Soft Multi-Directional Force Sensor for Underwater Robotic Application.

Tactile information is crucial for recognizing physical interactions, manipulation of an object, and motion planning for a robotic gripper; however, concurrent tactile technologies have certain limitations over directional force sensing. In particular, they are expensive, difficult to fabricate, and mostly unsuitable for underwater use. Here, we present a facile and cost-effective synthesis technique of a flexible multi-directional force sensing system, which is also favorable to be utilized in underwater environments. We made use of four flex sensors within a silicone-made hemispherical shell structure. Each sensor was placed 90° apart and aligned with the curve of the hemispherical shape. If the force is applied on the top of the hemisphere, all the flex sensors would bend uniformly and yield nearly identical readings. When force is applied from a different direction, a set of flex sensors would characterize distinctive output patterns to localize the point of contact as well as the direction and magnitude of the force. The deformation of the fabricated soft sensor due to applied force was simulated numerically and compared with the experimental results. The fabricated sensor was experimentally calibrated and tested for characterization including an underwater demonstration. This study would widen the scope of identification of multi-directional force sensing, especially for underwater soft robotic applications.

High resolution melting curve analysis enables rapid and reliable detection of G6PD variants in heterozygous females.

BACKGROUND: Like glucose-6-phosphate dehydrogenase (G6PD) deficient hemizygous males and homozygous females, heterozygous females could also manifest hemolytic crisis, neonatal hyperbilirubinemia or kernicterus upon exposure to oxidative stress induced by certain foods such as fava beans, drugs or infections. Although hemizygous males and homozygous females are easily detected by conventional G6PD enzyme assay method, the heterozygous state could be missed by the conventional methods as the mosaic population of both normal and deficient RBCs circulates in the blood. Thus the present study aimed to apply high resolution melting (HRM) curve analysis approach to see whether HRM could be used as a supplemental approach to increase the chance of detection of G6PD heterozygosity. RESULTS: Sixty-three clinically suspected females were evaluated for G6PD status using both enzyme assay and HRM analysis. Four out of sixty-three participants came out as G6PD deficient by the enzyme assay method, whereas HRM approach could identify nine participants with G6PD variants, one homozygous and eight heterozygous. Although only three out of eight heterozygous samples had G6PD enzyme deficiency, the HRM-based heterozygous G6PD variants detection for the rest of the samples with normal G6PD enzyme activities could have significance because their newborns might fall victim to serious consequences under certain oxidative stress. CONCLUSIONS: In addition to the G6PD enzyme assay, HRM curve analysis could be useful as a supplemental approach for detection of G6PD heterozygosity.

Parental vitamin D deficiency during pregnancy is associated with increased blood pressure in offspring via Panx1 hypermethylation.

Vitamin D deficiency is one of the most common nutritional deficiencies worldwide. Maternal vitamin D deficiency is associated with increased susceptibility to hypertension in offspring, but the reasons for this remain unknown. The aim of this study was to determine if parental vitamin D deficiency leads to altered DNA methylation in offspring that may relate to hypertension. Male and female Sprague-Dawley rats were fed a standard or vitamin D-depleted diet. After 10 wk, nonsibling rats were mated. The conceived pups received standard chow. We observed an increased systolic and diastolic blood pressure in the offspring from depleted parents (F1-depl). Genome-wide methylation analyses in offspring identified hypermethylation of the promoter region of the Pannexin-1 (Panx1) gene in F1-depl rats. Panx1 encodes a hemichannel known to be involved in endothelial-dependent relaxation, and we demonstrated that in F1-depl rats the increase in blood pressure was associated with impaired endothelial relaxation of the large vessels, suggesting an underlying biological mechanism of increased blood pressure in children from parents with vitamin deficiency. Parental vitamin D deficiency is associated with epigenetic changes and increased blood pressure levels in offspring.

Prospects of Graphene as a Potential Carrier-Transport Material in Third-Generation Solar Cells.

