Aberrant iPSC-derived human astrocytes in Alzheimer's disease

The pathological potential of human astroglia in Alzheimer's disease (AD) was analysed in vitro using induced pluripotent stem cell (iPSC) technology. Here, we report development of a human iPSC-derived astrocyte model created from healthy individuals and patients with either early-onset familial AD (FAD) or the late-onset sporadic form of AD (SAD). Our chemically-defined and highly efficient model provides >95% homogeneous populations of human astrocytes within 30 days of differentiation from cortical neural progenitor cells (NPCs). All astrocytes expressed functional markers including; glial fibrillary acidic protein (GFAP), excitatory amino acid transporter 1 (EAAT1), S100B and glutamine synthetase (GS) comparable to that of adult astrocytes in vivo. However, induced astrocytes derived from both SAD and FAD patients exhibit a pronounced pathological phenotype, with a significantly less complex morphological appearance, overall atrophic profiles, and abnormal localisation of key functional astroglial markers. Furthermore, NPCs derived from identical patients did not show any differences, therefore, validating that remodelled astroglia are not as a result of defective neuronal intermediates. This work not only presents a novel model to study the mechanisms of human astrocytes in vitro, but also provides an ideal platform for further interrogation of early astroglial cell-autonomous events in AD and the possibility of identification of novel therapeutic targets for the treatment of AD

Evaluation of the anti-diabetic potential of aqueous extract of Clerodendrum infortunatum L. in vivo in streptozotocin-induced diabetic Wistar rats

Diabetes Mellitus, the metabolic syndrome where the body either fails to produce or effectively utilize insulin, is associated with chronic morbidity. While a definitive cure for the disease is lacking, with the modern medicine offering mainly the means to control the extent of the disease, Complementary and Alternative Medicine (CAMs) offers additional/alternate means to tackle the disease. On the other hand, the lack of evidenced medical practices is a lacuna in most of the traditional medical applications. Clerodendrum infortunatum.L (Lamiaceae family), a perennial shrub found in the tropics, has been known for its numerous pharmacological properties and is found as a constituent in many Ayurvedic and Siddha drugs, especially for skin and respiratory ailments. The plant has a noted potential as anti-hyperglycemic and has been found to be used in traditional medicine for the treatment of diabetes. However, evidence based evaluations have not been conducted on the anti-hyperglycemic effect of the plant, especially with respect to the general mode of intake, i.e, the aqueous form. In the current study, the aqueous extract of C. infortunatum (CI), was scientifically assessed for its effect on streptozotocin induced diabetes in Wistar albino rats. The diabetic rats were divided into 5 groups of 6 animals each. For testing the efficacy of extracts, two groups were intra-orally provided with dosages of 200 mg/Kg and 400 mg/Kg of body weight of animals, respectively, of aqueous extracts of CI. Control groups were maintained for evaluation, which included vehicle control as well as with Glibenclamide, a standard anti-diabetic drug. The extracts at a dose of 400 mg/Kg body weight was found to be associated with significant amelioration of many of the diabetes induced conditions, suggesting that the plant extract could be a strong potential CAM candidate for therapeutic management of diabetes

Highly connected 3D chromatin networks established by an oncogenic fusion protein shape tumor cell identity.

Cell fate transitions observed in embryonic development involve changes in three-dimensional genomic organization that provide proper lineage specification. Whether similar events occur within tumor cells and contribute to cancer evolution remains largely unexplored. We modeled this process in the pediatric cancer Ewing sarcoma and investigated high-resolution looping and large-scale nuclear conformation changes associated with the oncogenic fusion protein EWS-FLI1. We show that chromatin interactions in tumor cells are dominated by highly connected looping hubs centered on EWS-FLI1 binding sites, which directly control the activity of linked enhancers and promoters to establish oncogenic expression programs. Conversely, EWS-FLI1 depletion led to the disassembly of these looping networks and a widespread nuclear reorganization through the establishment of new looping patterns and large-scale compartment configuration matching those observed in mesenchymal stem cells, a candidate Ewing sarcoma progenitor. Our data demonstrate that major architectural features of nuclear organization in cancer cells can depend on single oncogenes and are readily reversed to reestablish latent differentiation programs

