Specifics of Pharmacokinetics and Biodistribution of 5-Fluorouracil Polymeric Complex.

One of the promising and relevant directions in the treatment of oncological diseases is currently the development of a system for the delivery of antitumor drugs based on polyanions. Therefore, the aim of this work was to study the specifics of pharmacokinetics and biodistribution of a 5-Fluorouracil polymeric complex compared with commercial 5-Fluorouracil. MATERIALS AND METHODS: Monomeric methacrylic acid was used to synthesize polymers; 2-phenylpropane-2-ilbenzodithioate was used for the synthesis of poly(methacrylic acid). To study the molecular-weight characteristics of poly(methacrylic acid) by gel permeation chromatography, an experimental neoplasm model was obtained by grafting PC-1 cancer cells. Blood samples were drawn from the tail vein at different points in time. The rats were sacrificed via decapitation after drawing the last pharmacokinetic blood sample. To study the biodistribution, internal organs were isolated and analyzed. The measurements were carried out by high-performance liquid chromatography. RESULTS: Our results demonstrate that incorporation in a polymeric complex changes the pharmacokinetics and biodistribution profile of 5-FU. The polymeric complex was shown to accumulate to a higher level in the lung and spleen. CONCLUSION: The results obtained are the basis for further studies to verify the efficacy of the 5-Fluorouracil polymeric complex.

Delayed Impact of 2-Oxoadipate Dehydrogenase Inhibition on the Rat Brain Metabolism Is Linked to Protein Glutarylation.

Background: The DHTKD1-encoded 2-oxoadipate dehydrogenase (OADH) oxidizes 2-oxoadipate-a common intermediate of the lysine and tryptophan catabolism. The mostly low and cell-specific flux through these pathways, and similar activities of OADH and ubiquitously expressed 2-oxoglutarate dehydrogenase (OGDH), agree with often asymptomatic phenotypes of heterozygous mutations in the DHTKD1 gene. Nevertheless, OADH/DHTKD1 are linked to impaired insulin sensitivity, cardiovascular disease risks, and Charcot-Marie-Tooth neuropathy. We hypothesize that systemic significance of OADH relies on its generation of glutaryl residues for protein glutarylation. Using pharmacological inhibition of OADH and the animal model of spinal cord injury (SCI), we explore this hypothesis. Methods: The weight-drop model of SCI, a single intranasal administration of an OADH-directed inhibitor trimethyl adipoyl phosphonate (TMAP), and quantification of the associated metabolic changes in the rat brain employ established methods. Results: The TMAP-induced metabolic changes in the brain of the control, laminectomized (LE) and SCI rats are long-term and (patho)physiology-dependent. Increased glutarylation of the brain proteins, proportional to OADH expression in the control and LE rats, represents a long-term consequence of the OADH inhibition. The proportionality suggests autoglutarylation of OADH, supported by our mass-spectrometric identification of glutarylated K155 and K818 in recombinant human OADH. In SCI rats, TMAP increases glutarylation of the brain proteins more than OADH expression, inducing a strong perturbation in the brain glutathione metabolism. The redox metabolism is not perturbed by TMAP in LE animals, where the inhibition of OADH increases expression of deglutarylase sirtuin 5. The results reveal the glutarylation-imposed control of the brain glutathione metabolism. Glutarylation of the ODP2 subunit of pyruvate dehydrogenase complex at K451 is detected in the rat brain, linking the OADH function to the brain glucose oxidation essential for the redox state. Short-term inhibition of OADH by TMAP administration manifests in increased levels of tryptophan and decreased levels of sirtuins 5 and 3 in the brain. Conclusion: Pharmacological inhibition of OADH affects acylation system of the brain, causing long-term, (patho)physiology-dependent changes in the expression of OADH and sirtuin 5, protein glutarylation and glutathione metabolism. The identified glutarylation of ODP2 subunit of pyruvate dehydrogenase complex provides a molecular mechanism of the OADH association with diabetes.

