Transcriptional activation of p21 by Tranilast is mediated via transforming growth factor beta signal pathway

Preventive Effect of Synthetic Tryptophan Metabolite on Silicone Breast Implant-Induced Capsule Formation

BACKGROUND

In the field of plastic surgery, capsular contracture after silicone breast implant surgery is a major clinical problem. This experimental study confirms that the synthetic tryptophan metabolite N-(3',4'-dimethoxycinnamonyl) anthranilic acid (Tranilast) reduces capsule formation and prevents capsular contracture.

METHODS

Eighteen New Zealand white rabbits were divided into 2 groups. In the experimental group, implants were inserted into each rabbit, and oral synthetic tryptophan metabolite was administered daily at a dose of 5 mg/kg in 10 mL of saline. In the control group, rabbits received implants and the same amount of saline without the metabolite. After 2 months, peri-implant tissues were harvested and analyzed.

RESULTS

The thickness of the capsules and the inflammatory cell counts were decreased in the experimental group (P < 0.001). The collagen fibers in the experimental group were thinner, less dense, and more organized than in control group. The results of reverse transcription quantitative polymerase chain reaction analysis showed that the genes for transforming growth factor β1 (P = 0.002), alpha smooth muscle actin (P < 0.001), and collagen types I (P = 0.002) and III (P = 0.004) were underexpressed in the experimental groups. Furthermore, the counts of T-cell immunity-related cytokine presenting cells were decreased in the experimental groups (CD3, 4, 25, 45RA, 45RO, 69, interleukin-2, 4 [P < 0.001], and interferon γ [P = 0.028]).

CONCLUSIONS

This study confirms that a synthetic derivative of a tryptophan metabolite decreases capsule formation and prevents capsular contracture by inhibiting the differentiation of fibroblasts to myofibroblasts, selectively inhibiting collagen synthesis, and decreasing specific T-cell immune responses by changing anti-inflammatory cytokine expression.

Cardiac Fibrotic Remodeling on a Chip with Dynamic Mechanical Stimulation

Cardiac tissue is characterized by being dynamic and contractile, imparting the important role of biomechanical cues in the regulation of normal physiological activity or pathological remodeling. However, the dynamic mechanical tension ability also varies due to extracellular matrix remodeling in fibrosis, accompanied with the phenotypic transition from cardiac fibroblasts (CFs) to myofibroblasts. It is hypothesized that the dynamic mechanical tension ability regulates cardiac phenotypic transition within fibrosis in a strain-mediated manner. In this study, a microdevice that is able to simultaneously and accurately mimic the biomechanical properties of the cardiac physiological and pathological microenvironment is developed. The microdevice can apply cyclic compressions with gradient magnitudes (5-20%) and tunable frequency onto gelatin methacryloyl (GelMA) hydrogels laden with CFs, and also enables the integration of cytokines. The strain-response correlations between mechanical compression and CFs spreading, and proliferation and fibrotic phenotype remolding, are investigated. Results reveal that mechanical compression plays a crucial role in the CFs phenotypic transition, depending on the strain of mechanical load and myofibroblast maturity of CFs encapsulated in GelMA hydrogels. The results provide evidence regarding the strain-response correlation of mechanical stimulation in CFs phenotypic remodeling, which can be used to develop new preventive or therapeutic strategies for cardiac fibrosis.

Avenanthramides are bioavailable and have antioxidant activity in humans after acute consumption of an enriched mixture from oats

The consumption of polyphenols is associated with a decreased risk of cardiovascular disease. Avenanthramides (AV), alkaloids occurring only in oats, may have anti-atherosclerotic activity, but there is no information concerning their bioavailability and bioactivity in humans. We characterized the pharmacokinetics and antioxidant action of avenanthramide A, B, and C in healthy older adults in a randomized, placebo-controlled, 3-way crossover trial with 1-wk washout periods. Six free-living subjects (3 mol/L, 3 F; 60.8 +/- 3.6 y) consumed 360 mL skim milk alone (placebo) or containing 0.5 or 1 g avenanthramide-enriched mixture (AEM) extracted from oats. Plasma samples were collected over a 10-h period. Concentrations of AV-A, AV-B, and AV-C in the AEM were 154, 109, and 111 micromol/g, respectively. Maximum plasma concentrations of AV (free + conjugated) after consumption of 0.5 and 1 g AEM were 112.9 and 374.6 nmol/L for AV-A, 13.2 and 96.0 nmol/L for AV-B, and 41.4 and 89.0 nmol/L for AV-C, respectively. Times to reach the C(max) for both doses were 2.30, 1.75, and 2.15 h for AV-A, AV-B, and AV-C and half times for elimination were 1.75, 3.75, and 3.00 h, respectively. The elimination kinetics of plasma AV appeared to follow first-order kinetics. The bioavailability of AV-A was 4-fold larger than that of AV-B at the 0.5 g AEM dose. After consumption of 1 g AEM, plasma reduced glutathione was elevated by 21% at 15 min (P < or = 0.005) and by 14% at 10 h (P < or = 0.05). Thus, oat AV are bioavailable and increase antioxidant capacity in healthy older adults.