Editorial: Growth and Tissue Regeneration with focus on Proteoglycans

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Calanus finmarchicus as a novel source of health-promoting bioactive peptides: Enzymatic protein hydrolysis, characterization, and in vitro bioactivity

Calanus finmarchicus is a crustacean currently used as a source of marine lipid. The lipids are extracted by enzymatic protein hydrolysis, while the remaining peptide fraction is regarded as a byproduct. In the present work, ten different commercial proteases and endogenous C. finmarchicus proteases were used to produce a set of 63 protein hydrolysates. Protease concentration and hydrolysis time were varied. Hydrolysates were characterized using size-exclusion chromatography and 1H nuclear magnetic resonance spectroscopy. Addition of commercial proteases had unremarkable effect on the yield and molecular weight distribution. This was attributed to the strong impact of endogenous enzymes dominating the hydrolysis process. However, multivariate classification based on 1H NMR spectra revealed subtle variations in composition of hydrolysates produced using different enzymes. The hydrolysates were further evaluated for DPP-IV inhibition and antioxidant activity. The hydrolysates showed significantly higher bioactivity than the unhydrolyzed control. A representative hydrolysate (CaFi55) was fractionated using semipreparative size-exclusion chromatography. A fraction consisting of short peptides with an average chain length of five amino acids (F2), was identified as a major contributor to the DPP-IV inhibitory activity (IC50 = 0.70 ± 0.07 mg/mL)

Expansion of bovine skeletal muscle stem cells from spinner flasks to benchtop stirred-tank bioreactors for up to 38 days

Introduction: Successful long-term expansion of skeletal muscle satellite cells (MuSCs) on a large scale is fundamental for cultivating animal cells for protein production. Prerequisites for efficient cell expansion include maintaining essential native cell activities such as cell adhesion, migration, proliferation, and differentiation while ensuring consistent reproducibility. Method: This study investigated the growth of bovine MuSC culture using low-volume spinner flasks and a benchtop stirred-tank bioreactor (STR). Results and discussion: Our results showed for the first time the expansion of primary MuSCs for 38 days in a bench-top STR run with low initial seeding density and FBS reduction, supported by increased expression of the satellite cell marker PAX7 and reduced expression of differentiation-inducing genes like MYOG, even without adding p38-MAPK inhibitors. Moreover, the cells retained their ability to proliferate, migrate, and differentiate after enzymatic dissociation from the microcarriers. We also showed reproducible results in a separate biological benchtop STR run.Expansion of bovine skeletal muscle stem cells from spinner flasks to benchtop stirred-tank bioreactors for up to 38 dayspublishedVersio

Production of food-grade microcarriers based on by-products from the food industry to facilitate the expansion of bovine skeletal muscle satellite cells for cultured meat production

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Characterization of wooden breast myopathy: a focus on syndecans and ECM remodeling

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Primary bovine skeletal muscle cells enters apoptosis rapidly via the intrinsic pathway when available oxygen is removed

Muscle cells undergo changes post-mortem during the process of converting muscle into meat, and this complex process is far from revealed. Recent reports have suggested programmed cell death (apoptosis) to be important in the very early period of converting muscle into meat. The dynamic balance that occurs between anti-apoptotic members, such as Bcl-2, and pro-apoptotic members (Bid, Bim) helps determine whether the cell initiates apoptosis. In this study, we used primary bovine skeletal muscle cells, cultured in monolayers in vitro, to investigate if apoptosis is induced when oxygen is removed from the growth medium. Primary bovine muscle cells were differentiated to form myotubes, and anoxia was induced for 6h. The anoxic conditions significantly increased (P<0.05) the relative gene expression of anti- and pro-apoptotic markers (Aif, Bcl-2, Bid and Bim), and the PARK7 (P<0.05) and Grp75 (Hsp70) protein expressions were transiently increased. The anoxic conditions also led to a loss of mitochondrial membrane potential, which is an early apoptotic event, as well as cytochrome c release from the mitochondria. Finally, reorganization and degradation of cytoskeletal filaments occurred. These results suggest that muscle cells enters apoptosis via the intrinsic pathway rapidly when available oxygen in the muscle diminishes post-mortem.publishedVersio

Can postmortem proteolysis explain tenderness differences in various bovine muscles?

This study investigated the relationship between postmortem proteolysis, muscle pH decline, sarcomere length (SL), intramuscular fat (IMF) and Warner-Bratzler shear force (WBSF) in four bovine muscles (biceps femoris (BF), infraspinatus (IS), longissimus lumborum (LL), psoas major (PM). The WBSF was low in BF, IS and PM, while LL had a higher value (P<0.001), but still considered as tender. The PM had fastest pH decline (P<0.001), ultimate pH was lowest in LL and PM and highest for IS (P<0.001), sarcomeres were longest for PM and shortest for BF and LL (P<0.001), while IS and PM had more IMF than BF and LL (P=0.038). Troponin T degradation was similar in all muscles after 2d postmortem, however after 13d LL had more degradation than IS (P=0.003). The MMP-2 activity increased during storage (P=0.001), while IS had less activity than the other muscles (P=0.022). Although the variation in proteolytic activity could not explain the variation in WBSF, the study provides useful knowledge for the meat industry for optimising processing and storage procedures for different beef muscles.Can postmortem proteolysis explain tenderness differences in various bovine muscles?submittedVersio

Screening of by-products from the food industry as growth promoting agents in serum-free media for skeletal muscle cell culture.

The most significant cost driver for efficient bio-production of edible animal proteins is the cell culture media, where growth factors account for up to 96% of the total cost. The culture media must be serum-free, affordable, contain only food-grade ingredients, be efficient to promote cell growth and available in massive quantities. The commercially available serum substitutes are expensive and not necessarily food-grade. Identifying inexpensive food-safe alternatives to serum is crucial. By-products from food production are available in massive quantities, contain potential factors that can promote growth and are promising ingredients for serum replacement. The main goal of this study was to explore if food-grade by-product materials can be used as growth promoting agents in skeletal muscle cell culture to develop a tailor-made serum free media. Different by-products, including chicken carcass, cod backbone, eggshell membrane, egg white powder and pork plasma were enzymatically or chemically hydrolyzed. The hydrolysates in addition to lyophilized pork plasma and yeast extract were further characterized by size-exclusion chromatography, elemental combustion analysis and degree of hydrolysis. The materials were used as supplement to or replacement of commercial serum and further evaluated for their effect on metabolic activity, cell proliferation and cell cytotoxicity in muscle cells cultured in vitro. Our results indicate that none of the materials were cytotoxic to the skeletal muscle cells. Hydrolysates rich in peptides with approximately 2–15 amino acids in length were shown to improve cell growth and metabolic activity. Of all the materials tested pork plasma hydrolysates and yeast extract were the most promising. Pork plasma hydrolysates increased metabolic activity by 110% and cell proliferation with 48% when cultured in serum-free conditions for 3 days compared with control cells cultured with full serum conditions. Most interestingly, this response was dependent on both material and choice of enzyme used. We suggest that these materials have the potential to replace serum during cultivation and as such be included in a tailor-made serum-free media.submittedVersio

Vitamin K2 improves proliferation and migration of bovine skeletal muscle cells in vitro

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