Systemic Administration of Allogeneic Cord Blood Mononuclear Cells in Adults with Severe Acute Contusion Spinal Cord Injury: Phase 1/2a Pilot Clinical Study-Safety and Primary Efficacy Evaluation.

OBJECTIVE: Phase 1 of the SUBSCI I/IIa (Systemic Umbilical Cord Blood Administration in Patients with Acute Severe Contusion Spinal Cord Injury) study focused on safety and primary efficacy of multiple systemic infusions of allogeneic unrelated human umbilical cord blood mononuclear cells in patients with severe acute spinal cord contusion having severe neurologic deficit. The primary end point was safety. The secondary end point was the restoration of motor and sensory function in lower limbs within a 1-year period. METHODS: Ten patients with acute contusion spinal cord injury (SCI) and American Spinal Injury Association (ASIA) level A/B deficit were enrolled into phase 1. Patients were treated with 4 infusions of group-matched and rhesus-matched cord blood samples after primary surgery within 3 days after SCI. All patients were followed up for 12 months after SCI. Safety was assessed using adverse events classification depending on severity and relation to cell therapy. Primary efficacy was assessed using dynamics of deficit (ASIA scale). RESULTS: The overall number of adverse events reached 419 in 10 patients. Only 2 were estimated as possibly related to cell therapy, and the remaining 417 were definitely unrelated. Both adverse events were mild and clinically insignificant. No signs of immunization were found in participants. Analysis of clinical outcomes also showed that cell therapy promotes significant functional restoration of motor function. CONCLUSIONS: The data obtained suggest that systemic administration of allogeneic, non-human leukocyte antigen-matched human umbilical cord blood is safe and shows primary efficacy in adults with severe acute contusion SCI and ASIA level A/B deficit.

Immunopharmacological Properties of Methacrylic Acid Polymers as Potential Polymeric Carrier Constituents of Anticancer Drugs.

Cytostatic chemotherapeutics provide a classical means to treat cancer, but conventional treatments have not increased in efficacy in the past years, warranting a search for new approaches to therapy. The aim of the study was, therefore, to obtain methacrylic acid (MAA) (co)polymers and to study their immunopharmacological properties. 4-Cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl] pentanoic acid (CDSPA) and 2-cyano-2-propyl dodecyl trithiocarbonate (CPDT) were used as reversible chain transfer agents. Experiments were carried out in Wistar rats. The MTT assay was used to evaluate the cytotoxic effect of the polymeric systems on peritoneal macrophages. An experimental tumor model was obtained by grafting RMK-1 breast cancer cells. Serum cytokine levels of tumor-bearing rats were analyzed. The chain transfer agents employed in classical radical polymerization substantially reduced the molecular weight of the resulting polymers, but a narrow molecular weight distribution was achieved only with CDSPA and high CPDT concentrations. Toxicity was not observed when incubating peritoneal macrophages with polymeric systems. In tumor-bearing rats, the IL-10 concentration was 1.7 times higher and the IL-17 concentration was less than half that of intact rats. Polymeric systems decreased the IL-10 concentration and normalized the IL-17 concentration in tumor-bearing rats. The maximum effect was observed for a MAA homopolymer with a high molecular weight. The anion-active polymers proposed as carrier constituents are promising for further studies and designs of carrier constituents of drug derivatives.

Severe Spinal Cord Injury in Rats Induces Chronic Changes in the Spinal Cord and Cerebral Cortex Metabolism, Adjusted by Thiamine That Improves Locomotor Performance.