Third-generation solar cells are understood to be the pathway to overcoming the issues and drawbacks of the existing solar cell technologies. Since the introduction of graphene in solar cells, it has been providing attractive properties for the next generation of solar cells. Currently, there are more theoretical predictions rather than practical recognitions in third-generation solar cells. Some of the potential of graphene has been explored in organic photovoltaics (OPVs) and dye-sensitized solar cells (DSSCs), but it has yet to be fully comprehended in the recent third-generation inorganic-organic hybrid perovskite solar cells. In this review, the diverse role of graphene in third-generation OPVs and DSSCs will be deliberated to provide an insight on the prospects and challenges of graphene in inorganic-organic hybrid perovskite solar cells.

Assessment of radioactivity level and associated radiological hazard in riverbed samples within industrial areas.

Terrestrial gamma radiation is one of the major outdoor radiation exposures to the general public that varies substantially based on the type and geological properties of the soil. The objective of this study is to evaluate the naturally occurring radioactive materials (NORMs) distribution and assess the hazard parameters in the riverbank soil within various industrial zones in the densely populated Dhaka and Chattogram cities of Bangladesh. The mean activities of 226Ra (37 ± 3), 232Th (58 ± 4), and 40K (1129 ± 18) Bqkg-1 in the assessed soil samples were found to be slightly higher than the world average values 32, 35, and 420 Bqkg-1, respectively. The mean radium equivalent activity (207.49 Bqkg-1) and the external and internal hazard indices were within the recommended limits of 370 Bqkg-1 and <1, respectively. The mean absorbed dose rate (99.47 nGyhr-1), annual effective dose (0.12 mSva-1), ELCR (4.27 × 10-4), and gamma level index (1.58) exceeded the world average values 59 nGyhr-1, 0.07 mSva-1, 2.9 × 10-4, and 1 respectively. However, the studied areas are safe from a radiological viewpoint with no radiation health hazard to the people. The results of this study can be utilized to produce factual baseline data for future studies.

Plasma renin and outcome in the community: data from PREVEND.

AIMS: The renin-angiotensin system plays a central role in patients with established cardiovascular (CV) disease, but the prognostic effect of plasma renin in the community is unclear. METHODS AND RESULTS: The relationship between plasma renin concentration and CV events was studied in 6228 subjects who were enrolled in the Prevention of REnal and Vascular ENd-stage Disease (PREVEND) study, and who were not using antihypertensive medication. Plasma renin concentration was measured using a direct automated immunochemiluminescent assay. The mean (± SD) age was 47(± 12) years, 49% were male; the mean follow-up was 10.5 years. The median (Q1-Q3) plasma renin was 17.6 (10.9-27.2) µIU/mL, and plasma aldosterone was 119 (93-153) ng/L. The primary outcome was a composite of fatal (n = 27) and non-fatal (n = 408) CV events. Adjusted for age and sex each doubling of plasma renin was associated with a hazard ratio (HR) for the primary outcome of 1.22 (95% CI: 1.04-1.43; P= 0.015). In a multivariable model, plasma renin showed a positive correlation with heart rate and male sex and a negative correlation with blood pressure, urinary sodium, glucose, and N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) (adjusted R(2): 0.167, P< 0.001). After adjustment for covariates associated with plasma renin, the HR for reaching the primary outcome was 1.28 (95% CI: 1.09-1.49, P= 0.002). Plasma renin was associated with CV events regardless of blood pressure, but in subjects using antihypertensive medication this association was absent. CONCLUSION: Plasma renin concentration is associated with an increased risk for CV events in a community-based cohort not on antihypertensive medication.

Acceptability of a head-mounted assistive mouse controller for people with upper limb disability: An empirical study using the technology acceptance model.

