Репозиторий Университета

© 2019, Springer Science+Business Media, LLC, part of Springer Nature. The objective of the present study was to elucidate the effect of perinatal cobalt chloride (CoCl2) exposure on extramedullary erythropoiesis in suckling mice in relation to iron (Fe) content and transferrin receptor (TfR) expression. Pregnant ICR mice were subjected to a daily dose of 75 mg CoCl2/kg body weight 2–3 days prior and 18 days after delivery. Co exposure significantly increased erythrocyte count (RBC), and reduced the erythrocytic parameters mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) in the offspring. Total iron-binding capacity (TIBC) was decreased while bilirubin values were ~ 1.2-fold higher in the metal-exposed mice. Perinatal CoCl2 treatment also induced pathohistological changes in target organs (spleen, liver, and kidneys) as altered organ weight indices, leukocyte infiltration, abundant Kupffer cells in the liver, increased mesangial cellularity, and reduced capsular space in the kidney. CoCl2 administration induced significant 68-, 3.8-, 41.3-, and 162-fold increase of Co content in the kidney, spleen, liver, and RBC, respectively. Fe content in the target organs of CoCl2-treated mice was also significantly elevated. Immunohistochemical analysis demonstrated that TfR1 was well expressed in the renal tubules, hepatocytes, the red pulp, and marginal zone of white pulp in the spleen. TfR2 showed similar expression pattern, but its expression was stronger in the spleen and liver samples of Co-treated mice compared with that of the untreated controls. The results demonstrate that exposure to CoCl2 during late pregnancy and early postnatal period affects body and organ weights and alters hematological and biochemical parameters, iron content, and TfR expression in target organs.

© 2019, Springer Science+Business Media, LLC, part of Springer Nature. The objective of the present study was to elucidate the effect of perinatal cobalt chloride (CoCl2) exposure on extramedullary erythropoiesis in suckling mice in relation to iron (Fe) content and transferrin receptor (TfR) expression. Pregnant ICR mice were subjected to a daily dose of 75 mg CoCl2/kg body weight 2–3 days prior and 18 days after delivery. Co exposure significantly increased erythrocyte count (RBC), and reduced the erythrocytic parameters mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) in the offspring. Total iron-binding capacity (TIBC) was decreased while bilirubin values were ~ 1.2-fold higher in the metal-exposed mice. Perinatal CoCl2 treatment also induced pathohistological changes in target organs (spleen, liver, and kidneys) as altered organ weight indices, leukocyte infiltration, abundant Kupffer cells in the liver, increased mesangial cellularity, and reduced capsular space in the kidney. CoCl2 administration induced significant 68-, 3.8-, 41.3-, and 162-fold increase of Co content in the kidney, spleen, liver, and RBC, respectively. Fe content in the target organs of CoCl2-treated mice was also significantly elevated. Immunohistochemical analysis demonstrated that TfR1 was well expressed in the renal tubules, hepatocytes, the red pulp, and marginal zone of white pulp in the spleen. TfR2 showed similar expression pattern, but its expression was stronger in the spleen and liver samples of Co-treated mice compared with that of the untreated controls. The results demonstrate that exposure to CoCl2 during late pregnancy and early postnatal period affects body and organ weights and alters hematological and biochemical parameters, iron content, and TfR expression in target organs.

© 2020 Chen et al. The gene IL6ST encodes GP130, the common signal transducer of the IL-6 cytokine family consisting of 10 cytokines. Previous studies have identified cytokine-selective IL6ST defects that preserve LIF signaling. We describe three unrelated families with at least five affected individuals who presented with lethal Stüve-Wiedemann-like syndrome characterized by skeletal dysplasia and neonatal lung dysfunction with additional features such as congenital thrombocytopenia, eczematoid dermatitis, renal abnormalities, and defective acute-phase response. We identified essential loss-of-function variants in IL6ST (a homozygous nonsense variant and a homozygous intronic splice variant with exon skipping). Functional tests showed absent cellular responses to GP130-dependent cytokines including IL-6, IL-11, IL-27, oncostatin M (OSM), and leukemia inhibitory factor (LIF). Genetic reconstitution of GP130 by lentiviral transduction in patient-derived cells reversed the signaling defect. This study identifies a new genetic syndrome caused by the complete lack of signaling of a whole family of GP130-dependent cytokines in humans and highlights the importance of the LIF signaling pathway in pre- and perinatal development.

