The Alleviating Effect of Lagerstroemia indica Flower Extract on Stretch Marks through Regulation of Mast Cells.

Striae distensae (SD) or stretch marks are common linear scars of atrophic skin with disintegrating extracellular matrix (ECM) structures. Although fibroblasts contribute to the construction of ECM structure in SD, some studies have reported that mast cell degranulation causes the disruption of ECM in early SD lesions. Lagerstroemia indica flower (LIF) has traditionally been used in India as a diuretic. However, little is known about the effect and molecular action of Lagerstroemia indica flower extract (LIFE) on alleviating SD. This study evaluated the effects of LIFE on mast cell degranulation and the synthesis of ECM components in fibroblasts. LIFE inhibits the adhesion of rat basophilic leukemia (RBL) cells, RBL-2H3 on fibronectin (FN) and the expression of integrin, a receptor for FN, thereby reducing focal adhesion kinase (FAK) phosphorylation. In addition, LIFE attenuated the allergen-induced granules and cytokine interleukin 3 (IL-3) through the adhesion with FN. Moreover, the conditioned medium (CM) of activated mast cells decreases the synthesis of ECM components, and LIFE restores the abnormal expressions induced by activated mast cells. These results demonstrate that LIFE suppresses FN-induced mast cell activation and promotes the synthesis of ECM components in fibroblast, which indicates that LIFE may be a useful cosmetic agent for SD treatment.

Integrinß6-targeted immunoliposomes mediate tumor-specific drug delivery and enhance therapeutic efficacy in colon carcinoma.

PURPOSE: Adjuvant chemotherapy is one of the significant treatments for colon cancer in clinic. However, it does not achieve the desired therapeutic efficacy, largely due to chemotherapeutic resistance. Integrinß6 (ITGB6) is expressed in malignant colonic epithelia, but not in normal epithelia, and is associated with the progression, metastasis, and chemotherapeutic resistance of colon cancer. Accordingly, it is necessary to design therapeutic approaches for efficient and targeted drug delivery into ITGB6-positive cancer cells to improve chemotherapeutic efficacy in colon cancer. EXPERIMENTAL DESIGN: PEGylated liposomes were employed to design ITGB6-targeted immunoliposomes, which have ITGB6 monoclonal antibodies (mAbs) conjugated. We evaluated the ITGB6-targeted immunoliposomes internalization into colon cancer cells and examined 5-fluorouracil (5-FU)-induced cellular apoptosis produced by ITGB6-targeted immunoliposomes+5-FU. In addition, the biodistribution and antitumor efficiency of ITGB6-targeted immunoliposomes were observed in vivo. RESULTS: ITGB6-targeted immunoliposomes enhanced cellular internalization in ITGB6-positive colon cancer cells compared with liposomes. Furthermore, the ITGB6-targeted immunoliposome internalization was dependent on the ITGB6 expression level on cellular surface. ITGB6-targeted immunoliposomes decreased the 5-FU IC50 more than 90% in HT-29 and SW480ß6 cells relative to liposomes. Moreover, when loaded with 5-FU, ITGB6-targeted immunoliposomes produced an approximately 1.5-fold higher 5-FU-induced cellular apoptosis rate than liposomes. In vivo, the therapeutic activity of ITGB6-targeted immunoliposomes+5-FU was significantly superior, resulting in 25% to 35% reduction of tumor weight compared with 5-FU or liposomes+5-FU. CONCLUSIONS: ITGB6-targeted immunoliposomes provide a highly efficient approach for targeted drug delivery in colon cancer and thus offer the potential of a novel and promising anticancer strategy for clinical therapy.

In vitro induction of mucosa-type dendritic cells by all-trans retinoic acid.

