Cellular Loss Research Articles

Effects of acute alcohol intoxication on the respiration and dehydrogenase activity of rat pancreatic acini

The exocrine function of pancreatic acini cells is a highly energy-intensive process. A cell always needs to maintain a stable level of ATP balancing between states of activation and rest. Low-energy is one of the possible mechanisms contributing to the development of pancreatic diseases. The most commonly encountered disease of the pancreas is acute pancreatitis. It is known that excessive alcohol consumption causes the development of pancreatitis. The pathogenesis of this disease is linked to the cellular loss of energy, but the mechanism of alcohol’s effect on the mitochondria in pancreatic acini is unclear. This study’s main aim is to assess the impact of acute alcohol administration on the mitochondrial function of rat pancreatic acini. Wistar rats were administered ethanol (6 g/kg body weight) by oral gavage for 3 h before the experiment. A suspension of isolated pancreatic acini was obtained following collagenase digestion. Respiration of isolated pancreatic acini was studied with a Clark electrode. The maximal respiration rate was studied at different concentrations of protonophore FCCP (0.5–2 μM) in solutions containing glucose combined with oxidative substrates (pyruvate and glutamine, monomethyl-succinate or dimethyl-α-ketoglutarate). Dehydrogenase activity was measured by colorimetric method. Ethanol administration caused a significant increase in the activity of pyruvate dehydrogenase. It was confirmed that FCCP induced an increase in the respiration rate of pancreatic acinar cells in each experimental group. The addition of 1.5 μM FCCP reduced the respiration rate of pancreatic acini during the oxidation of glucose and monomethyl succinate or dimethyl-α-ketoglutarate, but not during the oxidation of glucose, pyruvate and glutamine substrates. The administration of ethanol had no impact on the basal or FCCP-uncoupled respiration of isolated pancreatic acini. The observed data are consistent with the findings of other researchers. However, alcohol exposure is not sufficient to cause mitochondrial damage in pancreatic acinar cells. In conclusion, acute ethanol administration does not cause mitochondrial dysfunction in the pancreas of rats but causes an increase in pyruvate dehydrogenase activity.

In vitro and in vivo effects of commercial and environmental microplastics on Unio delicatus.

Microplastics (MPs) are ubiquitous pollutants in freshwater environments. In this study, freshwater mussels, Unio delicatus, were exposed to both environmental MPs (e-MP) and commercial MPs (c-MP) that include green fluorescent MP (gf-MP), polyethylene (c-PE) and polystyrene (c-PS) at environmental concentrations (5 mg/L and 50 mg/L) over duration of 7 and 30 days. According to in vivo experiment results, both e-MPs and c-MPs induced significant changes in the total hemocyte counts of mussels (p < 0.05). Exposure to high concentrations of e-MPs and c-MPs for 7 days led to decreased cellular glutathione levels in the mussels, while exposure to low concentrations of e-MPs and c-PS for 7 days resulted in increased advanced oxidation protein products (AOPP). Mussels exposed to high concentrations of e-MPs for 30 days exhibited decreases in both glutathione levels and AOPP values. Although no damage was observed in tissues other than gills and digestive gland, histopathological alterations were observed in these tissues following exposure to 50 mg/L c-MPs. Additionally, MPs were observed in the intestine tissues. In vitro experiments using the MTT assay showed no significant difference in cell viability between the MP-exposed group and the control group at tested concentrations, with no observed dose-response relationship (p > 0.05). Nevertheless, certain cells exhibited signs of cell death, such as disrupted cellular structures, condensed nuclei, and loss of cellular integrity. These observations were consistent with mechanical compression, indicating that physical contact with MPs may result in cell damage or death. These findings demonstrate that environmentally relevant concentrations of MPs have toxic effects on freshwater mussels and multiple parameters provide valuable insight for the evaluation of health risks of organisms.

Insight into didecyl dimethyl ammonium bromide toxicity following acute exposure in pullets (Gallus gallusdomesticus).

Didecyl dimethyl ammonium bromide (DDAB) is a quaternary ammonium compound used for the sanitation of drinking water of poultry and water pipelines in farms. There is scarcity of information on the toxicology of DDAB in poultry. This study set out to profile the acute toxicity of DDAB in poultry. Issa brown pullets (n = 34) as experimental birds were orally administered varying doses of DDAB, using a syringe, after 12h fasting, and observed for toxicity over 14 days. Control birds (n = 10) were similarly given normal saline orally. Toxic signs in the experimental birds were depression, anorexia, adipsia, vocalization with foamy salivation, later emaciation and death. The LD50 was calculated as 458.00mg/kg. Birds given 2151mg/kg DDAB died within 24h, while those treated with 516mg/kg succumbed on Day 14. At necropsy, grossly, there were necrosis and sloughing of the oesophagus and intestines, pale and friable liver, congested and necrotic lungs, friable popped out kidneys and emaciated carcasses. Microscopically, desquamation and necrosis of the oesophagus, crop, proventriculus and intestines and disruption of the koilin membrane of the gizzard were observed. The lungs, liver and kidneys were congested with mononuclear cellular infiltration plus loss of architecture in the lungs and liver. In conclusion, at high doses, DDAB caused significant toxicity in chickens and these findings provide new information which could serve as a guide in the diagnosis of quaternary ammonium toxicity in chicken. The results could be extrapolated to other quaternary ammonium toxicities in related avian species.

