No abstract

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.

Rapid bone destruction often leads to permanent joint dysfunction in patients with septic arthritis, which is mainly caused by Staphylococcus aureus ( S . aureus ). Staphylococcal cell wall components are known to induce joint inflammation and bone destruction. Here, we show that a single intra-articular injection of S . aureus lipoproteins (Lpps) into mouse knee joints induced chronic destructive macroscopic arthritis through TLR2. Arthritis was characterized by rapid infiltration of neutrophils and monocytes. The arthritogenic effect was mediated mainly by macrophages/monocytes and partially via TNF-α but not by neutrophils. Surprisingly, a S . aureus mutant lacking Lpp diacylglyceryl transferase ( lgt ) caused more severe joint inflammation, which coincided with higher bacterial loads of the lgt mutant in local joints than those of its parental strain. Coinjection of pathogenic S . aureus LS-1 with staphylococcal Lpps into mouse knee joints caused improved bacterial elimination and diminished bone erosion. The protective effect of the Lpps was mediated by their lipid moiety and was fully dependent on TLR2 and neutrophils. The blocking of CXCR2 on neutrophils resulted in total abrogation of the protective effect of the Lpps. Our data demonstrate that S . aureus Lpps elicit innate immune responses, resulting in a double-edged effect. On the one hand, staphylococcal Lpps boost septic arthritis. On the other hand, Lpps act as adjuvants and activate innate immunity, which could be useful for combating infections with multiple drug-resistant strains.

In-silico bitterant prediction received the considerable attention due to the expensive and laborious experimental-screening of the bitterant. In this work, we collect the fully experimental dataset containing 707 bitterants and 592 non-bitterants, which is distinct from the fully or partially hypothetical non-bitterant dataset used in the previous works. Based on this experimental dataset, we harness the consensus votes from the multiple machine-learning methods (e.g., deep learning etc.) combined with the molecular fingerprint to build the bitter/bitterless classification models with five-fold cross-validation, which are further inspected by the Y-randomization test and applicability domain analysis. One of the best consensus models affords the accuracy, precision, specificity, sensitivity, F1-score, and Matthews correlation coefficient (MCC) of 0.929, 0.918, 0.898, 0.954, 0.936, and 0.856 respectively on our test set. For the automatic prediction of bitterant, a graphic program “e-Bitter” is developed for the convenience of users via the simple mouse click. To our best knowledge, it is for the first time to adopt the consensus model for the bitterant prediction and develop the first free stand-alone software for the experimental food scientist.

Melatonin has been shown to alleviate the effects of abiotic stress and to regulate plant development. Copper, a common heavy metal and soil pollutant, can suppress plant growth and development. In this work, we explored the protective effects of exogenous melatonin on lateral root formation in response to copper stress using melon seeds subjected to three germination treatments: CK1 (control), CK2 (300 μmol/L CuSO 4), and MT3 (300 μmol/L melatonin + 300 μmol/L CuSO 4). Melatonin pretreatment increased the antioxidant enzyme activities and root vigor, and decreased the proline and malondialdehyde (MDA) contents in the roots of copper-stressed melon seedlings. We then used transcriptomic and metabolomic analyses to explore the mechanisms by which exogenous melatonin protects against copper stress. There were 70 significant differentially expressed genes (DEGs) (28 upregulated, 42 downregulated) and 318 significantly differentially expressed metabolites (DEMs) (168 upregulated, 150 downregulated) between the MT3 and CK2 treatments. Melatonin pretreatment altered the expression of genes related to redox and cell wall formation processes. In addition, we found that members of the AP2/ERF, BBR/BPC, GRAS, and HD-ZIP transcription factor families may have vital roles in lateral root development. Melatonin also increased the level of Glutathione (GSH), which chelates excess Cu 2+. The combined transcriptomic and metabolomic analysis revealed DEGs and DEMs involved in jasmonic acid (JA) biosynthesis, including four lipoxygenase-related genes and two metabolites (linoleic acid and lecithin) related to melatonin's alleviation effect on copper toxicity. This research elucidated the molecular mechanisms of melatonin's protective effects in copper-stressed melon.

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.

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.