Our study aims at developing knowledge-based strategies minimizing chronic changes in the brain after severe spinal cord injury (SCI). The SCI-induced long-term metabolic alterations and their reactivity to treatments shortly after the injury are characterized in rats. Eight weeks after severe SCI, significant mitochondrial lesions outside the injured area are demonstrated in the spinal cord and cerebral cortex. Among the six tested enzymes essential for the TCA cycle and amino acid metabolism, mitochondrial 2-oxoglutarate dehydrogenase complex (OGDHC) is the most affected one. SCI downregulates this complex by 90% in the spinal cord and 30% in the cerebral cortex. This is associated with the tissue-specific changes in other enzymes of the OGDHC network. Single administrations of a pro-activator (thiamine, or vitamin B1, 1.2 mmol/kg) or a synthetic pro-inhibitor (triethyl glutaryl phosphonate, TEGP, 0.02 mmol/kg) of OGDHC within 15-20 h after SCI are tested as protective strategies. The biochemical and physiological assessments 8 weeks after SCI reveal that thiamine, but not TEGP, alleviates the SCI-induced perturbations in the rat brain metabolism, accompanied by the decreased expression of (acetyl)p53, increased expression of sirtuin 5 and an 18% improvement in the locomotor recovery. Treatment of the non-operated rats with the OGDHC pro-inhibitor TEGP increases the p53 acetylation in the brain, approaching the brain metabolic profiles to those after SCI. Our data testify to an important contribution of the OGDHC regulation to the chronic consequences of SCI and their control by p53 and sirtuin 5.

Tumor-associated macrophages: Role in the pathological process of tumorigenesis and prospective therapeutic use (Review).

The aim of the present study was to evaluate the current body of knowledge regarding tumor-associated macrophages (TAMs) and their potential use in antitumor therapy, based on their role in the pathological process of tumorigenesis. For this purpose, a critical analysis of published data and summarization of the findings available from original studies, focusing on the role of TAMs in the pathological process, and their potential therapeutic application was performed. Promising key avenues of research were identified in this field. The following issues seem the most promising and thus worth further investigation: i) The process of M1/M2 macrophage polarization, macrophage characteristics at intermediate polarization steps and their role in the tumor process; ii) determining the conditions necessary for transitions between the M1 and M2 macrophage phenotypes and the role of signals from the microenvironment in this process; iii) cause-and-effect associations between the quantity and quality of macrophages, and the prognosis and outcome of the pathological process; iv) modulation of macrophages and stimulation of their phagocytic activity with drugs; v) targeted vector-based systems for drug delivery to macrophages; and vi) targeted drug delivery systems with macrophages as carriers, thus potentially combining chemotherapy and immunotherapy.

Delayed Influence of Spinal Cord Injury on the Amino Acids of NO• Metabolism in Rat Cerebral Cortex Is Attenuated by Thiamine.

Severe spinal cord injuries (SCIs) result in chronic neuroinflammation in the brain, associated with the development of cognitive and behavioral impairments. Nitric oxide (NO•) is a gaseous messenger involved in neuronal signaling and inflammation, contributing to nitrosative stress under dysregulated production of reactive nitrogen species. In this work, biochemical changes induced in the cerebral cortex of rats 8 weeks after SCI are assessed by quantification of the levels of amino acids participating in the NO• and glutathione metabolism. The contribution of the injury-induced neurodegeneration is revealed by comparison of the SCI- and laminectomy (LE)-subjected animals. Effects of the operative interventions are assessed by comparison of the operated (LE/SCI) and non-operated animals. Lower ratios of citrulline (Cit) to arginine (Arg) or Cit to ornithine and a more profound decrease in the ratio of lysine to glycine distinguish SCI animals from those after LE. The data suggest decreased NO• production from both Arg and homoarginine in the cortex 8 weeks after SCI. Both LE and SCI groups show a strong decrease in the level of cortex glutathione. The neurotropic, anti-inflammatory, and antioxidant actions of thiamine (vitamin B1) prompted us to study the thiamine effects on the SCI-induced changes in the NO• and glutathione metabolism. A thiamine injection (400 mg/kg intraperitoneally) within 24 h after SCI abrogates the changes in the cerebral cortex amino acids related to NO•. Thiamine-induced normalization of the brain glutathione levels after LE and SCI may involve increased supply of glutamate for glutathione biosynthesis. Thus, thiamine protects from sequelae of SCI on NO•-related amino acids and glutathione in cerebral cortex.