Redundant Notch1 and Notch2 Signaling Is Necessary for IFNγ Secretion by T Helper 1 Cells During Infection with Leishmania major

The protective immune response to intracellular parasites involves in most cases the differentiation of IFNγ-secreting CD4+ T helper (Th) 1 cells. Notch receptors regulate cell differentiation during development but their implication in the polarization of peripheral CD4+ T helper 1 cells is not well understood. Of the four Notch receptors, only Notch1 (N1) and Notch2 (N2) are expressed on activated CD4+ T cells. To investigate the role of Notch in Th1 cell differentiation following parasite infection, mice with T cell-specific gene ablation of N1, N2 or both (N1N2ΔCD4Cre) were infected with the protozoan parasite Leishmania major. N1N2ΔCD4Cre mice, on the C57BL/6 L. major-resistant genetic background, developed unhealing lesions and uncontrolled parasitemia. Susceptibility correlated with impaired secretion of IFNγ by draining lymph node CD4+ T cells and increased secretion of the IL-5 and IL-13 Th2 cytokines. Mice with single inactivation of N1 or N2 in their T cells were resistant to infection and developed a protective Th1 immune response, showing that CD4+ T cell expression of N1 or N2 is redundant in driving Th1 differentiation. Furthermore, we show that Notch signaling is required for the secretion of IFNγ by Th1 cells. This effect is independent of CSL/RBP-Jκ, the major effector of Notch receptors, since L. major-infected mice with a RBP-Jκ deletion in their T cells were able to develop IFNγ-secreting Th1 cells, kill parasites and heal their lesions. Collectively, we demonstrate here a crucial role for RBP-Jκ-independent Notch signaling in the differentiation of a functional Th1 immune response following L. major infection

Discovering Transcription Factor Binding Sites in Highly Repetitive Regions of Genomes with Multi-Read Analysis of ChIP-Seq Data

Chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) is rapidly replacing chromatin immunoprecipitation combined with genome-wide tiling array analysis (ChIP-chip) as the preferred approach for mapping transcription-factor binding sites and chromatin modifications. The state of the art for analyzing ChIP-seq data relies on using only reads that map uniquely to a relevant reference genome (uni-reads). This can lead to the omission of up to 30% of alignable reads. We describe a general approach for utilizing reads that map to multiple locations on the reference genome (multi-reads). Our approach is based on allocating multi-reads as fractional counts using a weighted alignment scheme. Using human STAT1 and mouse GATA1 ChIP-seq datasets, we illustrate that incorporation of multi-reads significantly increases sequencing depths, leads to detection of novel peaks that are not otherwise identifiable with uni-reads, and improves detection of peaks in mappable regions. We investigate various genome-wide characteristics of peaks detected only by utilization of multi-reads via computational experiments. Overall, peaks from multi-read analysis have similar characteristics to peaks that are identified by uni-reads except that the majority of them reside in segmental duplications. We further validate a number of GATA1 multi-read only peaks by independent quantitative real-time ChIP analysis and identify novel target genes of GATA1. These computational and experimental results establish that multi-reads can be of critical importance for studying transcription factor binding in highly repetitive regions of genomes with ChIP-seq experiments

Sanal Flow Choking Leads to Hemorrhagic Stroke and Other Neurological Disorders in Earth and Human Spaceflight

