Dietary supplementation with inosine-5′-monophosphate improves the functional, energetic, and antioxidant status of liver and muscle growth in pigs

Inosine 5′-monophosphate (5′-IMP) is an essential nucleotide for de novo nucleotide biosynthesis and metabolism of energy, proteins, and antioxidants. Nucleotides are conditionally essential, as they cannot be produced sufficiently rapidly to meet the needs of the body in situations of oxidative stress or rapid muscle growth. A deficient intake of nucleotides can result in decreased ATP and GTP synthesis and impaired metabolism. We demonstrated that supplementation of finishing pig diets with 5′-IMP reduces the relative weight of the liver, and increases oxygen consumption during mitochondrial respiration without changing the ADP/O ratio, indicating an increase in the respiratory efficiency of liver mitochondria. We also observed a reduction in liver lipid peroxidation and an increase in muscle creatine. Moreover, 5′IMP supplementation increases slaughter weight, lean meat yield, sarcomere length, and backfat thickness in finishing barrows, demonstrating influence on protein metabolism. We suggest that 5′-IMP supplementation increase the mitochondrial respiratory capacity when the liver metabolic activity is stimulated, enhances antioxidant defense, and promotes muscle growth in finishing barrows.

Targeting Tumor Associated Antigens For The Development of Hepatocellular Carcinoma Treatment.

DBN possess the ability to induce bladder tumor as well as in the liver, and oesophagus when it is administered in the body.Exposure to DBN can happen by different modes such as by ingestion,inhalation as well through dermal contact.In the present investigation an attempt has been done to identify ,isolate as well to purify he TAA from the liver mitochondria of the mice which was exposed to DBN. It was found that mitochondrial membrane surface protein of DBN-exposed animals exhibited differential expression when compared with the control animals. A low molecular weight (~14 kDa) protein was found to be over expressed on liver mitochondrial membrane upon DBN exposure in mice as compared with the normal control and identified as TAA, showing the sign that some of the proteins could be used as TAA for further study.These identification and molecular characterization of TAAs will provide the basis for the development of cancer vaccines targeting TAAs.

Apoptosis indices in liver cell mitochondria in B16/F10 melanoma growing in presence of chronic neurogenic pain

