Alteration of Endothelins: A Common Pathogenetic Mechanism in Chronic Diabetic Complications

Endothelin (ET) peptides perform several physiological, vascular, and nonvascular functions and are widely distributed in a number of tissues. They are altered in several disease processes including diabetes. Alteration of ETs have been demonstrated in organs of chronic diabetic complications in both experimental and clinical studies. The majority of the effects of ET alteration in diabetes are due to altered vascular function. Furthermore, ET antagonists have been shown to prevent structural and functional changes induced by diabetes in animal models. This review discusses the contribution of ETs in the pathogenesis and the potential role of ET antagonism in the treatment of chronic diabetic complications

Revolutionizing the Biological Landscape: the Power of Genome Editing

In recent decades, the advent of genome editing has brought about profound transformations in biology, allowing for precise modifications to the genetic material of living organisms beyond traditional genetic manipulation methods. This summary explores the vast potential, diverse applications, and ethical considerations associated with genome editing. Led by CRISPR-Cas9, this technology revolutionizes genetic engineering by providing unparalleled accuracy and versatility. Scientists can now manipulate genes with unprecedented precision, impacting various fields such as agriculture and medicine. Genome editing facilitates the creation of genetically modified organisms with desirable traits, from enhancing crop disease resistance to pioneering human therapies. Moreover, it sheds light on gene function, offering crucial biological insights. Despite its transformative potential, ethical concerns accompany genome editing, especially in terms of editing the germ line and its implications for future generations. This necessitates ongoing discussions to address unintended consequences, highlighting the importance of responsible use. Ultimately, genome editing represents a revolutionary advancement with the potential to transform agriculture, medicine, and our understanding of life. Moving forward, inclusive dialogues involving scientists, ethicists, policymakers, and the public are essential to ensure the responsible application of genome editing for the benefit of humanity and the environment

A Study to Assess Changes in Cortisol Level and Heart Rate Variability between Fixed Duty and Shift Duty Health Care Providers in a Tertiary Care Hospital- A Cross-Sectional Study

Introduction: Increased demand of service 24 hours around the clock has divided the workers into 2 domains as “Fixed duty” and “Shift duty”. Personals associated with shift duty are increasing in numbers day by day. Shift duty or more specifically night duty is associated with increased stress which results in high morbidity and decrease in work efficiency. Cortisol hormone and Heart Rate Variability (HRV) are useful parameters to determine the effects of stress. Aim: To find any change in cortisol levels, HRV, Athens score among the fixed duty and shift duty healthcare providers. Materials and Methods: A descriptive cross-sectional comparative study was conducted in a tertiary care hospital at Kolkata between July, 15th to Sept, 15th 2021. Predesigned and pretested questionnaire was made and ethical clearance was taken from institutional IEC. Then after taking consent total 120 (60 fixed duty and 60 shift duty) healthcare providers were recruited for the study. Subjects of the study filled up a questionnaire {including Athens Insomnia Scale (AIS)}. After applying exclusion criteria (any cardiovascular, neurological, psychological, sleep disorder) 120 health individuals were taken five minutes short-term HRV (time and frequency domain) recording in supine posture and 4 PM blood sample (for cortisol) were obtained from the participants which was further analysed in Chemiluminescence Immunoassay (CLI). Data was analysed in SPSS version 20.0. Statistical tests like student t-test, Cron bach’s alpha and chi-square tests were applied significant p<0.05 (95% CI). Results: After analysis, shift duty workers showed a significant (p6) than fixed duty workers. Blood test showed that shift duty workers had significantly high evening cortisol level than fixed duty workers (p= 0.036). The time domain of HRV showed that the parameters like Standard Deviation all NN interval (SDNN) (p=0.001), Mean HR (p=0.037), RMSSD (p <0.001), NN50 (p=0.006), pNN50 (p=0.002) were significantly different in the two groups. Whereas the frequency domain of HRV showed that HF power was lower and LF power (p=0.002), LF/HF ratio (p <0.001) were significantly higher in shift duty workers. Conclusion: The study showed that shift duty workers had comparatively higher stress levels resulting in significantly high sympathetic drive and increased risk of insomnia. This can be associated with morbidity and ill health in the shifting duty workers

Alternative Sigma Factors in the Free State Are Equilibrium Mixtures of Open and Compact Conformations

