Ammonia elicits a different myogenic response in avian and murine myotubes

Ammonia Emission in Poultry Facilities: A Review for Tropical Climate Areas

Brazil is the largest broiler meat exporter in the world. This important economic activity generates income in different branches of the production chain. However, the decomposition of residues incorporated in the poultry litter generates several gases, among them ammonia. When emitted from the litter to the air, ammonia can cause several damages to animals and man, in addition to being able to convert into a greenhouse gas. Thus, the aim of this article was to carry out a review of the ammonia emission factors in the production of broilers, the methodologies for measuring, and the inventories of emissions already carried out in several countries. The main chemical processes for generating ammonia in poultry litter have been introduced and some practices that can contribute to the reduction of ammonia emissions have been provided. The PMU, Portable Monitoring Unit, and the SMDAE, Saraz Method for Determination of Ammonia Emissions, with the required adaptations, are methodologies that can be used to quantify the ammonia emissions in hybrid facilities with a natural and artificial ventilation system. An ammonia emission inventory can contribute to the control and monitoring of pollutant emissions and is an important step towards adopting emission reductions. However, quantifying the uncertainties about ammonia emission inventories is still a challenge to be overcome.

Exploring the Multimodal Role of Yucca schidigera Extract in Protection against Chronic Ammonia Exposure Targeting: Growth, Metabolic, Stress and Inflammatory Responses in Nile Tilapia (Oreochromis niloticus L.)

Simple Summary

Ammonia is a problematic environmental toxicant for aquatic species. The current study aimed to declare the modulatory effect(s) of YSE against chronic ammonia intoxication in Nile tilapia through its effects on growth performance, haemato-biochemical and antioxidant-related parameters, and histopathological changes, as well as the molecular gene expression of some genes related to appetite and growth, glucose and lipid metabolism and some inflammatory cytokines. Our results indicated that Yucca schidigera extract alleviated the adverse impacts induced by ammonia intoxication. YSE could be used as a functional water supplement in aquaculture.

Abstract

Ammonia is a critical hazardous nitrogen metabolic product in aquaculture. Despite trials for its control, ammonia intoxication remains one of the most critical issues to overcome. In this study, we explored the modulatory effect and potential mechanism by which Yucca schidigera extract (YSE) can ameliorate ammonia intoxication-induced adverse effects on tilapia health and metabolism. A total number of 120 Nile tilapia were evenly assigned into four groups with three replicates each. The first group served as normal control group; the second group was exposed to ammonia alone from the beginning of the experiment and for four weeks. The third group was supplied with YSE in water at a dose of 8 mg/L and exposed to ammonia. The fourth group was supplied with YSE only in water at a dose of 8 mg/L. YSE supplementation succeeded in improving water quality by reducing pH and ammonia levels. Moreover, YSE supplementation markedly alleviated chronic ammonia-induced adverse impacts on fish growth by increasing the final body weight (FBW), specific growth rate (SGR), feed intake and protein efficiency ratio (PER) while reducing the feed conversion ratio (FCR) via improvements in food intake, elevation of hepatic insulin-like growth factor (ILGF-1) and suppression of myostatin (MSTN) expression levels with the restoration of lipid reserves and the activation of lipogenic potential in adipose tissue as demonstrated by changes in the circulating metabolite levels. In addition, the levels of hepato-renal injury biomarkers were restored, hepatic lipid peroxidation was inhibited and the levels of hepatic antioxidant biomarkers were enhanced. Therefore, the current study suggests that YSE supplementation exerted an ameliorative role against chronic ammonia-induced oxidative stress and toxic effects due to its free radical-scavenging potential, potent antioxidant activities and anti-inflammatory effects.

Considerations for the development of cost-effective cell culture media for cultivated meat production

Innovation in cultivated meat development has been rapidly accelerating in recent years because it holds the potential to help attenuate issues facing production of dietary protein for a growing world population. There are technical obstacles still hindering large-scale commercialization of cultivated meat, of which many are related to the media that are used to culture the muscle, fat, and connective tissue cells. While animal cell culture media has been used and refined for roughly a century, it has not been specifically designed with the requirements of cultivated meat in mind. Perhaps the most common industrial use of animal cell culture is currently the production of therapeutic monoclonal antibodies, which sell for orders of magnitude more than meat. Successful production of cultivated meat requires media that is food grade with minimal cost, can regulate large-scale cell proliferation and differentiation, has acceptable sensory qualities, and is animal ingredient-free. Much insight into strategies for achieving media formulations with these qualities can be obtained from knowledge of conventional culture media applications and from the metabolic pathways involved in myogenesis and protein synthesis. In addition, application of principles used to optimize media for large-scale microbial fermentation processes producing lower value commodity chemicals and food ingredients can also be instructive. As such, the present review shall provide an overview of the current understanding of cell culture media as it relates to cultivated meat.

