Hasil untuk "Biochemistry"

J. Bos, E. Fearon, S. Hamilton et al.

F. McLafferty, Douglas B. Stauffer, E. Stenhagen et al.

Soha Issa, Yuval Klein, Eden Berda et al.

The ubiquitin-like protein NEDD8/Rub1 is initially translated as a precursor and undergoes maturation before becoming functional, a process mediated by the ubiquitin hydrolase UCHL3/Yuh1. Across studied organisms, the mature form of NEDD8/Rub1 modifies cullins, the central subunits of CRLs. NEDD8/Rub1 modification typically enhances CRL-mediated ubiquitination of key cellular regulators, leading to their proteasomal degradation. However, in S. cerevisiae, cullin modification by NEDD8/Rub1 occurs but does not regulate substrate turnover, prompting the question of whether NEDD8/Rub1 has a conserved role beyond CRL activation.Previous studies in S. cerevisiae have shown that increased production of reactive oxygen species (ROS) during the diauxic shift, a transition from glycolysis to mitochondrial respiration, inhibits cullin NEDDylation, though the specific enzymes affected remain unidentified. Here, we investigated how changes in the redox state affect Yuh1 catalytic function. Our findings reveal a thiol-based redox switch that modulates Yuh1 catalytic function in response to accumulated ROS. Our results suggest that the fine-tuning between the mature and precursor forms of NEDD8/Rub1 through temporal inactivation of Yuh1 is essential for maintaining mitochondrial integrity and enhancing resilience to oxidative stress. These results unveil a novel role for CRL-free NEDD8/Rub1 in redox signaling.

Liangwei Zhang, Shudi Liu, Xia Zhang et al.

Abstract It is a great challenge to discover novel chemical reactions suitable for biological analysis in a living system. The development of novel protein thiol blocking agents is a crucial need for exploring protein thiol functions in protein refolding, signal transduction, and redox regulation. We are always keen on seeking novel chemical reactions applied to endogenous biological macromolecules or protein thiol sensing, blocking, and labeling. In the present work, we have successfully developed a novel agent to block protein thiol by enhanced electron‐withdrawing inductive effects. This sensing and blocking process was detailedly monitored by UV‐vis, fluorescent spectra, and SDS‐Page gel separation. The spectral studies demonstrated that the agent could react ultrafastly with thiol within seconds at μM level. Furthermore, fluorescent imaging in cells and in vivo was further used for the validation of its ability to sensing and blocking thiol, providing evidence of downregulated protein thiols in Parkinson's disease. The enhanced electron‐withdrawing inductive effect strategy in this work may provide a general guideline for designing protein thiol agent.

Laura Micheli, Marzia Vasarri, Donatella Degl’Innocenti et al.

Psoriasis is a chronic immune-mediated inflammatory cutaneous disease characterized by elevated levels of inflammatory cytokines and adipokine Lipocalin-2 (LCN-2). Recently, natural plant-based products have been studied as new antipsoriatic compounds. We investigate the ability of a leaf extract of the marine plant <i>Posidonia oceanica</i> (POE) to inhibit psoriatic dermatitis in C57BL/6 mice treated with Imiquimod (IMQ). One group of mice was topically treated with IMQ (IMQ mice) for 5 days, and a second group received POE orally before each topical IMQ treatment (IMQ-POE mice). Psoriasis Area Severity Index (PASI) score, thickness, and temperature of the skin area treated with IMQ were measured in both groups. Upon sacrifice, the organs were weighed, and skin biopsies and blood samples were collected. Plasma and lesional skin protein expression of IL-17, IL-23, IFN-γ, IL-2, and TNF-α and plasma LCN-2 concentration were evaluated by ELISA. PASI score, thickness, and temperature of lesional skin were reduced in IMQ-POE mice, as were histological features of psoriatic dermatitis and expression of inflammatory cytokines and LCN-2 levels. This preliminary study aims to propose <i>P. oceanica</i> as a promising naturopathic anti-inflammatory treatment that could be introduced in Complementary Medicine for psoriasis.

Andrew L. Thomas, George E. Rottinghaus, Matheus Dela Libera Tres et al.

