Growth, nutrient accumulation and yield of onion as a function of micronutrient fertilization

ABSTRACT Micronutrients structurally constitute several enzymes and act as a cofactor of essential proteins to maintain cell function, thereby contributing to crop growth and yield. The objective of this study was to evaluate the leaf content, growth, accumulation of micronutrients, classification and yield of onion as a function of fertilization with boron, cooper and zinc in two years of cultivation. The experiments were carried out from June to November in 2018 and 2019, in a soil classified as Ultisol, both at the Rafael Fernandes Experimental Farm, belonging to the Universidade Federal Rural do Semiárido, in the municipality of Mossoró, Rio Grande do Norte, Brazil. The experimental design was in randomized blocks with 15 treatments and four replicates. The treatments consisted of application of doses of B, Cu and Zn, in two experiments. Contents of B, Cu and Zn in the diagnostic leaf, growth, accumulation of B, Cu and Zn in the leaf, bulb and total, classification and commercial, non-commercial and total yields were evaluated. Application of B, Cu and Zn did not influence the number of leaves, relation of bulb shape, leaf, bulb, and total dry mass and yield of onion. Application of B, Cu and Zn, respectively at doses of 1-2-1 kg ha-1 favored a greater accumulation of B, Zn and Cu in the bulb. Higher number of leaves, leaf dry mass, bulb dry mass, total dry mass, class 1 bulbs and non-commercial yield were produced in Experiment 1.

Antioxidant Roles of SGLT2 Inhibitors in the Kidney

The reduction-oxidation (redox) system consists of the coupling and coordination of various electron gradients that are generated thanks to serial reduction-oxidation enzymatic reactions. These reactions happen in every cell and produce radical oxidants that can be mainly classified into reactive oxygen species (ROS) and reactive nitrogen species (RNS). ROS and RNS modulate cell-signaling pathways and cellular processes fundamental to normal cell function. However, overproduction of oxidative species can lead to oxidative stress (OS) that is pathological. Oxidative stress is a main contributor to diabetic kidney disease (DKD) onset. In the kidney, the proximal tubular cells require a high energy supply to reabsorb proteins, metabolites, ions, and water. In a diabetic milieu, glucose-induced toxicity promotes oxidative stress and mitochondrial dysfunction, impairing tubular function. Increased glucose level in urine and ROS enhance the activity of sodium/glucose co-transporter type 2 (SGLT2), which in turn exacerbates OS. SGLT2 inhibitors have demonstrated clear cardiovascular benefits in DKD which may be in part ascribed to the generation of a beneficial equilibrium between oxidant and antioxidant mechanisms.

Small Drugs, Huge Impact: The Extraordinary Impact of Antisense Oligonucleotides in Research and Drug Development

Antisense oligonucleotides (ASOs) are an increasingly represented class of drugs. These small sequences of nucleotides are designed to precisely target other oligonucleotides, usually RNA species, and are modified to protect them from degradation by nucleases. Their specificity is due to their sequence, so it is possible to target any RNA sequence that is already known. These molecules are very versatile and adaptable given that their sequence and chemistry can be custom manufactured. Based on the chemistry being used, their activity may significantly change and their effects on cell function and phenotypes can differ dramatically. While some will cause the target RNA to decay, others will only bind to the target and act as a steric blocker. Their incredible versatility is the key to manipulating several aspects of nucleic acid function as well as their process, and alter the transcriptome profile of a specific cell type or tissue. For example, they can be used to modify splicing or mask specific sites on a target. The entire design rather than just the sequence is essential to ensuring the specificity of the ASO to its target. Thus, it is vitally important to ensure that the complete process of drug design and testing is taken into account. ASOs’ adaptability is a considerable advantage, and over the past decades has allowed multiple new drugs to be approved. This, in turn, has had a significant and positive impact on patient lives. Given current challenges presented by the COVID-19 pandemic, it is necessary to find new therapeutic strategies that would complement the vaccination efforts being used across the globe. ASOs may be a very powerful tool that can be used to target the virus RNA and provide a therapeutic paradigm. The proof of the efficacy of ASOs as an anti-viral agent is long-standing, yet no molecule currently has FDA approval. The emergence and widespread use of RNA vaccines during this health crisis might provide an ideal opportunity to develop the first anti-viral ASOs on the market. In this review, we describe the story of ASOs, the different characteristics of their chemistry, and how their characteristics translate into research and as a clinical tool.

