Silk fibroin scaffolds enhance cell commitment of adult rat cardiac progenitor cells

Injectable Self-Oxygenating Cardio-Protective and Tissue Adhesive Silk-Based Hydrogel for Alleviating Ischemia After Mi Injury

Myocardial infarction (MI) is a significant cardiovascular disease that restricts blood flow, resulting in massive cell death and leading to stiff and noncontractile fibrotic scar tissue formation. Recently, sustained oxygen release in the MI area has shown regeneration ability; however, improving its therapeutic efficiency for regenerative medicine remains challenging. Here, a combinatorial strategy for cardiac repair by developing cardioprotective and oxygenating hybrid hydrogels that locally sustain the release of stromal cell-derived factor-1 alpha (SDF) and oxygen for simultaneous activation of neovascularization at the infarct area is presented. A sustained release of oxygen and SDF from injectable, mechanically robust, and tissue-adhesive silk-based hybrid hydrogels is achieved. Enhanced endothelialization under normoxia and anoxia is observed. Furthermore, there is a marked improvement in vascularization that leads to an increment in cardiomyocyte survival by ≈30% and a reduction of the fibrotic scar formation in an MI animal rodent model. Improved left ventricular systolic and diastolic functions by ≈10% and 20%, respectively, with a ≈25% higher ejection fraction on day 7 are also observed. Therefore, local delivery of therapeutic oxygenating and cardioprotective hydrogels demonstrates beneficial effects on cardiac functional recovery for reparative therapy.

A Review on the Applications of Natural Biodegradable Nano Polymers in Cardiac Tissue Engineering

As cardiac diseases, which mostly result in heart failure, are increasing rapidly worldwide, heart transplantation seems the only solution for saving lives. However, this practice is not always possible due to several reasons, such as scarcity of donors, rejection of organs from recipient bodies, or costly medical procedures. In the framework of nanotechnology, nanomaterials greatly contribute to the development of these cardiovascular scaffolds as they provide an easy regeneration of the tissues. Currently, functional nanofibers can be used in the production of stem cells and in the regeneration of cells and tissues. The small size of nanomaterials, however, leads to changes in their chemical and physical characteristics that could alter their interaction and exposure to stem cells with cells and tissues. This article aims to review the naturally occurring biodegradable nanomaterials that are used in cardiovascular tissue engineering for the development of cardiac patches, vessels, and tissues. Moreover, this article also provides an overview of cell sources used for cardiac tissue engineering, explains the anatomy and physiology of the human heart, and explores the regeneration of cardiac cells and the nanofabrication approaches used in cardiac tissue engineering as well as scaffolds.

Artificial Scaffolds in Cardiac Tissue Engineering

Cardiovascular diseases are a leading cause of death worldwide. Current treatments directed at heart repair have several disadvantages, such as a lack of donors for heart transplantation or non-bioactive inert materials for replacing damaged tissue. Because of the natural lack of regeneration of cardiomyocytes, new treatment strategies involve stimulating heart tissue regeneration. The basic three elements of cardiac tissue engineering (cells, growth factors, and scaffolds) are described in this review, with a highlight on the role of artificial scaffolds. Scaffolds for cardiac tissue engineering are tridimensional porous structures that imitate the extracellular heart matrix, with the ability to promote cell adhesion, migration, differentiation, and proliferation. In the heart, there is an important requirement to provide scaffold cellular attachment, but scaffolds also need to permit mechanical contractility and electrical conductivity. For researchers working in cardiac tissue engineering, there is an important need to choose an adequate artificial scaffold biofabrication technique, as well as the ideal biocompatible biodegradable biomaterial for scaffold construction. Finally, there are many suitable options for researchers to obtain scaffolds that promote cell-electrical interactions and tissue repair, reaching the goal of cardiac tissue engineering.

