ascorbic-acid and Keloid

Vitamin C (L-ascorbic acid), a known enhancer of collagen deposition, has also been identified as an inhibitor of elastogenesis.. Present studies explored whether and how the L-ascorbic acid derivative (+) sodium L-ascorbate (SA) would affect production of collagen and elastic fibers in cultures of fibroblasts derived from normal human skin and dermal fat, as well as in explants of normal human skin, stretch-marked skin and keloids.. Effects of SA on the extracellular matrix production were assessed quantitatively by PCR analyses, western blots, biochemical assay of insoluble elastin and by immuno-histochemistry. We also evaluated effects of SA on production of the reactive oxygen species (ROS) and phosphorylation of IGF-I and insulin receptors.. SA, applied in 50-200 μM concentrations, stimulates production of both collagen and elastic fibers in all tested cultures. Moreover, combination of SA with a proline hydroxylase inhibitor induces a beneficial remodelling in explants of dermal scars, resulting in the inhibition of collagen deposition and induction of new elastogenesis. Importantly, we revealed that SA stimulates elastogenesis only after intracellular influx of non-oxidized ascorbate anions (facilitated by the sodium-dependent ascorbate transporter), that causes reduction of intracellular ROS, activation of c-Src tyrosine kinase and the enhancement of IGF-1-induced phosphorylation of the IGF-1 receptor that ultimately triggers elastogenic signalling pathway.. Our results endorse the use of this potent stimulator of collagen and elastin production in the treatment of wrinkled and stretch-marked skin. They also encourage inclusion of SA into therapeutic combinations with collagenogenesis inhibitors to prevent formation of dermal scars and keloids.

Topics: Adult; Ascorbic Acid; Biopsy; Collagen; Elasticity; Elastin; Extracellular Matrix; Female; Fibroblasts; Humans; Insulin-Like Growth Factor I; Keloid; Organ Culture Techniques; Phosphorylation; Prolyl-Hydroxylase Inhibitors; Reactive Oxygen Species; Receptor, IGF Type 1; Regeneration; Skin; Striae Distensae; Tropoelastin

Vitamin C is used as an anti-ageing agent because of its collagen enhancing effects. The precise cellular signalling mechanism of vitamin C is not well known. Here, we investigate the profibrotic mechanism of vitamin C against LL-37. Antimicrobial peptide LL-37 decreases collagen expression at mRNA and protein levels in human dermal fibroblasts (HDFs). The ability of LL-37 to inhibit collagen expression is dependent on phosphorylation of extracellular signal-regulated kinase (ERK). HDFs and human keloid fibroblasts were treated with vitamin C followed by 2 h of LL-37 treatment. Collagen mRNA expression and total soluble collagen production inhibited by LL-37 was enhanced by treatment with 0.5 mm vitamin C. Vitamin C also decreased intracellular reactive oxygen intermediates (ROI) levels that were increased by LL-37. Furthermore, the phosphorylation of ERK was analysed by Western blot following treatment with vitamin C and LL-37. Vitamin C turned off phosphorylation of ERK that was induced by LL-37. Ets-1 transcriptional factor, which is involved in the regulation of collagen expression by LL-37, was also inhibited by vitamin C. This study shows that vitamin C enhances collagen production by inhibiting the ERK pathway induced by LL-37.

Topics: Antimicrobial Cationic Peptides; Ascorbic Acid; Cathelicidins; Cells, Cultured; Collagen; Dermis; Extracellular Signal-Regulated MAP Kinases; Fibroblasts; Humans; Keloid; Proto-Oncogene Protein c-ets-1; Reactive Oxygen Species; RNA, Messenger; Signal Transduction