An Improved Practical Measuring Technique for Wireless Cellular Signal Path Loss Forecast in the African Terrain

Several studies on cellular signal path loss measurements at various locations under varying geographical and environmental circumstances in Africa have been conducted. Most of the techniques used, if not all, do not give consideration to the peculiar Africans’ road networks and building patterns, valleys, and hills that usually prevent the driving of motor cars within them when taking the signal strength measurements. The article presents an improved technique for wireless cellular signal strength measurement for better path loss prediction. The approach adopted for measurement is the regular grid outdoor foot technique. The technique was tested at various locations in the Ilorin metropolis and proved to be a better method of obtaining signal strength measurements. Although some of the signal strength values coincided with respect to distance when both methods were used, the drive test method overvalued the signal strength for study locations that were not in line of sight with the BTSs. These values range from 2 dBm to 8 dBm. If this technique is adopted, measurements will be taken in all vital locations that may not be accessible by means of a motor car drive test method, and more accurate values of the cellular signal strength will be obtained for better path loss prediction.

METTL1-mediated tRNA m7G methylation and translational dysfunction restricts breast cancer tumorigenesis by fueling cell cycle blockade

BackgroundRNA modifications of transfer RNAs (tRNAs) are critical for tRNA function. Growing evidence has revealed that tRNA modifications are related to various disease processes, including malignant tumors. However, the biological functions of methyltransferase-like 1 (METTL1)-regulated m7G tRNA modifications in breast cancer (BC) remain largely obscure.MethodsThe biological role of METTL1 in BC progression were examined by cellular loss- and gain-of-function tests and xenograft models both in vitro and in vivo. To investigate the change of m7G tRNA modification and mRNA translation efficiency in BC, m7G-methylated tRNA immunoprecipitation sequencing (m7G tRNA MeRIP-seq), Ribosome profiling sequencing (Ribo-seq), and polysome-associated mRNA sequencing were performed. Rescue assays were conducted to decipher the underlying molecular mechanisms.ResultsThe tRNA m7G methyltransferase complex components METTL1 and WD repeat domain 4 (WDR4) were down-regulated in BC tissues at both the mRNA and protein levels. Functionally, METTL1 inhibited BC cell proliferation, and cell cycle progression, relying on its enzymatic activity. Mechanistically, METTL1 increased m7G levels of 19 tRNAs to modulate the translation of growth arrest and DNA damage 45 alpha (GADD45A) and retinoblastoma protein 1 (RB1) in a codon-dependent manner associated with m7G. Furthermore, in vivo experiments showed that overexpression of METTL1 enhanced the anti-tumor effectiveness of abemaciclib, a cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitor.ConclusionOur study uncovered the crucial tumor-suppressive role of METTL1-mediated tRNA m7G modification in BC by promoting the translation of GADD45A and RB1 mRNAs, selectively blocking the G2/M phase of the cell cycle. These findings also provided a promising strategy for improving the therapeutic benefits of CDK4/6 inhibitors in the treatment of BC patients.

Feeding Eucommia ulmoides extract enhances protection against high-temperature stress in chicks

Chick's susceptibility to heat stress often leads to growth retardation, immune function impairment, disease, and mortality. This thesis explores the potential ameliorative effect of 0.8% Eucommia ulmoides extract (EUE) into the diet of heat-stressed chicks in a 15-d feeding trial. The investigation reveals that feeding EUE significantly enhances the BW, ADG, AFI, and F/G of chicks experiencing heat stress. Additionally, the EUE groups exhibited higher levels of T-AOC (at 7 and 15d), SOD (at 15 d), GSH-Px (at 15 d), as well as lower MDA concentrations (at 7 and 15d) in chick serum. Pathological changes and H&E staining revealed that EUE effectively improved tissue damage in the duodenum, heart, and stomach induced by heat stress in the chicks. The EUE groups also showed higher levels of IgA (at 7 d), IgG and IgM (at 7 and 15 d). RNA-seq and WGCNA analysis revealed that EUE mitigates cellular damage and losses in heat-stressed chicks primarily through pathways involving signal transduction, protein synthesis and degradation, as well as cell cycle regulation, particularly the latter. This investigation serves as a fundamental and cognitive framework for the development and application of Eucommia ulmoides feed additives aimed at safeguarding the well-being of chicks in adverse environmental conditions.

