Amino acids are organic compounds that are part of all tissues of the human body. They are responsible for metabolic processes and energy metabolism, ensuring the functioning of the body. Amino acids directly affect the state of the nervous system, regulating mental activity, mood and sleep.

These components are necessary for the formation of muscles, tendons and ligaments, as well as hair and skin. Without a sufficient amount of amino acids, active growth of muscle mass is impossible. In sports and fitness, amino acids increase the performance of an athlete and accelerate the process of building muscle mass. They help you recover faster after hard workouts and relieve muscle pain.

Beneficial properties of amino acids [1, p. 14]:

• creation of new cells;
• tissue regeneration;
• immune support;
• increase in muscle mass;
• normal course of metabolic processes;
• getting rid of excess weight;
• strengthening the nervous system and increasing concentration;
• providing the body with additional energy;
• improvement of the condition of skin, nails, hair.

Amino acids have antioxidant properties. These substances significantly slow down the aging process, keeping the skin young and elastic. They also stimulate sexual desire and increase libido.

All amino acids are divided into essential and non-essential. There are also partially replaceable substances that are synthesized in the human body in insufficient quantities. They can only be produced under certain conditions or during a certain age period.

Partially replaceable substances include cysteine, histidine, tyrosine, and arginine, which is not produced in children and adolescents. Sources of partially essential amino acids include lean meats, soybeans, peanuts, pumpkin seeds, cheese and lentils[2].

For proper functioning, the body uses 22 amino acids, of which 10 substances are synthesized independently. The remaining 9 components must be obtained from food or dietary supplements. The diet should also contain foods rich in partially essential amino acids[2].

Essential amino acids (BCAAs) are substances that are not produced by the human body. They can only come from food or synthetic food additives.

The category of essential amino acids includes 9 substances[3]:

• valine – a stimulant important for muscle metabolism and recovery after training;
• histidine is part of hemoglobin, stimulates tissue growth and repair;
• leucine – characterized by an anabolic effect, protects muscle tissue, and is also effective in the treatment of arthritis;
• isoleucine – promotes the formation of hemoglobin, accelerates muscle growth, helps cells absorb glucose;
• threonine – responsible for the balance of protein compounds in the body;
• methionine is a hepatoprotector and has a metabolic effect;
• lysine – has bactericidal properties, strengthens the immune system;
• tryptophan – an immunoprotector, participates in the synthesis of the hormone of happiness – serotonin;
• Phenylalanine is an important component used in the treatment of many diseases (vitiligo, ADHD, depressive disorders).

Nonessential amino acids include substances that are synthesized by the body itself. They are mainly produced in the liver.

List of essential amino acids[3]:

• asparagine – is involved in the production of ammonia and is necessary for the normal functioning of the nervous system;
• alanine – part of proteins and biologically active substances;
• proline – is an integral part of the collagen protein;
• glycine – part of biologically active compounds, acts as a receptor in the brain and spinal cord;
• carnitine – participates in the transport of fatty acids;
• taurine – plays an important role in lipid metabolism, accelerates wound healing;
• serine – a building material for creatine, is involved in the transformation of glycogen;
• ornithine – has anti-catabolic properties, used in sports medicine;
• glutamine – ensures muscle growth and strong immunity;
• glutamic acid – acts as a receptor.

Amino acids are necessary for athletes and ordinary people. These substances perform many important functions in the human body. Amino acids help you lose weight because they regulate metabolism and ensure the proper functioning of the digestive system.

The importance of amino acids for athletes cannot be overstated. With a lack of amino acids, it is difficult to imagine gaining muscle mass, effective training process and recovery from injuries.

Amino acids are found in most traditional foods and are also available as dietary supplements. The substances are safe to use and do not cause addiction or negative side effects.

Glutamine synthase: what kind of enzyme is this, and how does it promote metastasis?

The structure and functions of macrophages have been well studied, but the metabolic processes that occur in them still remain a mystery to scientists. Researchers decided to study the role of the enzyme glutamine synthase, which plays a decisive role in protein synthesis.

