Circulating levels of proglucagon-derived peptides are differentially regulated by the glucagon-like peptide-1 agonist liraglutide and the centrally acting naltrexone/bupropion and can predict future weight loss and metabolic improvements: A 6-month long interventional study.

AIM: To investigate the changes of circulating levels of all proglucagon-derived peptides (PGDPs) in individuals with overweight or obesity receiving liraglutide (3 mg) or naltrexone/bupropion (32/360 mg), and to explore the association between induced changes in postprandial PGDP levels and body composition, as well as metabolic variables, after 3 and 6 months on treatment. MATERIALS AND METHODS: Seventeen patients with obesity or with overweight and co-morbidities, but without diabetes, were assigned to receive once-daily oral naltrexone/bupropion 32/360 mg (n = 8) or once-daily subcutaneous liraglutide 3 mg (n = 9). Participants were assessed before treatment initiation and after 3 and 6 months on treatment. At the baseline and 3-month visits, participants underwent a 3-hour mixed meal tolerance test to measure fasting and postprandial levels of PGDPs, C-peptide, hunger and satiety. Clinical and biochemical indices of metabolic function, magnetic resonance-assessed liver steatosis and ultrasound-assessed liver stiffness were measured at each visit. RESULTS: Both medications improved body weight and composition, carbohydrate and lipid metabolism, and liver fat and function. Naltrexone/bupropion produced a weight-independent increase in the levels of proglucagon (P < .001) and decreases in glucagon-like peptide-2 (GLP-2), glucagon and the major proglucagon fragment (P ≤ .01), whereas liraglutide markedly upregulated total glucagon-like peptide-1 (GLP-1) levels in a weight-independent manner (P = .04), and similarly downregulated the major proglucagon fragment, GLP-2 and glucagon (P < .01). PGDP levels at the 3-month visit were positively and independently correlated with improvements in fat mass, glycaemia, lipaemia and liver function, and negatively with reductions in fat-free mass, at both the 3- and 6-month visits. CONCLUSIONS: PGDP levels in response to liraglutide and naltrexone/bupropion are associated with improvements in metabolism. Our study provides support for the administration of the downregulated members of the PGDP family as replacement therapy (e.g. glucagon), in addition to the medications currently in use that induced their downregulation (e.g. GLP-1), and future studies should explore whether the addition of other PGDPs (e.g. GLP-2) could offer additional benefits.

Recreating the extracellular matrix: novel 3D cell culture platforms in cancer research.

Cancer initiation and progression heavily rely on microenvironmental cues derived from various components of the niche including the extracellular matrix (ECM). ECM is a complex macromolecular network that governs cell functionality. Although the two-dimensional (2D) cell culture systems provide useful information at the molecular level and preclinical testing, they could not accurately represent the in vivo matrix microenvironmental architecture. Hence, it is no surprise that researchers in the last decade have focussed their efforts on establishing novel advanced in vitro culture models that mimic tumour and tissue-specific niches and interactions. These numerous three-dimensional (3D) culture systems that are now widely available, as well as those still under development, grant researchers with new, improved tools to study cancer progression and to explore innovative therapeutic options. Herein, we report on the emerging methods and cutting-edge technologies in 3D cell culture platforms and discuss their potential use in unveiling tumour microenvironmental cues, drug screening and personalized treatment.

Structural and Thermal Characterization of Protein Isolates from Australian Lupin Varieties as Affected by Processing Conditions.

Proteins from the full and defatted flours of L. angustifolius cv Jurien and L. albus cv Murringo were prepared using alkaline extraction and iso-electric precipitation. Isolates were either freeze dried or spray dried or pasteurized at 75 ± 3 °C/5 min before freeze-drying. Various structural properties were investigated to elucidate the varietal and processing-induced effect on molecular and secondary structure. Irrespective of processing, isolated proteins had a similar molecular size, with α-conglutin (412 kDa) and ß-conglutin (210 kDa) being principal fractions for the albus and angustifolius variety, respectively. Smaller peptide fragments were observed for the pasteurized and spray dried samples, indicating some degree of processing-induced changes. Furthermore, secondary structure characterization by Fourier-transform-infrared and circular dichroism spectroscopy showed ß-sheet and α-helical structure being the dominant structure, respectively. Thermal characterization showed two denaturation peaks corresponding to ß-conglutin (Td = 85-89 °C) and α-conglutin (Td = 102-105 °C) fractions. However, the enthalpy values for α-conglutin denaturation were significantly higher for albus species, which corroborates well with higher amounts of heat stable α-conglutin present. Amino acid profile was similar for all samples with limiting sulphur amino acid. In summary, commercial processing conditions did not have a profound effect on the various structural properties of lupin protein isolates, and properties were mainly determined by varietal differences.