TRPM2 Is Not Required for T-Cell Activation and Differentiation

Antigen recognition by the T-cell receptor induces a cytosolic Ca2+ signal that is crucial for T-cell function. The Ca2+ channel TRPM2 (transient receptor potential cation channel subfamily M member 2) has been shown to facilitate influx of extracellular Ca2+ through the plasma membrane of T cells. Therefore, it was suggested that TRPM2 is involved in T-cell activation and differentiation. However, these results are largely derived from in vitro studies using T-cell lines and non-physiologic means of TRPM2 activation. Thus, the relevance of TRPM2-mediated Ca2+ signaling in T cells remains unclear. Here, we use TRPM2-deficient mice to investigate the function of TRPM2 in T-cell activation and differentiation. In response to TCR stimulation in vitro, Trpm2-/- and WT CD4+ and CD8+ T cells similarly upregulated the early activation markers NUR77, IRF4, and CD69. We also observed regular proliferation of Trpm2-/- CD8+ T cells and unimpaired differentiation of CD4+ T cells into Th1, Th17, and Treg cells under specific polarizing conditions. In vivo, Trpm2-/- and WT CD8+ T cells showed equal specific responses to Listeria monocytogenes after infection of WT and Trpm2-/- mice and after transfer of WT and Trpm2-/- CD8+ T cells into infected recipients. CD4+ T-cell responses were investigated in the model of anti-CD3 mAb-induced intestinal inflammation, which allows analysis of Th1, Th17, Treg, and Tr1-cell differentiation. Here again, we detected similar responses of WT and Trpm2-/- CD4+ T cells. In conclusion, our results argue against a major function of TRPM2 in T-cell activation and differentiation.

Comparison of insulin sensitivity between healthy neonatal foals and horses using minimal model analysis

The equine neonate is considered to have impaired glucose tolerance due to delayed maturation of the pancreatic endocrine system. Few studies have investigated insulin sensitivity in newborn foals using dynamic testing methods. The objective of this study was to assess insulin sensitivity by comparing the insulin-modified frequently sampled intravenous glucose tolerance test (I-FSIGTT) between neonatal foals and adult horses. This study was performed on healthy neonatal foals (n = 12), 24 to 60 hours of age, and horses (n = 8), 3 to 14 years of age using dextrose (300 mg/kg IV) and insulin (0.02 IU/kg IV). Insulin sensitivity (SI), acute insulin response to glucose (AIRg), glucose effectiveness (Sg), and disposition index (DI) were calculated using minimal model analysis. Proxy measurements were calculated using fasting insulin and glucose concentrations. Nonparametric statistical methods were used for analysis and reported as median and interquartile range (IQR). SI was significantly higher in foals (18.3 L·min-1· μIU-1 [13.4–28.4]) compared to horses (0.9 L·min-1· μIU-1 [0.5–1.1]); (p < 0.0001). DI was higher in foals (12 × 103 [8 × 103−14 × 103]) compared to horses (4 × 102 [2 × 102−7 × 102]); (p < 0.0001). AIRg and Sg were not different between foals and horses. The modified insulin to glucose ratio (MIRG) was lower in foals (1.72 μIUinsulin2/10·L·mgglucose [1.43–2.68]) compared to horses (3.91 μIU insulin2/10·L·mgglucose [2.57–7.89]); (p = 0.009). The homeostasis model assessment of beta cell function (HOMA-BC%) was higher in horses (78.4% [43–116]) compared to foals (23.2% [17.8–42.2]); (p = 0.0096). Our results suggest that healthy neonatal foals are insulin sensitive in the first days of life, which contradicts current literature regarding the equine neonate. Newborn foals may be more insulin sensitive immediately after birth as an evolutionary adaptation to conserve energy during the transition to extrauterine life.

Heterologous infection and vaccination shapes immunity against SARS-CoV-2 variants

Immune imprinting For severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), immune responses to heterologous variants are influenced by a person’s infection history. Healthcare workers (HCWs) may be exposed to several doses and types of antigens, either by natural infection or by vaccination. Reynolds et al . studied a cohort of UK HCWs followed since March 2020. The immunological profiles of these people depended on how often the subject had encountered antigen and which variant was involved. Vaccine responses after infection were found to be less effective if the infection involved heterologous spike from a variant virus. Unfortunately, the N501Y spike mutation, found in many variants, seems to induce the regulatory T cell transcription factor FOXP3, indicating that the virus could subvert effective T cell function. Changes to antibody binding between variants also means that serology data using the Wuhan Hu-1 S1 receptor-binding domain sequence may not be a reliable measure of protection. —CA

Arsenic exposure during pregnancy and postpartum maternal glucose tolerance: evidence from Bangladesh

Background Arsenic exposure has been associated with gestational diabetes mellitus. However, the extent to which arsenic exposure during pregnancy is associated with postpartum glucose intolerance is unknown. Methods We studied 323 women in Bangladesh. We assessed arsenic exposure in early pregnancy via toenail and water samples. We measured fasting glucose and insulin in serum at a mean (SD) of 4.0 (3.5) weeks post-delivery. We ran covariate-adjusted, linear regression models to examine associations of arsenic concentrations with HOMA-IR, a marker of insulin resistance, and HOMA-β, a marker of beta cell function. Results Median (IQR) arsenic concentration was 0.45 (0.67) μg/g in toenails and 2.0 (6.5) μg/L in drinking water. Arsenic concentrations during pregnancy were not associated with insulin resistance or beta cell function postpartum. HOMA-IR was 0.07% (− 3.13, 3.37) higher and HOMA-β was 0.96% (− 3.83, 1.99) lower per IQR increment in toenail arsenic, but effect estimates were small and confidence intervals crossed the null. Conclusions Although arsenic exposure during pregnancy has been consistently associated with gestational diabetes mellitus, we found no clear evidence for an adverse effect on postpartum insulin resistance or beta cell function.

