Yunhi Cho

Suppression of putative tumour suppressor gene GLTSCR2 expression in human glioblastomas

Glioma tumour‐suppressor candidate region gene 2 (GLTSCR2/PICT‐1) is localized within the well‐known 1.4 Mb tumour‐suppressive region of chromosome 19q, which is frequently altered in various human tumours, including diffuse gliomas. Aside from its chromosomal localization, several lines of evidence, including PTEN‐phosphorylating and cell‐killing activities, suggests that GLTSCR2 participates in the suppression of tumour growth and development. However, little is known about the biological functions and molecular mechanisms of GLTSCR2 as a tumour suppressor gene. We investigated the pathological significance of GLTSCR2 expression in association with the development and progression of glioblastomas, the most common malignant brain tumour. We used real‐time PCR and western blot analysis to examine the expression levels of GLTSCR2 mRNA and protein in glioblastomas, normal brain tissue and in non‐glial tumour tissue of different origin, and found that GLTSCR2 expression is down‐regulated in glioblastomas. In addition, direct sequencing analysis and fluorescence in situ hybridization clearly demonstrates the presence of genetic alterations, such as a nonsense mutation and deletion, in the GLTSCR2 gene in glioblastomas. Finally, our immunohistochemical study demonstrates that GLTSCR2 is sequentially down‐regulated according to the histological malignant progression of the astrocytic glial tumour. Taken together, our results suggest that GLTSCR2 is involved in astrocytic glioma progression. Copyright

Royal jelly protects against ultraviolet B-induced photoaging in human skin fibroblasts via enhancing collagen production.

Royal jelly (RJ) is a honeybee product containing proteins, carbohydrates, fats, free amino acids, vitamins, and minerals. As its principal unsaturated fatty acid, RJ contains 10-hydroxy-2-decenoic acid (10-HDA), which may have antitumor and antibacterial activity and a capacity to stimulate collagen production. RJ has attracted interest in various parts of the world for its pharmacological properties. However, the effects of RJ on ultraviolet (UV)-induced photoaging of the skin have not been reported. In this study we measured the 10-HDA content of RJ by high-performance liquid chromatography and tested the effects of RJ on UVB-induced skin photoaging in normal human dermal fibroblasts. The effects of RJ and 10-HDA on UVB-induced photoaging were tested by measuring procollagen type I, transforming growth factor (TGF)-β1, and matrix metalloproteinase (MMP)-1 after UVB irradiation. The RJ contained about 0.211% 10-HDA. The UVB-irradiated human skin fibroblasts treated with RJ and 10-HDA had increased procollagen type I and TGF-β1 productions, but the level of MMP-1 was not changed. Thus RJ may potentially protect the skin from UVB-induced photoaging by enhancing collagen production.

Royal Jelly Increases Collagen Production in Rat Skin After Ovariectomy

Royal jelly (RJ) is a honeybee product that contains proteins, carbohydrates, fats, free amino acids, vitamins, and minerals. RJ has been reported to have antitumor, antibacterial, and wound-healing activities. We previously reported that RJ enhanced the migration of human dermal fibroblasts and altered the levels of cholesterol and sphinganine in an in vitro wound-healing model in addition to regulating skin photoaging following exposure to ultraviolet-B radiation. We established an animal model of skin aging in the context of estrogen deficiency and assessed the antiaging effects of RJ on skin. To establish an in vivo model of skin aging, bilateral ovariectomies were performed in 12-week-old virgin female Sprague-Dawley rats. Induction of osteoporosis was confirmed through two-dimensional images of the trabecular bone in the left femoral necks using microcomputed tomography. The protective effects of RJ ovariectomy-induced skin aging were examined by determining the protein expression of type I procollagen and matrix metalloproteinase (MMP)-1. The collagen content and epidermal thickness of skin tissue were measured by staining techniques. There was a significant difference in weight between sham-operated and ovariectomized groups. Food efficiency ratio did not differ significantly among the groups. The level of procollagen type I protein was increased in the dorsal skin of ovariectomized rats fed with a dietary supplement containing 1% RJ extract, but the level of MMP-1 was not altered. In particular, the amount of collagen recovered was close to the normal level. RJ may protect against skin aging by enhancing collagen production in rats with ovariectomy-induced estrogen deficiency.

Stimulatory effect of dietary red ginseng on epidermal hydration and ceramide levels in ultraviolet-irradiated hairless mice.

Ultraviolet (UV) irradiation induces skin dryness, largely by disruption of the epidermal barrier. In a search for dietary and plant compounds that would protect against skin dryness, we investigated the dietary effect of red ginseng (the steamed root of Panax ginseng C.A. Meyer) on epidermal levels of hydration and ceramides, the most important lipids for maintaining the epidermal barrier, in UV-irradiated mice. Albino hairless mice were fed either control diets (group UV [UV-irradiated control]) or diets with 0.5% (group H0.5) or 1% (group H1.0) red ginseng extract for 5 weeks in parallel with UV irradiation. A normal control group (group C) was fed a control diet without UV irradiation for 5 weeks. Skin dryness in group UV, as assessed by epidermal levels of hydration and ceramides, was significantly lower than those in group C. With no differences in food intake and weight gains among groups, epidermal levels of hydration and ceramides in group H0.5 were similar to those in group C. In addition, protein expression of serine palmitoyltransferase (SPT), a key enzyme involved in de novo ceramide synthesis, was increased in group H0.5. However, epidermal levels of hydration and ceramides in group H1.0 did not differ from those in group UV, in which ceramidase, an enzyme involved in ceramide degradation, was highly expressed. In conclusion, we demonstrate that dietary supplementation of 0.5% red ginseng protects skin from UV-induced dryness with an accumulation of ceramides due to elevated expression of SPT protein.

