Risk single-nucleotide polymorphism-mediated enhancer-promoter interaction drives keloids through long noncoding RNA down expressed in keloids.

BACKGROUND: Keloids represent one extreme of aberrant dermal wound healing and are characterized by fibroblast hyperproliferation and excessive deposition of extracellular matrix. Genetics is a major factor for predisposition to keloids and genome-wide association study has identified a single-nucleotide polymorphism (SNP) rs873549 at 1q41 as a susceptibility locus. The SNP rs873549, and the SNPs in strong linkage disequilibrium (LD) with rs873549, may be involved in keloid development. However, the functional significance of these SNPs in keloid pathogenesis remains elusive. OBJECTIVES: To investigate the function and mechanism of SNP rs873549 and the SNPs in strong LD with rs873549 in keloids. METHODS: SNPs in strong LD with rs873549 were analysed using Haploview. The expression levels of the genes near the susceptibility locus were analysed using quantitative real-time polymerase chain reaction. The interaction between rs1348270-containing enhancer and the long noncoding RNA down expressed in keloids (DEIK) (formerly RP11-400N13.1) promoter in fibroblasts was investigated using chromosome conformation capture. The enhancer activity of the rs1348270 locus was evaluated using luciferase reporter assay. Knockdown experiments were used to explore the function of DEIK in keloids. RNA-Seq was performed to investigate the mechanism by which DEIK regulates the expression of collagens POSTN and COMP. RESULTS: rs1348270, an enhancer-located SNP in strong LD with rs873549, mediated looping with the promoter of DEIK. The risk variant was associated with decreased enhancer-promoter interaction and DEIK down-expression in keloids. Mechanistically, downregulation of DEIK increased the expression of collagens POSTN and COMP through upregulating BMP2. Furthermore, correlation analysis revealed that DEIK expression was inversely correlated with BMP2, POSTN and COMP expression in both keloid and normal fibroblasts. CONCLUSIONS: Our findings suggest that the risk variant rs1348270 is located in an enhancer and is associated with the downregulation of DEIK in keloids, and that downregulation of DEIK increases the expression of collagens POSTN and COMP through BMP2 in keloid fibroblasts. These findings will help to provide a more thorough understanding of the role played by genetic factors in keloid development and may lead to new strategies for screening and therapy in keloid-susceptible populations.

TSP1 promotes fibroblast proliferation and extracellular matrix deposition via the IL6/JAK2/STAT3 signalling pathway in keloids.

Keloids are benign fibroproliferative diseases with abnormally proliferated bulges beyond the edge of the skin lesions, and they are characterized by uncontrolled fibroblast proliferation and excessive extracellular matrix deposition in the dermis. However, the definite mechanisms that increase fibroblast proliferation and collagen deposition in keloids remain unclear. Thrombospondin 1 (TSP1) has been suggested to play an important role in wound healing and fibrotic disorders, but its role in keloids is unknown. In this study, we aimed to clarify the specific role of TSP1 in keloids and explore the potential mechanism. Our results demonstrated that TSP1 was highly expressed in keloid lesions compared to normal skin. Knockdown of TSP1 in keloid fibroblasts decreased cell proliferation and collagen I deposition. Exogenous TSP1 treatment increased cell proliferation and collagen I deposition in normal fibroblasts. We further investigated the underlying mechanism and found that TSP1 promoted fibroblast proliferation and extracellular matrix deposition by upregulating the IL6/JAK2/STAT3 pathway. Moreover, we verified that TSP1 expression was positively correlated with IL6/STAT3 signalling activity in keloids. Taken together, our findings indicate that TSP1 promotes keloid development via the IL6/JAK2/STAT3 signalling pathway and blocking TSP1 may represent a potential strategy for keloid therapy.

Synthesis of cubic Ia-3d mesoporous silica in anionic surfactant templating system with the aid of acetate.

Mesoporous silica with three-dimensional (3D) bicontinuous cubic Ia-3d structure and fascinating caterpillar-like morphology was synthesized by using anionic surfactant N-lauroylsarcosine sodium (Sar-Na) as the template and 3-amionpropyltrimethoxysilane (APS) as the co-structure-directing agent (CSDA) with the aid of acetate. A phase transformation from high interfacial curvature 2D hexagonal to low interfacial curvature 3D cubic Ia-3d occurred in the presence of a proper amount of acetate. Other species of salts (excluding acetate) had the ability to induce the caterpillar-like morphology, but failed to induce the cubic Ia-3d mesostructure. Furthermore, [3-(2-aminoethyl)-aminopropyl]trimethoxysilane (DAPS) was also used as the CSDA to synthesize Ia-3d mesostructured silica under the aid of sodium acetate. After extraction of the anionic surfactants, amino and di-amine functionalized 3D bicontinuous cubic Ia-3d mesoporous silicas were obtained and used as supports to immobilize Pd nanoparticles for supported catalysts. The catalytic activity of the catalysts was tested by catalytic hydrogenation of allyl alcohol.