A long-term horticultural experiment was conducted at two geographically distinct sites in southern Missouri in 2011–15 to study the response of American elderberry [Sambucus nigra (L.) subsp. canadensis (L.) Bolli] to various soil nitrogen (N) fertilizer levels. Three commercially available elderberry cultivars (‘Adams II’, ‘Bob Gordon’, and ‘Wyldewood’) were used. The three cultivars were each assigned to 16 of 48 four-plant plots in a completely randomized manner at each site. Four replications of four N fertilizer treatments (0, 56, 112, 169 kg⋅ha−1 N) were randomly assigned to each cultivar’s plots and applied for 4 years (2012–15). Fruit yields, plant growth, phenology, and pest incidence were determined each year. Fruit quality was assessed by analyzing basic juice characteristics as well as organic acids, carbohydrates, anthocyanins, and polyphenols from 2012–14 samples. Leaf tissue analysis determined the plants’ mineral contents in 2012–14. Most factors evaluated were significantly affected by site, year, and cultivar, whereas the effects of N fertilizer treatment were less definitive. Fruit yields and plant growth increased with increasing N levels. For example, plants fertilized with 0, 56, 112, and 169 kg⋅ha−1 N produced 123, 137, 155, and 161 fruiting cymes per plot (5.8 m2), respectively. The eriophyid mite incidence was higher on fertilized plants, but other pests were not influenced by the N treatment. Basic fruit juice characteristics (soluble solids, pH, titratable acidity, polyphenols) were not influenced by the N treatment, whereas total anthocyanins were statistically higher in unfertilized plants. Levels of organic acids and carbohydrates in juice varied statistically among N treatments, but patterns were difficult to discern. Leaf N concentrations were correlated with N fertilizer levels—2.75% N with the highest fertilizer level compared with 2.55% N in unfertilized plants. Leaf levels of most other macronutrients varied, but consistent patterns did not emerge, and none of the micronutrients was different among N treatments. Although elderberry plants responded positively to increased N fertilizer levels in terms of plant growth and fruit yield, genetics (cultivar) and environment (site, year) were more influential on most other experimental factors evaluated.

Arju Hossain, Asif Ahsan, Imran Hasan et al.

Purpose Ultraviolet radiation causes skin cancer, but the exact mechanism by which it occurs and the most effective methods of intervention to prevent it are yet unknown. For this purpose, our study will use bioinformatics and systems biology approaches to discover potential biomarkers of skin cancer for early diagnosis and prevention of disease with applicable clinical treatments. Methods This study compared gene expression and protein levels in ultraviolet-mediated cultured keratinocytes and adjacent normal skin tissue using RNA sequencing data from the National Center for Biotechnology Information-Gene Expression Omnibus (NCBI-GEO) database. Then, pathway analysis was employed with a selection of hub genes from the protein-protein interaction (PPI) network and the survival and expression profiles. Finally, potential clinical biomarkers were validated by receiver operating characteristic (ROC) curve analysis. Results We identified 32 shared differentially expressed genes (DEGs) by analyzing three different subsets of the GSE85443 dataset. Skin cancer development is related to the control of several DEGs through cyclin-dependent protein serine/threonine kinase activity, cell cycle regulation, and activation of the NIMA kinase pathways. The cytoHubba plugin in Cytoscape identified 12 hub genes from PPI; among these 3 DEGs, namely, AURKA, CDK4 , and PLK1 were significantly associated with survival ( P  < 0.05) and highly expressed in skin cancer tissues. For validation purposes, ROC curve analysis indicated two biomarkers: AURKA (area under the curve (AUC) value = 0.8) and PLK1 (AUC value = 0.7), which were in an acceptable range. Conclusions Further translational research, including clinical experiments, teratogenicity tests, and in-vitro or in-vivo studies, will be performed to evaluate the expression of these identified biomarkers regarding the prognosis of skin cancer patients.

Elaine C. Petronilho, Guilherme C. de Andrade, Gileno dos S. de Sousa et al.

Abstract P53 Phase separation is crucial towards amyloid aggregation and p63 and p73 have enhanced expression in tumors. This study examines the phase behaviors of p53, p63, and p73. Here we show that unlike the DNA-binding domain of p53 (p53C), the p63C and p73C undergo phase separation, but do not form amyloids under physiological temperatures. Wild-type and mutant p53C form droplets at 4°C and aggregates at 37 °C with amyloid properties. Mutant p53C promotes amyloid-like states in p63C and p73C, recruiting them into membraneless organelles. Amyloid conversion is supported by thioflavin T and Congo red binding, increased light scattering, and circular dichroism. Full-length mutant p53 and p63C (or p73C) co-transfection shows reduced fluorescence recovery after photobleaching. Heparin inhibits the prion-like aggregation of p63C and p73C induced by p53C. These findings highlight the role of p53 in initiating amyloid aggregation in p63 and p73, opening avenues for targeting prion-like conversion in cancer therapy.