© 2019 Elsevier B.V. The α-Fe core/PrDy-FeCo-B(48 at.%)α-Fe(52 at.%) shell and GdPrDy(FeCo)B microwires were grown by pendant drop melt (PDM) extraction technique. Single core–shell microwires of ~80–100 μm diameter and 2–20 mm length manifest rectangular hysteresis loops corresponding to ~100 Oe switching magnetic fields. Bistability of the microwires relates to single domain state of the α-Fe inner core revealed by scanning electron microscopy (SEM). Rare-earth amorphous PrDy-FeCo-B shell of the microwire scanned by magnetic force microscope (MFM) possesses magnetization reversal nuclei corresponding to the α-Fe inclusions. Interwire magnetic dipole interaction and scattering of microwire size change shape of the magnetic hysteresis loop and increase coercive field up to 983 Oe, in chaotic ensembles of the core–shell microwires. The GdPrDy(FeCo)B microwires of the same sizes with no Fe core possess “butterfly” type of the hysteresis loop of high coercivity ~20 kOe.

© 2019 Elsevier B.V. Background: Skeletal muscle cells continuously generate reactive oxygen species (ROS). Excessive ROS can affect lipids resulting in lipid peroxidation (LPO). Here we investigated the effects of myotube intracellular calcium-induced signaling eliciting contractions on the LPO induction and the impact of LPO-product 4-hydroxynonenal (4-HNE) on physiology/pathology of myotubes using C2C12 myoblasts. Methods: C2C12 myoblasts were differentiated into myotubes, stimulated with caffeine and analyzed for the induction of LPO and formation of 4-HNE protein adducts. Further effects of 4-HNE on mitochondrial bioenergetics, NADH level, mitochondrial density and expression of mitochondrial metabolism genes were determined. Results: Short and long-term caffeine stimulation of myotubes promoted superoxide production, LPO and formation of 4-HNE protein adducts. Furthermore, low 4-HNE concentrations had no effect on myotube viability and cellular redox homeostasis, while concentrations from 10 μM and above reduced myotube viability and significantly disrupted homeostasis. A time and dose-dependent 4-HNE effect on superoxide production and mitochondrial NADH-autofluorescence was observed. Finally, 4-HNE had strong impact on maximal respiration, spare respiratory capacity, ATP production, coupling efficiency of mitochondria and mitochondrial density. Conclusion: Data presented in this work make evident for the first time that pathological 4-HNE levels elicit damaging effects on skeletal muscle cells while acute exposure to physiological 4-HNE induces transient adaptation. General significance: This work suggests an important role of 4-HNE on the regulation of myotube's mitochondrial metabolism and cellular energy production. It further signifies the importance of skeletal muscle cells hormesis in response to acute stress in order to maintain essential biological functions.

© 2019 Background: Relatively few studies investigated the importance of frailty in radical cystectomy (RC) patients. We tested the ability of frailty, using the Johns Hopkins Adjusted Clinical Groups indicator, to predict early perioperative outcomes after RC. Methods: RC patients were identified within the National Inpatient Sample database (2000–2015). The effect of frailty, age and Charlson Comorbidity Index were tested in five separate multivariable models predicting: (1) complications, (2) failure to rescue (FTR), (3) in-hospital mortality, (4) length of stay (LOS) and (5) total hospital charges (THCs). All models were weighted and adjusted for clustering, as well as all available patient and hospital characteristics. Results: Of 23,967 RC patients, 5833 (24.3%) were frail, 7721 (32.2%) were aged ≥75 years and 2832 (11.8%) had CCI ≥2. Frailty, age ≥75 years and CCI ≥2 were non-overlapping in 86.3% of the cohort. Any two or three of these features were recorded in 12.4 and 1.3%, respectively. Frailty was an independent predictor of all five examined endpoints and the magnitude of its association was stronger or at least equal than that of age ≥75 years and CCI ≥2. Conclusion: Frailty, advanced age and comorbidities represent non-overlapping patients’ characteristics. Of those, frailty represents the most consistent and strongest predictor of early adverse outcomes after RC. Ideally, all three indicators should be considered in retrospective, as well as prospective analyses. Pre-surgical recognition of frail patients should be ideally incorporate in clinical practice in order to address these patients to multimodal pre-habilitation programs that may potentially improve the perioperative prognosis.