Myogenic Response to Increasing Concentrations of Ammonia Differs between Mammalian, Avian, and Fish Species: Cell Differentiation and Genetic Study

Ammonia is very toxic to the body and has detrimental effects on many different organ systems. Using cultured myoblast cells, we examined ammonia's effect on myostatin expression, a negative regulator of skeletal muscle growth, and myotube diameters. The objective of this study was to examine how murine, avian, and fish cells respond to increasing levels of ammonia up to 50 mM. The murine myoblast cell line (C2C12), primary chick, and primary tilapia myoblast cells were cultured and then exposed to 10, 25, and 50 mM ammonium acetate, sodium acetate, and an untreated control for 24 h. High levels of ammonia were detrimental to the C2C12 cells, causing increased Myostatin (MSTN) expression and decreased myotube diameters between 10 and 25 mM (p < 0.002). Ammonia at 10 mM continued the positive myogenic response in the chick, with lower MSTN expression than the C2C12 cells and larger myotube diameters, but the myotube diameter at 50 mM ammonium acetate was significantly smaller than those at 10 and 25 mM (p < 0.001). However, chick myotubes at 50 mM were still significantly larger than the sodium acetate-treated and untreated control (p < 0.001). The tilapia cells showed no significant difference in MSTN expression or myotube diameter in response to increasing the concentrations of ammonia. Overall, these results confirm that increasing concentrations of ammonia are detrimental to mammalian skeletal muscle, while chick cells responded positively at lower levels but began to exhibit a negative response at higher levels, as the tilapia experienced no detrimental effects. The differences in ammonia metabolism strategies between fish, avian, and mammalian species could potentially contribute to the differences between species in response to high levels of ammonia. Understanding how ammonia affects skeletal muscle is important for the treatment of muscle wasting observed in liver failure patients.

Skeletal Muscle and the Effects of Ammonia Toxicity in Fish, Mammalian, and Avian Species: A Comparative Review Based on Molecular Research

Typically, mammalian and avian models have been used to examine the effects of ammonia on skeletal muscle. Hyperammonemia causes sarcopenia or muscle wasting, in mammals and has been linked to sarcopenia in liver disease patients. Avian models of skeletal muscle have responded positively to hyperammonemia, differing from the mammalian response. Fish skeletal muscle has not been examined as extensively as mammalian and avian muscle. Fish skeletal muscle shares similarities with avian and mammalian muscle but has notable differences in growth, fiber distribution, and response to the environment. The wide array of body sizes and locomotion needs of fish also leads to greater diversity in muscle fiber distribution and growth between different fish species. The response of fish muscle to high levels of ammonia is important for aquaculture and quality food production but has not been extensively studied to date. Understanding the differences between fish, mammalian and avian species’ myogenic response to hyperammonemia could lead to new therapies for muscle wasting due to a greater understanding of the mechanisms behind skeletal muscle regulation and how ammonia effects these mechanisms. This paper provides an overview of fish skeletal muscle and ammonia excretion and toxicity in fish, as well as a comparison to avian and mammalian species.

Glutamine synthetase in avian muscle contributes to a positive myogenic response to ammonia compared with mammalian muscle

In mammalian models of cirrhosis, plasma ammonia concentration increases, having numerous adverse effects, including sarcopenia. The objective of this study was to identify differences between avian and mammalian myogenic response to applied ammonia and glutamine. Primary chicken breast and thigh, primary rat, and C₂C₁₂ myotubes were treated with ammonium acetate (AA, 10 mM) or glutamine (10 mM) for 24 h and compared with sodium acetate (10 mM) and untreated controls. Myostatin mRNA was significantly higher in C₂C₁₂ and rat myotubes treated with AA compared with glutamine and controls (P < 0.01), whereas myostatin was unchanged in chicken myotubes. AA-treated C₂C₁₂ myotubes had significantly higher glutamine synthetase (GS) mRNA expression compared with controls, but GS protein expression was unchanged. In contrast, GS mRNA expression was unchanged in thigh myotubes, but GS protein expression was significantly higher in AA-treated thigh myotubes (P < 0.05). In both breast and thigh myotubes, intracellular glutamine concentration was significantly increased in AA- and glutamine-treated myotubes compared with controls but was only increased in glutamine-treated C₂C₁₂ and rat myotubes (P < 0.05). Glutamine concentration was significantly higher in all treatment media collected from avian myotube cultures compared with both C₂C₁₂ and rat media (P < 0.01). Myotube diameter was significantly larger in avian myotubes after treatment with both AA and glutamine (P < 0.05). C₂C₁₂ and rat myotubes had a significantly smaller myotube diameter after AA treatment (P < 0.001). Altogether, these data support species differences in skeletal muscle ammonia metabolism and suggest that glutamine synthesis is a mechanism of ammonia utilization in avian muscle.

Differential ammonia metabolism and toxicity between avian and mammalian species, and effect of ammonia on skeletal muscle: A comparative review

Comparative aspects of ammonia toxicity, specific to liver and skeletal muscle and skeletal muscle metabolism between avian and mammalian species are discussed in the context of models for liver disease and subsequent skeletal muscle wasting. The purpose of this review is to present species differences in ammonia metabolism and to specifically highlight observed differences in skeletal muscle response to excess ammonia in avian species. Ammonia, which is produced during protein catabolism and is an essential component of nucleic acid and protein biosynthesis, is detoxified mainly in the liver. While the liver is consistent as the main organ responsible for ammonia detoxification, there are evolutionary differences in ammonia metabolism and nitrogen excretory products between avian and mammalian species. In patients with liver disease and all mammalian models, inadequate ammonia detoxification and successive increased circulating ammonia concentration, termed hyperammonemia, leads to severe skeletal muscle atrophy, increased apoptosis and reduced protein synthesis, altogether having deleterious effects on muscle size and strength. Previously, an avian embryonic model, designed to determine the effects of increased circulating ammonia on muscle development, revealed that ammonia elicits a positive myogenic response. Specifically, induced hyperammonemia in avian embryos resulted in a reduction in myostatin, a well-known inhibitor of muscle growth, expression, whereas myostatin expression is significantly increased in mammalian models of hyperammonemia. These interesting findings imply that species differences in ammonia metabolism allow avians to utilize ammonia for growth. Understanding the intrinsic physiological mechanisms that allow for ammonia to be utilized for growth has potential to reveal novel approaches to muscle growth in avian species and will provide new targets for preventing muscle degeneration in mammalian species.