Введение. Печень по количеству, плотности митохондрий один из самых богатых органов, который также является критическим местом для множества метаболических путей. Цель исследования - изучение показателей апоптоза в митохондриях печени самок мышей линии С57ВL/6 при самостоятельном росте меланомы В16/F10 и на фоне коморбидной патологии - хронической нейрогенной боли. Методика. В эксперименте использовали мышей-самок (n=168) линии С57ВL/6. Группы: интактная (n=21); контрольная (n=21) - создание модели хронической нейрогенной боли (ХНБ), путем двусторонней перевязки седалищных нервов; группа сравнения (n=63) - подкожная трансплантация меланомы B16/F10; основная группа (ХНБ+B16/F10) (n=63) - подкожная трансплантация меланомы В16/F10 через 3 нед после моделировия ХНБ. В митохондриях печени методом ИФА определяли концентрацию: цитохрома С (нг/г белка), каспазы 9 (нг/г белка), Bcl-2 (нг/г белка), AIF (нг/г белка), кальция (Са 2+) (мМоль/г белка). Результаты. В митохондриях клеток печени через 1 нед роста меланомы относительно интактных значений фиксировали нарастание уровней AIF в 2,2 раза, цитохрома С в 1,7 раза (р<0,05) и снижение каспазы 9 в 2,0 раза; через 3 нед - падение кальция в 4,7 раза, AIF в 7,1 раза и цитохрома С в 1,7 раза (р<0,05) и накопление каспазы 9 - 1,6 раза (р<0,05). Развитие опухоли при ХНБ через 1 нед сопровождалось уменьшением концентрации AIF в 29,3 раза и цитохрома С в 2,0 раза по сравнению с контрольными значениями (ХНБ). Через 3 недели роста меланомы на фоне ХНБ фиксировали снижение уровней AIF в 6,6 раза, цитохрома С в 4,7 раза и кальция в 32,8 раза, уровень каспазы 9, напротив, повышался в 1,5 раза (р<0,05). Заключение. Наличие коморбидной патологии - ХНБ при опухолевом процессе способствует раннему возникновению нарушений в электронно-транспортной цепи митохондрий клеток печени. Background. The liver is one of the richest organs in terms of the number and density of mitochondria; it is also a critical site for many metabolic pathways. The aim of the study was to analyze indicators of apoptosis in liver mitochondria in female С57ВL/6 mice with B16/F10 melanoma growing alone and in presence of chronic neurogenic pain. Methods. Female С57ВL/6 mice (n=168) were studied. Animals were divided into groups: intact group (n=21); controls (n=21) with a model of chronic neurogenic pain (CNP) created by bilateral sciatic nerve ligation; comparison group (n=63) with subcutaneous transplantation of B16/F10 melanoma; main group (CNP+B16/F10) (n=63) with subcutaneous transplantation of B16/F10 melanoma 3 wks after modeling CNP. Cytochrome C (ng/g protein), caspase-9 (ng/g protein), Bcl-2 (ng/g protein), AIF (ng/g protein), and calcium (Ca2+) (mmol/g protein) were measured by ELISA in the liver mitochondrial fraction. Results. After 1 wk of melanoma growth, AIF increased by 2.2 times, cytochrome C increased by 1.7 times (p<0.05), and caspase-9 decreased by 2.0 times compared to the intact group values. After 3 wks, calcium decreased by 4.7 times, AIF by 7.1 times, cytochrome C by 1.7 times (p<0.05), and caspase-9 increased by 1.6 times (p<0.05). After 1 wk, tumor development in the presence of CNP was accompanied by decreases in AIF by 29.3 times and cytochrome C by 2.0 times, compared to control CNP values. After 3 wks of melanoma growth in presence of CNP, AIF decreased by 6.6 times, cytochrome C by 4.7 times, and calcium by 32.8 times. Caspase-9, on the contrary, increased by 1.5 times (p<0.05). Conclusions. The presence of CNP comorbidity during the tumor development facilitates earlier occurrence of disorders in the electron transport chain of hepatocyte mitochondria.

Age-Dependent Changes in the Function of Mitochondrial Membrane Permeability Transition Pore in Rat Liver Mitochondria

Mitochondria play an important role in the cell aging process. Changes in calcium homeostasis and/or increased reactive oxygen species (ROS) production lead to the opening of mitochondrial permeability transition pore (MPTP), depolarization of the inner mitochondrial membrane, and decrease of ATP production. Our work aimed to monitor age-related changes in the Ca2+ ion effect on MPTP and the ability of isolated rat liver mitochondria to accumulate calcium. The mitochondrial calcium retention capacity (CRC) was found to be significantly affected by the age of rats. Measurement of CRC values of the rat liver mitochondria showed two periods when 3 to17-week old rats were tested. 3-week and 17-week old rats showed lower CRC values than 7-week old animals. Similar changes were observed while testing calcium-induced swelling of rat liver mitochondria. These findings indicate that the mitochondrial energy production system is more resistant to calcium-induced MPTP opening accompanied by the damaging effect of ROS in adult rats than in young and aged animals.

Elovl2-Ablation Leads to Mitochondrial Membrane Fatty Acid Remodeling and Reduced Efficiency in Mouse Liver Mitochondria