Trends in extracellular matrix biology.

Extracellular matrixes (ECMs) are intricate 3-dimensional macromolecular networks of unique architectures with regulatory roles in cell morphology and functionality. As a dynamic native biomaterial, ECM undergoes constant but tightly controlled remodeling that is crucial for the maintenance of normal cellular behavior. Under pathological conditions like cancer, ECM remodeling ceases to be subjected to control resulting in disease initiation and progression. ECM is comprised of a staggering number of molecules that interact not only with one another, but also with neighboring cells via cell surface receptors. Such interactions, too many to tally, are of paramount importance for the identification of novel disease biomarkers and more personalized therapeutic intervention. Recent advances in big data analytics have allowed the development of online databases where researchers can take advantage of a stochastic evaluation of all the possible interactions and narrow them down to only those of interest for their study, respectively. This novel approach addresses the limitations that currently exist in studies, expands our understanding on ECM interactions, and has the potential to advance the development of targeted therapies. In this article we present the current trends in ECM biology research and highlight its importance in tissue integrity, the main interaction networks, ECM-mediated cell functional properties and issues related to pharmacological targeting.

Hyaluronan as "Agent Smith" in cancer extracellular matrix pathobiology: Regulatory roles in immune response, cancer progression and targeting.

Extracellular matrix (ECM) critically regulates cancer cell behavior by governing cell signaling and properties. Hyaluronan (HA) acts as a structural and functional ECM component that mediates critical properties of cancer cells in a molecular size-dependent manner. HA fragments secreted by cancer-associated fibroblasts (CAFs) reveal the correlation of HA to CAF-mediated matrix remodeling, a key step for the initiation of metastasis. The main goal of this article is to highlight the vital functions of HA in cancer cell initiation and progression as well as HA-mediated paracrine interactions among cancer and stromal cells. Furthermore, the HA implication in mediating immune responses to cancer progression is also discussed. Novel data on the role of HA in the formation of pre-metastatic niche may contribute towards the improvement of current theranostic approaches that benefit cancer management.

Pseudoexfoliation syndrome: The critical role of the extracellular matrix in pathogenesis and treatment.

Pseudoexfoliation syndrome (PEXS) is an age-related condition manifesting mainly in ocular tissues. PEXS is manifested through excess aggregation of fibrillary extracellular material at the anterior part of the eye that consists of a plethora of biomolecules, such as different proteoglycans (PGs) and glycosaminoglycans. PEXS is often linked to increased intraocular pressure, and can also lead to pseudoexfoliation glaucoma with very poor prognosis. Various stimuli are known to affect PEXS, including oxidation stress (OS), UV radiation and osmotic pressure. OS, is prominently involved on the progression of the syndrome as it promotes fibrogenesis, possibly via the induction of transforming growth factor-ß (TGF-ß) and other biomolecular effectors. In addition, PEXS initiation is tightly connected with the dysregulation of extracellular matrix (ECM) homeostasis since aberrant expression of ECM molecules is linked to both the accumulation and low degradation of pseudoexfoliation material. This article aims at uncovering the crucial role of various ECM effectors such as lysyl oxidase-like proteins, matrix metalloproteinases, and TGF-ß1, as well as the biochemical pathways involved in the development and the progression of the PEXS.

EGFR is a pivotal player of the E2/ERß - mediated functional properties, aggressiveness, and stemness in triple-negative breast cancer cells.