© 2019 Elsevier B.V. Objective: Being increasingly faced with the problem of pediatric nasal septal perforations, we have found that the surgical management of nasal septal perforations in children is not widely described in the litrature. The objective of our study was to demonstrate the results of different surgical techniques, including two original endoscopic techniques, in the septal perforation repair in children. Methods: 24 children, ranging between 6 and 17 years of age, with nasal septal perforations were operated using different endoscopic techniques from February 2015 to May 2019 at the special tertiary referral clinic. Apart from well-known techniques, such as anterior ethmoidal artery flap, intranasal bipedicled advancement flap, sublabial flap, free temporal fascia graft, we used two original techniques – inverted edges technique and cross-septal returned flap. Results: The total rate of complete perforation closure was 79% (19 of 24 patients). Regarding the reduction of symptoms, the efficacy of surgery was approaching 100%. The combination of inverted edges technique and anterior ethmoidal artery septal flap demonstrated the best results with no reperforations in all 10 cases. Using cross-septal returned flap, we achieved complete closure of perforation in 5 (83%) of 6 patients. The remaining techniques were performed rare and showed relatively low rates of success. There were 2 cases of complications (oronasal fistula), both developed in patients with sublabial mucosal flap. Conclusion: Use of endoscopic assistance, vascularized mucoperichondrial flaps and bilateral closure demonstrates high effectiveness in septal perforation surgical repair in children. Level of evidence: 4.

© 2019 The Author(s) Intradialytic hypotension is a frequent complication of chronic kidney disease. According to different authors, the incidence of this condition varies in severity and being recorded in 10–70% of cases during chronic intermittent hemodialysis. The development of severe chronic intradialytic hypotension in most cases is considered as a relative contraindication to kidney transplantation due to the risk of the graft dysfunction and loss in the early postoperative period. Meanwhile, there is no consensus on the lower limit of blood pressure, which would be an absolute contraindication for kidney transplantation. In addition, patients with intradialytic hypotension have the dialysis session reduced which leads to inadequate dialysis; also, they often have such complications as thrombosis of an arteriovenous fistula, as a result of which further dialysis sessions become impossible. In such cases, renal transplantation is a risky, but lifesaving operation. We present a clinical case report of kidney allotransplantation in a female patient with a history of bilateral nephrectomy, who had been suffering from severe chronic intradialytic hypotension for three years before the operation. After allograft transplantation, her blood pressure was normalized to reference values, and the graft function fully recovered.

© 2019 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM) Microbial cells sense the presence of xenobiotics and, in response, upregulate genes involved in pleiotropic drug resistance (PDR). In yeast, PDR activation to a major extent relies on the transcription factor Pdr1. In addition, many xenobiotics induce oxidative stress, which may upregulate PDR independently of Pdr1 activity. Mitochondria are important sources of reactive oxygen species under stressful conditions. To evaluate the relevance of this redox pathway, we studied the activation of PDR in the yeast Candida glabrata, which we treated with a mitochondrially targeted antioxidant plastoquinonyl-decyl-triphenylphosphonium and dodecyltriphenylphosphonium (C12TPP) as a control. We found that both compounds induced activation of PDR genes and decreased the intracellular concentration of the PDR transporter substrate Nile red. Interestingly, the deletion of PDR transporter gene CDR1 inhibited the decrease in Nile red accumulation induced by antioxidant plastoquinonyl-decyl-triphenylphosphonium but not that by C12TPP. Moreover, antioxidant alpha-tocopherol inhibited C12TPP-mediated activation of PDR in Δcdr1 but not in the wild-type strain. Furthermore, pre-incubation of yeast cells with low concentrations of hydrogen peroxide induced a decrease in the intracellular concentration of Nile red in Δcdr1 and Δpdr1 as well as in control cells. Deletion of PDR1 inhibited the C12TPP-induced activation of CDR1 but not that of FLR1, which is a redox-regulated PDR transporter gene. It appears that disruption of the PDR1/CDR1 regulatory circuit makes auxiliary PDR regulation mechanisms crucial. Our data suggest that redox regulation of PDR is dispensable in wild-type cells because of redundancy in the activation pathways, but is manifested upon deletion of CDR1.