Thioredoxin promotes the regeneration and binding of elastic fibre and basement membrane.

Thioredoxin (TRX), a ubiquitous protein with strong antioxidant activity, decreases in the skin with age. A decrease in TRX is expected to induce cellular senescence, chronic inflammation, and degeneration and loss of extracellular matrix (ECM), such as collagen and elastin within the skin. In this study, we investigated the effects of TRX addition to excised skin or skin models to understand the role of TRX on cells and ECM within the skin. To evaluate its effect on skin cells, we cultured a three-dimensional (3D) skin model in a medium containing TRX. The mRNA expression levels of proteins related to elastic and collagen fibres and the basement membrane were determined. Furthermore, 3D imaging and computational analysis were performed to evaluate the effect of TRX on the elastic fibres and extending COL VII structures in excised human skin after coculturing with TRX for 1, 4, 5 and 6 days. Thioredoxin application to a 3D skin model upregulated elastin, COLI and COLVII mRNA expression. Applying TRX to the excised skin increased the number of linear elastic fibres. This effect of TRX demonstrated a daily increment in a dose-dependent manner. Thioredoxin extended the fibrous structure of COL VII into the dermis, expanding its colocalization region with elastic fibres. These structural effects were confirmed using 3D imaging and computational methods. Thioredoxin elongates elastic fibres from the dermis to the basement membrane and extends the COL VII structure from the basement membrane to the dermis in excised human skin. These findings suggest the potential of TRX to protect the skin against age-related alterations such as wrinkles and sagging.

Gut-associated lymphoid tissue attrition associates with response to anti-α4β7 therapy in ulcerative colitis.

Vedolizumab (VDZ) is a first-line treatment in ulcerative colitis (UC) that targets the α4β7- mucosal vascular addressin cell adhesion molecule 1 (MAdCAM-1) axis. To determine the mechanisms of action of VDZ, we examined five distinct cohorts of patients with UC. A decrease in naïve B and T cells in the intestines and gut-homing (β7+) plasmablasts in circulation of VDZ-treated patients suggested that VDZ targets gut-associated lymphoid tissue (GALT). Anti-α4β7 blockade in wild-type and photoconvertible (KikGR) mice confirmed a loss of GALT size and cellularity because of impaired cellular entry. In VDZ-treated patients with UC, treatment responders demonstrated reduced intestinal lymphoid aggregate size and follicle organization and a reduction of β7+IgG+ plasmablasts in circulation, as well as IgG+ plasma cells and FcγR-dependent signaling in the intestine. GALT targeting represents a previously unappreciated mechanism of action of α4β7-targeted therapies, with major implications for this therapeutic paradigm in UC.

Disentangling top-down drivers of mortality underlying diel population dynamics of Prochlorococcus in the North Pacific Subtropical Gyre

Photosynthesis fuels primary production at the base of marine food webs. Yet, in many surface ocean ecosystems, diel-driven primary production is tightly coupled to daily loss. This tight coupling raises the question: which top-down drivers predominate in maintaining persistently stable picocyanobacterial populations over longer time scales? Motivated by high-frequency surface water measurements taken in the North Pacific Subtropical Gyre (NPSG), we developed multitrophic models to investigate bottom-up and top-down mechanisms underlying the balanced control of Prochlorococcus populations. We find that incorporating photosynthetic growth with viral- and predator-induced mortality is sufficient to recapitulate daily oscillations of Prochlorococcus abundances with baseline community abundances. In doing so, we infer that grazers in this environment function as the predominant top-down factor despite high standing viral particle densities. The model-data fits also reveal the ecological relevance of light-dependent viral traits and non-canonical factors to cellular loss. Finally, we leverage sensitivity analyses to demonstrate how variation in life history traits across distinct oceanic contexts, including variation in viral adsorption and grazer clearance rates, can transform the quantitative and even qualitative importance of top-down controls in shaping Prochlorococcus population dynamics.

Osteocalcin protects islet identity in low-density lipoprotein receptor knockout mice on high-fat diet.

