Anticancer Effect of Deuterium Depleted Water - Redox Disbalance Leads to Oxidative Stress

Heavy water inhibits DNA double-strand break repairs and disturbs cellular transcription, presumably via quantum-level mechanisms of kinetic isotope effects on hydrolytic enzyme reactions

Heavy water, containing the heavy hydrogen isotope, is toxic to cells, although the underlying mechanism remains incompletely understood. In addition, certain enzymatic proton transfer reactions exhibit kinetic isotope effects attributed to hydrogen isotopes and their temperature dependencies, indicative of quantum tunneling phenomena. However, the correlation between the biological effects of heavy water and the kinetic isotope effects mediated by hydrogen isotopes remains elusive. In this study, we elucidated the kinetic isotope effects arising from hydrogen isotopes of water and their temperature dependencies in vitro, focusing on deacetylation, DNA cleavage, and protein cleavage, which are crucial enzymatic reactions mediated by hydrolysis. Intriguingly, the intracellular isotope effects of heavy water, related to the in vitro kinetic isotope effects, significantly impeded multiple DNA double-strand break repair mechanisms crucial for cell survival. Additionally, heavy water exposure enhanced histone acetylation and associated transcriptional activation in cells, consistent with the in vitro kinetic isotope effects observed in histone deacetylation reactions. Moreover, as observed for the in vitro kinetic isotope effects, the cytotoxic effect on cell proliferation induced by heavy water exhibited temperature-dependency. These findings reveal the substantial impact of heavy water-induced isotope effects on cellular functions governed by hydrolytic enzymatic reactions, potentially mediated by quantum-level mechanisms underlying kinetic isotope effects.

Multifaceted Proteome Analysis at Solubility, Redox, and Expression Dimensions for Target Identification

Multifaceted interrogation of the proteome deepens the system-wide understanding of biological systems; however, mapping the redox changes in the proteome has so far been significantly more challenging than expression and solubility/stability analyses. Here, the first high-throughput redox proteomics approach integrated with expression analysis (REX) is devised and combined with the Proteome Integral Solubility Alteration (PISA) assay. The whole PISA-REX experiment with up to four biological replicates can be multiplexed into a single tandem mass tag TMTpro set. For benchmarking this compact tool, HCT116 cells treated with auranofin are analyzed, showing great improvement compared with previous studies. PISA-REX is then applied to study proteome remodeling upon stimulation of human monocytes by interferon α (IFN-α). Applying this tool to study the proteome changes in plasmacytoid dendritic cells (pDCs) isolated from wild-type versus Ncf1-mutant mice treated with interferon α, shows that NCF1 deficiency enhances the STAT1 pathway and modulates the expression, solubility, and redox state of interferon-induced proteins. Providing comprehensive multifaceted information on the proteome, the compact PISA-REX has the potential to become an industry standard in proteomics and to open new windows into the biology of health and disease.

The biological impact of deuterium and therapeutic potential of deuterium-depleted water

Since its discovery by Harold Urey in 1932, deuterium has attracted increased amounts of attention from the scientific community, with many previous works aimed to uncover its biological effects on living organisms. Existing studies indicate that deuterium, as a relatively rare isotope, is indispensable for maintaining normal cellular function, while its enrichment and depletion can affect living systems at multiple levels, including but not limited to molecules, organelles, cells, organs, and organisms. As an important compound of deuterium, deuterium-depleted water (DDW) possess various special effects, including but not limited to altering cellular metabolism and potentially inhibiting the growth of cancer cells, demonstrating anxiolytic-like behavior, enhancing long-term memory in rats, reducing free radical oxidation, regulating lipid metabolism, harmonizing indices related to diabetes and metabolic syndrome, and alleviating toxic effects caused by cadmium, manganese, and other harmful substances, implying its tremendous potential in anticancer, neuroprotective, antiaging, antioxidant, obesity alleviation, diabetes and metabolic syndrome treatment, anti-inflammatory, and detoxification, thereby drawing extensive attention from researchers. This review comprehensively summarizes the latest progress in deuterium acting on living organisms. We start by providing a snapshot of the distribution of deuterium in nature and the tolerance of various organisms to it. Then, we discussed the impact of deuterium excess and deprivation, in the form of deuterium-enriched water (DEW) and deuterium-depleted water (DDW), on living organisms at different levels. Finally, we focused on the potential of DDW as an adjuvant therapeutic agent for various diseases and disorders.

Deuterium-Depleted Water in Cancer Therapy: A Systematic Review of Clinical and Experimental Trials

Chemotherapy exhibits numerous side effects in anti-tumour therapy. The clinical experiments indicated that deuterium-depleted water (DDW) monotherapy or in combination with chemotherapy was beneficial in inhibiting cancer development. To further understand the potential mechanism of DDW in cancer therapy, we performed a systematic review. The data from experiments published over the past 15 years were included. PubMed, Cochrane and Web of Science (January 2008 to November 2023) were systemically searched. Fifteen studies qualified for review, including fourteen in vivo and in vitro trials and one interventional trial. The results showed that DDW alone or in combination with chemotherapy effectively inhibited cancer progression in most experiments. The combination treatment enhances the therapeutic effect on cancer compared with chemotherapeutic monotherapy. The inhibitory role of DDW in tumours is through regulating the reactive oxygen species (ROS)-related genes in Kelch-like ECH-associated protein 1 (Keap 1) and Nuclear erythroid 2-related factor 2 (Nrf2) signalling pathways, further controlling ROS production. An abnormal amount of ROS can inhibit the tumour progression. More extensive randomized controlled trials should be conducted to evaluate the accurate effect of DDW in Keap1-Nrf2 signalling pathways.