Glycyrrhizinate reduces portal hypertension in isolated perfused rat livers with chronic hepatitis.

AIM: To investigate the effects of diammonium glycyrrhizinate (Gly) on portal hypertension (PHT) in isolated portal perfused rat liver (IPPRL) with carbon tetrachloride (CCl4)-induced chronic hepatitis. METHODS: PHT model was replicated with CCl4 in rats for 84 d. Model was identified by measuring the ascetic amounts, hepatic function, portal pressure in vivo, splenic index, and pathological alterations. Inducible nitric oxide synthase (iNOS) in liver was assessed by immunohistochemistry. IPPRLs were performed at d0, d28, d56, and d84. After phenylephrine-induced constriction, Gly was geometrically used to reduce PHT. Gly action was expressed as median effective concentration (EC50) and area under the curve (AUC). Underlying mechanism was exploited by linear correlation between AUC values of Gly and existed iNOS in portal triads. RESULTS: PHT model was confirmed with ascites, splenomegaly, serum biomarkers of hepatic injury, and elevated portal pressure. Pathological findings had shown normal hepatic structure at d0, degenerations at d28, fibrosis at d56, cirrhosis at d84 in PHT rats. Pseudo lobule ratios decreased and collagen ratios increased progressively along with PHT development. Gly does dose-dependently reduce PHT in IPPRLs with CCl4-induced chronic hepatitis. Gly potencies were increased gradually along with PHT development, characterized with its EC50 at 2.80 × 10⁻¹°, 3.03 × 10⁻¹¹, 3.77 × 10⁻¹¹ and 4.65×10⁻¹¹ mol/L at d0, d28, d56 and d84, respectively. Existed iNOS was located at hepatocyte at d0, stellate cells at d28, stellate cells and macrophages at d56, and macrophages in portal triads at d84. Macrophages infiltrated more into portal triads and expressed more iNOS along with PHT development. AUC values of Gly were positively correlated with existed iNOS levels in portal triads. CONCLUSION: Gly reduces indirectly PHT in IPPRL with CCl4-induced chronic hepatitis. The underlying mechanisms may relate to rescue NO bioavailability from macrophage-derived peroxynitrite in portal triads.

A pharmacodynamic model of portal hypertension in isolated perfused rat liver.

AIM: To develop a pharmacodynamic model of portal hypertension from chronic hepatitis. METHODS: Pathological changes and collagen depositions were analyzed using morphometry to confirm CCl4-induced chronic hepatitis. At d0, d28, d56 and d84 of the process, the portal perfused velocities (µL/min) in isolated rat livers were exactly controlled with a quantified pump. The pressure (mmHg) was monitored with a Physiological System. The geometric concentrations of phenylephrine or acetylcholine were added to a fixed volume (300 mL) of the circulating perfusate. The equation, the median effective concentration and its 95% confidence intervals of phenylephrine or acetylcholine were regressed with Prism-4 software in non-linear fit and various slopes. In the isolated perfused rat livers with chronic hepatitis, both median effective concentrations were defined as the pharmacodynamic model of portal hypertension. RESULTS: At d0, d28, d56 and d84, the equations of portal pressure potency from the concentrations of phenylephrine used to constrict the portal vein in isolated perfused rat livers were Y = 0.1732 + 0.3970/[1 + 10((-4.3061-0.4407 X))], Y = -0.004934 + 0.12113/[1 + 10((-3.1247-0.3262 X))], Y = 0.0104 + 0.2643/[1 + 10((-8.8462-0.9579 X))], and Y = 0.01603 + 0.12107/[1 + 10((-5.1134-0.563 X))]; the median effective concentrations were 1.69 × 10⁻¹° mol/L, 2.64 × 10⁻¹° mol/L, 5.82 × 10⁻¹° mol/L, and 8.24 × 10⁻¹° mol/L, respectively. The equations from the concentrations of acetylcholine used to relax the portal vein were Y = -0.4548 + 0.3274/[1 + 10((6.1538 + 0.5554 X))], Y = -0.05391 + 0.06424/[1 + 10((3.8541 + 0.3469 X))], Y = -0.2733 + 0.22978/[1 + 10((3.0472 + 0.3008 X))], and Y = -0.0559 + 0.053178/[1 + 10((5.6336 + 0.5883 X))]; the median effective concentrations were 8.40 × 10⁻¹° mol/L, 7.73 × 10⁻¹² mol/L, 5.98 × 10⁻¹¹ mol/L, and 2.66 × 10⁻¹° mol/L, respectively. CONCLUSION: A pharmacodynamic model of portal hypertension in isolated perfused rat livers with chronic hepatitis was defined as the median effective concentrations of phenylephrine and acetylcholine.