Metabolic syndrome (MetS) is an increasing global health threat and strong risk factor for type 2 diabetes (T2D). MetS causes both hyperinsulinemia and islet size overexpansion, and pancreatic β-cell failure impacts insulin and proinsulin secretion, mitochondrial density, and cellular identity loss. The low-density lipoprotein receptor knockout (LDLr-/-) model combined with high-fat diet (HFD) has been used to study alterations in multiple organs, but little is known about the changes to β-cell identity resulting from MetS. Osteocalcin (OC), an insulin-sensitizing protein secreted by bone, shows promising impact on β-cell identity and function. LDLr-/- mice at 12 months were fed chow or HFD for 3 months ± 4.5 ng/h OC. Islets were examined by immunofluorescence for alterations in nuclear Nkx6.1 and PDX1 presence, insulin-glucagon colocalization, islet size and %β-cell and islet area by insulin and synaptophysin, and mitochondria fluorescence intensity by Tomm20. Bone mineral density (BMD) and %fat changes were examined by Piximus Dexa scanning. HFD-fed mice showed fasting hyperglycemia by 15 months, increased weight gain, %fat, and fasting serum insulin and proinsulin; concurrent OC treatment mitigated weight increase and showed lower proinsulin-to-insulin ratio, and higher BMD. HFD increased %β and %islet area, while simultaneous OC-treatment with HFD was comparable to chow-fed mice. Significant reductions in nuclear PDX1 and Nkx6.1 expression, increased insulin-glucagon colocalization, and reduction in β-cell mitochondria fluorescence intensity were noted with HFD, but largely prevented with OC administration. OC supplementation here suggests a benefit to β-cell identity in LDLr-/- mice and offers intriguing clinical implications for countering metabolic syndrome.

Cytotoxicity of vanadium dioxide nanoparticles to human embryonic kidney cell line: Compared with vanadium(IV/V) ions

Vanadium dioxide (VO2) is a class of thermochromic material with potential applications in various fields. Massive production and wide application of VO2 raise the concern of its potential toxicity to human, which has not been fully understood. Herein, a commercial VO2 nanomaterial (S-VO2) was studied for its potential toxicity to human embryonic kidney cell line HEK293, and two most common vanadium ions, V(IV) and V(V), were used for comparison to reveal the related mechanism. Our results indicate that S-VO2 induces dose-dependent cellular viability loss mainly through the dissolved V ions of S-VO2 outside the cell rather than S-VO2 particles inside the cell. The dissolved V ions of S-VO2 overproduce reactive oxygen species to trigger apoptosis and proliferation inhibition via several signaling pathways of cell physiology, such as MAPK and PI3K-Akt, among others. All bioassays indicate that the differences in toxicity between S-VO2, V(IV), and V(V) in HEK293 cells are very small, supporting that the toxicity is mainly due to the dissolved V ions, in the form of V(V) and/or V(IV), but the V(V)’s behavior is more similar to S-VO2 according to the gene expression analysis. This study reveals the toxicity mechanism of nanosized VO2 at the molecular level and the role of dissolution of VO2, providing valuable information for safe applications of vanadium oxides.

A reproducible method to study traumatic injury-induced zebrafish brain regeneration.

Traumatic brain injury (TBI) can be caused by a sudden blow or jolt to the head, causing irreversible brain damage leading to cellular and functional loss. Mammals cannot repair such damage, which may increase the risk of progressive neurodegeneration. Unlike mammals, lower vertebrates such as zebrafish have the astounding capability to regenerate their brains. A model system would be of great value to study zebrafish brain regeneration. Here, we describe a physical method to induce traumatic injury in the zebrafish brain and outline a pipeline to utilize this model system to explore various aspects of brain regeneration. This will significantly advance the fields of regenerative biology and neuroscience. The method includes inducing TBI and validating this through histological assays, immunohistochemistry, and gene expression analysis. By using this model system, researchers will be able to gain valuable insights into the cellular and molecular mechanisms underlying brain regeneration. Understanding these mechanisms could lead to the identification of potential strategies to address neurodegenerative conditions in higher vertebrates.

The Sensitization of Murine Hematopoietic Progenitors and Stem Cells to DNA Damaging Agents By Quizartinib Is Associated with the Transcriptional Downregulation of DNA Damage Repair Genes