Aminat Mohammed Ahmed, Menbere Leul Mekonnen, Kebede Nigussie Mekonnen

Nutrient enrichment of the aquatic system promotes eutrophication, which degrades the aesthetic and economic value of water systems. On the other hand, the global supply of nutrients such as phosphate is dwindling. Hence, from the viewpoint of both eutrophication and sustainable use of nutrients, their removal and recovery from wastewater is critical. Among the various technologies practiced today, adsorption represents an economically feasible, and operationally simple technique. However, to utilize the potential of adsorption, finding effective adsorbents has been an ongoing research process preoccupying scientists. Among the various adsorbents, biopolymer nanocomposites (alginate, cellulose, chitosan, and lignin) showed promising potential. This is due to their abundance, non-toxicity, ease of modification, etc. Hence, in this review article, the utility of this class of adsorbents, particularly for nutrient removal and recovery, is addressed. Further, the various approaches to the modification of biopolymers, and their typical features for the simultaneous removal of nutrients are also discussed.

Iva Ganeva, Koini Lim, Jerome Boulanger et al.

Summary: Lipid droplets (LDs) are intracellular organelles responsible for storing surplus energy as neutral lipids. Their size and number vary enormously. In white adipocytes, LDs can reach 100 μm in diameter, occupying >90% of the cell. Cidec, which is strictly required for the formation of large LDs, is concentrated at interfaces between adjacent LDs and facilitates directional flux of neutral lipids from the smaller to the larger LD. The mechanism of lipid transfer is unclear, in part because the architecture of interfaces between LDs remains elusive. Here we visualize interfaces between LDs by electron cryo-tomography and analyze the kinetics of lipid transfer by quantitative live fluorescence microscopy. We show that transfer occurs through closely apposed monolayers, is slowed down by increasing the distance between the monolayers, and follows exponential kinetics. Our data corroborate the notion that Cidec facilitates pressure-driven transfer of neutral lipids through two “leaky” monolayers between LDs.

S. Shabir, A. Asiaf

Objective: Ovarian cancer is the most dreadful gynecological malignancy among females worldwide, with worst prognosis and non-effectiveness of its screening markers yielding false negative cases. The aim of the present study was to investigate the clinicopathological and epidemiological profile of ovarian cancer patients in Kashmir ethnicity. Patients and Methods: The present observational cross-sectional study was conducted on 50 ovarian cancer patients who reported to the Department of General Surgery and Medical Oncology, SKIMS, Srinagar, from 2017 to 2019 and on 50 healthy female volunteers as age-matched controls. The clinicopathological and epidemiological profiles of the ovarian cancer patients were compared with those of normal controls. A detailed description of clinico-pathological, epidemiological, and etiological data was obtained from the in-patient record and questionnaire method and analyzed by Student's t-test to estimate statistically significant differences between cases and controls. The blood samples were assessed for CA-125 levels. p ≥ 0.05 differences were considered statistically significant. Results: Of the 50 ovarian cancer patients, the most affected (48%) age group was 44–59 years. The majority (64%) of the patients belonged to stages III and IV of the disease. Abdominal distension and pelvic pain were the most frequent symptoms observed in 46% and 44% of cases, respectively. Using Pearson’s correlation coefficient, we observed a significant negative correlation of risk of ovarian cancer with menarcheal age and a highly significant positive correlation with menopausal age, age at marriage, BMI, and CA125 in ovarian cancer patients. Conclusions: Most of the patients presented in an advanced stage of the disease and had CA125 levels of 500 U/ml. Awareness must be raised among women regarding the symptoms, warning signs, and risk factors of ovarian cancer because doing so will facilitate the early diagnosis of the disease.

