Fluorescent Carbon Dots for Sensitive and Rapid Monitoring of Intracellular Ferrous Ion

Although iron is an essential constituent for almost all living organisms, iron dyshomeostasis at a cellular level may trigger oxidative stress and neuronal damage. Hence, there are numerous reported carbon dots (CDs) that have been synthesized and applied to determine intracellular iron ions. However, among reported CDs focused to detect Fe3+ ions, only a few CDs have been designed to specifically determine Fe2+ ions over Fe3+ ions for monitoring of intracellular Fe2+ ions. We have developed the nitrogen-doped CDs (NCDs) for fluorescence turn-off detection of Fe2+ at cellular level. The as-synthesized NCDs exhibit a strong blue fluorescence and low cytotoxicity, acting as fluorescence probes to detect Fe2+ as low as 0.702 µM in aqueous solution within 2 min and visualize intracellular Fe2+ in the concentration range from 0 to 500 µM within 20 min. The as-prepared NCDs possess some advantages such as high biocompatibility, strong fluorescence properties, selectivity, and rapidity for intracellular Fe2+ monitoring, making NCDs an excellent nanoprobe for biosensing of intracellular ferrous ions.

Behavioral and Neuroanatomical Consequences of Cell-Type Specific Loss of Dopamine D2 Receptors in the Mouse Cerebral Cortex

Developmental dysregulation of dopamine D2 receptors (D2Rs) alters neuronal migration, differentiation, and behavior and contributes to the psychopathology of neurological and psychiatric disorders. The current study is aimed at identifying how cell-specific loss of D2Rs in the cerebral cortex may impact neurobehavioral and cellular development, in order to better understand the roles of this receptor in cortical circuit formation and brain disorders. We deleted D2R from developing cortical GABAergic interneurons (Nkx2.1-Cre) or from developing telencephalic glutamatergic neurons (Emx1-Cre). Conditional knockouts (cKO) from both lines, Drd2fl/fl, Nkx2.1-Cre+ (referred to as GABA-D2R-cKO mice) or Drd2fl/fl, Emx1-Cre+ (referred to as Glu-D2R-cKO mice), exhibited no differences in simple tests of anxiety-related or depression-related behaviors, or spatial or nonspatial working memory. Both GABA-D2R-cKO and Glu-D2R-cKO mice also had normal basal locomotor activity, but GABA-D2R-cKO mice expressed blunted locomotor responses to the psychotomimetic drug MK-801. GABA-D2R-cKO mice exhibited improved motor coordination on a rotarod whereas Glu-D2R-cKO mice were normal. GABA-D2R-cKO mice also exhibited spatial learning deficits without changes in reversal learning on a Barnes maze. At the cellular level, we observed an increase in PV+ cells in the frontal cortex of GABA-D2R-cKO mice and no noticeable changes in Glu-D2R-cKO mice. These data point toward unique and distinct roles for D2Rs within excitatory and inhibitory neurons in the regulation of behavior and interneuron development, and suggest that location-biased D2R pharmacology may be clinically advantageous to achieve higher efficacy and help avoid unwanted effects.

Recent Advances in Computational Modeling of Biomechanics and Biorheology of Red Blood Cells in Diabetes

Diabetes mellitus, a metabolic disease characterized by chronically elevated blood glucose levels, affects about 29 million Americans and more than 422 million adults all over the world. Particularly, type 2 diabetes mellitus (T2DM) accounts for 90–95% of the cases of vascular disease and its prevalence is increasing due to the rising obesity rates in modern societies. Although multiple factors associated with diabetes, such as reduced red blood cell (RBC) deformability, enhanced RBC aggregation and adhesion to the endothelium, as well as elevated blood viscosity are thought to contribute to the hemodynamic impairment and vascular occlusion, clinical or experimental studies cannot directly quantify the contributions of these factors to the abnormal hematology in T2DM. Recently, computational modeling has been employed to dissect the impacts of the aberrant biomechanics of diabetic RBCs and their adverse effects on microcirculation. In this review, we summarize the recent advances in the developments and applications of computational models in investigating the abnormal properties of diabetic blood from the cellular level to the vascular level. We expect that this review will motivate and steer the development of new models in this area and shift the attention of the community from conventional laboratory studies to combined experimental and computational investigations, aiming to provide new inspirations for the development of advanced tools to improve our understanding of the pathogenesis and pathology of T2DM.