Conformational switching upon core RNA polymerase binding is an integral part of functioning of bacterial sigma factors. Here, we have studied dynamical features of two alternative sigma factors. A study of fluorescence resonance energy transfer and hydrodynamic measurements in Escherichia coli σ32 suggest a compact shape like those found in complex with anti-sigma factors. On the other hand, the fluorescence anisotropy of probes attached to different regions of the protein and previous hydrogen exchange measurements suggest significant internal flexibility, particularly in the C-terminal half and region 1. In a homologous sigma factor, σF of Mycobacterium tuberculosis, emission spectra and fluorescence resonance energy transfer between the single tryptophan (W112) and probes placed in different regions suggest a compact conformation for a major part of the N-terminal half encompassing region 2 and the flexible C-terminal half. Fluorescence anisotropy measurements suggest significant flexibility in the C-terminal half and region 1, as well. Thus, free alternative sigma factors may be in equilibrium between two conformations: a compact one in which the promoter interacting motifs are trapped in the wrong conformation and another less abundant one with a more open and flexible conformation. Such flexibility may be important for promoter recognition and interaction with many partner proteins

Role of cortactin homolog HS1 in transendothelial migration of natural killer cells.

Natural Killer (NK) cells perform many functions that depend on actin assembly, including adhesion, chemotaxis, lytic synapse assembly and cytolysis. HS1, the hematopoietic homolog of cortactin, binds to Arp2/3 complex and promotes actin assembly by helping to form and stabilize actin filament branches. We investigated the role of HS1 in transendothelial migration (TEM) by NK cells. Depletion of HS1 led to a decrease in the efficiency of TEM by NK cells, as measured by transwell assays with endothelial cell monolayers on porous filters. Transwell assays involve chemotaxis of NK cells across the filter, so to examine TEM more specifically, we imaged live-cell preparations and antibody-stained fixed preparations, with and without the chemoattractant SDF-1α. We found small to moderate effects of HS1 depletion on TEM, including whether the NK cells migrated via the transcellular or paracellular route. Expression of HS1 mutants indicated that phosphorylation of HS1 tyrosines at positions 222, 378 and 397 was required for rescue in the transwell assay, but HS1 mutations affecting interaction with Arp2/3 complex or SH3-domain ligands had no effect. The GEF Vav1, a ligand of HS1 phosphotyrosine, influenced NK cell transendothelial migration. HS1 and Vav1 also affected the speed of NK cells migrating across the surface of the endothelium. We conclude that HS1 has a role in transendothelial migration of NK cells and that HS1 tyrosine phosphorylation may signal through Vav1

Expression Rescue of HS1 Mutants in HS1-depleted NK Cells.

<p>A) Phosphorylation of HS1 Tyr397 in response to SDF-1α. Immunoblots probed with anti-Phospho-Tyr397 and anti-HS1. NK cells (5 x 10⁶) treated with SDF-1α (30 ng/mL) for the indicated times (min). B—D) Function of HS1 mutants in TEM by transwell assay. Number of cells in the lower chamber, as a percentage of the mean of the control sample value on each day, with box and whisker plots. Boxes: 25th to 75th percentiles; whiskers: minimum and maximum values. B) Mutations of phosphorylated tyrosine residues. Compared to control siRNA (blue), HS1 depletion by siRNA causes decreased TEM (red), and the defect is rescued by expression of wild-type HS1 (green) or siRNA-resistant wild-type HS1 (purple). Expression of siRNA-resistant forms of single-mutant HS1 Y378F (black), single-mutant HS1 Y397F (brown) or double-mutant HS1 Y378F Y397F (dark blue) does not rescue the defect, comparing their values to the value for siRNA-resistant wild-type (purple). Expression of siRNA-resistant HS1 Y222F (orange) rescues with a value that is slightly less, but not statistically significant, from that of siRNA-resistant wild type. Asterisks indicate *P>0.05, **P>0.005 (unpaired Student’s t-test, N = 6–9). C) Mutation of Arp2/3 complex binding site. Expression of siRNA-resistant HS1 with mutation of DDW residues to AAA (orange) rescues the defect, with no difference compared to siRNA-resistant wild-type HS1. N = 6 in each case. D) Mutation of SH3 domain at ligand-binding site. Expression of siRNA-resistant HS1 with the mutation W466K (orange) rescues the defect, with no difference compared to siRNA-resistant wild-type HS1. n = 6 in each case.</p