroblasts was 1.90,2.51 and 3.04 times respectively (all P ＜ 0.05),the expression of CatG protein was 1.88,3.97 and 4.72 times respectively (P ＜ 0.05),and the supernatant level of CatG protein was 1.36,1.50 and 1.66 times respectively (P ＜ 0.05),that in the control group,and there was an increasing trend in all the above three parameters with increasing dose of UVA.Conclusion Acute UVA radiation can promote the expression and secretion of CatG by human dermal fibroblasts.

MAPK pathway regulates ultraviolet A-induced cathepsin K expression in human dermal fibroblasts / 中华皮肤科杂志

Objective To investigate whether ultraviolet A UVA)-induced CatK expression is regulated by the mitogen-activated protein kinases (MAPK) signaling pathway in human dermal fibroblasts in vitro.Methods Human dermal fibroblasts were obtained from circumcised foreskin of children,and subjected to primary culture.After several passages of subculture,some fibroblasts were irradiated with UVA at a dose of 10 J/cm2.Western blot was performed to measure the expressions of total and phosphorylated JNK (t-and p-JNK) and P38 (t-and p-P38) at 0.75,1.5,3 and 6 hours after the irradiation.Some fibroblasts were divided into six groups:control group receiving no treatment,SP group treated with SP600125 of 800 nmol/L,SB group treated with SB203580 of 10 μmol/L,UVA group irradiated with UVA at a dose of 10 J/cm2,UVA-SP group treated with SP600125 for 1 hour before and for 1.5 or 48 hours after UVA irradiation at 10 J/cm2,UVA-SB group treated with SB203580 for 1 hour before and for 1.5 or 48 hours after UVA radiation at 10 J/cm2.Subsequently,Western blot was performed to determine the expressions of p-c-Jun and p-MAPKAPK2 in these groups at 1.5 hours after the UVA irradiation,and reverse transcription (RT)-PCR and Western blot to detect the mRNA and protein expressions of CatK at 48 hours after the UVA irradiation,respectively.Statistical analysis was carried out by t test,one way analysis of variance and least significant difference (LSD)-t test.Results The expression levels (gray values) of p-JNK and p-P38 were significantly increased at 0.75 hour (4.77 ± 0.19 and 2.44 ± 0.13 respectively,both P ＜ 0.05) and 1.5 hours (4.68 ± 0.09 and 2.30 ± 0.04 respectively,both P ＜ 0.05),but showed no significant changes at 3 hours (both P ＞ 0.05) and 6 hours (both P ＞ 0.05) after the UVA irradiation compared with those before the irradiation (3.2 ± 0.27 and 1.61 ± 0.08 respectively).A significant decrease was observed in the expression of p-c-Jun in the UVA-SP group and p-MAPKAPK2 in the UVA-SB group compared with the UVA group (p-c-Jun,2.55 ± 0.48 vs.4.85 ±0.96; p-MAPKAPK2,1.16 ± 0.12 vs.2.46 ± 0.09,both P ＜ 0.05).The CatK mRNA and protein expressions were attenuated by 61.1％ and 44.3％ respectively in the UVA-SP group (both P ＜ 0.05),and by 71.3％ and 50.4％ respectively in the UVA-SB group (both P ＜ 0.05) in comparison with the UVA group.The UVA-SP group also showed a significant reduction in CatK mRNA and protein expressions as compared with the UVA-SB group (both P ＜ 0.05).Conclusion Both JNK and P38 signaling pathways,especially the JNK pathway,may contribute to the upregulation of CatK expression in dermal fibroblasts induced by UVA irradiation.

Effects of ultraviolet A irradiation on the expression of cathepsin K in human dermal fibroblasts / 中华皮肤科杂志

