Acid In Human Skin Fibroblasts Research Articles

Blackcurrant Anthocyanins Increase the Levels of Collagen, Elastin, and Hyaluronic Acid in Human Skin Fibroblasts and Ovariectomized Rats.

Blackcurrants (Ribes nigrum L.) contain high levels of anthocyanin polyphenols, which have beneficial effects on health, owing to their antioxidant and anticarcinogenic properties. Phytoestrogens are plant-derived substances with estrogenic activity, which could have beneficial effects on the skin. Estradiol secretion decreases during menopause, reducing extracellular matrix (ECM) component production by skin fibroblasts. Using a normal human female skin fibroblast cell line (TIG113) and ovariectomized rats, the present study investigated whether an anthocyanin-rich blackcurrant extract (BCE) and four blackcurrant anthocyanins have novel phytoestrogenic activities that could benefit the skin in menopausal women. In TIG113 cells, a microarray and the Ingenuity® Pathway Analysis showed that 1.0 μg/mL of BCE upregulated the expression of many estrogen signaling-related genes. A quantitative RT-PCR analysis confirmed that BCE (1.0 or 10.0 μg/mL) and four types of anthocyanins (10 μM) altered the mRNA expression of ECM proteins and enzymes involved in ECM turnover. Immunofluorescence staining indicated that the anthocyanins stimulated the expression of ECM proteins, such as collagen (types I and III) and elastin. Dietary administration of 3% BCE to ovariectomized rats for 3 months increased skin levels of collagen, elastin, and hyaluronic acid. This is the first study to show that blackcurrant phytoestrogens have beneficial effects on skin experimental models.

Role of peroxisomal oxidation in the conversion of arachidonic acid to eicosatrienoic acid in human skin fibroblasts

Human skin fibroblasts converted [5,6,8,9,11,12,14,15- 3H]arachidonic acid ([ 3H]20:4) to eicosatrienoic acid (20:3), but appreciable amounts of radiolabeled 20:3 were not detected in corresponding incubations with [1- 14C]20:4. This indicates that the main pathway for synthesizing 20:3 from arachidonic acid in the fibroblast involves oxidative removal of the carboxyl group of arachidonic acid. Fibroblasts deficient in long-chain acyl coenzyme A dehydrogenase (LCAD) converted [ 3H]20:4 to [ 3H]20:3. However, Zellweger fibroblasts that are deficient in peroxisomal fatty acid oxidation did not, indicating that the oxidative removal of the carboxyl group occurs in the peroxisomes. [ 3H]Hexadecatrienoic acid (16:3) was the main product that accumulated when [ 3H]20:4 was incubated with normal, LCAD deficient, and very long-chain acyl coenzyme A dehydrogenase (VLCAD) deficient fibroblasts, but Zellweger fibroblasts did not form this product. Normal fibroblasts converted [ 3H] 16:3 to radiolabeled 20:3 and arachidonic acid. These findings suggest that some of the 16:3 produced from arachidonic acid by peroxisomal β-oxidation can be recycled and that this recycling process constitutes a novel pathway for the conversion of arachidonic acid to 20:3 in human fibroblasts.

Modulation of UVA-induced lipid peroxidation and suppression of UVB-induced ornithine decarboxylase response by all-trans-retinoic acid in human skin fibroblasts in vitro.