Effects of Deuterium Depletion on Age-Declining Thymopoiesis In Vivo

The thymus provides maturation and migration of T cells to peripheral organs of immunity, where they recognize diverse antigens and maintain immunological memory and self-tolerance. The thymus is known to be involved with age and in response to stress factors. Therefore, the search for approaches to the restoration of thymopoiesis is of great interest. The present investigation was aimed at evaluating how prolonged deuterium depletion affects morphogenetic processes and the physiological transition of the thymus to age-related involution. The study was performed on 60 male Wistar rats subjected to consumption of deuterium-depleted water with a 10 ppm deuterium content for 28 days. The control rats consumed distilled water with a normal deuterium content of 150 ppm. The examination found no significant differences in body weight gain or the amount of water consumed. The exposed rats exhibited similar to control dynamics of the thymus weight but significant changes in thymic cell maturation according to cytofluorimetric analysis of thymic subpopulations. Changes in T cell production were not monotonic and differentially engaged morphogenetic processes of cell proliferation, differentiation, and migration. The reactive response to deuterium depletion was a sharp increase in the number of progenitor CD4-CD8- cells and their differentiation into T cells. The compensatory reaction was inhibition of thymopoiesis with more pronounced suppression of differentiation of T-cytotoxic lymphocytes, followed by intensification of emigration of mature T cells to the bloodstream. This period lasts from 3 to 14 days, then differentiation of thymic lymphocytes is restored, later cell proliferation is activated, and finally the thymopoiesis rate exceeds the control values. The increase in the number of thymic progenitor cells after 3-4 weeks suggests consideration of deuterium elimination as a novel approach to prevent thymus involution.

How Mitochondrial Signaling Games May Shape and Stabilize the Nuclear-Mitochondrial Symbiosis

The eukaryotic lineage has enjoyed a long-term "stable" mutualism between nucleus and mitochondrion, since mitochondrial endosymbiosis began about 2 billion years ago. This mostly cooperative interaction has provided the basis for eukaryotic expansion and diversification, which has profoundly altered the forms of life on Earth. While we ignore the exact biochemical details of how the alpha-proteobacterial ancestor of mitochondria entered into endosymbiosis with a proto-eukaryote, in more general terms, we present a signaling games perspective of how the cooperative relationship became established, and has been maintained. While games are used to understand organismal evolution, information-asymmetric games at the molecular level promise novel insights into endosymbiosis. Using a previously devised biomolecular signaling games approach, we model a sender-receiver information asymmetric game, in which the informed mitochondrial sender signals and the uninformed nuclear receiver may take actions (involving for example apoptosis, senescence, regeneration and autophagy/mitophagy). The simulation shows that cellularization is a stabilizing mechanism for Pareto efficient sender/receiver strategic interaction. In stark contrast, the extracellular environment struggles to maintain efficient outcomes, as senders are indifferent to the effects of their signals upon the receiver. Our hypothesis has translational implications, such as in cellular therapy, as mitochondrial medicine matures. It also inspires speculative conjectures about how an analogous human-AI endosymbiosis may be engineered.

Ultralight Ultrafast Enzymes

Inorganic materials depleted of heavy stable isotopes are known to deviate strongly in some physicochemical properties from their isotopically natural counterparts. Here we explored for the first time the effect of simultaneous depletion of the heavy carbon, hydrogen, oxygen and nitrogen isotopes on the bacterium E. coli and the enzymes expressed in it. Bacteria showed faster growth, with most proteins exhibiting higher thermal stability, while for recombinant enzymes expressed in depleted media, faster kinetics was discovered. At room temperature, luciferase, thioredoxin and dihydrofolate reductase and Pfu DNA polymerase showed up to a 250 % increase in activity compared to the native counterparts, with an additional ∼50 % increase at 10 °C. Diminished conformational and vibrational entropy is hypothesized to be the cause of the accelerated kinetics. Ultralight enzymes may find an application where extreme reaction rates are required.

Effect of Uncaria tomentosa aqueous extract on the response to palmitate-induced lipotoxicity in cultured skeletal muscle cells

BACKGROUND

Type 2 diabetes mellitus (T2DM) is frequently associated with dyslipidemia, which corresponds to the increase in the triglycerides and fatty acid concentrations in tissues, such as the skeletal muscle. Also, T2DM molecular mechanism involves increasing in reactive oxygen species (ROS) production and oxidative stress. The use of herbal medicines such as Uncaria tomentosa (Ut) has been proposed as an auxiliary treatment for patients with T2DM. In this study, it was evaluated the effect of Ut aqueous extract on cell viability and ROS production, in skeletal myoblasts from C2C12 lineage exposed to the free fatty acid palmitate (PA).

METHODS

Cells were incubated with PA in different concentrations ranging from 10 to 1000 μM, for 24 or 48 h, for cytotoxicity assay. Cell death, DNA fragmentation and ROS production assays were performed in cell cultures incubated with PA for 24 h, in the pre (preventive condition) or post treatment (therapeutic condition) with 250 μg/ml Ut aqueous extract, for 2 or 6 h. Cell death was evaluated by MTT method or flow cytometry. ROS generation was measured by fluorescence spectroscopy using the DCFDA probe.