Triple-negative breast cancer (TNBC) is defined by aggressive behavior, limited response to chemotherapy and lower overall survival rates. The increased metastatic potential of TNBC is a combined result of extensive extracellular matrix (ECM) remodeling that leads to cytoskeleton rearrangement and activation of epithelial-to-mesenchymal transition (EMT). The overexpression of epidermal growth factor receptor (EGFR) in TNBC tumors has been linked to induced expression of EMT-related molecules. EMT activation has often been associated with increased metastasis and stemness. Recently, we described the crucial role of EGFR/estrogen receptor beta (ERß) interplay in the regulation of invasion and cell-matrix interactions. In this study, we report on the EGFR-ERß functional relationship in connection to the aggressiveness and cancer stem cell (CSC)-like characteristics of TNBC cells. ERß-suppressed and MDA-MB-231 cells were subjected to downstream EGFR inhibition and/or estradiol stimulation to assess alterations in functional parameters as well as in morphological characteristics, studied by scanning electron, atomic force, and immunofluorescence microscopies. Moreover, the expression and localization of key EMT and CSC-related markers were also evaluated by real-time qPCR, immunofluorescence microscopy, and flow cytometry. EGFR inhibition resulted in an overall suppression of aggressive functional characteristics, which occurred in an ERß-mediated manner. These changes could be attributed to a reduction, at the molecular level, of EMT and stemness-linked markers, most notably reduced expression of Notch signaling constituents and the cell surface proteoglycan, syndecan-1. Collectively, our study highlights the importance of EGFR signaling as a key effector of aggressiveness, EMT, and stemness in an ERß-dependent way in TNBC.

Exosomes and the extracellular matrix: a dynamic interplay in cancer progression.

Exosomes are a subtype of extracellular vesicles (EVs) composed of a lipid bilayer, which carry various cargoes such as nucleic acids, proteins, and bioactive lipids. Cancer cells release exosomes to promote cell communication and interaction with the extracellular matrix (ECM). ECM regulates the secretion and uptake of exosomes. Moreover, the cargo of exosomes can control ECM remodeling, thus affecting cancer progression. Aside from the rearrangement of ECM, exosomal cargo also modulates different signaling pathways that maintain homeostasis and play a major role in tumor growth and immune evasion in the tumor microenvironment (TME). Exosomes are now widely recognized as circulating biomarkers for diagnosis and prognosis. Their role in cancer initiation, progression, and chemoresistance is becoming increasingly clear from preclinical and clinical investigations, thereby gaining interest for their potential use as cancer diagnostics tools, but also for the development of future innovative cancer therapeutics. In this mini review we outline and discuss the correlation between exosomes, TME and cancer progression, while focusing on the potential role of exosomes as diagnostic and prognostic biomarkers, as well as therapeutic vehicles for drug delivery.

Characteristics of Soy Protein Prepared Using an Aqueous Ethanol Washing Process.

Currently, the predominant process for soy protein concentrate (SPC) production is aqueous ethanol washing of hexane-extracted soy meal. However, the use of hexane is less desired, which explains the increased interest in cold pressing for oil removal. In this study, cold-pressed soy meal was used as the starting material, and a range of water/ethanol ratios was applied for the washing process to produce SPCs. Washing enriched the protein content for the SPCs, regardless of the solvent used. However, we conclude that washing with water (0% ethanol) or solvents with a high water/ethanol ratio (60% and above) can be more advantageous. Washing with a high water/ethanol ratio resulted in the highest yield, and SPCs with the highest protein solubility and water holding capacity. The water-only washed SPC showed the highest viscosity, and formed gels with the highest gel strength and hardness among all the SPCs at a similar protein concentration. The variations in the functionality among the SPCs were attributed to protein changes, although the effects of non-protein constituents such as sugar and oil might also be important. Overall, the aqueous ethanol washing process combined with cold-pressed soy meal created SPCs comparable to commercial SPC in terms of composition, but with varied functionalities that are relevant for novel soy-food developments.

Removal of phenolic compounds from de-oiled sunflower kernels by aqueous ethanol washing.

Selective removal of phenolic compounds (PCs) from de-oiled sunflower kernel is generally considered a key step for food applications, but this often leads to protein loss. PC removal yield and protein loss were assessed during an aqueous or aqueous ethanol washing process with different temperatures, pH-values and ethanol contents. PC yield and protein loss increased when the ethanol content was < 60% or when a higher temperature was applied. Our main finding is that preventing protein loss should be the key objective when selecting process conditions. This can be achieved using solvents with high ethanol content. Simulation of the multi-step exhaustive process showed that process optimization is possible with additional washing steps. PC yield of 95% can be achieved with only 1% protein loss using 9 steps and 80% ethanol content at 25℃. The functional properties of the resulting concentrates were hardly altered with the use of high ethanol solvents.

Functionality of Ingredients and Additives in Plant-Based Meat Analogues.