The presidential election of the human body: applying contextual learning to promote connections between the student and the curricular content

Using real-world situations to engage students in learning specific content is preconized by educational research as an effective strategy. However, motivating students to establish personal and emotional connections with the curricular content is challenging. We presented a didactic strategy named The presidential election of the human body, created to use the presidential election context to engage students in studying cell function and structure using role-playing and appropriation of scientific concepts. Four groups of students (N=124) of the science and mathematics teacher training program chose a cell of the human body to impersonate, they studied the biology of their cell, and they ran in a presidential election campaign. They created slogans, videos, and materials for their campaign, and on the day of the election, the group of the students voted for the best slogan. The didactic strategy was capable of stimulating the appropriation of the characteristics of the cells they represented. The majority (75%) of the elected candidates represented cells that are linked to the nervous system. Musicality and humor were the most frequent styles that appeared in the slogans. Students strongly agreed that they enjoyed the activity and considered it valuable for contextualizing the learning of anatomy and physiology. Thus, the activity is a didactic resource to stimulate the students to embrace the content they are learning in a contextualized momentum of a presidential election.

Greater Glycemic Burden Is Associated with Further Poorer Glycemic Control in Newly-Diagnosed Type 2 Diabetes Mellitus Patients

Aims: hyperglycemia impairs pancreatic β-cell function instantly, also known as glucotoxicity. It is unknown whether this insult is temporary or sustained, and little real-world evidence needs to reflect the relationship between hyperglycemic burden, per se, and glycemic durability. Materials and Methods: a retrospective observational cohort study was conducted to recruit newly-diagnosed type 2 diabetes mellitus (T2DM) patients. Durability was defined as the episode from first glycated hemoglobin A1c (HbA1c) below 7.0% to where it exceed 8.0% (with treatment failure) or where study ended (without treatment failure). Glycemic burden was defined with the area above a burden value line (HbA1c = 6.5%) but under the HbA1c curve (AUC), and it was then divided into two compartments with the demarcation timepoint once HbA1c was treated below or equal to 7.0%; the former AUC’ represented the initial insult; the latter AUC” represented the residual part. Multivariable regression models assessed factors associated with durability in whole participants and two distinct subgroups: patients with baseline HbA1c > 7.0% or ≤7.0%. Results: 1048 eligible participants were recruited and analyzed: 291 patients with treatment failure (durability 26.8 ± 21.1 months); 757 patients without treatment failure (durability 45.1 ± 31.8 months). Besides age, glycemic burden was the only constant determinant in the two subgroups. AUC’ or AUC” increased treatment failure, respectively, in baseline HbA1c > 7.0% or ≤7.0% subgroup [per 1%/90 days hazard ratio (95% confidence interval): 1.026 (1.018–1.034) and 1.128 (1.016–1.253)]. Other determinants include baseline HbA1c, initial OAD, and education level. Conclusions: in patients with newly-diagnosed T2DM, glycemic durability was negatively associated with greater glycemic burden.

The circular RNA circGlis3 protects against islet β-cell dysfunction and apoptosis during obesity

The molecular link between obesity and β-cell decompensation that causes diabetes remains incompletely understood. Here we found that circGlis3, a circular RNA derived from Glis3, plays a critical role in islet β-cell compensation. circGlis3 was increased in islets of obese mouse models and moderately diabetic individuals with compensated β-cell function by Quaking (QKI)-mediated splicing. Overexpression of circGlis3 functions to restrain islet β-cell dysfunction and maintain β-cell mass in high-fat diet (HFD) fed mice and Leprdb/db mice. The cellular levels of circGlis3 modulate both insulin synthesis and secretion and lipotoxicity-induced apoptosis, resulting in profound changes in β-cell compensation. In an obesity model, circGlis3 promotes the synthesis and secretion of insulin by upregulating NeuroD1 and Creb1 through sponging miR-124-3p. In addition, we identified SCOTIN and fused in sarcoma (FUS) as interacting proteins using quantitative mass spectrometry. We demonstrated that the binding of SCOTIN to circGlis3 regulated the apoptosis of β-cell. And more, FUS binding to circGlis3 could decrease free circGlis3 in cytoplasm and block mechanism of circGlis3 via abnormal stable formation of stress granules (SGs) in hyperactive response to chronic stresses in obesity that is thought to contribute to the β-cell decompensation. These findings highlight a physiological role for circRNAs in compensation and indicate that modulation of circGlis3 expression may represent a potential strategy to protect against islet β-cell dysfunction and apoptosis during obesity.