Background: The FLT3 inhibitor quizartinib induces quiescence of murine hematopoietic progenitors, and this affords their protection from S phase specific chemotherapies. In this study we investigated whether quizartinib can also protect hematopoietic progenitors from the cytotoxic effects of DNA damaging chemotherapies and radiation. Methods: C57BL/6 mice were primed with 30 mg/kg of quizartinib or vehicle (5% cyclodextrin) by oral gavage, and treated with DNA damaging chemotherapies, either cyclophosphamide, carboplatin, cisplatin, temozolomide or mitoxantrone 6 hours later, or 5.5Gy total body irradiation (TBI) after 9 hours. This TBI dose represents half the 11 Gy split dose used for bone marrow conditioning of C57BL/6 mice prior to HSC transplantation. Bone marrow cells were analyzed by flow cytometry after 3 to 6 days to identify progenitor and stem cell populations. Results: In contrast to quizartinib's protection against the cytotoxic effects of 5-FU and gemcitabine, all 5 DNA-damaging chemotherapies caused an increased loss of total bone marrow cellularity when mice were primed with quizartinib compared to vehicle primed controls. Flow cytometry analysis revealed that the numbers of myeloid and multipotent progenitors, and short-term and long-term hematopoietic stem cells (HSCs), were markedly lower in the quizartinib-treated mice. DNA damage and the resultant cell death caused by ionizing radiation is cell cycle specific, particularly for cells traversing from G 1 to S phases of the cell cycle. The ability of quizartinib to induce quiescence in myeloid and multipotent progenitors suggested that quizartinib may protect these cells from radiation. To test this, mice were dosed with vehicle or 30 mg/kg of quizartinib and 9 hours later exposed mice to 5.5 Gy of TBI. Analysis of bone marrow cells at day 6 revealed that total bone marrow cellularity and the numbers of progenitor and stem cells were markedly reduced in quizartinib-dosed mice compared to vehicle controls. For subsequent experiments mice were treated with 3 Gy TBI because the combination of quizartinib and 5.5 Gy caused severe myeloablation. As part of a series of experiments examining the kinetics of quizartinib's sensitization of bone marrow cells we tested whether the sensitization was maintained when mice were dosed with quizartinib 24 hours prior to 3 Gy TBI. Analysis of bone marrow cells 6 days later revealed that quizartinib dosed mice showed a significantly greater loss of total bone marrow cells, progenitor cells and stem cells compared to vehicle dosed mice (Figure 1). To identify possible mechanisms by which quizartinib sensitizes hematopoietic progenitors to DNA damaging agents we investigated quantitative gene expression profiling of the HPC7 hematopoietic progenitor cell line. These cells provide a suitable in vitro model since quizartinib induces their quiescence and provides protection against 5-FU. HPC7 cells were treated with 100 µM quizartinib, or vehicle, for 18 hr before RNA was harvested and sent for Next-generation sequencing. We found that quiescence induction in HPC7 cells by quizartinib correlated with the transcriptional downregulation of a wide range of genes involved in DNA damage repair pathways (including Brca1/2, Rad51, Palb2, Chek1 and Nbn), thus providing a possible mechanism for the enhanced cytotoxic effects of DNA damaging agents. Conclusions: Quizartinib sensitizes hematopoietic progenitors and stem cells to DNA-damaging agents, an effect that correlates with the transcriptional downregulation of many DNA damage repair genes. The enhanced depletion of hematopoietic progenitors and stem cells by DNA damaging agents in the presence of quizartinib has important clinical implications. Administering concurrent DNA damaging chemotherapy or radiotherapy with quizartinib treatment should be avoided. However, this interaction could facilitate a reduction in radiation/chemotherapy doses administered for bone marrow conditioning prior to HSC transplantation. By reducing these doses, but not compromising the conditioning process, non-hematopoietic side effects could be minimized and may allow currently excluded patients to be considered for HSC transplantation. Disclosure: This study was partly funded by Daiichi Sankyo.

Establishing a Pathogenic Role for NK Cells As Drivers of Bone Marrow Failure in the Myelodysplastic Syndromes (MDS)