Polymeric Biomaterials for the Treatment of Cardiac Post-Infarction Injuries

Cardiac regeneration aims to reconstruct the heart contractile mass, preventing the organ from a progressive functional deterioration, by delivering pro-regenerative cells, drugs, or growth factors to the site of injury. In recent years, scientific research focused the attention on tissue engineering for the regeneration of cardiac infarct tissue, and biomaterials able to anatomically and physiologically adapt to the heart muscle have been proposed as valuable tools for this purpose, providing the cells with the stimuli necessary to initiate a complete regenerative process. An ideal biomaterial for cardiac tissue regeneration should have a positive influence on the biomechanical, biochemical, and biological properties of tissues and cells; perfectly reflect the morphology and functionality of the native myocardium; and be mechanically stable, with a suitable thickness. Among others, engineered hydrogels, three-dimensional polymeric systems made from synthetic and natural biomaterials, have attracted much interest for cardiac post-infarction therapy. In addition, biocompatible nanosystems, and polymeric nanoparticles in particular, have been explored in preclinical studies as drug delivery and tissue engineering platforms for the treatment of cardiovascular diseases. This review focused on the most employed natural and synthetic biomaterials in cardiac regeneration, paying particular attention to the contribution of Italian research groups in this field, the fabrication techniques, and the current status of the clinical trials.

Sex-based differences after a single bout of exercise on PGC1α isoforms in skeletal muscle: A pilot study

To date, there are limited and incomplete data on possible sex-based differences in fiber-types of skeletal muscle and their response to physical exercise. Adult healthy male and female mice completed a single bout of endurance exercise to examine the sex-based differences of the peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α), heat shock protein 60 (Hsp60), interleukin 6 (IL-6) expression, as well as the Myosin Heavy Chain (MHC) fiber-type distribution in soleus and extensor digitorum longus (EDL) muscles. Our results showed for the first time that in male soleus, a muscle rich of type IIa fibers, endurance exercise activates specifically genes involved in mitochondrial biogenesis such as PGC1 α1 isoform, Hsp60 and IL-6, whereas the expression of PGC1 α2 and α3 was significantly upregulated in EDL muscle, a fast-twitch skeletal muscle, independently from the gender. Moreover, we found that the acute response of different PGC1α isoforms was muscle and gender dependent. These findings add a new piece to the huge puzzle of muscle response to physical exercise. Given the importance of these genes in the physiological response of the muscle to exercise, we strongly believe that our data could support future research studies to personalize a specific and sex-based exercise training protocol.

Engineering Functional Cardiac Tissues for Regenerative Medicine Applications

PURPOSE OF REVIEW

Tissue engineering has expanded into a highly versatile manufacturing landscape that holds great promise for advancing cardiovascular regenerative medicine. In this review, we provide a summary of the current state-of-the-art bioengineering technologies used to create functional cardiac tissues for a variety of applications in vitro and in vivo.

RECENT FINDINGS

Studies over the past few years have made a strong case that tissue engineering is one of the major driving forces behind the accelerating fields of patient-specific regenerative medicine, precision medicine, compound screening, and disease modeling. To date, a variety of approaches have been used to bioengineer functional cardiac constructs, including biomaterial-based, cell-based, and hybrid (using cells and biomaterials) approaches. While some major progress has been made using cellular approaches, with multiple ongoing clinical trials, cell-free cardiac tissue engineering approaches have also accomplished multiple breakthroughs, although drawbacks remain. This review summarizes the most promising methods that have been employed to generate cardiovascular tissue constructs for basic science or clinical applications. Further, we outline the strengths and challenges that are inherent to this field as a whole and for each highlighted technology.

Comparative effectiveness of three-dimensional scaffold, differentiation media and co-culture with native cardiomyocytes to trigger in vitro cardiogenic differentiation of menstrual blood and bone marrow stem cells

The main purpose of this study was to find effectiveness of 3D silk fibroin scaffold in comparison with co-culturing in presence of native cardiomyocytes on cardiac differentiation propensity of menstural blood(MenSCs)-versus bone marrow-derived stem-cells (BMSCs). We showed that both 3D fibroin scaffold and co-culture system supported efficient cardiomyogenic differentiation of MenSCs and BMSCs, as judged by the expression of cardiac-specific genes and proteins, Connexin-43, Connexin-40, alpha Actinin (ACTN-2), Tropomyosin1 (TPM1) and Cardiac Troponin T (TNNT2). No significant difference (except for higher expression of ACTN-2 in co-cultured MenSCs) was found between differentiation potential of the cells cultured in 3D fibroin scaffold and co-culture system. Collectively, our results imply that inductive signals served by biological factors of native cardiomyocytes to trigger cardiogenic differentiation of stem-cells may be efficiently provided by natural and biocompatible 3D fibroin scaffold suggesting the usefulness of this construct for cardiac tissue engineering.

