Antifibrotic Effects of (−)-Epicatechin on High Glucose Stimulated Cardiac Fibroblasts

AUTHORS

Alejandra Garate-Carrillo, Israel Ramirez-Sanchez, Justina Nguyen, Julisa Gonzalez, Guillermo Ceballos, and Francisco Villarreal

ABSTRACT

Cardiac fibrosis is one of the hallmarks of a diabetic cardiomyopathy. When activated, cardiac fibroblasts (CFs) increase the production of extracellular matrix proteins. Transforming growth factor (TGF)-β1 is known to mediate cardiac fibrosis through the SMAD pathway. High glucose (HG = 25 mM) cell culture media can activate CFs using TGF-β1. There is a need to identify effective antifibrotic agents. Studies in animals indicate that treatment with (−)-epicatechin (Epi) appears capable of reducing myocardial fibrosis. Epi binds to G-protein coupled estrogen receptor (GPER) and activates downstream pathways. We evaluated the potential of Epi to mitigate the development of a profibrotic phenotype in HG stimulated CFs. CF primary cultures were isolated from young male rats and were exposed for up to 48 h HG media and treated with vehicle or 1 μM Epi. Relevant profibrotic end points were measured by the use of various biochemical assays. HG exposure of CFs increased TGF-β1 protein levels by ∼15%, fibronectin ∼25%, urea levels ∼60%, proline incorporation ∼70%, and total collagen ∼15%. Epi treatment was able to significantly block HG induced increases in TGF-β1, fibronectin, urea, proline, and total collagen protein levels. GPER levels were reduced by HG and restored in CFs treated with Epi an effect associated with the activation (i.e., phosphorylation) of c-Src. Epi treatment also reverted SMAD levels. Altogether, results demonstrate that CFs cultured in HG acquire a profibrotic phenotype, which is blocked by Epi an effect, likely mediated at least, in part, by GPER effects on the SMAD/TGF-β1 pathway.

N-3 Long Chain Fatty Acids Supplementation, Fatty Acids Desaturase Activity, and Colorectal Cancer Risk: A Randomized Controlled Trial

AUTHORS

Harvey J. Murff, Martha J. Shrubsole, Qiuyin Cai, Timothy Su, Jennings H. Dooley, Sunny S. Cai, Wei Zheng & Qi Daic

ABSTRACT

Introduction

n-3 long-chain polyunsaturated fatty acids (LCPUFA) have anti-inflammatory effects and may reduce colorectal cancer risk. The purpose of this study was to evaluate the effects of n-3 LCPUFA supplementation on markers of rectal cell proliferation and apoptosis and examine how genetic variation in desaturase enzymes might modify this effect.

Methods

We conducted a randomized, double-blind, control six-month trial of 2.5 grams of n-3 LCPUFA per day compared to olive oil. Study participants had a history of colorectal adenomas. Randomization was stratified based on the gene variant rs174535 in the fatty acid desaturase 1 enzyme (FADS1). Our primary outcome was change in markers of rectal epithelial proliferation and apoptosis.

Results

A total of 141 subjects were randomized. We found no difference in apoptosis markers between participants randomized to n-3 LCPUFA compared to olive oil (P = 0.41). N-3 LCPUFA supplementation increased cell proliferation in the lower colonic crypt compared to olive oil (P = 0.03) however baseline indexes of proliferation were different between the groups at randomization. We found no evidence that genotype modified the effect.

Conclusions

Our study did not show evidence of a proliferative or pro-apoptotic effect on n-3 LCPUFA supplementation on rectal mucosa regardless of the FADS genotype.

Early extubation to noninvasive respiratory support of former preterm lambs improves long-term respiratory outcomes

AUTHORS

Mar Janna Dahl, Chiara Veneroni, Anna Lavizzari, Sydney Bowen, Haleigh Emerson, Andrew Rebentisch, Elaine Dawson, Kyle Summers, Luke Pettet, Zhengming Wang, Donald M. Null, Bradley A. Yoder, Raffaele L. Dellacà, and Kurt H. Albertine

ABSTRACT

Invasive mechanical ventilation (IMV) and exposure to oxygen-rich gas during early postnatal life are contributing factors for long-term pulmonary morbidities faced by survivors of preterm birth and bronchopulmonary dysplasia. The duration of IMV that leads to long-term pulmonary morbidities is unknown. We compared two durations of IMV (3 h vs. 6 days) during the first 6–7 days of postnatal life in preterm lambs to test the hypothesis that minimizing the duration of IMV will improve long-term respiratory system mechanics and structural outcomes later in life. Moderately preterm (∼85% gestation) lambs were supported by IMV for either 3 h or 6 days before weaning from all respiratory support to become former preterm lambs. Respiratory system mechanics and airway reactivity were assessed monthly from 1 to 6 mo of chronological postnatal age by the forced oscillation technique. Quantitative morphological measurements were made for smooth muscle accumulation around terminal bronchioles and indices of alveolar formation. Minimizing IMV to 3 h led to significantly better (P < 0.05) baseline respiratory system mechanics and less reactivity to methacholine in the first 3 mo of chronological age (2 mo corrected age), significantly less (P < 0.05) accumulation of smooth muscle around peripheral resistance airways (terminal bronchioles), and significantly better (P < 0.05) alveolarization at the end of 5 mo corrected age compared with continuous IMV for 6 days. We conclude that limiting the duration of IMV following preterm birth of fetal lambs leads to better respiratory system mechanics and structural outcomes later in life.