Although clinical evidence of improvement of human skin photodamage by all-trans-retinoic acid (atRA) has accumulated, evidence for its preventative effects against photodamage is limited. Here we studied human skin fibroblasts in vitro. For determination of atRA uptake and metabolism, cells were treated with 3 or 10 microM atRA and retinoids analyzed by HPLC. After 16h a peak of cellular retinoid levels was reached, mainly atRA and 13-cis-RA. At this time point cells were irradiated with UVA (1-20 J/cm2) or UVB (5-500 mJ/cm2). TBARS in medium supernatant were used as an indicator of lipid peroxidation; ornithine decarboxylase (ODC) activity served as a marker of the mutagenic and carcinogenic effects of UV light. 1 h post irradiation (p.i.) with 20 J/cm2 UVA, TBARS production was enhanced by a 3 microM atRA treatment (121+/-5% of vehicle treated cells) and decreased by a 10 microM atRA treatment (75+/-2% of vehicle treated cells), and not significantly altered in UVB irradiated cells. 24 h p.i. with 50 mJ/cm2 UVB, ODC activity peaked in vehicle treated cells at a 7.4+/-0.2-fold increase compared to sham irradiated control cells, and was reduced to a 4.9+/-0.2-fold increase by 3 microM atRA. Treatment with 10 microM atRA further decreased ODC activity (3.7+/-1.0-fold increase) and this delayed activity peak occurred at 36 h p.i. ODC activity was not significantly enhanced by UVA irradiation. These results suggest that in normal human skins fibroblast atRA and/or its metabolites influence the UVA-induced lipid peroxidation by at least two distinct antagonistic mechanisms, while the ODC response to UVB-induced DNA damage possibly involves a ROS-independent, retinoid-sensitive regulatory pathway.

Restoration of myo-inositol uptake by eicosapentaenoic acid in human skin fibroblasts cultured in high-glucose medium

The effects of elevated glucose and eicosapentaenoic acid (EPA, C20:5 ω3) on myo-inositol uptake in human skin fibroblasts (HSF) were evaluated. Myo-inositol incorporation into HSF was dependent on an active transport system via Na +-K + ATPase activity based on the results with Na + deprivation and ouabain (5 mM). Although glucose (27.5, 55 mM) inhibited 2-[ 3H] myo-inositol uptake, the addition of EPA (3×10 −4M) prevented glucose-mediated inhibition. Since EPA decreased glucose-mediated inhibition of myo-inositol uptake, this agent might ameliorate some of the devastating functions associated with diabetes.

Formation of cholic acid from 3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-cholestanoic acid in human skin fibroblasts.

Whether 3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-cholestanoic acid (THCA) was converted into cholic acid in human skin fibroblasts was examined. THCA was incubated with subcellular fractions of cultured skin fibroblasts in the presence of NAD+, ATP, CoA, and Mg2+. The reaction products were analyzed by thin-layer chromatography and high-performance liquid chromatography after p-bromophenacyl ester derivatization. The highest specific activity was found in the light mitochondrial fraction (2.71 nmol/mg protein/h). The specific activity was about 9-fold higher than that in heavy mitochondrial fraction. The peroxisomal fraction prepared from the light mitochondrial fraction by sucrose gradient centrifugation was also able to catalyze the conversion of THCA into cholic acid. The specific activity in this fraction was a further 2.2-fold higher than that in the light mitochondrial fraction. These results suggest that cultured human skin fibroblasts are able to convert THCA into cholic acid, and that the activity exists in peroxisomes.

Enhancement of lethality of near-ultraviolet by p-aminobenzoic acid in human skin fibroblasts deficient in dna repair

AbstractIntroduction Para-aminobenzoic acid (PABA) is widely used as a topical sunscreen to protect the skin from the harmful effects of ultraviolet (UV) light. PABA acts as a UV filter since its ultraviolet absorption extends beyond that of DNA down to about 320 nm. As such, PABA protects the DNA of skin cells from photolysis. However, synergetic side effects of near-UV photoexcited PABA in pyrimidine dimer-repair-deficient E. coli cells have been reported1 and dimer formation of E. coli. DNA has been demonstrated by chemical analysis.2 Similar sensitization has been observed with mammalian cells including mouse lymphoma cell line3 and human skin fibroblasts,4 and in the latter case the formation of pyrimidine dimers was demonstrated. In this study we confirm the involvement of DNA damage in PABA photosensitization of human cells through the extent of sensitization of cells killing by comparing a DNA-repair-deficient with a normal human skin fibroblast cell line.