Evidences are escalating on the diverse neurological disorders associated with COVID-19 pandemic due to the nanoscale Sanal flow choking (PMC7267099). The Sanal flow choking occurs at relatively high and low blood viscosity. Sanal flow choking leads to aneurysm, hemorrhagic-stroke and other neurological-disorders if the vessel geometry is having divergence, bifurcation, stenosis and/or occlusion regions (PMC7933821). Nanoscale Sanal flow choking is more susceptible at microgravity condition due to altered variations of blood viscosity, turbulence and the blood pressure ratio (BPR). Astronauts/Cosmonauts experienced neurological disorders during human spaceflight and thereafter. V.R.S.Kumar et al. (2021) reported that the asymptomatic episodes in the cardiovascular system are due to the internal flow choking (Biofluid/ Sanal flow choking) at a critical blood pressure ratio (BPR), which is regulated by the biofluid/blood heat capacity ratio (BHCR).  As the pressure of the nanoscale biofluid / non-continuum-flows rises, fluid viscosity increases and average-mean-free-path diminishes and thus, the Knudsen number lowers heading to a zero-slip wall-boundary condition with the compressible flow regime, which increases the risk of Sanal flow choking and the shock wave generation causing asymptomatic cardiovascular disease. Microgravity environment decreases plasma volume and increases the hematocrit compared with the situation on the Earth surface, which increases the relative viscosity of blood causing an early Sanal flow choking. Herein, we established that the disproportionate blood-thinning treatment increases the risk of the nanoscale Sanal flow choking due to the enhanced boundary-layer-blockage factor. The risk could be diminished by concurrently reducing the viscosity of biofluid/ blood and flow-turbulence by increasing the thermal-tolerance-level in terms of BHCR and/or by decreasing the BPR through new drug discovery or using companion medicine with the traditional blood thinners or other health care management. We recommend all astronauts/cosmonauts should wear ambulatory blood pressure and thermal level monitoring devices similar to a wristwatch throughout the space travel for the diagnosis, prognosis and prevention of internal flow choking leading to asymptomatic cardiovascular disease including neurological disorders.</p

Critical Blood Pressure Ratio and Memory Effects are Risk Factors for Stroke - Discovery of Biofluid Choking a Paradigm Shift in the Diagnostics Sciences of Hemorrhage and Ischaemic Heart Disease

Biofluid choking, a compressible fluid flow effect, occurs anywhere in the circulatory system including vasa vasorum when the blood/biofluid velocity is equal or above to the local velocity of sound. The choking and unchoking could occur due to the variations in the blood pressure-ratio (BPR) and blood/biofluid heat capacity ratio (BHCR). At the choked condition, Blood pressure ratio (SBP / DBP) is a unique function of BHCR (Cp/Cv). A model capable to predict the lower critical hemorrhage index (LCHI) correlating with BPR and BHCR is developed herein for forecasting the risk of stroke and myocardial infarction (MI) through in silico studies. Through in vitro studies LCHI is predicted for healthy subjects. Using aspirin to reduce viscosity augment Reynolds number, which leads to high turbulence and enhanced boundary layer blockage creating an early undesirable cavitation, choking and shock waves in vessels with plaque and / or boundary-layer blockage (peak at winter). Cavitation is quite noisy and can be sufficiently violent to physically damage valves and blood vessels. Memory effects and transient pressure-spikes due to shock waves developed over the years in the choked blood-vessels create its walls stiffer and prone to rupture in the subsequent strokes.</p

Biofluid choking a paradigm shift in the diagnostic sciences of stroke - Blood pressure ratio and heat capacity ratio are the risk factors for hemorrhage and heart attack