© 2019 Elsevier Ltd The lens capsule, a thin specialized basement membrane that encloses the crystalline lens, is essential for both the structural and biomechanical integrity of the lens. Knowing the mechanical properties of the lens capsule is important for understanding its physiological functioning, role in accommodation, age-related changes, and for providing a better treatment of a cataract. In this review, we have described the techniques used for the lens capsule biomechanical testing on the macro- and microscale and summarized the current knowledge about its mechanical properties.

© 2019 Elsevier B.V. Background: A large number of systemic diseases can be linked to oral candida pathogenicity. The global trend of invasive candidiasis has increased progressively and is often accentuated by increasing Candida albicans resistance to the most common antifungal medications. Photodynamic therapy (PDT) is a promising therapeutic approach for oral microbial infections. A new formulation of 5-aminolevulinic acid (5%ALA) in a thermosetting gel (t) (5%ALA-PTt) was patented and recently has become available on the market. However, its antimicrobial properties, whether mediated or not by PDT, are not yet known. In this work we characterised them. Methods: We isolated a strain of C. albicans from plaques on the oral mucus membrane of an infected patient. Colonies of this strain were exposed for 1 24 h, to 5%ALA-PTt, 5%ALA-PTt buffered to pH 6.5 (the pH of the oral mucosa) (5%ALA-PTtb) or not exposed (control). The 1 h-exposed samples were also irradiated at a wavelength of 630 nm with 0.14 watts (W) and 0.37 W/cm2 for 7 min at a distance of <1 mm. Results and conclusion: The 5% ALA-PTt preparation was shown to be effective in reducing the growth of biofilm and inoculum of C. albicans. This effect seems to be linked to the intrinsic characteristics of 5%ALA-TPt, such acidic pH and the induction of free radical production. This outcome was significantly enhanced by the effect of PDT at relatively short incubation and irradiation times, which resulted in growth inhibition of both treated biofilm and inoculum by ∼80% and ∼95%, respectively.

© 2019 Elsevier GmbH Background: Essential trace elements and minerals play a significant role in neurodevelopment. Although certain studies demonstrated impaired essential trace element and mineral status in children with ADHD, the existing data are insufficient. The objective of the present study was to assess serum trace element and mineral levels in children with ADHD. Methods: Serum trace element and mineral levels in 68 children with ADHD and 68 neurotypical controls were assessed using ICP-MS at NexION 300D (PerkinElmer Inc., USA) equipped with ESI SC-2 DX4 autosampler (Elemental Scientific Inc., USA). Results: Serum Cr, Mg, and Zn levels in children with ADHD were 21 % (p = 0.010), 4 % (p = 0.005), and 7 % (p = 0. 001) lower as compared to the healthy controls, respectively. In turn, serum Cu/Zn values were 11 % higher than those in the control group. Age and gender had a significant impact on serum element levels in ADHD. Particularly, preschool children were characterized by significantly increased Cu (+8 %; p = 0.034), and Cu/Zn (+19 %; p < 0.001) values, whereas serum Zn (-9 %; p = 0.004) level was decreased. In primary school-aged children only 6 % (p = 0.007) lower Mg levels were observed. Both boys and girls with ADHD were characterized by 8 % (p = 0.016) lower serum Zn levels and 10 % (p = 0.049) higher Cu/Zn values when compared to neurotypical girls. Boys with ADHD also had significantly higher Cu/Zn, exceeding the respective control values by 12 % (p = 0.021), predominantly due to a 7 % (p = 0.035) decrease in serum Zn. Serum Mg levels were also found to be significantly lower than those in neurotypical children by 5 % (p = 0.007). In adjusted regression models serum Cr (β=-0.234; p = 0.009) and Cu/Zn (β = 0.245; p = 0.029) values were significantly associated with ADHD, respectively. Two-way ANOVA revealed a significant impact of ADHD on Cr, Mg, Zn, and Cu/Zn, whereas age was associated with Cu, I, Mg, Mo, and Cu/Zn, whereas gender accounted only for variability in serum Mn levels. Principal component analysis (PCA) also revealed significant contributions of Mg, Zn, and Cu/Zn values to ADHD variability. Conclusions: Hypothetically, the observed decrease of essential trace elements, namely Mg and Zn, and elevation of Cu/Zn may significantly contribute to the risk of ADHD or its severity and/or comorbidity.

