Elastin Gene Expression In Fibroblasts Research Articles

Biochemical and gene expression studies reveal the potential of Aspergillus oryzae-fermented broken rice and brewers' rice water extracts as anti-photoageing agents.

In this study, UVA- and UVB-irradiated human fibroblasts were used to investigate the anti-photoaging efficacy of two aqueous extracts from Aspergillus oryzae-fermented broken rice (FBR) and brewers' rice (FBrR). As UVA and UVB can damage the dermal and epidermal layers, respectively, two UV radiation approaches were utilised: i) direct UVA irradiation on fibroblasts, and ii) UVB-irradiated keratinocytes indirectly co-cultured with fibroblasts to observe their epithelial-mesenchymal interaction during UVB-induced photoaging. The anti-photoaging properties were tested utilising biochemical tests and quantitative polymerase chain reaction (qPCR). The treatment of UV-irradiated human fibroblasts with FBR and FBrR dramatically downregulates MMP-1 and SFE gene expression. Nonetheless, MMP-1 secretion was inhibited by FBR and FBrR, with more substantial decreases in UVB-treated co-cultures, ranging from 0.76- to 1.89-fold relative to the untreated control. In UVA-treated fibroblasts, however, the elastase-inhibiting activity of FBR and FBrR is up to 1.63-fold and 2.13-fold more potent, respectively. In addition, post-UV irradiation treatment with FBR and FBrR was able to repair and enhance collagen formation in UVA-irradiated fibroblasts. Both FBR and FBrR were able to upregulate elastin gene expression in fibroblasts under both culture conditions, especially at 50 µg/mL. The pro-inflammatory cytokines TNF-, IL-1ß, and IL-6 were likewise lowered by FBR and FBrR, which may have contributed to the anti-photoaging effect of the UVB-treated co-culture. These results reveal that FBR and FBrR inhibit photoaging in human fibroblasts under both UV induction conditions. In conclusion, FBR and FBrR may be attractive bio-ingredients for usage in the cosmetic sector as cosmeceuticals.

Highly variable cutis laxa resulting from a dominant splicing mutation of the elastin gene

Autosomal dominant congenital cutis laxa (ADCL) is genetically heterogeneous and shows clinical variability. Only seven ADCL families with mutations in the elastin gene (ELN) have been described previously. We present morphological and molecular genetic studies in a cutis laxa kindred with a previously undescribed highly variable phenotype caused by a novel ELN mutation c.1621 C > T. The proband presented with severe cutis laxa, severe congenital lung disease previously undescribed in ADCL and pulmonary artery disease, which is often seen in ARCL but rare in ADCL. He also developed infantile spasms (OMIM 308350; West syndrome), which we consider a coincidental association although recessive cutis laxa or even digenic inheritance cannot be excluded. Electron microscopy of the proband's dermis revealed only mild rarefication of elastic fibers (in contrast to most recessive cutis laxa types). Apart from mild elastic fiber fragmentation, dermal morphology of the proband's father was within normal range. Molecular analysis of the ELN gene using genomic DNA from blood and RNA from cultured skin fibroblasts indicated a novel splice site mutation in the proband and his clinically healthy father. Analysis of ELN expression in fibroblasts provided evidence for a dominant-negative effect in the child, while due to an unknown mechanism, the father showed haploinsufficiency which might explain the significant clinical variability.

Mechanism of Abnormal Elastin Gene Expression in the Pinguecular Part of Pterygia

Elastodysplasia and elastodystrophy are two known manifestations in the conjunctival, ie, pinguecular, part of pterygia. But the mechanisms are still not understood. The purpose of this study is to investigate the mechanism of enhanced elastin gene expression in fibroblasts from the pinguecular part of pterygia, which is related to abnormal elastic fiber expression in the pinguecular part of pterygia. Elastin in surgical specimens of normal conjunctiva and the pinguecular part of pterygia from age-matched patients was detected by immunohistochemical staining. Northern hybridization and quantification of radiolabeled tropoelastin were performed in conjunctival fibroblasts cultured under different doses of ultraviolet (UV) B irradiation, and in cultured pinguecular fibroblasts from pterygia. In vitro translation was also performed to analyze the tropoelastin production in rabbit reticulocyte lysate. The level of tropoelastin in reticulolysates from UV-treated conjunctival and pinguecular fibroblasts of pterygia was higher than in normal conjunctival fibroblasts. The coding sequence and 3'- untranslated region of tropoelastin mRNAs were amplified by reverse transcription-polymerase chain reaction, and mutations were checked by DNA sequencing. Immunohistochemical staining revealed elastin in pinguecular subepithelial connective tissues of pterygia, but not in normal conjunctiva. Tropoelastin mRNA levels were not elevated in cultured pinguecular or conjunctival fibroblasts with or without ultraviolet B irradiation. However, tropoelastin synthesis was enhanced in culture medium of pinguecular and UV-irradiated conjunctival fibroblasts, but not in normal conjunctival fibroblasts. Direct DNA sequencing revealed mutations in the 3'-untranslated region but not in the coding sequence of tropoelastin mRNA, in both pinguecular and UV-irradiated conjunctival fibroblasts. The increased expression of tropoelastin in pinguecular and UV-irradiated fibroblasts is not a result of increased levels of steady-state mRNA, but is a result of posttranscriptional modification of tropoelastin.

Human recombinant interleukin-1 beta up-regulates elastin gene expression in dermal fibroblasts. Evidence for transcriptional regulation in vitro and in vivo.

The effects of human recombinant interleukin (IL)-1 beta on elastin gene expression were studied in human skin fibroblast cultures by Northern hybridization and transient transfection experiments. Incubation of the cells with IL-1 beta elevated the elastin mRNA steady-state levels by approximately 3- to 4-fold. A similar increase was noted at the protein level, when estimated by indirect immunofluorescence of cultured cells. This effect was independent of the on-going protein synthesis, as tested by incubation with cycloheximide. Transient transfections of the dermal fibroblasts with a human elastin promoter/chloramphenicol acetyltransferase (CAT) reporter gene construct suggested transcriptional regulation, since the CAT activity in cells incubated with IL-1 beta was similarly increased approximately 3-fold. Enhancement of the human elastin promoter activity by IL-1 beta was also noted in fibroblast cultures established from the skin and lungs of transgenic mice which have integrated the human promoter/CAT construct into their genome and express it in a tissue-specific manner. Furthermore, subcutaneous injection of IL-1 beta to the mice resulted in a approximately 4-fold elevation of the CAT activity in the skin after a 30-h incubation, as compared to the CAT activity in the skin of control animals. Collectively, these data indicate that IL-1 beta up-regulates elastin gene expression in fibroblast cultures as well as in the skin in vivo, and the activation occurs at the transcriptional level.