NFAM1 Promotes Pro-Inflammatory Cytokine Production in Mouse and Human Monocytes

NFAT activating protein with ITAM motif 1 (NFAM1) is an ITAM bearing-transmembrane receptor that has been reported to play a role in B cell signaling and development. We performed expression analysis of NFAM1 using publicly available gene expression data sets and found that NFAM1 expression is significantly induced in intestinal biopsies from Crohn’s disease (CD) and ulcerative colitis (UC) patients. At the cellular level, we further observed high expression of NFAM1 in monocytes and neutrophils, and low expression in B and T cells. To explore the role of NFAM1 in multiple immune cells and its potential role in IBD, we generated NFAM1-/- mice. In contrast with previous reports using NFAM1-transgenic mice, NFAM1-/- mice have no obvious defects in immune cell development, or B cell responses. Interestingly, NFAM1-/- monocytes produce reduced levels of TNF-α in response to activation by multiple IBD-relevant stimuli, including CD40L, TLR ligands and MDP. Additional cytokines and chemokines such as IL-6, IL-12, CCL3 and CCL4 are also reduced in CD40L stimulated NFAM1-/- monocytes. Collectively, these findings indicate that NFAM1 promotes monocyte activation, thereby amplifying the response to diverse stimuli. Similarly, we observed that deletion of NFAM1 in human monocytes reduces expression of CD40L-induced CCL4. Lastly, to assess the role of NFAM1 in IBD, we compared development of anti-CD40 induced colitis in NFAM1+/+ and NFAM1-/- mice. We found that although NFAM1 deletion had no impact on development of gut pathology, we did observe a decrease in serum TNF-α, confirming that NFAM1 promotes pro-inflammatory cytokine production in vivo. Taken together, we conclude that NFAM1 functions to amplify cytokine production and should be further evaluated as a therapeutic target for treatment of autoimmune disease.

Sructural rearrangements of NTRK genes: characteristics, methods of detection and targeted therapy for cancer

Background. The first-generation trk inhibitors, larotrectinib and entrectinib, were approved by the u.s. Food and drug administration (Fda) for the treatment of advanced solid tumors harboring NTRK gene fusions in November 2018 and in august 2019, respectively. The purpose of the study was to present upto-date data on the structure and functions of ntrk genes, the frequency of occurrence of rearrangements with their participation, the consequences of their occurrence at the cellular level, methods of detecting such rearrangements, as well as targeted drugs used in the presence of chimeric NTRK genes. Material and methods. A systemic literature search was conducted in pubmed ncbi, Web of science, scopus databases. Results. The products of NTRK genes are receptors for neurotrophins, and their high expression is normally observed only in a narrow range of tissue types. Intrachromosomal or interchromosomal rearrangements lead to a significant increase in the level of expression of the chimeric gene regulated by the strong promoter of the partner gene. The high transcriptional activity of such a gene, along with the constant activation of the kinase activity of the protein product, leads to the activation of metabolic pathways responsible for cell escape from apoptosis and disruption of the regulation of the cell cycle. The occurrence of chimeric NTRK genes varies between different types of tumors, with the highest (up to 90 %) in rare cancers (secretory carcinoma of the breast, secretory carcinoma of the salivary glands, congenital mesoblastic nephroma, children’s fibrosarcoma). Larotrectinib and entrectinib are highly effective targeted drugs in suppressing the growth of a tumor carrying NTRK rearrangements, regardless of the type of tumor. In this regard, the introduction of new high-precision methods for the detection of chimeric NTRK genes, as well as the study of the mechanisms of the development of resistance with the assumption of ways to overcome it, seems relevant. Conclusion. Rearrangements of NTRK genes are quite common in various types of oncology and are an effective target for modern targeted drugs.