Water extract of gromwell (Lithospermum erythrorhizon) enhances migration of human keratinocytes and dermal fibroblasts with increased lipid synthesis in an in vitro wound scratch model.

Background: Although organic extracts of gromwell (Lithospermum erythrorhizon) have been shown to promote wound healing, the wound healing effects of water extracts of gromwell (WG) that are commonly used in traditional remedies have not been elucidated. Objective: We investigated whether WG promotes the migration and/or proliferation of cultured human keratinocytes (CHK) or dermal fibroblasts in parallel with increases in lipid synthesis during in vitro wound healing. Methods: CHK or fibroblasts were treated with 1–1,000 µg/ml WG for up to 48 h following scratch wound formation. Cell migration was assessed by measuring coverage (in percent) from the wound margin, while cell proliferation and lipid synthesis were determined by [3H]thymidine incorporation into DNA fractions, and [3H]palmitate or [3H]serine incorporation into lipid fractions, respectively. Results: Low-dose WG (1 µg/ml) enhanced the wound coverage for both CHK and fibroblasts at 24 h, while cell proliferation was not altered in either cell types. Synthesis of both total lipids and individual lipid classes, including phospholipids, sphingolipids and neutral lipids, were found to be increased at 24 h in CHK treated with 1 µg/ml WG; in similarly treated fibroblasts, only the syntheses of sphingolipids (such as ceramides and glucosylceramides), but not other lipid species, were significantly increased. In contrast, a higher dose of WG (10–1,000 µg/ml) did not enhance wound coverage, and 100 µg/ml WG neither altered cell proliferation nor lipid synthesis in both CHK and fibroblasts. Conclusion: Low-dose WG (1 µg/ml) enhances the migration of both CHK and fibroblasts with increased lipid synthesis in an in vitro wound scratch model.

Increased OPG/RANKL ratio in the conditioned medium of soybean-treated osteoblasts suppresses RANKL-induced osteoclast differentiation

Soybean is a major dietary source of isoflavones, particularly daidzein and genistein, which stimulate osteoblastic functions that are initiated by binding to estrogen receptor (ER)-α and ER-β found on osteoblasts. However, coupled with a low expression of ER-α and ER-β in osteoclasts, the inhibitory effects of soy isoflavones on osteoclast differentiation is likely mediated through paracrine factors produced by osteoblasts. Therefore, in this study, we investigated whether soybean can indirectly inhibit osteoclast differentiation through the modulation of osteoclastic factors produced by osteoblasts. Treatment with soybean extracts increased the levels of osteoprotegerin (OPG) and decreased those of receptor activator of nuclear factor-κB ligand (RANKL) in the conditioned medium (CM) of MC3T3-E1 osteoblasts. Subsequently, the RANKL-induced RAW264.7 osteoclast formation was markedly inhibited by treatment with CM collected from MC3T3-E1 osteoblasts incubated with soybean extracts (S-CM). Similarly, S-CM significantly attenuated the RANKL-induced increase in the mRNA and protein levels of matrix metalloproteinase-9 (MMP-9), a potential biomarker gene of osteoclast differentiation, through the suppression of nuclear factor of activated T cells c1 (NFATc1) activation. Of note, a soybean concentration of 0.001 mg/ml further increased the OPG/RANKL ratio compared to treatment with a 0.1 mg/ml soybean concentration and was overall, more effective at inhibiting RANKL-induced osteoclast formation and MMP-9 expression. Taken together, our data demonstrate that treatment with soybean extracts stimulates the secretion of OPG and inhibits that of RANKL, thus inhibiting RANKL-induced osteoclast differentiation through the suppression of NFATc1 activation.

Effect of Ascorbic Acid, Silicon, Fe, Proline and Lysine on Proliferation and Collagen Synthesis in the Human Dermal Fibroblast Cell (HS27)

Dept. of Medical Nutrition, Graduate School of East-West Medical Science, Kyung Hee University, Gyeonggi 446-701, KoreaAbstractIn the dermis, fibroblast plays an important role in the turnover of the dermal extracellular matrix. Collagen Ⅰ and Ⅲ, which are the most important dermal proteins of the extracellular matrix, function as a stabilizing scaffold of dermal connective tissues, as well as a regulator of differentiation and migration of dermal cells. In this study, we investigated the effect of various nutrients, such as ascorbic acid, silicon, Fe, lysine and proline which function as cofactors or building blocks on collagen synthesis. When the physiological concentrations of ascorbic acid (0~100 μM), silicon (0~50 μM), Fe (0~50 μM), lysine (0~150 μM) and proline (0~300 μM) were treated at HS27 for either 3 or 5 days, 5 day treatment of ascorbic acid at the low concentration (5~10 μM) increased the expression of collagen Ⅰ and Ⅲ protein by 115~1300% without increasing cell proliferation. 3 or 5 days treatment of Fe increased the expression of collagen Ⅰ and Ⅲ proteins up to 323% in parallel with cell proliferation by 164%. However, cell proliferation and expression of collagen Ⅰ and Ⅲ protein in silicon treated HS27 did not differ. Proline and lysine only increased cell proliferation up to 247.9%. Taken together, we demonstrate that the physiological concentrations of ascorbic acid and Fe enhance the expression of collagen Ⅰ and Ⅲ protein for treatment of 3 or 5 days.Key words: human dermal fibroblast, collagen, ascorbic acid, silicon, Fe