Author reported conclusively through the state-of-the-art closed-form analytical methodology that the stroke and the transient-ischemic-attack could occur due to the boundary-layer induced blockage at the transition region while attaining the biofluid choking condition without any iota of symptom of plaque formation in the arteries particularly with bifurcation regions. At the biofluid choking condition, the systolic-to-diastolic blood pressure ratio (BPR) is a unique function of the blood/biofluid heat capacity ratio (BHCR). The biofluid flow choking occurs when the blood/biofluid velocity in the blockage region (boundary-layer and/or plaque-induced blockage) is equal to the local velocity of sound. Biofluid choking is more susceptible during winter due to an enhanced blood viscosity. Sanal flow choking creates cavitation and shock waves leading to pressure-overshoot causing stroke and/or Spontaneous coronary artery dissection (SCAD). The SCAD is more severe for the vessels with high-relaxation modulus as a result of the memory effect (stroke history) carried over the years due to choking and unchoking phenomena due to the fluctuating BPR. While using the blood-thinners and/or drugs with anticoagulant properties the dynamic viscosity of blood decreases and as a result Reynolds number increases and the laminar flow could be disrupted and become turbulent and thereby the boundary-layer-blockage factor increases leading to an early biofluid choking, cavitation and shock wave generation. The author concluded that suppressing the turbulence level and simultaneously reducing the blood viscosity are the key tasks to prevent heart attack and stroke, which could be achieved through a single-medicine or a companion-medicine, with traditional-anticoagulants-drugs, capable to increase the BHCR or decrease the BPR. The author also concluded through an analytical model that the stents could reduce the risk of MI but no better than drugs owing to the fact the biofluid choking could occur with and without stent.</p

Lopsided Blood-thinning Drug Increases the Risk of Internal Flow Choking and Shock Wave Generation Causing Asymptomatic Stroke

An overdose of blood-thinning drug reduces blood viscosity (BV) and increases Reynolds number causing high-turbulence leading to the Sanal flow choking (PMCID: PMC7267099). Asymptomatic stroke could be diminished by concurrently lessening the BV and flow turbulence by rising thermal tolerance level in terms of biofluid/blood heat capacity ratio (BHCR) or by decreasing the blood pressure ratio (BPR). In conclusion, BPR must always be lower than 1.8257 as dictated by the lowest BHCR of the evolved gas (CO2) for prohibiting asymptomatic stroke.</p

Lopsided Blood-thinning Drug Increases the Risk of Internal Flow Choking and Shock Wave Generation Causing Asymptomatic Stroke

Lopsided Blood-thinning Drug Increases the Risk of Internal Flow Choking and Shock Wave Generation Causing Asymptomatic Stroke Author Block: V R SANAL KUMAR, ISRO; S.K.Choudhary, AIIMS; P.K.Radhakrishnan, GU; Suresh Menon, GT; Vrishank Raghav, AU; K.K.N Namboodiri, Sapna E.Sreedharan, SCTIMST; Bharath R.S, Nichith C, C.Oommen, IISc; V.Sankar, IITK; A.Sukumaran, KCT; Arun K, DHMMC; A.Pal, Tharikaa R.K, AU, Abhirami R, AIMS. IntroductionConsequence of lopsided blood-thinning-drug, lowering blood-viscosity (BV), is bleeding and very frequently asymptomatic-hemorrhage (AH) and the acute-heart-failure (AHF) happen. V.R.S.Kumar et al. (2020) reported that such asymptomatic episodes are due to the internal flow choking in the cardiovascular system (CVS) at a critical blood-pressure-ratio (BPR), which is regulated by biofluid/blood heat capacity ratio (BHCR). MethodsThe closed-form-analytical-methodology is used for correlating BV, BPR, BHCR, vessel geometry and ejection fraction (EF). In vitro method is used for the BHCR estimation of healthy subjects. In silico method is used for demonstrating the Sanal flow choking. ResultsThe analytical models reveal that the relatively high and low BV are risk factors of internal flow choking. In vitro study shows that N2, O2, CO2 &amp;amp; Ar gases are predominant in fresh-blood samples of the healthy subjects at a temperature range of 37-400 C (98.6-1040 F), which increases the risk of flow-choking. In silico results demonstrated the Sanal flow choking followed by the shock wave generation and pressure-overshoot in a simulated artery with the divergent/bifurcation region. ConclusionsAn overdose of blood-thinning drug reduces BV and increases Reynolds number causing high-turbulence leading to the Sanal flow choking. Asymptomatic stroke could be diminished by concurrently lessening the BV and flow turbulence by rising thermal tolerance level in terms of BHCR or by decreasing the BPR. In conclusion, BPR must always be lower than 1.8257 as dictated by the lowest BHCR of the evolved gas for prohibiting asymptomatic stroke.</p