Increased Toll-like Receptor-MyD88-NFκB-Proinflammatory neuroimmune signaling in the orbitofrontal cortex of humans with alcohol use disorder

AUTHORS

Ryan P. Vetreno, Liya Qin, Leon G. Coleman Jr, Fulton T. Crews

ABSTRACT

Background: Many brain disorders, including alcohol use disorder (AUD), are associated with induction of multiple proinflammatory genes. One aspect of proinflammatory signaling is progressive increases in expression across cells and induction of other innate immune genes. High-mobility group box 1 (HMGB1) heteromers contribute to amplification by potentiating multiple proinflammatory responses, including Tolllike receptors (TLRs). TLR signaling recruits coupling proteins linked to nuclear transcription factors that induce proinflammatory cytokines and chemokines and their respective receptors. We tested the hypothesis that AUD induction of TLR expression increases levels of proinflammatory genes and cellular signaling cascades in association with neurodegeneration in the orbitofrontal cortex (OFC).

Methods: Postmortem human OFC tissue samples (n = 10) from males diagnosed with

AUD were compared to age-matched moderate drinking controls (CON). Neuroimmune

signaling molecules were assessed using immunohistochemistry for protein and reverse transcription polymerase chain reaction for messenger RNA (mRNA).

Results: In the AUD OFC, we report induction of the endogenous TLR agonist HMGB1as well as all TLRs assessed (i.e., TLR2-TLR9) except TLR1. This was accompanied by increased expression of the TLR adaptor protein myeloid differentiation primary response 88 (MyD88), activation of the proinflammatory nuclear transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), and downstream induction of proinflammatory cytokines, chemokines, and their corresponding receptors. Several of these proinflammatory signaling markers are expressed in glia and neurons. The induction of HMGB1-TLR-MyD88-NFκB proinflammatory signaling pathways correlates with neurodegeneration (i.e., Fluoro-Jade B), lifetime alcohol consumption, and age of drinking onset.

Conclusion: These data implicate the induction of HMGB1-TLR-MyD88-NFκB cascades through coordinated glial and neuronal signaling as contributors to the neurodegeneration seen in the postmortem human OFC of individuals with AUD

Flexible Osteogenic Glue as an All-In-One Solution to Assist Fracture Fixation and Healing

AUTHORS

Jincheng Tang, Kun Xi, Hao Chen, Lingjun Wang, Dongya Li, Yun Xu, Tianwen Xin, Liang Wu, Yidi Zhou, Jiang Bian, Zhengwei Cai, Huilin Yang, Lianfu Deng, Yong Gu, Wenguo Cui, Liang Chen

ABSTRACT

Osteogenic glue that reproduces the natural bone composition represents the final frontier of orthopedic adhesives with the potential to revolutionize surgical strategies against comminuted fractures. However, it is difficult to achieve an all-in-one formula, which could provide flexible and reliable adhesiveness while avoiding interfering with or even promoting the healing of glued fractures. Herein, an osteogenic glue characterized by inorganic-in-organic integration between amine-modified mesoporous bioactive glass nanoparticles (AMBGN) and bioadhesive gelatin-dextran network (GelDex) is introduced as an all-in-one tool to flexibly adhere and splice bone fragments and subsequently guide fracture healing during degradation. Relying on such integration, a 4-fold improvement in cohesiveness is presented, followed by a nearly 5-fold enhancement in adhesive strength in ex vivo porcine bone samples. The reversible and re-adjustable adhesiveness also enables glue to effectively splice intricate fragments from highly comminuted fractures in the rabbit radius in an in vivo environment. Moreover, well-preserved organic–inorganic integrity during degradation of the glue guides sustained interfacial osteogenesis and achieve satisfying healing outcomes in glued fractures, as observed by the 2-fold improvement in biomechanical and radiological performance compared with commercially available cyanoacrylate adhesives. The current findings propose an all-in-one solution for the fixation of bone fragments during surgery.

Vascular Mechanobiology: Homeostasis, Adaptation, and Disease

AUTHORS

Jay D. Humphrey and Martin A. Schwartz

ABSTRACT

Cells of the vascular wall are exquisitely sensitive to changes in their mechanical environment. In healthy vessels, mechanical forces regulate signaling and gene expression to direct the remodeling needed for the vessel wall to maintain optimal function. Major diseases of arteries involve maladaptive remodeling with compromised or lost homeostatic mechanisms. Whereas homeostasis invokes negative feedback loops at multiple scales to mediate mechanobiological stability, disease progression often occurs via positive feedback that generates mechanobiological instabilities. In this review, we focus on the cell biology, wall mechanics, and regulatory pathways associated with arterial health and how changes in these processes lead to disease. We discuss how positive feedback loops arise via biomechanical and biochemical means. We conclude that inflammation plays a central role in overriding homeostatic pathways and suggest future directions for addressing therapeutic needs