Objective To observe the expression changes of cathepsin K (CatK) in human dermal fibroblasts at different time points after different doses of ultraviolet A (UVA) irradiation.Methods Dermal fibroblasts were isolated from circumcised foreskins of children,and subjected to primary culture and subculture.Cells at third-tenth passage were used in the following experiment.Some fibroblasts were irradiated with UVA of 10 J/cm2 and collected at 24,48 and 72 hours separately after the irradiation,and some fibroblasts were irradiated with UVA of 10,20 and 30 J/cm2 separately and harvested 48 hours later.The fibroblasts receiving no irradiation served as the control group.Reverse transcription PCR and Western blot were carried out to detect the mRNA and protein expressions of CatK in fibroblasts,respectively.Results Compared with the control fibroblasts,those irradiated with UVA of 10 J/cm2 showed a significant elevation in the mRNA and protein expression levels of CatK on day 1 (0.351 ± 0.038 vs.0.177 ± 0.006,1.76 ± 0.27 vs.0.82 ± 0.45,respectively,both P＜ 0.05),day 2 (0.510 ± 0.017 vs.0.176 ± 0.002,2.97 ± 0.36 vs.1.58 ± 0.15,respectively,both P＜ 0.05) and day 3 (0.313 ± 0.012 vs.0.173 ± 0.002,2.23 ± 0.14 vs.1.29 ± 0.32,respectively,both P ＜ 0.05),with the highest expressions of CatK mRNA and protein observed on day 2.Within the range of 10-30 J/cm2,UVA enhanced the CatK mRNA and protein expression levels in a dose-dependent manner.In detail,at 48 hours after the irradiation with UVA of 10,20 and 30 J/cm2,the CatK mRNA expression level in the irradiated fibroblasts was 2.34,2.91 and 3.18 times,and the CatK protein expression level 1.77,2.82 and 3.64 times,respectively,that in the control fibroblasts (all P ＜ 0.05).Conclusion The expression of CatK is up-regulated in human dermal fibroblasts after UVA irradiation.

Expressions of aspartic proteinase and cysteine proteinase in photoaged fibroblasts / 中华皮肤科杂志

Objective To investigate the expression changes of aspartic proteinase (cathepsin D) and cysteine proteinase (cathepsin K) in photoaged fibroblasts. Methods The senescence of human fibroblasts was induced via culture in the presence of 8-methoxypsralen (MOP) of 50 mg/L in darkness for 24 hours followed by irradiation with UVA of 80 kJ/m~2. Then, aged fibroblasts were confirmed by senescence-associated β-galactosidase (SA-β-gal) staining. Real-time RT-PCR and Western blot were carried out to detect the mRNA and protein expressions of cathepsin D and cathepsin K in photoaged and normal control fibroblasts, respectively. Results Western blot showed a significant difference between photoaged and control fibroblasts in the grey scale of cathepsin D and cathepsin K (3.25 ± 0.33 vs 14.18 ± 2.25, f = 30.61, P < 0.01; 2.39 ± 0.66 vs 29.38 ± 4.62, t = 12.63, P< 0.01). The △Ct values for cathepsin D and cathepsin K mRNA were 2.79 ± 0.17 and -0.92 ± 0.06, respectively, in photoaged fibroblasts, significantly lower than those in the control fibroblasts (4.54 ± 0.34, 2.57 ± 0.13, t = 20.78, 28.50, respectively, both P < 0.01). According to the value of 2~(-△△Ct), the expression of cathepsin D and cathepsin K mRNA decreased 0.24 ± 0.021 and 0.09 ± 0.005 folds, respectively, in photoaged fibroblasts compared with the control fibroblasts. Conclusion The expression of cathepsin D and cathepsin K is decreased in photoaged fibroblasts.

In Vitro Porcine Buccal Permeation of Propranolol Hydrochloride and Its Influencing Factors / 复旦学报（医学版）

PurposeTo investigate the permeation of model drug,propranolol hydrochloride, through the excised porcine buccal mucosa. To study the influences of various factors on the buccal absorption also studied. MethodsUsing excised porcine buccal mucosa permeation test in vitro. By means of changing the medium pH, osmotic concentration, drug concentration, the concentration of various penetration enhancers including sodium glycodeoxycholate (GDC), sodium glycocholate (GC), dimethy1-β-cyclodextrin (DMβCD), and hydropropyl-β-cyclodextrin(HPβCD). The permeation rates and permeability coefficients(P) were determined and evaluated. The solubilities and apparent partition coefficients also determined in some tests. ResultsThe result showed that the P were increased when porcine buccal mucosae were pretreated with every penetration enhancement of certain concentration, increased as the pH of test solution rose from 4.9 to 9.1. The P remained constant as the concentration of propranolol hydrochloride increased from 5 to 80 mg/ml, decreased with the increasing of osmotic concentration Conclusions The absorption of propranolol hydrochloride through porcine buccal mucosa is a typical passive process, and affected by penetration enhancers, medium pH, osmotic concentration.