© 2019 Elsevier B.V. 20-hydroxycholesterol is a signaling oxysterol with immunomodulating functions and, thus, structural analogues with reporter capabilities could be useful for studying and modulating the cellular processes concerned. We have synthesized three new 20-hydroxycholesterol-like pregn-5-en-3β-ol derivatives with fluorescent 7-nitrobenzofurazan (NBD) or Raman-sensitive alkyne labels in their side-chains. In silico computations demonstrated the compounds possess good membrane permeability and can bind within active sites of known 20-hydroxycholesterol targets (e.g. Smoothened and yeast Osh4) and some other sterol-binding proteins (human LXRβ and STARD1; yeast START-kins Lam4S2 and Lam2S2). Having found good predicted membrane permeability and binding to some yeast proteins, we tested the compounds on microorganisms. Fluorescent microscopy indicated the uptake of the steroids by both Saccharomyces cerevisiae and Yarrowia lipolytica, whereas only S. cerevisiae demonstrated conversion of the compounds into 3-O-acetates, likely because 3-O-acetyltransferase Atf2p is present only in its genome. The new compounds provide new options to study the uptake, intracellular distribution and metabolism of sterols in yeast cells as well as might be used as ligands for sterol-binding proteins.

© 2019 The Author(s) Intradialytic hypotension is a frequent complication of chronic kidney disease. According to different authors, the incidence of this condition varies in severity and being recorded in 10–70% of cases during chronic intermittent hemodialysis. The development of severe chronic intradialytic hypotension in most cases is considered as a relative contraindication to kidney transplantation due to the risk of the graft dysfunction and loss in the early postoperative period. Meanwhile, there is no consensus on the lower limit of blood pressure, which would be an absolute contraindication for kidney transplantation. In addition, patients with intradialytic hypotension have the dialysis session reduced which leads to inadequate dialysis; also, they often have such complications as thrombosis of an arteriovenous fistula, as a result of which further dialysis sessions become impossible. In such cases, renal transplantation is a risky, but lifesaving operation. We present a clinical case report of kidney allotransplantation in a female patient with a history of bilateral nephrectomy, who had been suffering from severe chronic intradialytic hypotension for three years before the operation. After allograft transplantation, her blood pressure was normalized to reference values, and the graft function fully recovered.

© 2019 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM) Microbial cells sense the presence of xenobiotics and, in response, upregulate genes involved in pleiotropic drug resistance (PDR). In yeast, PDR activation to a major extent relies on the transcription factor Pdr1. In addition, many xenobiotics induce oxidative stress, which may upregulate PDR independently of Pdr1 activity. Mitochondria are important sources of reactive oxygen species under stressful conditions. To evaluate the relevance of this redox pathway, we studied the activation of PDR in the yeast Candida glabrata, which we treated with a mitochondrially targeted antioxidant plastoquinonyl-decyl-triphenylphosphonium and dodecyltriphenylphosphonium (C12TPP) as a control. We found that both compounds induced activation of PDR genes and decreased the intracellular concentration of the PDR transporter substrate Nile red. Interestingly, the deletion of PDR transporter gene CDR1 inhibited the decrease in Nile red accumulation induced by antioxidant plastoquinonyl-decyl-triphenylphosphonium but not that by C12TPP. Moreover, antioxidant alpha-tocopherol inhibited C12TPP-mediated activation of PDR in Δcdr1 but not in the wild-type strain. Furthermore, pre-incubation of yeast cells with low concentrations of hydrogen peroxide induced a decrease in the intracellular concentration of Nile red in Δcdr1 and Δpdr1 as well as in control cells. Deletion of PDR1 inhibited the C12TPP-induced activation of CDR1 but not that of FLR1, which is a redox-regulated PDR transporter gene. It appears that disruption of the PDR1/CDR1 regulatory circuit makes auxiliary PDR regulation mechanisms crucial. Our data suggest that redox regulation of PDR is dispensable in wild-type cells because of redundancy in the activation pathways, but is manifested upon deletion of CDR1.