RESULTS

Cell viability was reduced to approximately 44% after the incubation with PA for 24 h from the concentration of 500 µM. In the incubation of cells with 500 μM PA and Ut extract for 6 h, in both conditions (preventive or therapeutic), it was observed an increase of 27 and 70% in cell viability respectively, in comparison to the cultures incubated with only PA. Also, the incubation of cultures with 500 μM PA, for 24 h, increased 20-fold the ROS formation, while the treatment with Ut extract, for 6 h, both in the preventive or therapeutic conditions, promoted decrease of 21 and 55%, respectively.

CONCLUSION

The Ut extract was efficient in promoting cell protection against PA lipotoxicity and ROS generation, potentially preventing oxidative stress in C2C12 skeletal muscle cells. Since T2DM molecular mechanism involves oxidative stress condition and it is often associated with dyslipidemia and fatty acid accumulation in muscle tissue, these results open perspectives for the use of Ut as an auxiliary strategy for T2DM management.

Synergistic anticancer effects of crocin combined with deuterium-depleted water on HT-29 cells

Colorectal cancer is one of the most common types of cancer in the world and the study of the role of nutrients in preventing or inhibiting the growth of this cancer is of interest to scientists. In this article, the synergistic effect of deuterium-depleted water(DDW) and crocin at specific concentrations on HT-29 cells was investigated. In this regard, HT-29 cells were grown in RPMI medium containing DDW, alone and in combination with crocin for 24, 48 and 72 h. Cell viability, cell cycle changes and antioxidant enzymes status were determined by MTT assay, flow cytometry and quantitative luminescence methods, respectively. The results of these analyses proved the cell growth inhibitory effect of deuterium alone and its synergistic effect in combination with crocin. The cell cycle analysis showed an increase in the number of cells in the G0 and G1 phases whereas there was a decrease in the number of cells in the S, G2 and M phases. The activities of superoxide dismutase and catalase enzymes also decreased compared to the control group that is a reason to increase Malonyl dialdehyde factor. The results suggested that a combination of DDW and crocin can open a new strategic approach in the prevention and treatment of colorectal cancer.

A Preliminary Study Indicating Improvement in the Median Survival Time of Glioblastoma Multiforme Patients by the Application of Deuterium Depletion in Combination with Conventional Therapy

Glioblastoma multiforme (GBM) and malignant gliomas are the most common primary malignant brain tumors. Temozolomide (TMZ) chemotherapy plus radiation therapy (RT), admi-mistered after debulking surgery, increased the median survival time (MST) from 12.1 months with RT alone merely to 14.6 months, respectively. In this study, the actions of deuterium-depleted water (DDW) on the survival of GBM patients who also received conventional therapies was investigated. Without changing the conventional treatment, the daily fluid intake of the patients was wholly replaced with DDW in 1.5-2 L per day volume to reduce the D concentration in their bodies. The primary endpoint was the MST. The 55 patients involved in this study, who received conventional treatment and consumed DDW, showed a longer MST (30 months) compared to the historical control (12.1-14.6 months). There was a massive difference between the two genders in the calculated MST values; it was 25 months in the male subgroup (n = 33) and 42 months in the female subgroup (n = 22), respectively. The MST was 27 months without TMZ treatment (38 patients) and 42 months in the TMZ-treated group (17 patients), respectively. For the selected 31 patients, who consumed DDW in the correct way in addition to their conventional treatments, their MST was calculated as 30 months. Within this group, the 20 subjects who had relapsed before DDW treatment had 30 months of MST, but in those 10 subjects who were in remission when DDW treatment started, their MST was 47 months. In the subgroup of patients who began their DDW treatment parallel with radiotherapy, their MST was again 47 months, and it was 25 months when their DDW treatment was started at 8 weeks or later after the completion of radiotherapy. Altogether, these survival times were substantially prolonged compared to the prospective clinical data of patients with primary GBM. Consequently, if conventional therapies are supplemented with D depletion, better survival can be achieved in the advanced stage of GBM than with the known targeted or combination therapies. Application of DDW is recommended in all stages of the disease before surgery and in parallel with radiotherapy, and repeated DDW courses are advised when remission has been achieved.

Bilateral Shifts in Deuterium Supply Similarly Change Physiology of the Pituitary–Thyroid Axis, but Differentially Influence Na+/I− Symporter Production

Deuterium, a stable isotope of hydrogen, is abundant in organisms. It is known to produce various biological effects. However, its impact in thyroid hormone synthesis and secretion is poorly studied. The aim of this investigation was to evaluate the dynamics of thyroid hormones and pituitary thyroid-stimulating hormone secretion during bilateral shifts in deuterium supply and assess a possible role of the Na+/I− symporter (NIS), the main iodide transporter, in altered thyroid function. The experiment was performed on adult male Wistar rats, which consumed deuterium-depleted ([D] = 10 ppm) and deuterium-enriched ([D] = 500,000 ppm) water for 21 days. The assessment of total thyroxine and triiodothyronine and their free fractions, as well as thyroid-stimulating hormone in blood serum, revealed the rapid response of the thyroid gland to shifts in the deuterium/protium balance. The present investigation shows that the bilateral changes in the deuterium body content similarly modulate thyroid hormone production and functional activity of the pituitary gland, but the responses of the thyroid and pituitary glands differ. The response of the thyroid cells was to increase the synthesis of the hormones and the pituitary thyrotropes, in order to reduce the production of the thyroid-stimulating hormone. The evaluation of NIS serum levels found a gradual increase in the rats that consumed deuterium-enriched water and no differences in the group exposed to deuterium depletion. NIS levels in both groups did not correlate with thyroid hormones and pituitary thyroid-stimulating hormone production. The data obtained show that thyroid gland has a higher sensitivity to shifts in the deuterium body content than the hypothalamic–pituitary complex, which responded later but similarly in the case of deuteration or deuterium depletion. It indicates a different sensitivity of the endocrine glands to alterations in deuterium content. It suggests that thyroid hormone production rate may depend on deuterium blood/tissue and cytosol/organelle gradients, which possibly disturb the secretory process independently of the NIS.