Background: Myelodysplastic syndromes (MDS) are characterized by aberrant bone-marrow (BM) morphology leading to a clonal impairment of hematopoiesis. Worsening BM failure (BMF) and increasing myeloblasts are observed as the predominant consequences of MDS disease progression from very low risk (VLR) to higher risk (HR) to acute myeloid leukemia (AML). Patients are stratified based on the degree of BMF and risk of AML transformation to help guide treatment decisions. Approximately 30% of MDS patients exhibit various autoimmune diseases that can include autoantibodies targeting neutrophils, erythrocytes, and/or platelets. Autoimmune phenomena play an important role in MDS yet are poorly characterized. We hypothesized that early in LR-MDS, dysregulated interactions between stromal cells and developing Natural Killer (NK)/T-cells promote rapid/unregulated development resulting in autoreactivity ( Fig. 1A). We predict dual effector mechanisms: CD16-mediated antibody-dependent cellular cytotoxicity (ADCC) and loss of HLA class I (HLA-I) expression by developing hematopoietic lineage cells making them targets for “missing-self” reactivity ( Fig. 1A). NK cells are important sentinel cells that recognize tumors and dysfunctional cells that lose expression of HLA class I. Such surveillance is guided by interactions between NK inhibitory receptors and HLA class I ligands that ‘train’ NK cells to distinguish diseased cells, exhibiting perturbed HLA expression, from healthy cells with normal expression. The effects of these interactions combined with expression of activating receptors (e.g. CD16, NKG2D, DNAM1, FasL, TRAIL) allow NK cells to engage a target cell through many activating mechanisms, importantly including antibodies eliciting an antibody-dependent cellular cytotoxicity (ADCC) reaction. Autoantibodies are well-established in MDS, yet no one has profiled whether they may trigger ADCC/complement. Further, no one has ever thoroughly characterized BMMCs from LR-MDS patients before. In our study, we observed a clear link between signatures of bone marrow failure at LR-MDS and a significant increase in BM CD57+NK and CD8 T cells expressing a highly activated and dysregulated phenotype. Method: Ex-vivo profiling of 19 MDS patients (N=10 LR/IR-MDS, N=9 HR-MDS) BM mononuclear cells (BMMCs) was performed by mass cytometry (CyTOF)( Fig.1B). Cells were stained with three different antibody panels each consisting of 44 antibodies focused on: specific markers of hematopoiesis and myeloid or lymphoid cell lineages; specific markers of development, effector function, homing, exhaustion, and T-cell memory and proliferation; expression of HLA class I and activating ligands which are critical regulators of NK inhibition. Results: In our study we observed that a major fraction of MDS patients present with clonal-like expansions of BM-derived CD57+CD8+T-cells and natural killer (NK) cells that strongly correlate with autoimmune-cytopenias and BMF-enriched in LR-MDS (Fig.#). We observed that NK-cells and non-classical T-cells were significantly expanded (&amp;gt;2-fold) in LR MDS compared to HR-MDS and healthy-control BM (p&amp;lt;0.01). These non-classical CD57+CD8+T-cells co-expressed HLA-I-reactive and inhibitory NKG2A/KIR receptors as well as activating CD16, NKG2C, NKG2D, NKp46, TRAIL, FasL. In cancers, these cells use innate-like, TCR-independent mechanisms (traditionally ascribed to NK-cells) to target HLA-I-deficient tumor cells. Strikingly, HLA-I was significantly elevated on myeloblasts in LR-MDS compared to HR-MDS (p=0.0007)( Fig.1B), demonstrating NK-evasion strategies, but strongly reduced on dendritic cells, granulocytes, and CD4+T-cells, suggesting susceptible immune targets for destruction by NK-cells (and innate-like CD8+T-cells) (p&amp;lt; 0.0001) ( Fig.1B). BM-derived CD57+NK and CD8+T-cells all co-express very high levels of CD16 making them particularly ADCC reactive. Conclusion: We identified novel innate-like CD8+CD57+ T-cell and NK-cell populations that may play a role in LR-MDS disease pathogenesis. We predict that a strategy to target these cells could help restore hematopoiesis early in the disease state. This may also reduce pressure on myeloblasts to increase HLA-I, permitting improved immune surveillance to control the blast burden and prevention MDS/AML progression. Further experiments are ongoing to validate our observations.

Mechanosensitivity and mechanotransductive properties of osteoclasts.

Mechanical loading is essential for maintaining bone health. Here, we aimed to investigate the role of ATP and ADP in the mechanotransduction of bone-resorptive osteoclasts. Single osteoclast in primary cultures from 10 to 12-wk-old mice was mechanically stimulated by a gentle touch with a micropipette. Changes in cytosolic free calcium [Ca2+]i were analyzed in Fura-2 loaded osteoclasts. The cell injury was assessed by analyzing the cellular Fura-2 loss and classified as severe or mild using k-means. Osteoclasts responded to mechanical stimuli with transient calcium elevation (primary responders) and transduced these signals to neighboring cells, which responded with delayed calcium elevations (secondary responders). Severely injured osteoclasts had higher calcium transients than mildly injured cells. Fluid shear stress similarly induced reversible cell injury in osteoclasts. Secondary responses were abolished by treatment with A-804598, a specific inhibitor of P2X7, but not suramin, a broad P2 receptor blocker. Osteoclasts responded to ATP and ADP with concentration-dependent changes in [Ca2+]i. We performed osteoclast micropipette stimulation in the presence of phosphoenolpyruvate and pyruvate kinase which converted all ADP in solution to ATP, or with hexokinase converting all ATP to ADP. Osteoclasts with mild membrane injury demonstrated similar calcium responses in ATP and ADP-rich environments. However, when the mechanotransductive signal to severe osteoclast injury was converted to ADP, the fraction of secondary responders and their [Ca2+]i amplitude was higher. This study suggests the importance of osteoclast mechanobiology and the role of ADP-mediated signaling in conditions of altered mechanical loading associated with bone loss.NEW & NOTEWORTHY Osteoclasts are rarely considered as cells that participate in mechanical signaling in bone. We show that osteoclasts are capable of sensing and transmitting mechanical signals to neighboring cells. Mechanical stimulation commonly induces minor repairable membrane injury in osteoclasts. ATP and especially ADP were found to play important roles in the mechanoresponsiveness of osteoclasts. This study highlights the importance of osteoclast mechanobiology especially in conditions of altered mechanical loading associated with bone loss, such as in microgravity.

Walk Locomotion Kinematic Changes in a Model of Penetrating Hippocampal Injury in Male/Female Mice and Rats.