Meat analogue research and development focuses on the production of sustainable products that recreate conventional meat in its physical sensations (texture, appearance, taste, etc.) and nutritional aspects. Minced products, like burger patties and nuggets, muscle-type products, like chicken or steak-like cuts, and emulsion products, like Frankfurter and Mortadella type sausages, are the major categories of meat analogues. In this review, we discuss key ingredients for the production of these novel products, with special focus on protein sources, and underline the importance of ingredient functionality. Our observation is that structuring processes are optimized based on ingredients that were not originally designed for meat analogues applications. Therefore, mixing and blending different plant materials to obtain superior functionality is for now the common practice. We observed though that an alternative approach towards the use of ingredients such as flours, is gaining more interest. The emphasis, in this case, is on functionality towards use in meat analogues, rather than classical functionality such as purity and solubility. Another trend is the exploration of novel protein sources such as seaweed, algae and proteins produced via fermentation (cellular agriculture).

Key Matrix Remodeling Enzymes: Functions and Targeting in Cancer.

Tissue functionality and integrity demand continuous changes in distribution of major components in the extracellular matrices (ECMs) under normal conditions aiming tissue homeostasis. Major matrix degrading proteolytic enzymes are matrix metalloproteinases (MMPs), plasminogen activators, atypical proteases such as intracellular cathepsins and glycolytic enzymes including heparanase and hyaluronidases. Matrix proteases evoke epithelial-to-mesenchymal transition (EMT) and regulate ECM turnover under normal procedures as well as cancer cell phenotype, motility, invasion, autophagy, angiogenesis and exosome formation through vital signaling cascades. ECM remodeling is also achieved by glycolytic enzymes that are essential for cancer cell survival, proliferation and tumor progression. In this article, the types of major matrix remodeling enzymes, their effects in cancer initiation, propagation and progression as well as their pharmacological targeting and ongoing clinical trials are presented and critically discussed.

Circulating Heparan Sulfate Proteoglycans as Biomarkers in Health and Disease.

Cell-surface heparan sulfate proteoglycans (HSPGs) play key roles in regulating cell behavior, cell signaling, and cell matrix interactions in both physiological and pathological conditions. Their soluble forms from glycocalyx shedding are not merely waste products, but, rather, bioactive molecules, detectable in serum, which may be useful as diagnostic and prognostic markers. In addition, as in the case of glypican-3 in hepatocellular carcinoma, they may be specifically expressed by pathological tissue, representing promising targets for immunotherapy. The primary goal of this comprehensive review is to critically survey the main findings of the clinical data from the last 20 years and provide readers with an overall picture of the diagnostic and prognostic value of circulating HSPGs. Moreover, issues related to the involvement of HSPGs in various pathologies, including cardiovascular disease, thrombosis, diabetes and obesity, kidney disease, cancer, trauma, sepsis, but also multiple sclerosis, preeclampsia, pathologies requiring surgery, pulmonary disease, and others will be discussed.

Alternatives to Meat and Dairy.

The increasing size and affluence of the global population have led to a rising demand for high-protein foods such as dairy and meat. Because it will be impossible to supply sufficient protein to everyone solely with dairy and meat, we need to transition at least part of our diets toward protein foods that are more sustainable to produce. The best way to convince consumers to make this transition is to offer products that easily fit into their current habits and diets by mimicking the original foods. This review focuses on methods of creating an internal microstructure close to that of the animal-based originals. One can directly employ plant products, use intermediates such as cell factories, or grow cultured meat by using nutrients of plant origin. We discuss methods of creating high-quality alternatives to meat and dairy foods, describe their relative merits, and provide an outlook toward the future.

ΕGFR/ERß-Mediated Cell Morphology and Invasion Capacity Are Associated with Matrix Culture Substrates in Breast Cancer.