Emerging Role of Deuterium/Protium Disbalance in Cell Cycle and Apoptosis

Deuterium, a stable isotope of hydrogen, is a component of water and organic compounds. It is the second most abundant element in the human body after sodium. Although the concentration of deuterium in an organism is much lower than that of protium, a wide variety of morphological, biochemical, and physiological changes are known to occur in deuterium-treated cells, including changes in fundamental processes such as cell division or energy metabolism. The mode and degree of changes in cells and tissues, both with an increase and a decrease in the concentration of deuterium, depends primarily on the time of exposure, as well as on the concentration. The reviewed data show that plant and animal cells are sensitive to deuterium content. Any shifts in the D/H balance outside or inside cells promote immediate responses. The review summarizes reported data on the proliferation and apoptosis of normal and neoplastic cells in different modes of deuteration and deuterium depletion in vivo and in vitro. The authors propose their own concept of the effects of changes in deuterium content in the body on cell proliferation and death. The altered rate of proliferation and apoptosis indicate a pivotal role of the hydrogen isotope content in living organisms and suggest the presence of a D/H sensor, which is yet to be detected.

The underexplored links between cancer and the internal body climate: Implications for cancer prevention and treatment

In order to effectively manage and cure cancer we should move beyond the general view of cancer as a random process of genetic alterations leading to uncontrolled cell proliferation or simply a predictable evolutionary process involving selection for traits that increase cell fitness. In our view, cancer is a systemic disease that involves multiple interactions not only among cells within tumors or between tumors and surrounding tissues but also with the entire organism and its internal "milieu". We define the internal body climate as an emergent property resulting from spatial and temporal interactions among internal components themselves and with the external environment. The body climate itself can either prevent, promote or support cancer initiation and progression (top-down effect; i.e., body climate-induced effects on cancer), as well as be perturbed by cancer (bottom-up effect; i.e., cancer-induced body climate changes) to further favor cancer progression and spread. This positive feedback loop can move the system towards a "cancerized" organism and ultimately results in its demise. In our view, cancer not only affects the entire system; it is a reflection of an imbalance of the entire system. This model provides an integrated framework to study all aspects of cancer as a systemic disease, and also highlights unexplored links that can be altered to both prevent body climate changes that favor cancer initiation, progression and dissemination as well as manipulate or restore the body internal climate to hinder the success of cancer inception, progression and metastasis or improve therapy outcomes. To do so, we need to (i) identify cancer-relevant factors that affect specific climate components, (ii) develop 'body climate biomarkers', (iii) define 'body climate scores', and (iv) develop strategies to prevent climate changes, stop or slow the changes, or even revert the changes (climate restoration).

A novel deuterium-based model for measurement of exogenous surfactant using deuterium-depleted water

Stable isotope tracers, like ¹³ C, can be used for the measurement of the partition between the endogenous and exogenous pulmonary disaturated-phosphatidylcholine (DSPC). Deuterium labeling methods are still not fully explored. Our aim was to investigate the feasibility of using deuterium-depleted water (DDW) and deuterium-enriched water (DEW) to measure endogenous and exogenous pulmonary DSPC in a rabbit model of surfactant depletion. Data obtained from the ¹³ C dilution method were used as a reference. We studied 9 adult rabbits: 4 drank DDW and 5 DEW for 5 days. Lung surfactant depletion was induced at Day 5 by repeated saline bronchoalveolar lavages (BAL), which were stored as a pool (BAL pool). After endogenous surfactant depletion, rabbits received exogenous surfactant followed by a second BAL depletion procedure (End-Experiment Pool). DSPC quantity, and palmitic acid (PA)-DSPC ² H/¹ H (δ² H) and ¹³ C/¹² C ratios (δ¹³ C) of exogenous surfactant batches and of BAL pools were measured by High-Resolution Mass Spectrometry. The amount of exogenous surfactant recovered from the lungs ranged from 45% to 81% and, it was highly correlated with those obtained with the use of the ¹³ C (r = 0.9844, p < 0.0001). We demonstrated that commercially available purified DDW and even low doses of DEW can be used to modify the deuterium background of endogenous surfactants with the purpose of measuring the contribution of exogenous surfactants to the endogenous alveolar surfactant pool.