Efficient induction of mucosal immunity usually employs nasal or oral vaccination while parenteral immunization generally is ineffective at generating mucosal immune responses. This relates to the unique ability of resident mucosal dendritic cells (DC) to induce IgA switching and to imprint mucosa-specific homing receptors on lymphocytes. Based on the well-established plasticity of the DC system, this study sought to investigate whether peripheral DC could be modulated toward "mucosa-type" DC by treatment with immunomodulatory, and therefore potentially adjuvant-like, factors. In this study, we show that monocyte-derived DCs pretreated with the vitamin A derivative all-trans retinoic acid (RA) indeed acquired several attributes characteristic of mucosal DC: secretion of TGF-beta and IL-6 and the capacity to augment mucosal homing receptor expression and IgA responses in cocultured lymphocytes. Addition of a TGF-beta-neutralizing Ab to cocultures significantly inhibited alpha4beta7 integrin, but not CCR9 mRNA expression by the lymphocytes. Both alpha4beta7 integrin and CCR9 mRNA expression, but not IgA production, were suppressed in the presence of a RA receptor antagonist. None of the observed effects on the lymphocytes were influenced by citral, a retinal dehydrogenase inhibitor, arguing against a role for de novo-synthesized RA. Collectively, our findings identified a novel role for RA as a mucosal immune modulator targeting DC. Our results further demonstrate that DC can act as efficient carriers of RA at least in vitro. Consequently, RA targeting of DC shows potential for promoting vaccine-induced mucosal immune responses via a parenteral route of immunization.

Cloning and characterization of osteoclast precursors from the RAW264.7 cell line.

Osteoclasts are bone-resorbing cells that differentiate from macrophage precursors in response to receptor activator of NF-kappaB ligand (RANKL). In vitro models of osteoclast differentiation are principally based on primary cell cultures, which are poorly suited to molecular and transgene studies because of the limitations associated with the use of primary macrophage. RAW264.7 is a transfectable macrophage cell line with the capacity to form osteoclast-like cells. In the present study, we have identified osteoclast precursors among clones of RAW264.7 cells. RAW264.7 cell were cloned by limiting dilution and induced to osteoclast differentiation by treatment with recombinant RANKL. Individual RAW264.7 cell clones formed tartrate resistant acid phosphatase (TRAP)-positive multinuclear cells to various degrees with RANKL treatment. All clones tested expressed the RANKL receptor RANK. Each of the clones expressed the osteoclast marker genes TRAP and cathepsin-K mRNA with RANKL treatment. However, we noted that only select clones were able to form large, well-spread, TRAP-positive multinuclear cells. Clones capable of forming large TRAP-positive multinuclear cells also expressed beta3 integrin and calcitonin receptor mRNAs and were capable of resorbing a mineralized matrix. All clones tested activated NF-kappaB with RANKL treatment. cDNA expression profiling of osteoclast precursor RAW264.7 cell clones demonstrates appropriate expression of a large number of genes before and after osteoclastic differentiation. These osteoclast precursor RAW264.7 cell clones provide a valuable model for dissecting the cellular and molecular regulation of osteoclast differentiation and activation.

Induction of alpha-catenin, integrin alpha3, integrin beta6, and PDGF-B by 2,8-dihydroxyadenine crystals in cultured kidney epithelial cells.

BACKGROUND: Homozygous adenine phosphoribosyltransferase (APRT) deficiency is associated with 2,8-dihydroxyadenine (DHA) nephrolithiasis. Using whole kidney RNA from Aprt knockout mice, we previously showed that the renal deposition of DHA leads to changes in the expression of genes involved in tissue injury. To determine the cellular basis for these changes, we investigated gene expression in cultured human kidney (NHK-C) and African green monkey (BSC-1) epithelial cells exposed to DHA or calcium oxalate monohydrate (COM) crystals. METHODS: First-strand cDNAs, synthesized from mRNA isolated from treated and untreated cells, were hybridized to membrane-bound cDNA arrays containing 588 genes associated with various physiological and pathological processes. Changes in gene expression were confirmed by reverse transcription PCR. RESULTS: Twenty-seven percent of the array cDNAs were expressed in untreated NHK-C cells at varying levels relative to a housekeeping gene. The expression of three adhesion molecules (alpha-catenin, integrin alpha3, and integrin beta6) and platelet-derived growth factor B (PDGF-B) was elevated following exposure of NHK-C cells to DHA. Increased expression of the adhesion molecules was also observed in BSC-1 cells, but PDGF-B expression could not be detected. COM crystals also stimulated the expression of these four genes in NHK-C cells, but the expression profile was quantitatively different compared with DHA. CONCLUSIONS: These findings suggest that DHA crystals stimulate the expression of specific genes in kidney epithelial cells and that the pathways for DHA-induced cell injury may be similar to those for COM crystals. The induction of adhesion molecules and PDGF-B may affect cell-cell or cell-matrix interactions and/or alter the actin cytoskeleton. These alterations may ultimately contribute to crystal-induced renal injury.