© 2019 Elsevier Ltd The lens capsule, a thin specialized basement membrane that encloses the crystalline lens, is essential for both the structural and biomechanical integrity of the lens. Knowing the mechanical properties of the lens capsule is important for understanding its physiological functioning, role in accommodation, age-related changes, and for providing a better treatment of a cataract. In this review, we have described the techniques used for the lens capsule biomechanical testing on the macro- and microscale and summarized the current knowledge about its mechanical properties.

© 2019 Elsevier B.V. Background: A large number of systemic diseases can be linked to oral candida pathogenicity. The global trend of invasive candidiasis has increased progressively and is often accentuated by increasing Candida albicans resistance to the most common antifungal medications. Photodynamic therapy (PDT) is a promising therapeutic approach for oral microbial infections. A new formulation of 5-aminolevulinic acid (5%ALA) in a thermosetting gel (t) (5%ALA-PTt) was patented and recently has become available on the market. However, its antimicrobial properties, whether mediated or not by PDT, are not yet known. In this work we characterised them. Methods: We isolated a strain of C. albicans from plaques on the oral mucus membrane of an infected patient. Colonies of this strain were exposed for 1 24 h, to 5%ALA-PTt, 5%ALA-PTt buffered to pH 6.5 (the pH of the oral mucosa) (5%ALA-PTtb) or not exposed (control). The 1 h-exposed samples were also irradiated at a wavelength of 630 nm with 0.14 watts (W) and 0.37 W/cm2 for 7 min at a distance of <1 mm. Results and conclusion: The 5% ALA-PTt preparation was shown to be effective in reducing the growth of biofilm and inoculum of C. albicans. This effect seems to be linked to the intrinsic characteristics of 5%ALA-TPt, such acidic pH and the induction of free radical production. This outcome was significantly enhanced by the effect of PDT at relatively short incubation and irradiation times, which resulted in growth inhibition of both treated biofilm and inoculum by ∼80% and ∼95%, respectively.

© 2019 Elsevier GmbH Background: Essential trace elements and minerals play a significant role in neurodevelopment. Although certain studies demonstrated impaired essential trace element and mineral status in children with ADHD, the existing data are insufficient. The objective of the present study was to assess serum trace element and mineral levels in children with ADHD. Methods: Serum trace element and mineral levels in 68 children with ADHD and 68 neurotypical controls were assessed using ICP-MS at NexION 300D (PerkinElmer Inc., USA) equipped with ESI SC-2 DX4 autosampler (Elemental Scientific Inc., USA). Results: Serum Cr, Mg, and Zn levels in children with ADHD were 21 % (p = 0.010), 4 % (p = 0.005), and 7 % (p = 0. 001) lower as compared to the healthy controls, respectively. In turn, serum Cu/Zn values were 11 % higher than those in the control group. Age and gender had a significant impact on serum element levels in ADHD. Particularly, preschool children were characterized by significantly increased Cu (+8 %; p = 0.034), and Cu/Zn (+19 %; p < 0.001) values, whereas serum Zn (-9 %; p = 0.004) level was decreased. In primary school-aged children only 6 % (p = 0.007) lower Mg levels were observed. Both boys and girls with ADHD were characterized by 8 % (p = 0.016) lower serum Zn levels and 10 % (p = 0.049) higher Cu/Zn values when compared to neurotypical girls. Boys with ADHD also had significantly higher Cu/Zn, exceeding the respective control values by 12 % (p = 0.021), predominantly due to a 7 % (p = 0.035) decrease in serum Zn. Serum Mg levels were also found to be significantly lower than those in neurotypical children by 5 % (p = 0.007). In adjusted regression models serum Cr (β=-0.234; p = 0.009) and Cu/Zn (β = 0.245; p = 0.029) values were significantly associated with ADHD, respectively. Two-way ANOVA revealed a significant impact of ADHD on Cr, Mg, Zn, and Cu/Zn, whereas age was associated with Cu, I, Mg, Mo, and Cu/Zn, whereas gender accounted only for variability in serum Mn levels. Principal component analysis (PCA) also revealed significant contributions of Mg, Zn, and Cu/Zn values to ADHD variability. Conclusions: Hypothetically, the observed decrease of essential trace elements, namely Mg and Zn, and elevation of Cu/Zn may significantly contribute to the risk of ADHD or its severity and/or comorbidity.