Breast cancer accounts for almost one in four cancer diagnoses in women. Studies in breast cancer patients have identified several molecular markers, indicators of aggressiveness, which help toward more individual therapeutic approaches. In triple-negative breast cancer (TNBC), epidermal growth factor receptor (EGFR) overexpression is associated with increased metastatic potential and worst survival rates. Specifically, abnormal EGFR activation leads to altered matrix metalloproteinases' (MMPs) expression and, hence, extracellular matrix (ECM) degradation, resulting in induced migration and invasion. The use of matrix substrates for cell culture gives the opportunity to mimic the natural growth conditions of the cells and their microenvironment, as well as cell-cell and cell-matrix interactions. The aim of this study was to evaluate the impact of EGFR inhibition, estrogen receptor beta (ERß) and different matrix substrates [type I collagen and fibronectin (FN)] on the functional properties, expression of MMPs and cell morphology of ERß-positive TNBC cells and shERß ones. Our results highlight EGFR as a crucial regulator of the expression and activity levels of MMPs, while ERß emerges as a mediator of MMP7 and MT1-MMP expression. In addition, the EGFR/ERß axis impacts the adhesion and invasion potential of breast cancer cells on collagen type I. Images obtained by scanning electron microscope (SEM) from cultures on the different matrix substrates revealed novel observations regarding various structures of breast cancer cells (filopodia, extravesicles, tunneling nanotubes, etc.). Moreover, the significant contribution of EGFR and ERß in the morphological characteristics of these cells is also demonstrated, hence highlighting the possibility of dual pharmacological targeting.

Oxidative stability of soy proteins: From ground soybeans to structured products.

The production of soy protein-based foods requires multiple-step, intensive processing and storage of soy ingredients, which can increase the product's susceptibility to oxidation. Therefore, we investigated the oxidative stability of soy protein-based products subjected to different relevant conditions or treatments: over storage of soy flours, over fractionation to yield soy protein isolate (SPI), and over subsequent thermomechanical processing to yield a model structured product. Soy flours were stable to lipid and protein oxidation over 250 days storage in chilled or ambient conditions. The fractionation process applied to make SPI did not increase substantially protein carbonylation, but increased surface-exposed hydrophobicity and decreased free thiols, compared to the starting defatted flour. Subsequent processing of hydrated SPI powder at 140 °C further increased protein carbonylation to a high extent. Therefore, we conclude that soy flours can be stable over long storage times, but processing to yield structured foods products promote protein oxidation.

A Pilot Study About the Dysfunction of Adipose Tissue in Male, Sleep Apneic Patients in Relation to Psychological Symptoms.

Introduction: Obstructive sleep apnea (OSA) and its cardiometabolic alterations are closely associated with visceral obesity. Patients with OSA frequently present with symptoms of depression and anxiety. Although these subjective symptoms of OSA are the result of complex biological dysregulation, it remains unclear if they have a direct effect on the dysfunction of adipose tissue. Methods: In a pilot, prospective, randomized study, we evaluated 10 recently diagnosed male patients with severe OSA by full polysomnography (PSG) and 4 male non-apneic subjects matched for age and body mass index (BMI) with abdomen adipose tissue biopsies. Subjects with diabetes/prediabetes and cardiovascular and psychiatric diseases and who are current smokers were excluded. All patients underwent anthropometric measurements and completed the following questionnaires: Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), and Hospital Anxiety and Depression Scale (HADS-A and HADS-D). Fasting venous blood samples were collected on the day after PSG, between 8:00 and 9:00 a.m., after an overnight fast. Fat biopsies were performed at the same time periods and adipose tissue samples of 300 mg were obtained from abdominal fat. Fat cell size, extent of fibrosis, vascularity, leukocyte common antigen inflammatory infiltration, and tissue macrophage accumulation were microscopically evaluated. Results: The mean age of the group was 47.4 ± 13.8 years, with mean BMI of 35.8 ± 4.8 kg/m2 and mean apnea-hypopnea index of 79.4 ± 46.1 events per hour of sleep (severe OSA). HADS-A and HADS-D scores were 5.8 ± 2.3 (3.0-8.0) and 4.7 ± 2.3 (2.0-8.0), respectively. HADS-A score correlated positively with macrophage accumulation in fat biopsy (r = 0.82, p = 0.047), whereas ESS, FSS, and HADS-D did not. Severity of fibrosis correlated largely with waist circumference (r = -0.66, p = 0.038) and neck circumference (r = -0.790, p = 0.006). Respiratory events correlated negatively with the extent of vascularization of adipose tissue (r = -0.614, p = 0.05). Conclusions: In the preliminary results of our pilot study, we assessed that the symptoms of anxiety mainly contribute to macrophage accumulation, whereas the increased number of respiratory events reduces the extent of vascularization in visceral fat in OSA. Based on this observation, further larger studies are required to verify if anxious OSA patients are more vulnerable to the metabolic manifestations of the syndrome.

Endovascular Repair of a Complex Isolated Dissecting Aneurysm of the Superior Mesenteric Artery.