Deuterium-depleted water: A new tracer to label pulmonary surfactant lipids in adult rabbits

Stable isotope tracing can be safely used for metabolic studies in animals and humans. The endogenous biosynthesis of lipids (lipogenesis) is a key process throughout the entire life but especially during brain and lung growth. Adequate synthesis of pulmonary surfactant lipids is indispensable for life. With this study, we report the use of deuterium-depleted water (DDW), suitable for human consumption, as metabolic precursor for lipogenesis. We studied 13 adult rabbits for 5 days. Four rabbits drank tap water (TW) and served as controls; in four animals, DDW was substituted to drinking water, whereas five drank deuterium-enriched water (DEW). After 5 days, a blood sample and a bronchoalveolar lavage (BAL) sample were collected. The ² H/¹ H (δ² H) of BAL palmitic acid (PA) desaturated phosphatidylcholine (DSPC), the major phospholipid of pulmonary surfactant, and of plasma water was determined by high-resolution mass spectrometry. We found that the δ² H values of DDW, DEW and TW were -984 ± 2‰, +757 ± 2‰ and -58 ± 1‰, respectively. After 5 days, plasma water values were -467 ± 87‰, +377 ± 56‰ and -53 ± 6‰, and BAL DSPC-PA was -401 ± 27‰, -96 ± 38‰ and -249 ± 9‰ in the DDW, DEW and TW, respectively. With this preliminary study, we demonstrated the feasibility of using DDW to label pulmonary surfactant lipids. This novel approach can be used in animals and in humans, and we speculate that it could be associated with more favourable study compliance than DEW in human studies.

Blocking the Increase of Intracellular Deuterium Concentration Prevents the Expression of Cancer-Related Genes, Tumor Development, and Tumor Recurrence in Cancer Patients

The possible role of the naturally occurring deuterium in the regulation of cell division was first described in the 1990s. To investigate the mechanism of influence of deuterium (D) on cell growth, expression of 236 cancer-related and 536 kinase genes were tested in deuterium-depleted (40 and 80 ppm) and deuterium-enriched (300 ppm) media compared to natural D level (150 ppm). Among genes with expression changes exceeding 30% and copy numbers over 30 (124 and 135 genes, respectively) 97.3% of them was upregulated at 300 ppm D-concentration. In mice exposed to chemical carcinogen, one-year survival data showed that deuterium-depleted water (DDW) with 30 ppm D as drinking water prevented tumor development. One quarter of the treated male mice survived 344 days, the females 334 days, while one quarter of the control mice survived only 188 and 156 days, respectively. In our human retrospective study 204 previously treated cancer patients with disease in remission, who consumed DDW, were followed. Cumulative follow-up time was 1024 years, and average follow-up time per patient, 5 years (median: 3.6 years). One hundred and fifty-six patients out of 204 (77.9%) did not relapse during their 803 years cumulative follow-up time. Median survival time (MST) was not calculable due to the extremely low death rate (11 cancer-related deaths, 5.4% of the study population). Importantly, 8 out of 11 deaths occurred several years after stopping DDW consumption, confirming that regular consumption of DDW can prevent recurrence of cancer. These findings point to the likely mechanism in which consumption of DDW keeps D-concentration below natural levels, preventing the D/H ratio from increasing to the threshold required for cell division. This in turn can serve as a key to reduce the relapse rate of cancer patients and/or to reduce cancer incidence in healthy populations.

Reduction of Deuterium Level Supports Resistance of Neurons to Glucose Deprivation and Hypoxia: Study in Cultures of Neurons and on Animals

The effect of a reduced deuterium (D) content in the incubation medium on the survival of cultured neurons in vitro and under glucose deprivation was studied. In addition, we studied the effect of a decrease in the deuterium content in the rat brain on oxidative processes in the nervous tissue, its antioxidant protection, and training of rats in the T-shaped maze test under hypoxic conditions. For experiments with cultures of neurons, 7-8-day cultures of cerebellar neurons were used. Determination of the rate of neuronal death in cultures was carried out using propidium iodide. Acute hypoxia with hypercapnia was simulated in rats by placing them in sealed vessels with a capacity of 1 L. The effect on oxidative processes in brain tissues was assessed by changes in the level of free radical oxidation and malondialdehyde. The effect on the antioxidant system of the brain was assessed by the activity of catalase. The study in the T-maze was carried out in accordance with the generally accepted methodology, the skill of alternating right-sided and left-sided loops on positive reinforcement was developed. This work has shown that a decrease in the deuterium content in the incubation medium to a level of -357‱ has a neuroprotective effect, increasing the survival rate of cultured neurons under glucose deprivation. When exposed to hypoxia, a preliminary decrease in the deuterium content in the rat brain to -261‱ prevents the development of oxidative stress in their nervous tissue and preserves the learning ability of animals in the T-shaped maze test at the level of the control group. A similar protective effect during the modification of the 2H/1H internal environment of the body by the consumption of DDW can potentially be used for the prevention of pathological conditions associated with the development of oxidative stress with damage to the central nervous system.

Deuterium-depleted water stimulates GLUT4 translocation in the presence of insulin, which leads to decreased blood glucose concentration

Deuterium (D) is a stable isotope of hydrogen (H) with a mass number of 2. It is present in natural waters in the form of HDO, at a concentration of 16.8 mmol/L, equivalent to 150 ppm. In a phase II clinical study, deuterium depletion reduced fasting glucose concentration and insulin resistance. In this study, we tested the effect of subnormal D-concentration on glucose metabolism in a streptozotocin (STZ)-induced diabetic rat model. Animals were randomly distributed into nine groups to test the effect of D2O (in a range of 25-150 ppm) on glucose metabolism in diabetic animals with or without insulin treatment. Serum glucose, fructose amine-, HbA1c, insulin and urine glucose levels were monitored, respectively. After the 8-week treatment, membrane-associated GLUT4 fractions from the soleus muscle were estimated by Western blot technique. Our results indicate that, in the presence of insulin, deuterium depletion markedly reduced serum levels of glucose, -fructose amine, and -HbA1c, in a dose-dependent manner. The optimal concentration of deuterium was between 125 and 140 ppm. After a 4-week period of deuterium depletion, the highest membrane-associated GLUT4 content was detected at 125 ppm. These data suggest that deuterium depletion dose-dependently enhances the effect of insulin on GLUT4 translocation and potentiates glucose uptake in diabetic rats, which explains the lower serum glucose, -fructose amine, and -HbA1c concentrations. Based on our experimental data, deuterium-depleted water could be used to treat patients with metabolic syndrome (MS) by increasing insulin sensitivity. These experiments indicate that naturally occurring deuterium has an impact on metabolic regulations.

