The scaffold protein CARD9 plays an essential role in antifungus immunity and is implicated in mediating Dectin-1/Sykinduced NF-B activation in response to Candida albicans infection. However, the molecular mechanism by which CARD9 mediates C. albicans-induced NF-B activation is not fully characterized. Here we demonstrate that CARD9 is involved in mediating NF-B activation induced by the hyphal form of C. albicans hyphae (Hyphae) but not by its heat-inactivated unicellular form. Our data show that inhibiting Dectin-2 expression selectively blocked Hyphae-induced NF-B, whereas inhibiting Dectin-1 mainly suppressed zymosan-induced NF-B, indicating that Hyphae-induced NF-B activation is mainly through Dectin-2 and not Dectin-1. Consistently, we find that the hyphae stimulation induces CARD9 association with Bcl10, an adaptor protein that functions downstream of CARD9 and is also involved in C. albicans-induced NF-B activation. This association is dependent on Dectin-2 but not Dectin-1 following the hyphae stimulation. Finally, we find that although both CARD9 and Syk are required for Hyphae-induced NF-B activation, they regulate different signaling events in which CARD9 mediates IB␣ kinase ubiquitination, whereas Syk regulates IB␣ kinase phosphorylation. Together, our data demonstrated that CARD9 is selectively involved in Dectin-2-induced NF-B activation in response to C. albicans hyphae challenging.Candida albicans is a major opportunistic fungal pathogen that predominantly causes infection to cancer patients and immunocompromised individuals. During C. albicans infection, macrophages and dendritic cells recognize components from the fungal cell wall through their pattern recognition receptors (1, 2), which triggers a series of signaling cascades leading to activation of various transcription factors including NF-B (1). The activation of NF-B and other transcription factors further induce the expression of various cytokines and chemokines and inflammatory responses. However, the pattern recognition receptors that recognize fungal cell wall components are not fully defined (3).NF-B is a family of transcription factors that control the expression of pro-inflammatory genes in immune cells (4). In resting cells, the activity of NF-B is tightly controlled by the IB family of proteins, which bind to NF-B dimers and keep these dimers in the cytoplasm. The canonical NF-B activation pathway by most of NF-B-inducing stimuli activates the IB␣ kinase (IKK) 2 complex. The IKK complex is controlled by signal-induced phosphorylation of IKK␣ and IKK␤ subunits (5) and signal-induced K63-linked ubiquitination of the regulatory subunit NEMO (6). The activated IKK complex in turn phosphorylates IB␣ proteins on N-terminal conserved serine residues to target them for ubiquitination-dependent degradation (5). This process releases NF-B and allows its translocation into the nucleus for the activation of its target genes (4). Although it has been shown that bacterial and viral infections induce IKK activation by Toll-like receptors (TLR...

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Asiaticoside (ATS) isolated from the leaves of Centella asiatica possesses strong wound-healing properties and reduces scar formation. However, the specific effects of asiaticoside on the formation of keloidal scars remain unknown. In the present study, we evaluated the in vitro effects of asiaticoside on the proliferation, collagen expression, and transforming growth factor (TGF)-β/Smad signaling of keloid-derived fibroblasts. Fibroblasts isolated from keloid tissue and normal skin tissues were treated with asiaticoside at different concentrations. Afterwards, they were subjected to RT-PCR and Western blot analyses. The inhibitory effects of asiaticoside on fibroblast viability were assayed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Asiaticoside decreased fibroblast proliferation in a time- and dose-dependent manner. It also inhibited type I and type III collagen protein and mRNA expressions. In addition, asiaticoside reduced the expression of both TGF-βRI and TGF-βRII at the transcriptional and translational level. Moreover, it increased the expression of Smad7 protein and mRNA. However, asiaticoside did not influence the expression of Smad2, Smad3, Smad4, phosphorylated Smad2, and phosphorylated Smad3. Taken together, these results suggest that asiaticoside could be of potential use in the treatment and/or prevention of hypertrophic scars and keloids.

Background: Treatment of chronic wounds using traditional surgical procedures is challenging because of the low graft take rates. This study investigated the combination approach of split-thickness autografts with harvested skin cell suspension for chronic wound treatment. Click here to watch video footage recorded by the author about the contents of this paper.

Therapeutic, II.