The fatty acid elongase ELOngation of Very-Long-chain fatty acids protein 2 (ELOVL2) controls the elongation of polyunsaturated fatty acids (PUFA) producing precursors for omega-3, do-cosahexaenoic acid (DHA), and omega-6, docosapentaenoic acid (DPAn6) in-vivo. Expectedly, Elovl2-ablation drastically reduced the DHA and DPAn6 in liver mitochondrial membranes. Unexpectedly, however, total PUFAs levels decreased further than could be explained by Elovl2 ablation. The lipid peroxidation process was not involved in PUFAs reduction since malondial-dehyde-lysine (MDAL) and other oxidative stress biomarkers were not enhanced. The content of mitochondrial respiratory chain proteins remained unchanged. Still, membrane remodeling was associated with high voltage-dependent anion channel (VDAC) and adenine nucleotide trans-locase 2 (ANT2), a possible reflection of the increased demand on phospholipid transport to the mitochondria. Mitochondrial function was impaired despite preserved content of the respiratory chain proteins and the absence of oxidative damage. Oligomycin-insensitive oxygen consumption increased, and coefficients of respiratory control were reduced by 50%. The mitochondria became very sensitive to fatty acid-induced uncoupling and permeabilization, where ANT2 is involved. Mitochondrial volume and number of peroxisomes increased as revealed by transmission elec-tron microscopy. In conclusion, the results imply that endogenous DHA production is vital for the normal function of mouse liver mitochondria and could be relevant not only for mice but also for human metabolism.

Enhanced resistance to Ca2+-induced mitochondrial permeability transition in the long-lived red-footed tortoise Chelonoidis carbonaria

The interaction between supraphysiological cytosolic Ca2+ levels and mitochondrial redox imbalance mediates the mitochondrial permeability transition (MPT). MPT is involved in cell death, diseases, and aging. This study compared the liver mitochondrial Ca2+ retention capacity and oxygen consumption in the long-lived red-footed tortoise (Chelonoidis carbonaria) to the rat as a reference standard. Mitochondrial Ca2+ retention capacity, a quantitative measure of MPT sensitivity, was remarkably higher in tortoises than rats. This difference was minimized in the presence of the MPT inhibitors, ADP and cyclosporine A. However, the Ca2+ retention capacities of tortoise and rat liver mitochondria were similar when both MPT inhibitors were present simultaneously. NADH-linked phosphorylating respiration rates of tortoise liver mitochondria represented only 30% of the maximal electron transport system capacity, indicating a limitation imposed by the phosphorylation system. These results suggested underlying differences in putative MPT structural components (e.g. ATP synthase, adenine nucleotide translocase (ANT), and cyclophilin D) between tortoises and rats. Indeed, in tortoise mitochondria, titrations of inhibitors of the oxidative phosphorylation components revealed a higher limitation of ANT. Furthermore, cyclophilin D activity was approximately 70% lower in tortoises than in rats. Investigation of critical properties of mitochondrial redox control that affect MPT demonstrated that tortoise and rat liver mitochondria exhibited similar rates of H2O2 release and glutathione redox status. Overall, our findings suggest that constraints imposed by ANT and cyclophilin D, putative components or regulators of the MPT pore, are associated with the enhanced resistance to Ca2+-induced MPT in tortoises.

New Properties and Mitochondrial Targets of Polyphenol Agrimoniin as a Natural Anticancer and Preventive Agent

Agrimoniin is a polyphenol from the group of tannins with antioxidant and anticancer activities. It is assumed that the anticancer action of agrimoniin is associated with the activation of mitochondria-dependent apoptosis, but its mitochondrial targets have not been estimated. We examined the direct influence of agrimoniin on different mitochondrial functions, including the induction of the mitochondrial permeability transition pore (MPTP) as the primary mechanism of mitochondria-dependent apoptosis. Agrimoniin was isolated from Agrimonia pilosa Ledeb by multistep purification. The content of agrimoniin in the resulting substance reached 80%, as determined by NMR spectroscopy. The cytotoxic effect of purified agrimoniin was confirmed on the cultures of K562 and HeLa cancer cells by the MTT assay. When tested on isolated rat liver mitochondria, agrimoniin at a low concentration (10 µM) induced the low-amplitude swelling, which was inhibited by the MPTP inhibitors ADP and cyclosporine A, activated the opening of MPTP by calcium ions and stimulated the respiration supported by succinate oxidation. Also, agrimoniin reduced the electron acceptor DCPIP in a concentration-dependent manner and chelated iron ions. Owing to all these properties, agrimoniin can stimulate apoptosis or activate mitochondrial functions, which can be helpful in the prevention and elimination of stagnant pathological states.