Association of the malate dehydrogenase-citrate synthase metabolon is modulated by intermediates of the Krebs tricarboxylic acid cycle

Mitochondrial malate dehydrogenase (MDH)-citrate synthase (CS) multi-enzyme complex is a part of the Krebs tricarboxylic acid (TCA) cycle ‘metabolon’ which is enzyme machinery catalyzing sequential reactions without diffusion of reaction intermediates into a bulk matrix. This complex is assumed to be a dynamic structure involved in the regulation of the cycle by enhancing metabolic flux. Microscale Thermophoresis analysis of the porcine heart MDH-CS complex revealed that substrates of the MDH and CS reactions, NAD⁺ and acetyl-CoA, enhance complex association while products of the reactions, NADH and citrate, weaken the affinity of the complex. Oxaloacetate enhanced the interaction only when it was present together with acetyl-CoA. Structural modeling using published CS structures suggested that the binding of these substrates can stabilize the closed format of CS which favors the MDH-CS association. Two other TCA cycle intermediates, ATP, and low pH also enhanced the association of the complex. These results suggest that dynamic formation of the MDH-CS multi-enzyme complex is modulated by metabolic factors responding to respiratory metabolism, and it may function in the feedback regulation of the cycle and adjacent metabolic pathways.

Response of Pituitary-Thyroid Axis to a Short-Term Shift in Deuterium Content in the Body

We studied functional changes in rat pituitary-thyroid axis after a short-term shift in deuterium body content. Male Wistar rats consumed deuterium-enriched (500,000 ppm) or deuterium-depleted water (10 ppm) for 24 h. Rats of both experimental groups demonstrated elevated concentration of bound with transport proteins thyroxine and reduced level of thyroid-stimulating hormone in serum. No changes in the rate of thyroxine conversion to triiodothyronine were found. Thus, both the increase and reduction of deuterium body content produced similar changes in the function of the pituitary-thyroid axis with primary affection of the thyroid gland, indicative of its higher sensitivity to shift in deuterium levels.

Kinetic isotope effects and synthetic strategies for deuterated carbon-11 and fluorine-18 labelled PET radiopharmaceuticals

The deuterium labelling of pharmaceuticals is a useful strategy for altering pharmacokinetic properties, particularly for improving metabolic resistance. The pharmacological effects of such metabolites are often assumed to be negligible during standard drug discovery and are factored in later at the clinical phases of development, where the risks and benefits of the treatment and side-effects can be wholly assessed. This paradigm does not translate to the discovery of radiopharmaceuticals, however, as the confounding effects of radiometabolites can inevitably show in preliminary positron emission tomography (PET) scans and thus complicate interpretation. Consequently, the formation of radiometabolites is crucial to take into consideration, compared to non-radioactive metabolites, and the application of deuterium labelling is a particularly attractive approach to minimise radiometabolite formation. Herein, we provide a comprehensive overview of the deuterated carbon-11 and fluorine-18 radiopharmaceuticals employed in PET imaging experiments. Specifically, we explore six categories of deuterated radiopharmaceuticals used to investigate the activities of monoamine oxygenase (MAO), choline, translocator protein (TSPO), vesicular monoamine transporter 2 (VMAT2), neurotransmission and the diagnosis of Alzheimer's disease; from which we derive four prominent deuteration strategies giving rise to a kinetic isotope effect (KIE) for reducing the rate of metabolism. Synthetic approaches for over thirty of these deuterated radiopharmaceuticals are discussed from the perspective of deuterium and radioisotope incorporation, alongside an evaluation of the deuterium labelling and radiolabelling efficacies across these independent studies. Clinical and manufacturing implications are also discussed to provide a more comprehensive overview of how deuterated radiopharmaceuticals may be introduced to routine practice.

VEGFR2 inhibition hampers breast cancer cell proliferation via enhanced mitochondrial biogenesis

Objective:

Vascular endothelial growth factor (VEGF), apart from its predominant roles in angiogenesis, can enhance cancer cell proliferation, but its mechanisms remain elusive. The purpose of the present study was therefore to identify how VEGF regulates cancer cell proliferation.

Methods:

VEGF effects on cancer cell proliferation were investigated with the VEGF receptor 2 inhibitor, Ki8751, and the breast cancer cell lines, MCF-7 and MDA-MB-231, using flow cytometry, mass spectrometry, immunoblotting, and confocal microscopy. Data were analyzed using one-way analysis of variance followed by Tukey’s multiple comparison test.

