TXNRD1: A Key Regulator Involved in the Ferroptosis of CML Cells Induced by Cysteine Depletion In Vitro

Cysteine metabolism plays a critical role in cancer cell survival. Cysteine depletion was reported to inhibit tumor growth and induce pancreatic cancer cell ferroptosis. Nevertheless, the effect of cysteine depletion in chronic myeloid leukemia (CML) remains to be explored. In this work, we showed that cysteine depletion can induce K562/G01 but not K562 cell death in the form of ferroptosis. However, the glutathione (GSH)/glutathione peroxidase 4 (GPX4) pathways of the two CML cell lines were both blocked after cysteine depletion. This unexpected outcome guided us to perform RNA-Seq to screen the key genes that affect the sensitivity of CML cells to cysteine depletion. Excitingly, thioredoxin reductase 1 (TXNRD1), which related to cell redox metabolism, was significantly upregulated in K562/G01 cells after cysteine depletion. We further inferred that the upregulation is negatively feedback by the enzyme activity decrease of TXNRD1. Then, we triggered the ferroptosis by applying TXNRD1 shRNA and TXNRD1 inhibitor auranofin in K562 cells after cysteine depletion. In summary, we have reason to believe that TXNRD1 is a key regulator involved in the ferroptosis of CML cells induced by cysteine depletion in vitro. These findings highlight that cysteine depletion serves as a potential therapeutic strategy for overcoming chemotherapy resistance CML.

The changes in the morpho-functional state of the green alga Ulva intestinalis L. in the Barents Sea under the influence of diesel fuel

The Changes in the morpho-functional state of the green algae Ulva intestinalis L. Intestine of the Barents Sea under the influence of diesel fuel (DF) in doses from 1 to 150 mg/l were studied. It has been shown that the reaction of the algae to the presence of diesel fuel (DF) depends on the toxicant and the duration of exposure. The addition of an petroleum product to the medium in a volume of 1 - 5 mg/l (20-100 MAC) does not lead to the death of algae, however, it causes a decrease in photosynthetic activity and the content of photosynthetic pigments. DF concentrations in the medium from 50 mg/L (1000 MAC) to 150 mg/L (3000 MAC) cause active irreversible changes in algae: disruption of cell structure, suppression of photosynthetic activity, decrease in the concentration of photosynthetic pigments, changes in catalase activity, as well as the number of cultivated epiphytic bacteria. When the content of DF in water is 150 mg/l, various algae die after 3 days of the experiment.

TNF-ɑ Induces Methylglyoxal Accumulation in Lumbar Herniated Disc of Patients With Radicular Pain

Lumbar disc herniation (LDH) with radicular pain is a common and complicated musculoskeletal disorder. Our previous study showed that LDH-induced methylglyoxal (MG) accumulation contributed to radicular pain. The underlying mechanisms through which MG accumulates are poorly understood. In the present study, we found that both MG and tumor necrosis factor-alpha (TNF-ɑ) levels in the herniated disc of patients with radicular pain were significantly increased, and the activity of Glyoxalase 1 (GLO1), the rate-limiting enzyme that metabolizes MG, was decreased. In rats, the LDH model was mimicked by implantation of autologous nucleus pulposus (NP) to the left lumbar five spinal nerve root. The mechanical allodynia was observed in LDH rats. Besides, MG and TNF-ɑ levels were increased, and GLO1 activity was significantly decreased in the implanted NP. In cultured rat NP cells, stimulation with the inflammatory mediator TNF-ɑ reduced GLO1 activity and expression. These results suggested that TNF-ɑ-induced GLO1 activity decrease contributed to MG accumulation in the herniated disc of patients with radicular pain.

Photocatalytic Degradation of Methylene Blue Dye by Electrospun Binary and Ternary Zinc and Titanium Oxide Nanofibers

Synthetic dyes, dispersed in water, have harmful effects on human health and the environment. In this work, Ti and/or Zn oxide nanofibers (NFs) with engineered architecture and surface were produced via electrospinning followed by calcination. Calcination and subsequent cooling were operated at fast rates to generate porous NFs with capture centers to reduce the recombination rate of the photogenerated charges. After morphological and microstructural characterisation, the NFs were comparatively evaluated as photocatalysts for the removal of methylene blue from water under UV irradiation. The higher band gap and lower crystallinity were responsible for the lower photocatalytic activity of the ternary oxides (ZnTiO3 and Zn2TiO4) towards the degradation of the dye. The optimal loads of the highly performing binary oxides were determined. By using 0.66 mg mL−1 wurtzite ZnO for the discoloration of an aqueous solution with a dye concentration of 15 µM, a higher rate constant (7.94 × 10−2 min−1) than previously reported was obtained. The optimal load for anatase TiO2 was lower (0.33 mg mL−1). The corresponding rate constant (1.12 × 10−1 min−1) exceeds the values reported for the commonly used P25–TiO2 benchmark. The catalyst can be reused twice without any regeneration treatment, with 5.2% and 18.7% activity decrease after the second and third use, respectively.