The histone deacetylase inhibitor SAHA induces HSP60 nitration and its extracellular release by exosomal vesicles in human lung-derived carcinoma cells

HSP60 undergoes changes in quantity and distribution in some types of tumors suggesting a participation of the chaperonin in the mechanism of transformation and cancer progression. Suberoylanilide hydroxamic acid (SAHA), a member of a family of histone deacetylase inhibitors (HDACi), has anti-cancer potential but its interaction, if any, with HSP60 has not been elucidated. We investigated the effects of SAHA in a human lung-derived carcinoma cell line (H292). We analysed cell viability and cycle; oxidative stress markers; mitochondrial integrity; HSP60 protein and mRNA levels; and HSP60 post-translational modifications, and its secretion. We found that SAHA is cytotoxic for H292 cells, interrupting the cycle at the G2/M phase, which is followed by death; cytotoxicity is associated with oxidative stress, mitochondrial damage, and diminution of intracellular levels of HSP60; HSP60 undergoes a post-translational modification and becomes nitrated; and nitrated HSP60 is exported via exosomes. We propose that SAHA causes ROS overproduction and mitochondrial dysfunction, which leads to HSP60 nitration and release into the intercellular space and circulation to interact with the immune system. These successive steps might constitute the mechanism of the anti-tumor action of SAHA and provide a basis to design supplementary therapeutic strategies targeting HSP60, which would be more efficacious than the compound alone.

Nandrolone decanoate interferes with testosterone biosynthesis altering blood-testis barrier components

The aim of this study was to investigate whether nandrolone decanoate (ND) use affects testosterone production and testicular morphology in a model of trained and sedentary mice. A group of mice underwent endurance training while another set led a sedentary lifestyle and were freely mobile within cages. All experimental groups were treated with either ND or peanut oil at different doses for 6 weeks. Testosterone serum levels were measured via liquid chromatography–mass spectrometry. Western blot analysis and quantitative real‐time PCR were utilized to determine gene and protein expression levels of the primary enzymes implicated in testosterone biosynthesis and gene expression levels of the blood–testis barrier (BTB) components. Immunohistochemistry and immunofluorescence were conducted for testicular morphological evaluation. The study demonstrated that moderate to high doses of ND induced a diminished serum testosterone level and altered the expression level of the key steroidogenic enzymes involved in testosterone biosynthesis. At the morphological level, ND induced degradation of the BTB by targeting the tight junction protein‐1 (TJP1). ND stimulation deregulated metalloproteinase‐9, metalloproteinase‐2 (MMP‐2) and the tissue inhibitor of MMP‐2. Moreover, ND administration resulted in a mislocalization of mucin‐1. In conclusion, ND abuse induces a decline in testosterone production that is unable to regulate the internalization and redistribution of TJP1 and may induce the deregulation of other BTB constituents via the inhibition of MMP‐2. ND may well be considered as both a potential inducer of male infertility and a potential risk factor to a low endogenous bioavailable testosterone.

Effects of Conjugated Linoleic Acid Associated With Endurance Exercise on Muscle Fibres and Peroxisome Proliferator-Activated Receptor γ Coactivator 1 α Isoforms

Conjugated linoleic acid (CLA) has been reported to improve muscle hypertrophy, steroidogenesis, physical activity, and endurance capacity in mice, although the molecular mechanisms of its actions are not completely understood. The aim of the present study was to identify whether CLA alters the expression of any of the peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) isoforms, and to evaluate the possible existence of fibre-type-specific hypertrophy in the gastrocnemius and plantaris muscles. Mice were randomly assigned to one of four groups: placebo sedentary, CLA sedentary, placebo trained, or CLA trained. The CLA groups were gavaged with 35 μl per day of Tonalin® FFA 80 food supplement containing CLA throughout the 6-week experimental period, whereas the placebo groups were gavaged with 35 μl sunflower oil each day. Each administered dose of CLA corresponded to approximately 0.7 g/kg or 0.5%, of the dietary daily intake. Trained groups ran 5 days per week on a Rota-Rod for 6 weeks at increasing speeds and durations. Mice were sacrificed by cervical dislocation and hind limb posterior muscle groups were dissected and used for histological and molecular analyses. Endurance training stimulated mitochondrial biogenesis by PGC1α isoforms (tot, α1, α2, and α3) but CLA supplementation did not stimulate PGC1α isoforms or mitochondrial biogenesis in trained or sedentary mice. In the plantaris muscle, CLA supplementation induced a fibre-type-specific hypertrophy of type IIx muscle fibres, which was associated with increased capillary density and was different from the fibre-type-specific hypertrophy induced by endurance exercise (of types I and IIb muscle fibres). J. Cell. Physiol. 232: 1086-1094, 2017. © 2016 Wiley Periodicals, Inc.

