Radiation-induced signaling results in mitochondrial impairment in mouse heart at 4 weeks after exposure to X-rays

BACKROUND: Radiation therapy treatment of breast cancer, Hodgkin's disease or childhood cancers expose the heart to high local radiation doses, causing an increased risk of cardiovascular disease in the survivors decades after the treatment. The mechanisms that underlie the radiation damage remain poorly understood so far. Previous data show that impairment of mitochondrial oxidative metabolism is directly linked to the development of cardiovascular disease. METHODOLOGY/PRINCIPAL FINDINGS: In this study, the radiation-induced in vivo effects on cardiac mitochondrial proteome and function were investigated. C57BL/6N mice were exposed to local irradiation of the heart with doses of 0.2 Gy or 2 Gy (X-ray, 200 kV) at the age of eight weeks, the control mice were sham-irradiated. After four weeks the cardiac mitochondria were isolated and tested for proteomic and functional alterations. Two complementary proteomics approaches using both peptide and protein quantification strategies showed radiation-induced deregulation of 25 proteins in total. Three main biological categories were affected: the oxidative phophorylation, the pyruvate metabolism, and the cytoskeletal structure. The mitochondria exposed to high-dose irradiation showed functional impairment reflected as partial deactivation of Complex I (32%) and Complex III (11%), decreased succinate-driven respiratory capacity (13%), increased level of reactive oxygen species and enhanced oxidation of mitochondrial proteins. The changes in the pyruvate metabolism and structural proteins were seen with both low and high radiation doses. CONCLUSION/SIGNIFICANCE: This is the first study showing the biological alterations in the murine heart mitochondria several weeks after the exposure to low- and high-dose of ionizing radiation. Our results show that doses, equivalent to a single dose in radiotherapy, cause long-lasting changes in mitochondrial oxidative metabolism and mitochondria-associated cytoskeleton. This prompts us to propose that these first pathological changes lead to an increased risk of cardiovascular disease after radiation exposure.     

Evaluation of clinical outcomes,laboratory and imaging data of patients with solid tumor infected with COVID-19 infection

Background: COVID-19 is associated with higher mortality rates in patients with cancer. In this study, we aimed to evaluate the clinical outcomes, and laboratory and imaging data of patients with solid tumor infected with COVID-19 infection. Methods: This is a cross-sectional retrospective study performed in 2020-2022 on 85 patients with a previous diagnosis of solid tumors infected with COVID-19. We included all patients with tumors of solid organs that were diagnosed with COVID-19 infection and required hospitalization those patients previously hospitalized for treatments and were infected with COVID-19 during hospitalization. Demographic data of patients were collected using a checklist. We collected data regarding clinical outcome (discharge, hospitalization or death), duration of hospitalization, requiring ICU admission, duration of hospitalization divided by received drugs and type of tumor and mean survival time. Furthermore, we collected laboratory data from all patients. The radiologic characteristics of patients were also extracted from their data. Results: Breast cancer was the most common solid tumor (34.9%), followed by lung cancer (19.3%). The mortality rate was 24.1% (20 patients). The highest mortality rate in this study was for metastatic intestinal cancer to the lung (100%, one patient), followed by metastatic prostatic cancer to lung (50%, three patients). The highest hospitalization duration was for patients with glioblastoma multiform (GBM) (30 days). The mean survival time among patients with mortality was 19.15±1.80 days. The mean CT severity score of all patients was 27.53±22.90. Patient’s most common radiologic sign was air space consolidation (89.1%). The highest CT severity score was found in patients with stomach cancer (46.67±5.77). Conclusion: The mortality rate in this study was 24.1%. Based on the results of our study and previous research, special care should be provided to patients with solid tumors during the COVID-19 pandemic and in infected cases.     

Label-free detection of nucleic acid and protein microarrays by scanning Kelvin nanoprobe

A high-resolution scanning Kelvin nanoprobe is introduced as an alternative technique to the conventional fluorescence and mass spectrometric detection methods currently employed in nucleic acid and protein microarray technology. The new instrument is capable of the highly sensitive discernment of surface biochemical events taking place at molecular level such as nucleic acid hybridization and antibody-antigen interaction. The method involves measurement of changes in work function and surface potential instigated by such interactions. Being a label-free and non-contact technique, the structure, spatial configuration, local properties or function of the molecular system under study are not affected, nor perturbed by intercalating dyes, a strong electric field or ionizing beam. Subsequent to scanning, the microarray can be examined by other alternative approaches. Nucleic acids and proteins have been printed in microarray format on slides with a gold film in place using gold-sulphur interactive chemistry. Hybridization of nucleic acids for complementary and mismatched configurations shows consistent and reproducible values of work function. Differentiation of single internal mismatches is demonstrated. Protein concentration and formation of antibody-antigen pairs can be visualized and examined with high sensitivity and good inter-spot reproducibility.     

A new approach to estimation of the number of central synapse(s) included in the H-reflex

Background  

Among the main clinical applications of the H-reflex are the evaluation of the S1 nerve root conductivity such as radiculopathy and measurement of the excitability of the spinal motoneurons in neurological conditions. An attempt has been made to reduce the pathway over which H-reflex can be obtained in a hope to localize a lesion to the S1 nerve root, so the S1 central loop has been suggested. The main goal of this study is the estimation of the H-reflex number of synapse(s) for better understanding of the physiology of this practical reflex.     