Traumatic brain injury has been the leading cause of mortality and morbidity in human beings. One of the most susceptible structures to this damage is the hippocampus due to cellular and synaptic loss and impaired hippocampal connectivity to the brain, brain stem, and spinal cord. Thus, hippocampal damage in rodents using a stereotaxic device could be an adequate method to study a precise lesion from CA1 to the dentate gyrus structures. We studied male and female rats and mice, analyzing hindlimb locomotion kinematics changes to compare the locomotion kinematics using the same methodology in rodents. We measure (1) the vertical hindlimb metatarsus, ankle, and knee joint vertical displacements (VD) and (2) the factor of dissimilarity (DF). The VD in intact rats in metatarsus, ankle, and knee joints differs from that in intact mice in similar joints. In rats, the vertical displacement through the step cycle changed in the left and right metatarsus, ankle, and knee joints compared to the intact group versus the lesioned group. More subtle changes were also observed in mice. DF demonstrates contrasting results when studying locomotion kinematics of mice or rats and sex-dependent differences. Thus, a precise lesion in a rodent's hippocampal structure discloses some hindlimb locomotion changes related to species and sex. Thus, we only have a qualitative comparison between murine species. In order to make a comparison with other species, we should standardize the model.

25 High-resolution MRI Reveals Selective Patterns of Hippocampal Subfield Atrophy in Focal Epilepsy

Objective:Hippocampal pathology is a consistent feature in persons with temporal lobe epilepsy (TLE) and a strong biomarker of memory impairment. Histopathological studies have identified selective patterns of cell loss across hippocampal subfields in TLE, the most common being cellular loss in the cornu ammonis 1 (CA1) and dentage gyrus (DG). Structural neuroimaging provides a non-invasive method to understand hippocampal pathology, but traditionally only at a whole-hippocampal level. However, recent methodological advances have enabled the non-invasive quantification of subfield pathology in patients, enabling potential integration into clinical workflow. In this study, we characterize patterns of hippocampal subfield atrophy in patients with TLE and examine the associations between subfield atrophy and clinical characteristics.Participants and Methods:High-resolution T2 and T1-weighted MRI were collected from 31 participants (14 left TLE; 6 right TLE; 11 healthy controls [HC], aged 18-61 years). Reconstructions of hippocampal subfields and estimates of their volumes were derived using the Automated Segmentation of Hippocampal Subfields (ASHS) pipeline. Total hippocampal volume was calculated by combining estimates of the subfields CA1-3, DG, and subiculum. To control for variations in head size, all volume estimates were divided by estimates of total brain volume. To assess disease effects on hippocampal atrophy, hippocampi were recoded as either ipsilateral or contralateral to the side of seizure focus. Two sample t-tests at a whole-hippocampus level were used to test for ipsilateral and contralateral volume loss in patients relative to HC. To assess whether we replicated the selective histopathological patterns of subfield atrophy, we carried out mixed-effects ANOVA, coding for an interaction between diagnostic group and hippocampal subfield. Finally, to assess effects of disease load, non-parametric correlations were performed between subfield volume and age of first seizure and duration of illness.Results:Patients had significantly smaller total ipsilateral hippocampal volume compared with HC (d=1.23, p&lt;.005). Contralateral hippocampus did not significantly differ between TLE and HC. Examining individual subfields for the ipsilateral hemisphere revealed significant main-effects for group (F(1, 29)=8.2, p&lt;0.01), subfields (F(4, 115)=550.5, p&lt;0.005), and their interaction (F(4, 115)=8.1, p&lt;0.001). Post-hoc tests revealed that TLE had significantly smaller volume in the ipsilateral CA1 (d=-2.0, p&lt;0.001) and DG (d = -1.4, p&lt;0.005). Longer duration of illness was associated with smaller volume of ipsilateral CA2 (p=-0.492, p&lt;0.05) and larger volume of contralateral whole-hippocampus (p=0.689, p&lt;0.001), CA1 (p=0.614, p &lt; 0.005), and DG (p=0.450, p&lt;0.05).Conclusions:Histopathological characterization after surgery has revealed important associations between hippocampal subfield cell loss and memory impairments in patients with TLE. Here we demonstrate that non-invasive neuroimaging can detect a pattern of subfield atrophy in TLE (i.e., CA1/DG) that matches the most common form of histopathologically-observed hippocampal sclerosis in TLE (HS Type 1) and has been linked directly to both verbal and visuospatial memory impairment. Finally, we found evidence that longer disease duration is associated with larger contralateral hippocampal volume, driven by increases in CA1 and DG. This may reflect subfield-specific functional reorganization to the unaffected brain tissue, a compensatory effect which may have important implications for patient function and successful treatment outcomes.