INTRODUCTION: Isolated dissection of the superior mesenteric artery (SMA) is rare and remains the most common reason for aneurysmal degeneration of the vessel. The treatment is challenging and not standardised. The purpose of this report is to demonstrate that coiling of the false lumen is a good alternative for dissecting SMA aneurysms. REPORT: A 50 year old male presented with a 3.3 cm dissecting aneurysm of the SMA and epigastric pain of moderate severity. More than 50% of the ileal arteries arose from the collapsed true lumen. Via transfemoral access the true lumen was catheterised. An open cell balloon expandable stent was deployed at the proximal and a closed cell self expandable stent at the distal end of the dissection flap. Through the cells of the first stent a microcatheter was advanced into the false lumen and 33 coils were deployed into the aneurysm sac. A stent graft was deployed within the first stent leading to the total exclusion of the aneurysm. Follow up at three months was uneventful and the patency was assessed by contrast enhanced ultrasound. DISCUSSION: Coiling of the false aneurysm is a good alternative for dissecting SMA aneurysms, where no other open surgical or endovascular options are applicable.

Advances in targeting epidermal growth factor receptor signaling pathway in mammary cancer.

Breast cancer is the most common malignancy among women worldwide. The role of epidermal growth factor receptor (EGFR) in many epithelial malignancies has been established, since it is dysregulated, overexpressed or mutated. Its overexpression has been associated with increased aggressiveness and metastatic potential in breast cancer. The well-established interplay between EGFR signaling pathway and estrogen receptors (ERs) as well as major extracellular matrix (ECM) mediators is crucial for regulating basic functional properties of breast cancer cells, including migration, proliferation, adhesion and invasion. EGFR activation leads to endocytosis of the receptor with implications in the regulation of downstream signaling effectors, the modulation of autophagy and cell survival. Therefore, EGFR is considered as a promising therapeutic target in breast cancer. Several anti-EGFR therapies (i.e. monoclonal antibodies and tyrosine kinase inhibitors) have been evaluated both in vitro and in vivo, making their way to clinical trials. However, the response rates of anti-EGFR therapies in the clinical trials is low mainly due to chemoresistance. Novel drug design, phytochemicals and microRNAs (miRNAs) are assessed as new therapeutic approaches against EGFR. The main goal of this review is to highlight the importance of targeting EGFR signaling pathway in terms of its crosstalk with ERs, the involvement of ECM effectors and epigenetics. Moreover, recent insights into the design of specialized delivery systems contributing in the development of novel diagnostic and therapeutic approaches in breast cancer are addressed.

Physical equivalency of wild type and galactose α 1,3 galactose free porcine pericardium; a new source material for bioprosthetic heart valves.

UNLABELLED: Humans make high levels of antibody to carbohydrates with terminal galactose α 1,3 galactose (Gal) modifications. This Gal antigen is widely expressed in other mammals and is present on an array of current animal derived biomedical devices including bioprosthetic heart valves. There is growing interest in using Gal-free animal tissues from Gal knockout pigs (GTKO) as these tissues would not be affected by anti-Gal antibody mediated injury. In this study we compare the composition and biophysical characteristics of glutaraldehyde fixed porcine pericardium from standard and GTKO pigs. We show that with the exception of the Gal antigen which is only present in standard pig tissue both GTKO and standard pig tissue have the same general morphology and collagen content. Moreover uniaxial stress testing and suture retention testing indicate the tissues are equivalent in tensile strength. These studies indicate that genetic disruption of the α-galactosyltransferase (GGTA-1) which blocks synthesis of the Gal antigen has no significant impact on the structural integrity of porcine pericardium and suggest that this tissue could be directly substituted for standard pig pericardium in biomedical devices such as bioprosthetic heart valves. STATEMENT OF SIGNIFICANCE: Surgical heart valve replacement is a proven life saving therapy to treat heart valve dysfunction due to birth defects, infection and the effects of aging. Bioprosthetic heart valves (BHV) made from glutaraldehyde fixed animal tissues are an effective durable therapy in older patients (>60years) but exhibit age-dependent structural valve degeneration (SVD) in younger patients (<60years). SVD is principally caused by BHV calcification. Immune injury contributes to age-dependent SVD through the interaction of galactose α 1,3 galactose (Gal) a dominant xenogeneic antigen present on commercial BHVs and universally abundant human anti-Gal antibody. This study measures the tissue equivalency between standard pig pericardium and Gal-free pericardium from genetically modified pigs as a first step towards making Gal-free BHVs.