Results:

VEGF blockade by Ki8751 significantly reduced cancer cell proliferation, and enhanced breast cancer cell apoptosis. Mass spectrometric analyses revealed that Ki8751 treatment significantly upregulated the expression of mitochondrial proteins, suggesting the involvement of mitochondrial biogenesis. Confocal microscopy and flow cytometric analyses showed that Ki8751 treatment robustly increased the mitochondrial masses of both cancer cells, induced endomitosis, and arrested cancer cells in the high aneuploid phase. VEGFR2 knockdown by shRNAs showed similar effects to those of Ki8751, confirming the specificity of Ki8751 treatment. Enhanced mitochondrial biogenesis increased mitochondrial oxidative phosphorylation and stimulated reactive oxygen species (ROS) production, which induced cancer cell apoptosis. Furthermore, Ki8751 treatment downregulated the phosphorylation of Akt and PGC1α, and translocated PGC1α into the nucleus. The PGC1α alterations increased mitochondrial transcription factor A (TFAM) expression and subsequently increased mitochondrial biogenesis.

Conclusions:

VEGF enhances cancer cell proliferation by decreasing Akt-PGC1α-TFAM signaling-mediated mitochondrial biogenesis, ROS production, and cell apoptosis. These findings suggested the anticancer potential of Ki8751 via increased mitochondrial biogenesis and ROS production.

Deuterium Depletion Inhibits Cell Proliferation, RNA and Nuclear Membrane Turnover to Enhance Survival in Pancreatic Cancer

The effects of deuterium-depleted water (DDW) containing deuterium (D) at a concentration of 25 parts per million (ppm), 50 ppm, 105 ppm and the control at 150 ppm were monitored in MIA-PaCa-2 pancreatic cancer cells by the real-time cell impedance detection xCELLigence method. The data revealed that lower deuterium concentrations corresponded to lower MiA PaCa-2 growth rate. Nuclear membrane turnover and nucleic acid synthesis rate at different D-concentrations were determined by targeted [1,2-13C2]-D-glucose fate associations. The data showed severely decreased oxidative pentose cycling, RNA ribose 13C labeling from [1,2-13C2]-D-glucose and nuclear membrane lignoceric (C24:0) acid turnover. Here, we treated advanced pancreatic cancer patients with DDW as an extra-mitochondrial deuterium-depleting strategy and evaluated overall patient survival. Eighty-six (36 male and 50 female) pancreatic adenocarcinoma patients were treated with conventional chemotherapy and natural water (control, 30 patients) or 85 ppm DDW (56 patients), which was gradually decreased to preparations with 65 ppm and 45 ppm deuterium content for each 1 to 3 months treatment period. Patient survival curves were calculated by the Kaplan-Meier method and Pearson correlation was taken between medial survival time (MST) and DDW treatment in pancreatic cancer patients. The MST for patients consuming DDW treatment (n = 56) was 19.6 months in comparison with the 6.36 months' MST achieved with chemotherapy alone (n = 30). There was a strong, statistically significant Pearson correlation (r = 0.504, p < 0.001) between survival time and length and frequency of DDW treatment.

Platelet factor 4 enhances CD4+ T effector memory cell responses via Akt-PGC1α-TFAM signaling-mediated mitochondrial biogenesis

BACKGROUND

Cell metabolism drives T cell functions, while platelets regulate overall CD4+ T cell immune responses.

OBJECTIVE

To investigate if platelets influence cell metabolism and thus regulate CD4+ T effector memory cell (Tem) responses.

METHODS

Human CD4+ Tem cells were activated with αCD3/αCD28 and cultured without or with platelets or platelet-derived mediators.

RESULTS

Polyclonal stimulation induced rapid and marked Th1 and Treg cell activation of CD4+ Tem cells. Platelet co-culture enhanced Th1 response transiently, while it persistently enhanced Treg cell activation of Tem cells, with an enhancement that plateaued by day 3. Platelet factor 4 (PF4) was the key platelet-derived mediator regulating CD4+ Tem cell responses, which involved cellular metabolisms as indicated by mass spectrometric analyses. PF4 exerted its effects via its receptor CXCR3, attenuated Akt activity, and reduced PGC1α phosphorylation, and resulted in elevations of PGC1α function and mitochondrial transcription factor A (TFAM) synthesis. The latter increased mitochondrial biogenesis, and subsequently enhanced Th1 and Treg responses. Consistent with these observations, inhibition of mitochondrial function by rotenone counteracted the enhancements by recombinant PF4, and TFAM overexpression by TFAM-adenovirus infection mimicked PF4 effects. Furthermore, increased mitochondrial mass elevated oxygen consumption, and enhanced adenosine triphosphate and reactive oxygen species production, which, in turn, stimulated Th1 (T-bet) and Treg (FoxP3) transcription factor expression and corresponding CD4+ T effector cell responses.

CONCLUSIONS

Platelets enhance CD4+ T cell responses of Tem cells through PF4-dependent and Akt-PGC1α-TFAM signaling-mediated mitochondrial biogenesis. Hence, PF4 may be a promising intervention target of platelet-regulated immune responses.

Inequality in the Frequency of the Open States Occurrence Depends on Single 2H/1H Replacement in DNA

In the present study, the effect of 2H/1H isotopic exchange in hydrogen bonds between nitrogenous base pairs on occurrence and open states zones dynamics is investigated. These processes are studied using mathematical modeling, taking into account the number of open states between base pairs. The calculations of the probability of occurrence of open states in different parts of the gene were done depending on the localization of the deuterium atom. The mathematical modeling study demonstrated significant inequality (dependent on single 2H/1H replacement in DNA) among three parts of the gene similar in length of the frequency of occurrence of the open states. In this paper, the new convenient approach of the analysis of the abnormal frequency of open states in different parts of the gene encoding interferon alpha 17 was presented, which took into account both rising and decreasing of them that allowed to make a prediction of the functional instability of the specific DNA regions. One advantage of the new algorithm is diminishing the number of both false positive and false negative results in data filtered by this approach compared to the pure fractile methods, such as deciles or quartiles.