Conjugated Polyamines in Root Plasma Membrane Enhanced the Tolerance of Plum Seedling to Osmotic Stress by Stabilizing Membrane Structure and Therefore Elevating H+-ATPase Activity

Polyamines are small positively charged molecules in plants and play important functions in many biological processes under various environmental stresses. One of the most confounding problems relating to polyamines (PAs) in stresses is the lack of understanding of the mechanisms underlying their function(s). Furthermore, a limited number of studies have addressed this issue at the sub-cellular level, especially in tree plants under drought stress. Therefore, in this research, by simulating natural drought stress with polyethylene glycol (PEG) osmotic stress, the relationship between the levels of conjugated polyamines and the activity of H+-ATPase in the plasma membrane was elucidated with the roots of two plum (Prunus salicina L.) cultivars, which were different in drought tolerance, as experimental materials. Furthermore, free PA levels and the activities of S-adenosylmethionine decarboxylase (SAMDC) and transglutaminase (TGase), which were closely associated with the levels of free and conjugated PAs, were also detected. Results showed that under osmotic stress, the increases of the levels of non-covalently conjugated (non-CC) spermidine (Spd) and spermine (Spm), covalently conjugated (CC) putrescine (Put) and Spd in the plasma membrane of drought-tolerant Ganli No. 5 were more significant than those of drought-sensitive Suli No. 3, indicating that these conjugated PAs might be involved in the tolerance of plum seedlings to stress. Furthermore, the conjugated PAs were closely correlated with plum seedling growth, water retention capacity, plasma membrane damage degree, and hydrogen (H+)-ATPase activity in the plasma membrane. To get more complementary pieces of evidence, we subjected plum seedlings to combined treatments of PEG and exogenous PA (Spd and Spm), and an inhibitor of SAMDC [methylglyoxal-bis (guanylhydrazone), (MGBG)] or TGase (o-phenanthroline). These results collectively suggested that non-CC Spd and Spm, CC Put and Spd in plasma membrane might function in enhancing the tolerance of plum seedlings to osmotic stress by stabilizing membrane structure and therefore elevating H+-ATPase activity.

COMPARATIVE STUDY OF PLATELET COUNT IN DIABETIC AND NON-DIABETIC GERIATRIC POPULATION

Geriatric population (> 60 years) is rapidly increasing in India, It has been increased upto 8.6% in 2011. Diabetes Mellitus (DM) is a metabolic disorder and a major health problem, a?ecting a large section of the Indian population, especially as its incidence increases with advancing age. Host of complications are associated with this disease, one of which is the e?ect on platelet count. This study compares platelet count between diabetic and non-diabetic elderly. It is observed that Hyperglycaemia in diabetic persons is responsible for increased Thrombopoietin production at the cellular level, which leads to raised platelet count -Reticulated Thrombocytosis – when compared to non diabetics. Platelets, especiallyreticulated thrombocytes are associated with uncontrolled blood sugar levels in the body and are well known for their role in artherosclerotic cardiovascular disease (CVD). Keywords: platelet count, diabetic and non-diabetic & geriatric.

High fat diet-induced obesity prolongs critical stages of the spermatogenic cycle in a Ldlr−/−.Leiden mouse model

Obesity can disturb spermatogenesis and subsequently affect male fertility and reproduction. In our study, we aim to elucidate at which cellular level of adult spermatogenesis the detrimental effects of obesity manifest. We induced high fat diet (HFD) obesity in low-density lipoprotein receptor knock-out Leiden (Ldlr−/−.Leiden) mice, and studied the morphological structure of the testes and histologically examined the proportion of Sertoli cells, spermatocytes and spermatids in the seminiferous tubules. We examined sperm DNA damage and chromatin condensation and measured plasma levels of leptin, testosterone, cholesterol and triglycerides. HFD-induced obesity caused high plasma leptin and abnormal testosterone levels and induced an aberrant intra-tubular organisation (ITO) which is associated with an altered spermatids/spermatocytes ratio (2:1 instead of 3:1). Mice fed a HFD had a higher level of tubules in stages VII + VIII in the spermatogenic cycle. The stages VII + VII indicate crucial processes in spermatogenic development like initiation of meiosis, initiation of spermatid elongation, and release of fully matured spermatids. In conclusion, HFD-induced obese Ldlr−/−.Leiden mice develop an aberrant ITO and alterations in the spermatogenic cycle in crucial stages (stages VII and VII). Thereby, our findings stress the importance of lifestyle guidelines in infertility treatments.