Application of Collagen Scaffold in Tissue Engineering: Recent Advances and New Perspectives

Collagen is the main structural protein of most hard and soft tissues in animals and the human body, which plays an important role in maintaining the biological and structural integrity of the extracellular matrix (ECM) and provides physical support to tissues. Collagen can be extracted and purified from a variety of sources and offers low immunogenicity, a porous structure, good permeability, biocompatibility and biodegradability. Collagen scaffolds have been widely used in tissue engineering due to these excellent properties. However, the poor mechanical property of collagen scaffolds limits their applications to some extent. To overcome this shortcoming, collagen scaffolds can be cross-linked by chemical or physical methods or modified with natural/synthetic polymers or inorganic materials. Biochemical factors can also be introduced to the scaffold to further improve its biological activity. This review will summarize the structure and biological characteristics of collagen and introduce the preparation methods and modification strategies of collagen scaffolds. The typical application of a collagen scaffold in tissue engineering (including nerve, bone, cartilage, tendon, ligament, blood vessel and skin) will be further provided. The prospects and challenges about their future research and application will also be pointed out.

Skeletal muscle Heat shock protein 60 increases after endurance training and induces peroxisome proliferator-activated receptor gamma coactivator 1 α1 expression

Heat shock protein 60 (Hsp60) is a chaperone localizing in skeletal muscle mitochondria, whose role is poorly understood. In the present study, the levels of Hsp60 in fibres of the entire posterior group of hindlimb muscles (gastrocnemius, soleus, and plantaris) were evaluated in mice after completing a 6-week endurance training program. The correlation between Hsp60 levels and the expression of four isoforms of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α) were investigated only in soleus. Short-term overexpression of hsp60, achieved by in vitro plasmid transfection, was then performed to determine whether this chaperone could have a role in the activation of the expression levels of PGC1α isoforms. The levels of Hsp60 protein were fibre-type specific in the posterior muscles and endurance training increased its content in type I muscle fibers. Concomitantly with the increased levels of Hsp60 released in the blood stream of trained mice, mitochondrial copy number and the expression of three isoforms of PGC1α increased. Overexpressing hsp60 in cultured myoblasts induced only the expression of PGC1 1α, suggesting a correlation between Hsp60 overexpression and PGC1 1 α activation.

Alcoholic Liver Disease: A Mouse Model Reveals Protection by Lactobacillus fermentum

OBJECTIVES

Alcoholism is one of the most devastating diseases with high incidence, but knowledge of its pathology and treatment is still plagued with gaps mostly because of the inherent limitations of research with patients. We developed an animal model for studying liver histopathology, Hsp (heat-shock protein)-chaperones involvement, and response to treatment.

METHODS

The system was standardized using mice to which ethanol was orally administered alone or in combination with Lactobacillus fermentum following a precise schedule over time and applying, at predetermined intervals, a battery of techniques (histology, immunohistochemistry, western blotting, real-time PCR, immunoprecipitation, 3-nitrotyrosine labeling) to assess liver pathology (e.g., steatosis, fibrosis), and Hsp60 and iNOS (inducible form of nitric oxide synthase) gene expression and protein levels, and post-translational modifications.

RESULTS

Typical ethanol-induced liver pathology occurred and the effect of the probiotic could be reliably monitored. Steatosis score, iNOS levels, and nitrated proteins (e.g., Hsp60) decreased after probiotic intake.

CONCLUSIONS

We describe a mouse model useful for studying liver disease induced by chronic ethanol intake and for testing pertinent therapeutic agents, e.g., probiotics. We tested L. fermentum, which reduced considerably ethanol-induced tissue damage and deleterious post-translational modifications of the chaperone Hsp60. The model is available to test other agents and probiotics with therapeutic potential in alcoholic liver disease.