Slight Deuterium Enrichment in Water Acts as an Antioxidant: Is Deuterium a Cell Growth Regulator?

Small admixtures in water, e.g. of metal ions, often act as cell growth regulators. Here we report that enrichment of deuterium content in water, normally found at 8 mm concentration, two-three folds increases cell proliferation and lowers the oxidative stress level as well. Acting as an anti-oxidant, deuterium-enriched water prevents the toxic effect of such oxidative agents as hydrogen peroxide and auranofin. This action is opposite to that of deuterium depletion that is known to suppress cell growth and induce oxidative stress in mitochondria. We thus hypothesize that deuterium may be a natural cell growth regulator that controls mitochondrial oxidation-reduction balance. Because growth acceleration is reduced approximately by half by addition to water a minute amount (0.15%) of ¹⁸O isotope, at least part of the deuterium effect on cell growth can be explained by the isotopic resonance phenomenon. A slight (≈2-fold) enrichment of deuterium in water accelerates human cell growth. Quantitative MS based proteomics determined changes in protein abundances and redox states and found that deuterium-enriched water acts mainly through decreasing ROS production in mitochondria. This action is opposite to that of deuterium depletion that suppresses cell growth by inducing oxidative stress. Thus deuterium may be a natural cell growth regulator that controls mitochondrial oxidation-reduction balance. The role of isotopic resonance in this effect was validated by further experiments on bacteria.

Impact of D2O on the peptidization of L-alanine

This is our fifth consecutive study carried out in an order to collect experimental evidence on the impact of heavy water (D2O) on the spontaneous peptidization of proteinogenic α-amino acids and this time its subject matter is L-alanine (L-Ala). Our four earlier studies have been focused on the two sulfur-containing α-amino acids (i.e., L-cysteine (L-Cys) and L-methionine (L-Met)), and on two structurally related α-amino acids (i.e., L-proline (L-Pro) and L-hydroxyproline (L-Hyp)). It seemed interesting to assess the effect exerted by D2O on L-Ala, the simplest chiral (endogenous and proteinogenic) α-amino acid with as low molar weight, as 89.09 g mol−1 only. As analytical techniques, we used high-performance liquid chromatography with the diode array detection (HPLC–DAD), mass spectrometry (MS), and scanning electron microscopy (SEM). The obtained results make it clear that the impact of heavy water on the dynamics of the spontaneous peptidization of L-Ala is even stronger than with the four other α-amino acids discussed earlier (although in all five cases, heavy water significantly hampers spontaneous oscillatory peptidization). Unlike in the four previous cases, though, the solubility of L-Ala in pure D2O is quite low and it takes twice as much time to dissolve it in D2O than in MeOH + X, 70:30 (v/v). Consequently, the peptidization of L-Ala in heavy water is even more obstructed than it was the case with the other investigated α-amino acids and it results in considerable yields of the L-Ala crystals (most probably at least partially deuterated) at the expense of the L-Ala-derived peptides. Perhaps it might be interesting to add that out of five α-amino acids investigated so far, which can be divided into two groups of endogenous and exogenous species, two endogenous species (L-Cys and L-Pro) undergo spontaneous oscillatory peptidization in an aqueous-organic solvent (i.e., in the absence of D2O) following the circadian rhythm, whereas two exogenous ones (i.e., L-Met and L-Hyp) do not. The third endogenous species (L-Ala) first undergoes two initials oscillations which are damped (not periodic) and the oscillatory changes are on a scale of ca. 10 h (as estimated with use of the Fourier transform approach) and after that, the system reaches a steady state.

Possible Mechanisms of Biological Effects Observed in Living Systems during 2H/1H Isotope Fractionation and Deuterium Interactions with Other Biogenic Isotopes

This article presents the original descriptions of some recent physics mechanisms (based on the thermodynamic, kinetic, and quantum tunnel effects) providing stable 2H/1H isotope fractionation, leading to the accumulation of particular isotopic forms in intra- or intercellular space, including the molecular effects of deuterium interaction with 18O/17O/16O, 15N/14N, 13C/12C, and other stable biogenic isotopes. These effects were observed mainly at the organelle (mitochondria) and cell levels. A new hypothesis for heavy nonradioactive isotope fractionation in living systems via neutron effect realization is discussed. The comparative analysis of some experimental studies results revealed the following observation: "Isotopic shock" is highly probable and is observed mostly when chemical bonds form between atoms with a summary odd number of neutrons (i.e., bonds with a non-compensated neutron, which correspond to the following equation: Nn - Np = 2k + 1, where k ϵ Z, k is the integer, Z is the set of non-negative integers, Nn is number of neutrons, and Np is number of protons of each individual atom, or in pair of isotopes with a chemical bond). Data on the efficacy and metabolic pathways of the therapy also considered 2H-modified drinking and diet for some diseases, such as Alzheimer's disease, Friedreich's ataxia, mitochondrial disorders, diabetes, cerebral hypoxia, Parkinson's disease, and brain cancer.