Valiyaveetil Anjana, Kakkoprath Thekkeveetil Madavan

Introduction: The Emergency Departments (ED) are equipped with Point-of-Care (POC) Blood Gas Analysers (BGA) which deliver fast results on multiple parameters of arterial/venous blood. There is no consensus among ED physicians on the reliability of electrolyte results by POC Arterial Blood Gas (ABG) analysis compared to venous serum electrolyte from Central Laboratory Analyser/Auto-Analyser (CLA/AA). Aim: To compare the electrolyte (sodium and potassium) by POC arterial BGA (ABL800 Flex Radiometer) with venous electrolyte by CLA (Beckman Coulter AU 5800). Materials and Methods: This cross-sectional study was performed in the ED and Central Laboratory of the tertiary teaching hospital from 1st July 2018 to 31st July 2019. A total of 254 critically ill adult patients with various aetiologies, were enrolled in the study. The arterial and venous blood samples were collected for electrolyte measurement within a span of 15 minutes. The ABG samples, anticoagulated with liquid heparin, were processed in POC BGA. The venous samples collected in plain tubes were analysed in CLA. The results of sodium and potassium were compared by the mean, correlation coefficient, p-value, and Bland Altman Plots {95% Limit of Agreement (LOA)}. Results: Out of 254 paired samples (mean age: 63±15 years), 157 (61.8%) were males and 97 (38.2%) females. The mean sodium values were 131.9±7.7 mmol/L in ABG and 132.3±7.1 mmol/L in CLA (p-value <0.0001). The mean difference was 0.4 mmol/L. The mean potassium values were 3.9±1.0 mmol/L (ABG) and 4.2±0.9 mmol/L (CLA), {p-value <0.0001}. The mean difference was 0.3 mmol/L. These differences were within the accepted range specified by the United States Clinical Laboratory Improvement Amendments. There were statistically significant strong positive correlations between the measurements of the two instruments r=0.78 for sodium and r=0.76 for potassium. The 95% LOA for sodium and potassium on both the instruments were -10.03 to 9.09 mmol/L and -1.49 to 0.97 mmol/L respectively, both wide and unacceptable. Conclusion: The arterial sodium and potassium measurements by BGA were not reliable in decision making in ED when compared to the venous serum by CLA as the 95% LOA was wide and unacceptable. Hence, sodium and potassium values by BGA alone might not be used as criteria for management without confirmation from venous serum values by CLA

Necmi Arslan , Selda Kargin Kaytez , Ramazan Ocal et al.

Merve Yılmaz, Monireh Bakhshpour, Ilgım Göktürk et al.

The heterogeneity and metastatic features of cancer cells lead to a great number of casualties in the world. Additionally, its diagnosis as well as its treatment is highly expensive. Therefore, development of simple but effective diagnostic systems which detect the molecular markers of cancer is of great importance. The molecular changes on cancer cell membranes serve as targets, such as HER2/neu receptor which is detected on the surface of highly metastatic breast cancer cells. We have aimed to develop a specific and simple quartz crystal microbalance (QCM)-based system to identify HER2/neu expressing breast cancer cells via a receptor-specific monoclonal antibody. First, the QCM chip was coated with polymeric nanoparticles composed of hydroxyethylmethacrylate (HEMA) and ethylene glycol dimethacrylate (EDMA). The nanoparticle coated QCM chip was then functionalized by binding of HER2/neu antibody. The breast cancer cells with/without HER2/neu receptor expression, namely, SKBR3, MDA-MB 231 and also mouse fibroblasts were passed over the chip at a rate of 10–500 cells/mL and the mass changes (Δm) on cell/cm² unit surface of sensor were detected in real-time. The detection limit of the system was 10 cells/mL. Thus, this QCM-based HER2/neu receptor antibody functionalized system might be used effectively in the detection of HER2/neu expressing SKBR3 breast cancer cells.

Phuoc Truong Nguyen, Santiago Garcia-Vallvé, Pere Puigbò

Early characterization of emerging viruses is essential to control their spread, such as the Zika Virus outbreak in 2014. Among other non-viral factors, host information is essential for the surveillance and control of virus spread. Flaviviruses (genus <i>Flavivirus</i>), akin to other viruses, are modulated by high mutation rates and selective forces to adapt their codon usage to that of their hosts. However, a major challenge is the identification of potential hosts for novel viruses. Usually, potential hosts of emerging zoonotic viruses are identified after several confirmed cases. This is inefficient for deterring future outbreaks. In this paper, we introduce an algorithm to identify the host range of a virus from its raw genome sequences. The proposed strategy relies on comparing codon usage frequencies across viruses and hosts, by means of a normalized Codon Adaptation Index (CAI). We have tested our algorithm on 94 flaviviruses and 16 potential hosts. This novel method is able to distinguish between arthropod and vertebrate hosts for several flaviviruses with high values of accuracy (virus group 91.9% and host type 86.1%) and specificity (virus group 94.9% and host type 79.6%), in comparison to empirical observations. Overall, this algorithm may be useful as a complementary tool to current phylogenetic methods in monitoring current and future viral outbreaks by understanding host–virus relationships.