Evaluation of the effects of 5-fluorouracil and cyclophosphamide on Lathyrus sativus L.

Background The effect of 5-fluorouracil (5FU) and cyclophosphamide (CP) on grass pea (Lathyrus sativus L.) has been studied. Results The effect of the selected drugs on radicle length, colchicine induces polyploidy and in vitro callus growth has been studied (concentration used: 5-Fluorouracil—0.01, 0.1, 1 and 10 mM; Cyclophosphamide—1, 10, 20 and 30 mM). The biochemical studies on superoxide dismutase, catalase and lipid peroxidase activity also studied. Radicle length, polyploidy percentage and callus growth decrease in both the drugs in a dose-dependent manner. The SOD, catalase and LP activity decrease with the increase in drug concentration except for low dose (for 5FU—0.01 mM and 1 mM for CP). Induced polyploidy (Control B) than water germinated seedling (Control A) shows higher enzyme activity but a decrease in the increased dose of drugs. Conclusions The present work has been done to assess the effective potentiality of two anticancerous drugs 5FU and CP with an objective to establish plant system as a model for preliminary screening of anticancerous lead compounds. The result of the present work would pave the way for the screening of unknown lead compounds with the potentiality to act as base analogue and DNA cross-linking drugs. This system is faster, cost-effective and convenient than animal model.

MO626EFFECTS OF RAMIPRIL IN LUNG AND KIDNEY ANGIOTENSIN CONVERTING ENZYME 2 (ACE2) EXPRESSION IN A TYPE 2 DIABETIC MURINE MODEL: LESSONS FOR COVID-19 INFECTION

Background and Aims Angiotensin converting enzyme 2 (ACE2) is one of the components of the renin-angiotensin system (RAS) that mainly degrades angiotensin II to angiotensin-(1-7). ACE2 is predominantly expressed in the kidney and the heart, but it has been evidenced in type 2 alveolar lung cells, where it acts as a receptor for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this context, a controversy arose as to whether the use of RAS blockers could increase ACE2 lung expression and the risk infection by COVID-19. This study aimed to investigate the effect of an ACE inhibitor (Ramipril) on ACE2 expression in experimental diabetes. Method 12 weeks old diabetic db/db mice (n=7) were given ramipril (8 mg/Kg/day) during 8 weeks or the respective vehicle. db/m (n=7) vehicle-treated non-diabetic mice were included as controls. ACE2 mRNA expression and enzymatic activity were studied in kidney, heart and lung samples of these animals to identify if the diabetic condition or treatment with ramipril modulated ACE2 expression. Results In vehicle-treated diabetic db/db animals, ACE2 mRNA expression was significantly increased in the kidney (p<0.001) and ramipril treatment reversed this effect (p=0.026). In the heart, ACE2 expression decreased in db/db when compared to db/m littermates (p=0.035) and ramipril had no effect. We found no differences in ACE2 gene expression in the lung. Besides, ACE2 enzymatic activity was increased in the kidney (29%) and also in the lung (16%) of db/db mice when compared to controls. Ramipril treatment decreased ACE2 activity a 19% in the lung and had no effect in the kidney when compared to untreated db/db (see figure). In the heart, ACE2 activity tended to decrease in db/db mice (29%) when compared to db/m and ramipril increased ACE2 activity (18%) but did not exceed the cardiac ACE2 activity of the db/m. Conclusion ACE2 is increased in the kidney and the lung, and decreased in the heart of diabetic mice. Ramipril treatment restores ACE2 levels. The results suggest that ACE inhibitors do not increase ACE2 expression and the activity decrease exerted in the lung may be protective against COVID-19 infection.

The Pah-R261Q mouse reveals oxidative stress associated with amyloid-like hepatic aggregation of mutant phenylalanine hydroxylase

Phenylketonuria (PKU) is caused by autosomal recessive variants in phenylalanine hydroxylase (PAH), leading to systemic accumulation of L-phenylalanine (L-Phe) that may reach neurotoxic levels. A homozygous Pah-R261Q mouse, with a highly prevalent misfolding variant in humans, reveals the expected hepatic PAH activity decrease, systemic L-Phe increase, L-tyrosine and L-tryptophan decrease, and tetrahydrobiopterin-responsive hyperphenylalaninemia. Pah-R261Q mice also present unexpected traits, including altered lipid metabolism, reduction of liver tetrahydrobiopterin content, and a metabolic profile indicative of oxidative stress. Pah-R261Q hepatic tissue exhibits large ubiquitin-positive, amyloid-like oligomeric aggregates of mutant PAH that colocalize with selective autophagy markers. Together, these findings reveal that PKU, customarily considered a loss-of-function disorder, can also have toxic gain-of-function contribution from protein misfolding and aggregation. The proteostasis defect and concomitant oxidative stress may explain the prevalence of comorbid conditions in adult PKU patients, placing this mouse model in an advantageous position for the discovery of mutation-specific biomarkers and therapies.