Active-site peptide "fingerprinting" of glycosidases in complex mixtures by mass spectrometry. Discovery of a novel retaining beta-1,4-glycanase in Cellulomonas fimi

New proteomics methods are required for targeting and identification of subsets of a proteome in an activity-based fashion. Here, we report the first gel-free, mass spectrometry-based strategy for mechanism-based profiling of retaining beta-endoglycosidases in complex proteomes. Using a biotinylated, cleavable 2-deoxy-2-fluoroxylobioside inactivator, we have isolated and identified the active-site peptides of target retaining beta-1,4-glycanases in systems of increasing complexity: pure enzymes, artificial proteomes, and the secreted proteome of the aerobic mesophilic soil bacterium Cellulomonas fimi. The active-site peptide of a new C. fimi beta-1,4-glycanase was identified in this manner, and the peptide sequence, which includes the catalytic nucleophile, is highly conserved among glycosidase family 10 members. The glycanase gene (GenBank accession number DQ146941) was cloned using inverse PCR techniques, and the protein was found to comprise a catalytic domain that shares approximately 70% sequence identity with those of xylanases from Streptomyces sp. and a family 2b carbohydrate-binding module. The new glycanase hydrolyzes natural and artificial xylo-configured substrates more efficiently than their cello-configured counterparts. It has a pH dependence very similar to that of known C. fimi retaining glycanases.     

Salicylate poly(vinyl chloride) membrane electrode based on (2-[(E)-2-(4-nitrophenyl) hydrazono]-1-phenyl-2-(2-quinolyl)-1-ethanone) Cu(II)

A new salicylate-selective electrode based on the complex of (2-[(E)-2-(4-nitrophenyl)hydrazono]-1-phenyl-2-(2-quinolyl)-1-ethanone) Cu(II) as the membrane carrier was developed. The electrode exhibited a good Nernstian slope of -59.6+/-1.0 mV/decade and a linear range of 1.0 x 10(-6) to 1.0M for salicylate. The limit of detection was 5.0 x 10(-7) M. The electrode had a fast response time of 10 s and can be used for more than 3 months. The selective coefficients were determined by the fixed interference method and could be used in the pH range of 4.0 to 10.5. The electrode was employed as an indicator electrode for direct determination of salicylate in pharmaceutical and biological samples.     

Hyaluronan suppresses epidermal differentiation in organotypic cultures of rat keratinocytes

Hyaluronan (hyaluronic acid, HA) is an abundant matrix component between keratinocytes of the epidermis in vivo, but its function there remains unclear. We used a lift culture model, in which rat epidermal keratinocytes (REKs) stratify at an air-liquid interface, to ask whether HA may regulate epidermal proliferation and/or differentiation. In this model, early markers of differentiation (keratin 10), and later markers (profilaggrin, keratohyalin granules, cornified layers) are faithfully expressed, both temporally and spatially. HA, measured using two different analytical techniques, accumulated to high levels only in the presence of an intact basement membrane that seals the epidermal compartment. To test whether HA has a functional role in differentiation, Streptomyces hyaluronidase (StrepH, 1 U/ml; digests >95% of HA within 4 h) was added daily to lift cultures during stratification time-course experiments over 5 days. In StrepH-treated cultures, the expression of profilaggrin and the number and size of keratohyalin granules were significantly increased relative to controls using semiquantitative histological analyses. The StrepH-related accumulation of K10 protein and profilaggrin/filaggrin were confirmed by Western analyses. Thus, it appears that the presence of intercellular HA in the epidermis acts as a brake upon intracellular events that occur during keratinocyte differentiation.     

Nucleic acid synthesis in cancerous cells under the effect of gnidilatimonoein from Daphne mucronata

Cytotoxicity evaluation of gnidilatimonoein, the most active isolated diterpene ester from Daphne mucronata [Sadeghi H, Mianabadi M, Yazdanparast R, (2002) Journal of Tropical. Medicinal Plant1 3: 169-173], revealed the strong antiproliferative activity among several different human cancer cell lines (K562, CCRF-CEM, HL-60 and MOLT-4 leukemia cell lines, LNCaP-FGC-10 a prostate cancer cell line) and a mouse BALB/C fibrosarcoma cell line (WEHI-164). Using flow cytometry technique, it was found that treatment of the most responsive cells (K562) with gnidilatimonoein inhibited the progression of cells through G1 phase by almost 15% compared to the untreated cells. The population of the treated cells in the S and G2 phases also reduced by 8.3% and 5.4%, respectively. Based on the extent of [3H]-thymidine and [3H]-uridine incorporation into DNA and RNA, respectively, the major metabolic effects of gnidilatimonoein were found to be mainly on DNA and to a less extent on RNA synthesis. Additionally, the activity of inosine-5'-monophosphate dehydrogenase (IMPDH), under the effects of genidilatimonoein, was reduced in the treated cells by 44%. These data strongly suggest that the purine biosynthetic pathway is significantly affected by gnidilatimonoein.