Macrophages in Cancer

Despite their primary role in fighting infections, some cancer cells have evolved strategies to survive by hijacking macrophages, effectively turning these immune sentinels into allies. This phenomenon allows cancer cells to thrive and metastasize, complicating treatment efforts. Tumors can release signals that reprogram macrophages into a “pro-tumor” phenotype, supporting tumor growth instead of attacking it.

Glutamine Synthase: Role and Impact

One critical enzyme in this process is glutamine synthase. This enzyme is essential for synthesizing glutamine, an amino acid that is vital for various cellular functions, including protein synthesis, nucleotide synthesis, and the maintenance of cellular energy levels. In the context of macrophages, glutamine synthase appears to play a pivotal role in maintaining their pro-tumor characteristics.

Recent research has illuminated the metabolic processes occurring within macrophages, which remain somewhat enigmatic. Scientists have focused on the role of glutamine synthase in modulating the behavior of these immune cells. The findings suggest that this enzyme is necessary for sustaining the pro-tumor phenotype of macrophages. Specifically, when glutamine synthase activity is inhibited, macrophages can revert to their original immune functions—actively combating cancer cells.

Metabolic Changes and Therapeutic Implications

Professor Massimiliano Mazzone, one of the leaders of the study, emphasizes the significance of these results: “Both in vitro and in vivo, to my surprise, the change in macrophage metabolism is evident in tumor growth. Inhibition of glutamine synthase led to altered cells returning to their original task—fighting cancer cells—and reestablishing their role in the immune system.” This suggests that targeting glutamine synthase could be a transformative approach in cancer therapy.

By blocking glutamine synthase, researchers observed a shift in macrophage metabolism that not only reinstated their tumor-fighting capabilities but also potentially reduced tumor angiogenesis—the formation of new blood vessels that supply nutrients to tumors. The suppression of this enzyme may thereby inhibit metastasis and impede cancer progression.

Future Directions in Cancer Treatment

The implications of this research are significant for the field of metabolic immunotherapy. Increased glutamine synthase activity has been identified as a marker of macrophage transformation in malignant tumors. By suppressing this enzyme, scientists believe they can alter cell metabolism to help inhibit cancer metastasis.

As a result, new therapeutic strategies may emerge, focusing on pharmacological inhibition of glutamine synthase or employing genetic engineering to modify macrophage behavior. An assay for detecting glutamine synthase inhibitors has already been developed, serving as a foundational step for future drug development.

The potential for new drug formulations based on these findings could revolutionize how we approach cancer treatment, particularly in countries facing rising cancer rates. Ultimately, understanding the metabolic intricacies of macrophages and their relationship with enzymes like glutamine synthase could lead to innovative therapies that enhance the immune response against cancer.

It turned out that glutamine synthase is necessary to maintain “pro-tumor” macrophages. Scientists assume that blocking this enzyme should activate glycolysis (the process of converting glucose into mass), which in turn affects the growth of blood vessels and helps prevent metastases. Professor Massimiliano Mazzone, one of the study’s leaders, comments on the results: “Both in vitro and in vivo, to my surprise, the change in macrophage metabolism is evident in tumor growth. Inhibition of glutamine synthase led to the fact that the altered cells returned to their original task – fighting cancer cells – and again became the basis of the immune system. Moreover, our results point to blocking glutamine synthase as a key therapeutic way to return macrophages to normal and prevent metastases. This can be done pharmacologically or using genetic engineering.” The results of this study, according to scientists, show that the methods of so-called metabolic immunotherapy are currently important in countries with cancer. Increased glutamine synthase activity is a marker of macrophage transformation in malignant tumors, and its suppression alters cell metabolism in a way that helps suppress cancer metastasis. The researchers believe that this finding opens up interesting possibilities for the development of new drugs. An assay for detecting glutamine synthase inhibitors has already been developed, but it will serve as a starting point for future drug development.