BackgroundBasic fibroblast growth factor (bFGF) plays an important role in promoting wound healing and reducing scar, but the possible molecular mechanisms are still unclear. Our previous studies have found that activating the Notch1/Jagged1 pathway can inhibit the differentiation of epidermal stem cells (ESCs) to myofibroblasts (MFB). Herein, we document that bFGF reduces scar by inhibiting the differentiation of ESCs to MFB via activating the Notch1/Jagged1 pathway.MethodsIn in-vitro study, ESCs were isolated from 10 neonatal SD rats (1–3 days old), cultured in keratinocyte serum-free medium, and divided into six groups: bFGF group, bFGF + SU5402 group, bFGF + DAPT group, siJagged1 group, bFGF + siJagged1 group, and control group. Jagged1 of the ESCs in the siJagged1 group and bFGF + siJagged1 group was knocked down by small-interfering RNA transfection. Expression of ESC markers (CK15/CK10), MFB markers (α-SMA, Collagen I, Collagen III), and Notch1/Jagged1 components (Jagged1, Notch1, Hes1) was detected by FCM, qRT-PCR, and western blot analysis to study the relationships of bFGF, ESCs, and Notch1/Jagged1 pathway. In in-vivo study, the wound healing time and scar hyperplasia were observed on rabbit ear scar models. The quality of wound healing was estimated by hematoxylin and eosin staining and Masson staining. Expression of ESC markers, MFB markers and Notch1/Jagged1 components was elucidated by immunohistochemistry, immunofluorescence, and western blot analysis.ResultsThe in-vitro study showed that bFGF could significantly upregulate the expression of ESC markers and Notch1/Jagged1 components, while downregulating the expression of MFB markers at the same time. However, these effects could be obviously decreased when we knocked down Jagged1 or added DAPT. Similarly, in in-vivo study, bFGF also exhibited its functions in inhibiting the differentiation of rabbit ESCs to MFB by activating the Notch1/Jagged1 pathway, which improved the wound healing quality and alleviated scar significantly.ConclusionThese results provide evidence that bFGF can reduce scar by inhibiting the differentiation of ESCs to MFB via the Notch1/Jagged1 pathway, and present a new promising potential direction for the treatment of scar.

Transforming growth factor-β (TGF-β)/Smad signaling plays a key role in excessive fibrosis and keloid formations. Smad7 is a negative feedback regulator that prevents activation of TGF-β/Smad signaling. However, the regulatory mechanism for Smad7 in the keloid pathogenic process remains elusive. Here, we show that expression of TIEG1 is markedly higher in keloid fibroblasts, whereas protein, mRNA, and promoter activity levels of Smad7 are decreased. When TIEG1 was knocked down with small interfering RNA, both the promoter activity and protein expression of Smad7 were increased, whereas collagen production and the proliferation, migration, and invasion of keloid fibroblasts were decreased. In contrast, TIEG1 overexpression led to a decrease in Smad7 expression and Smad7 promoter activity. Upon TGF-β1 stimulation, TIEG1 promoted Smad2 phosphorylation by down-regulating Smad7. Luciferase reporter assays and chromatin immunoprecipitation assays further showed that TIEG1 can directly bind a GC-box/Sp1 site located between nucleotides -1392 and -1382 in the Smad7 promoter to repress Smad7 promoter activity. Taken together, these findings show that TIEG1 is highly expressed in human keloids and that it directly binds and represses Smad7 promoter-mediated activation of TGF-β/Smad2 signaling, thus providing clues for development of TIEG1 blocking strategies for therapy or prophylaxis of keloids.

A consensus meeting of leading Asian hypertension experts was held in January 2007 in Seoul, Korea, to discuss how to address the growing challenge of hypertension management in the region. This report summarises key recommendations from the group, including: raising public awareness about the impact of hypertension; improving physician education and training; increasing early detection, for example through routine blood pressure measurement; and development and adoption of pan-Asian treatment guidelines, which would greatly facilitate research into hypertension and its management. The group conclude that these challenges can only be met through a collaborative effort of government, healthcare professionals, food and healthcare industries, and patients and the public. Food and healthcare industries need to develop healthy foods and support healthy living programmes, while increasing research into antihypertensive medications in Asia. Government officials and policy makers need to be made aware of the value of investing in hypertension awareness, prevention and management programmes.