WHAT IS NORMAL COGNITIVE AGING?

При помощи Адденбрукской когнитивной шкалы (ACE-III), теста Струпа (ТС), Шкалы памяти Векслера (WMS) и Батареи лобной дисфункции (FAB) нами были обследованы 44 респондента практически здоровой «возрастной нормы» 52-95 лет. В зависимости от возраста выборка была разделена на две группы - в 1-ю вошли лица младше 65 лет (64 года включительно), 2-ю составили испытуемые старше 65 лет. Статистически достоверные различия результатов обследования респондентов двух групп посредством ACE-III обнаружены по показателю память и общему баллу методики, при этом по мере увеличения возраста снижался уровень показателей когнитивного функционирования, измеренных посредством ACE-III. Результаты сравнения данных обследования при помощи ТС свидетельствуют о снижении темпа работы в условиях нагрузки и ослаблении гибкости организации мыслительной деятельности и концентрации внимания, а также о повышенной интерференции у лиц старшей возрастной группы, обследованной нами. Корреляционный анализ данных ТС и возраста обследованных показал, что с возрастом происходит снижение когнитивного контроля над обработкой информации, нарастают интерферирующие воздействия, снижается точность и темп деятельности, а сама деятельность становится более ригидной. Результаты корреляционного анализа показателей WMS и возраста продемонстрировали снижение уровня психического контроля над деятельностью, ухудшение памяти в зрительной модальности, нарастание снижения оперативной памяти по мере его увеличения. По мере старения у обследованных здоровых испытуемых обнаружено ухудшение лобных (регуляторных) функций, оцененных при помощи FAB. Using the Addenbrooke’s Cognitive Examination (ACE-III), the Stroop Test (ST), the Wechsler Memory Scale (WMS), and the Frontal Assessment Battery (FAB), we examined 44 respondents of an almost healthy «age norm» from 52 to 95 years old. Depending on age, the sample was divided into 2 groups, the first group included people under the age of 65 years (64 years old inclusive), the second group consisted of subjects over 65 years old. Statistically significant differences in the results of the survey of respondents of the two groups by the ACE-III were found in Memory and Total score indicators, while the level of cognitive functioning measured by the ACE-III decreased with age. The results of comparing the survey data using the Stroop Test indicate a decrease in the pace of work under load conditions and a weakening in the flexibility of organization of mental activity and concentration of attention, as well as increased interference in individuals of a more age group examined by us. Correlation analysis of the Stroop test data and the age of the examined showed cognitive control over information processing decreases, interfering influences increase, accuracy and pace of activity decrease, and the activity itself becomes more rigidas age increases. The results of the correlation analysis of the indicators of the WMS and age demonstrated a decrease in the level of mental control over activity, a deterioration of memory in the visual modality, and a progressive working memory reduction as age increases. With the growth of age, a decrease in frontal (executive) functions of healthy subjects, evaluated by the FAB, was found.

Monokaryotic Pleurotus sapidus Strains with Intraspecific Variability of an Alkene Cleaving DyP-Type Peroxidase Activity as a Result of Gene Mutation and Differential Gene Expression

The basidiomycete Pleurotus sapidus produced a dye-decolorizing peroxidase (PsaPOX) with alkene cleavage activity, implying potential as a biocatalyst for the fragrance and flavor industry. To increase the activity, a daughter-generation of 101 basidiospore-derived monokaryons (MK) was used. After a pre-selection according to the growth rate, the activity analysis revealed a stable intraspecific variability of the strains regarding peroxidase and alkene cleavage activity of PsaPOX. Ten monokaryons reached activities up to 2.6-fold higher than the dikaryon, with MK16 showing the highest activity. Analysis of the PsaPOX gene identified three different enzyme variants. These were co-responsible for the observed differences in activities between strains as verified by heterologous expression in Komagataella phaffii. The mutation S371H in enzyme variant PsaPOX_high caused an activity increase alongside a higher protein stability, while the eleven mutations in variant PsaPOX_low resulted in an activity decrease, which was partially based on a shift of the pH optimum from 3.5 to 3.0. Transcriptional analysis revealed the increased expression of PsaPOX in MK16 as reason for the higher PsaPOX activity in comparison to other strains producing the same PsaPOX variant. Thus, different expression profiles, as well as enzyme variants, were identified as crucial factors for the intraspecific variability of the PsaPOX activity in the monokaryons.