A review on magnetic and spintronic neurostimulation: challenges and prospects

In the treatment of neurodegenerative, sensory and cardiovascular diseases, electrical probes and arrays have shown quite a promising success rate. However, despite the outstanding clinical outcomes, their operation is significantly hindered by non-selective control of electric fields. A promising alternative is micromagnetic stimulation (μMS) due to the high permeability of magnetic field through biological tissues. The induced electric field from the time-varying magnetic field generated by magnetic neurostimulators is used to remotely stimulate neighboring neurons. Due to the spatial asymmetry of the induced electric field, high spatial selectivity of neurostimulation has been realized. Herein, some popular choices of magnetic neurostimulators such as microcoils (μcoils) and spintronic nanodevices are reviewed. The neurostimulator features such as power consumption and resolution (aiming at cellular level) are discussed. In addition, the chronic stability and biocompatibility of these implantable neurostimulator are commented in favor of further translation to clinical settings. Furthermore, magnetic nanoparticles (MNPs), as another invaluable neurostimulation material, has emerged in recent years. Thus, in this review we have also included MNPs as a remote neurostimulation solution that overcomes physical limitations of invasive implants. Overall, this review provides peers with the recent development of ultra-low power, cellular-level, spatially selective magnetic neurostimulators of dimensions within micro- to nano-range for treating chronic neurological disorders. At the end of this review, some potential applications of next generation neuro-devices have also been discussed.

Epstein-Barr Virus BGLF2 commandeers RISC to interfere with cellular miRNA function

The Epstein-Barr virus (EBV) BGLF2 protein is a tegument protein with multiple effects on the cellular environment, including induction of SUMOylation of cellular proteins. Using affinity-purification coupled to mass-spectrometry, we identified the miRNA-Induced Silencing Complex (RISC), essential for miRNA function, as a top interactor of BGLF2. We confirmed BGLF2 interaction with the Ago2 and TNRC6 components of RISC in multiple cell lines and their co-localization in cytoplasmic bodies that also contain the stress granule marker G3BP1. In addition, BGLF2 expression led to the loss of processing bodies in multiple cell types, suggesting disruption of RISC function in mRNA regulation. Consistent with this observation, BGLF2 disrupted Ago2 association with multiple miRNAs. Using let-7 miRNAs as a model, we tested the hypothesis that BGLF2 interfered with the function of RISC in miRNA-mediated mRNA silencing. Using multiple reporter constructs with 3’UTRs containing let-7a regulated sites, we showed that BGLF2 inhibited let-7a miRNA activity dependent on these 3’UTRs, including those from SUMO transcripts which are known to be regulated by let-7 miRNAs. In keeping with these results, we showed that BGLF2 increased the cellular level of unconjugated SUMO proteins without affecting the level of SUMO transcripts. Such an increase in free SUMO is known to drive SUMOylation and would account for the effect of BGLF2 in inducing SUMOylation. We further showed that BGLF2 expression inhibited the loading of let-7 miRNAs into Ago2 proteins, and conversely, that lytic infection with EBV lacking BGLF2 resulted in increased interaction of let-7a and SUMO transcripts with Ago2, relative to WT EBV infection. Therefore, we have identified a novel role for BGLF2 as a miRNA regulator and shown that one outcome of this activity is the dysregulation of SUMO transcripts that leads to increased levels of free SUMO proteins and SUMOylation.