Effects of Nandrolone Stimulation on Testosterone Biosynthesis in Leydig Cells

Anabolic androgenic steroids (AAS) are among the drugs most used by athletes for improving physical performance, as well as for aesthetic purposes. A number of papers have showed the side effects of AAS in different organs and tissues. For example, AAS are known to suppress gonadotropin‐releasing hormone, luteinizing hormone, and follicle‐stimulating hormone. This study investigates the effects of nandrolone on testosterone biosynthesis in Leydig cells using various methods, including mass spectrometry, western blotting, confocal microscopy and quantitative real‐time PCR. The results obtained show that testosterone levels increase at a 3.9 μM concentration of nandrolone and return to the basal level a 15.6 μM dose of nandrolone. Nandrolone‐induced testosterone increment was associated with upregulation of the steroidogenic acute regulatory protein (StAR) and downregulation of 17a‐hydroxylase/17, 20 lyase (CYP17A1). Instead, a 15.6 µM dose of nandrolone induced a down‐regulation of CYP17A1. Further in vivo studies based on these data are needed to better understand the relationship between disturbed testosterone homeostasis and reproductive system impairment in male subjects. J. Cell. Physiol. 231: 1385–1391, 2016. © 2015 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc.

Biomaterial Approaches for Stem Cell-Based Myocardial Tissue Engineering

Adult and pluripotent stem cells represent a ready supply of cellular raw materials that can be used to generate the functionally mature cells needed to replace damaged or diseased heart tissue. However, the use of stem cells for cardiac regenerative therapies is limited by the low efficiency by which stem cells are differentiated in vitro to cardiac lineages as well as the inability to effectively deliver stem cells and their derivatives to regions of damaged myocardium. In this review, we discuss the various biomaterial-based approaches that are being implemented to direct stem cell fate both in vitro and in vivo. First, we discuss the stem cell types available for cardiac repair and the engineering of naturally and synthetically derived biomaterials to direct their in vitro differentiation to the cell types that comprise heart tissue. Next, we describe biomaterial-based approaches that are being implemented to enhance the in vivo integration and differentiation of stem cells delivered to areas of cardiac damage. Finally, we present emerging trends of using stem cell-based biomaterial approaches to deliver pro-survival factors and fully vascularized tissue to the damaged and diseased cardiac tissue.

The potential of stem cells in the treatment of cardiovascular diseases

Although the adult mammalian heart was once believed to be a post-mitotic organ without any capacity for regeneration, recent findings have challenged this dogma. A modified view assigns to the mammalian heart a measurable capacity for regeneration throughout life. The ultimate goals of the cardiac regeneration field have been pursued by multiple strategies, including understanding the developmental biology of cardiomyocytes and cardiac stem and progenitor cells, applying chemical genetics, and engineering biomaterials and delivery methods that facilitate cell transplantation. Successful stimulation of endogenous regenerative capacity in injured adult mammalian hearts can benefit from studies of natural cardiac regeneration.

Endurance exercise and conjugated linoleic acid (CLA) supplementation up-regulate CYP17A1 and stimulate testosterone biosynthesis

A new role for fat supplements, in particular conjugated linoleic acid (CLA), has been delineated in steroidogenesis, although the underlying molecular mechanisms have not yet been elucidated. The aims of the present study were to identify the pathway stimulated by CLA supplementation using a cell culture model and to determine whether this same pathway is also stimulated in vivo by CLA supplementation associated with exercise. In vitro, Leydig tumour rat cells (R2C) supplemented with different concentrations of CLA exhibited increasing testosterone biosynthesis accompanied by increasing levels of CYP17A1 mRNA and protein. In vivo, trained mice showed an increase in free plasma testosterone and an up-regulation of CYP17A1 mRNA and protein. The effect of training on CYP17A1 expression and testosterone biosynthesis was significantly higher in the trained mice supplemented with CLA compared to the placebo. The results of the present study demonstrated that CLA stimulates testosterone biosynthesis via CYP17A1, and endurance training led to the synthesis of testosterone in vivo by inducing the overexpression of CYP17A1 mRNA and protein in the Leydig cells of the testis. This effect was enhanced by CLA supplementation. Therefore, CLA-associated physical activity may be used for its steroidogenic property in different fields, such as alimentary industry, human reproductive medicine, sport science, and anti-muscle wasting.