Evaluations of haematological profile in geriatric patients in a tertiary care hospital

Ageing is the process which has an impact on all the cells, tissues, organ systems, and organisms. Alterations or modifications in the bone marrow are observed with ageing. Increased risk of myeloproliferative disorders, anaemia, and a deteriorating adaptive immunity are signs of age-related hematologic alterations, as is a loss in bone marrow cellularity. Evaluations of haematological parameters can be used to track the disease's development. Hence, this retrospective study was designed to evaluate the haematological profile of geriatric patients and to compare the haematological parameters between males and females. The Complete Blood Count reports of 445 patients aged 60 years and above were selected for this retrospective study. The backbone computerized data of these cases were taken from central laboratory of Yenepoya Medical College Hospital. Haematological profile was studied and analyzed from selected cases. The independent sample t test was used to compare the haematological parameters of males and females.P value&lt;0.05 was considered as significant.The results obtained showed that there was a statistical significance in lymphocytes, Eosinophils, MCH, MCHC in Geriatrics patients. There was no statistical significance in haemoglobin, neutrophils, monocytes, platelet count, MCV, PCV, and RBC count .Major abnormalities were found in Haemoglobin and lymphocytes than other haematological parameters. Incidence of anaemia was 77.8% and lymphocytopenia 77.9%.The most frequently observed haematological abnormalities in elderly persons were anaemia and lymphocytopenia. Anaemia was seen to be higher in females than males. Lymphocytopenia was seen to be higher in males than females. Early evaluations of haematological profile will reduce morbidity and mortality among the geriatric patients.

Regulatory T cell-like response to SARS-CoV-2 in Jamaican fruit bats (Artibeus jamaicensis) transduced with human ACE2.

Insectivorous Old World horseshoe bats (Rhinolophus spp.) are the likely source of the ancestral SARS-CoV-2 prior to its spillover into humans and causing the COVID-19 pandemic. Natural coronavirus infections of bats appear to be principally confined to the intestines, suggesting fecal-oral transmission; however, little is known about the biology of SARS-related coronaviruses in bats. Previous experimental challenges of Egyptian fruit bats (Rousettus aegyptiacus) resulted in limited infection restricted to the respiratory tract, whereas insectivorous North American big brown bats (Eptesicus fuscus) showed no evidence of infection. In the present study, we challenged Jamaican fruit bats (Artibeus jamaicensis) with SARS-CoV-2 to determine their susceptibility. Infection was confined to the intestine for only a few days with prominent viral nucleocapsid antigen in epithelial cells, and mononuclear cells of the lamina propria and Peyer's patches, but with no evidence of infection of other tissues; none of the bats showed visible signs of disease or seroconverted. Expression levels of ACE2 were low in the lungs, which may account for the lack of pulmonary infection. Bats were then intranasally inoculated with a replication-defective adenovirus encoding human ACE2 and 5 days later challenged with SARS-CoV-2. Viral antigen was prominent in lungs for up to 14 days, with loss of pulmonary cellularity during this time; however, the bats did not exhibit weight loss or visible signs of disease. From day 7, bats had low to moderate IgG antibody titers to spike protein by ELISA, and one bat on day 10 had low-titer neutralizing antibodies. CD4+ helper T cells became activated upon ex vivo recall stimulation with SARS-CoV-2 nucleocapsid peptide library and exhibited elevated mRNA expression of the regulatory T cell cytokines interleukin-10 and transforming growth factor-β, which may have limited inflammatory pathology. Collectively, these data show that Jamaican fruit bats are poorly susceptible to SARS-CoV-2 but that expression of human ACE2 in their lungs leads to robust infection and an adaptive immune response with low-titer antibodies and a regulatory T cell-like response that may explain the lack of prominent inflammation in the lungs. This model will allow for insight of how SARS-CoV-2 infects bats and how bat innate and adaptive immune responses engage the virus without overt clinical disease.

Synergetic effect of reduced graphene oxide and reticulated open-cell aluminum hybrid composite foam for high-performance electromagnetic wave absorption

In the present work, open-cell aluminum-reduced graphene oxide composite (Al-rGO) foam with varying concentrations of reduced graphene oxide (rGO) was fabricated through the template method and foam's electrical, mechanical, and electromagnetic shielding behavior was studied. The reticulated Al-rGO foam allows the electromagnetic wave (EMW) to go inside the structure and resulting in multiple scattering which enhances the wave absorption capacity of the material. Adding rGO into open-cell aluminium foam (OCAF) enhances its shielding properties, particularly the absorption component. The Al-rGO3 foam shows a total EMI shielding of ∼62 dB at 8.4 GHz frequency and out of which 61.34 dB (> 99% of total shielding) is the absorption component. The Al-rGO foam also exhibited maximum compressive strength of 2.96 MPa and EMI shielding of ∼62 dB at 1.5 wt% rGO, even though the electrical conductivity reduces with rGO content. This may be due to a greater degree of multiple scattering of EMW inside the cellular structure and different energy losses at rGO-Al interfaces. This work shows a new way to use the lightweight metallic structure for high EMW absorption applications with good mechanical stability in the defense and aerospace sectors.