The effects of ascorbic acid and hydrocortisone on activity of prolyl hydroxylase in fibroblasts from keloid and normal human dermis were investigated and compared to the effects of these agents on collagen synthesis. Prolyl hydroxylase activity in normal fibroblasts grown to confluency in 1.5 microM hydrocortisone was approximately half that of cells grown without the steroid. The concentration of hydrocortisone effective in reducing enzyme activity was the same as that for reducing the rate of collagen synthesis; a half-maximal effect on both parameters was achieved at 10(-7) M. Hydrocortisone lowered enzyme activity through most of the culture cycle. Fibroblasts derived from keloids were significantly less subject to hydrocortisone-mediated reduction of prolyl hydroxylase activity and rate of collagen synthesis. This difference between keloid and normal cells was dependent on the simultaneous presence of ascorbic acid and hydrocortisone. These data suggest that the defect in wound healing that results in keloid formation is associated with a change in a regulatory mechanism that controls the rate of collagen synthesis and is sensitive to physiological levels of hydrocortisone. Continuous culture of fibroblasts in medium supplemented with ascorbic acid also lowered prolyl hydroxylase activity. Unlike the effect of hydrocortisone, growth in ascorbate increased the rate of collagen synthesis and affected keloid and normal strains equally.

Topics: Ascorbic Acid; Culture Techniques; DNA; Fibroblasts; Humans; Hydrocortisone; Keloid; Procollagen-Proline Dioxygenase; Time Factors

The rate of proline transport increases significantly when human dermal fibroblasts are grown with 1.5 microM hydrocortisone. Fibroblasts derived from keloid tissue are significantly more stimulated than normal fibroblasts. An average increase of 41% is obtained with 8 normal strains, whereas uptake in 8 keloid-derived strains increases 210%. Similar results are obtained with the system A amino acid analogue 2-(methylamino)isobutyric acid, for which the uptake rate increases 87% and 329% in normal and keloid cells, respectively. The hydrocortisone-mediated increase in proline transport and the difference between keloid and normal fibroblasts are observed throughout the culture cycle and after depletion of amino acid pools. The uptake of nine other amino acids are differentially altered in normal and keloid cells. Competition experiments with 2-(methylamino)isobutyric acid indicate that the greatest differences occur with amino acids that are transported preferentially by the A system. Inhibition of the hydrocortisone-mediated increase by progesterone and a lag period of approximately 3 h indicate that hydrocortisone is regulating proline transport by a cytosolic receptor mechanism.

Topics: Amino Acids; Aminoisobutyric Acids; Ascorbic Acid; Biological Transport; Cell Cycle; Cells, Cultured; Fibroblasts; Humans; Hydrocortisone; Keloid; Progesterone; Proline

Topics: Adolescent; Ascorbic Acid; Child; Citrates; Citrus; Female; Humans; Keloid; Male; Postoperative Care; Recurrence; Skin Transplantation; Time Factors; Transplantation, Autologous; Wound Healing

Topics: Animals; Ascorbic Acid; Catalase; Chick Embryo; Collagen; Dithiothreitol; Humans; Iron; Keloid; Ketoglutaric Acids; Lidocaine; Mixed Function Oxygenases; Proline; Psoriasis; Skin; Tritium

Topics: Adrenal Glands; Animals; Ascorbic Acid; Chick Embryo; Culture Techniques; Humans; Hyaluronoglucosaminidase; Hydrocortisone; Keloid; Methods; Staining and Labeling; Tissue Extracts

Topics: Adrenal Cortex Hormones; Ascorbic Acid; Bandages; Breast; Cicatrix; Eyelids; Face; Humans; Keloid; Nutritional Physiological Phenomena; Rhinoplasty; Splints; Surgery, Plastic; Suture Techniques; Tranquilizing Agents; Wound Healing

Topics: Ascorbic Acid; Cicatrix; Collagen; Humans; Keloid; Mixed Function Oxygenases; Proline; Skin; Tritium

Topics: Administration, Oral; Ascorbic Acid; Chlorophenols; Humans; Iron; Keloid; Nutrition Therapy; Vitamins