© 2019 Elsevier B.V. 20-hydroxycholesterol is a signaling oxysterol with immunomodulating functions and, thus, structural analogues with reporter capabilities could be useful for studying and modulating the cellular processes concerned. We have synthesized three new 20-hydroxycholesterol-like pregn-5-en-3β-ol derivatives with fluorescent 7-nitrobenzofurazan (NBD) or Raman-sensitive alkyne labels in their side-chains. In silico computations demonstrated the compounds possess good membrane permeability and can bind within active sites of known 20-hydroxycholesterol targets (e.g. Smoothened and yeast Osh4) and some other sterol-binding proteins (human LXRβ and STARD1; yeast START-kins Lam4S2 and Lam2S2). Having found good predicted membrane permeability and binding to some yeast proteins, we tested the compounds on microorganisms. Fluorescent microscopy indicated the uptake of the steroids by both Saccharomyces cerevisiae and Yarrowia lipolytica, whereas only S. cerevisiae demonstrated conversion of the compounds into 3-O-acetates, likely because 3-O-acetyltransferase Atf2p is present only in its genome. The new compounds provide new options to study the uptake, intracellular distribution and metabolism of sterols in yeast cells as well as might be used as ligands for sterol-binding proteins.

© 2019 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM) Microbial cells sense the presence of xenobiotics and, in response, upregulate genes involved in pleiotropic drug resistance (PDR). In yeast, PDR activation to a major extent relies on the transcription factor Pdr1. In addition, many xenobiotics induce oxidative stress, which may upregulate PDR independently of Pdr1 activity. Mitochondria are important sources of reactive oxygen species under stressful conditions. To evaluate the relevance of this redox pathway, we studied the activation of PDR in the yeast Candida glabrata, which we treated with a mitochondrially targeted antioxidant plastoquinonyl-decyl-triphenylphosphonium and dodecyltriphenylphosphonium (C12TPP) as a control. We found that both compounds induced activation of PDR genes and decreased the intracellular concentration of the PDR transporter substrate Nile red. Interestingly, the deletion of PDR transporter gene CDR1 inhibited the decrease in Nile red accumulation induced by antioxidant plastoquinonyl-decyl-triphenylphosphonium but not that by C12TPP. Moreover, antioxidant alpha-tocopherol inhibited C12TPP-mediated activation of PDR in Δcdr1 but not in the wild-type strain. Furthermore, pre-incubation of yeast cells with low concentrations of hydrogen peroxide induced a decrease in the intracellular concentration of Nile red in Δcdr1 and Δpdr1 as well as in control cells. Deletion of PDR1 inhibited the C12TPP-induced activation of CDR1 but not that of FLR1, which is a redox-regulated PDR transporter gene. It appears that disruption of the PDR1/CDR1 regulatory circuit makes auxiliary PDR regulation mechanisms crucial. Our data suggest that redox regulation of PDR is dispensable in wild-type cells because of redundancy in the activation pathways, but is manifested upon deletion of CDR1.