Due to limited motor capabilities, people with upper limb disabilities have trouble utilizing a typical mouse while operating a computer. Different wearable Assistive Mouse Controllers (AMCs) have been developed to overcome their challenges. However, these people may not be able to realize the importance, ease of use, and social approval of these AMCs due to their fear of new technology, lack of confidence, and lack of ingenuity. These may negatively affect their attitude and intention toward accepting AMCs for equitable human-computer interaction. This study presents the development of a sensor-based head-mounted AMC, followed by an empirical analysis of its acceptance using the Technology Acceptance Model (TAM) from the socioeconomic perspective of Bangladesh. In a similar vein, we examined the effects of three additional psychological constructs-technology anxiety, confidence, and innovation, on its acceptance along with the original components of the TAM. A total of 150 individuals with stroke-induced upper limb disability participated in an online survey, and their responses were analyzed using confirmatory factor analysis and structural equation modeling, following the general least square method. Analysis revealed, about 96.44% of the participants had positive attitude towards the AMC, and almost 88.56% of them had positive intentions to accept it. Furthermore, about 68.61% of them expressed signs of anxiety, 96.35% were confident, and 94.16% of them had an innovative mindset in terms of device usage. The findings imply that individuals with an innovative mentality are more capable of comprehending the practical implications of a new technology than those without one. It is also feasible to reduce technological anxiety and boost a user's confidence while using an AMC by combining an innovative mentality with straightforward device interaction techniques. Additionally, peer encouragement and motivation can significantly enhance their positive attitude towards accepting the AMC for facilitating their interaction with a computer.

BdSL47: A complete depth-based Bangla sign alphabet and digit dataset.

Sign Language Recognition (SLR) is crucial for enabling communication between the deaf-mute and hearing communities. Nevertheless, the development of a comprehensive sign language dataset is a challenging task due to the complexity and variations in hand gestures. This challenge is particularly evident in the case of Bangla Sign Language (BdSL), where the limited availability of depth datasets impedes accurate recognition. To address this issue, we propose BdSL47, an open-access depth dataset for 47 one-handed static signs (10 digits, from ০ to ৯; and 37 letters, from অ to ँ) of BdSL. The dataset was created using the MediaPipe framework for extracting depth information. To classify the signs, we developed an Artificial Neural Network (ANN) model with a 63-node input layer, a 47-node output layer, and 4 hidden layers that included dropout in the last two hidden layers, an Adam optimizer, and a ReLU activation function. Based on the selected hyperparameters, the proposed ANN model effectively learns the spatial relationships and patterns from the depth-based gestural input features and gives an F1 score of 97.84 %, indicating the effectiveness of the approach compared to the baselines provided. The availability of BdSL47 as a comprehensive dataset can have an impact on improving the accuracy of SLR for BdSL using more advanced deep-learning models.

Trends in the Prevalence of Hypertension and Type 2 Diabetes in Bangladesh (2010-2020): A Systematic Review and Meta-Analysis.

BACKGROUND: The prevalence of cardiovascular diseases (CVDs) and type 2 diabetes mellitus (T2DM) has increased in Bangladesh. This paper has reviewed published studies on hypertension and T2DM from 2010 to 2020 in Bangladesh and conducted a meta-analysis. METHODS: The PubMed database was used for systematic search. Hypertension and T2DM were considered for measuring pooled prevalence by meta-analysis. The random-effects model was used to calculate the pooled prevalence of hypertension (n = 30) and T2DM (n = 21) in relevant studies. The quality of the reviewed studies was determined by sampling strategy, sample size, and outcome assessment. The meta-analysis protocol was registered at PROSPERO (CRD42020206315). RESULTS: The pooled hypertension and T2DM prevalence was 21.6% (95% CI: 18.8%-24.4%) and 13.6% (95% CI: 10.8%-16.5%), respectively. Females were more hypertensive than males (M vs. F: 18.6% vs. 24.8%), and T2DM was higher in females (M vs. F: 12.4% vs. 13.3%). Urban dwellers were more hypertensive and diabetic than rural people (urban vs. rural: 28.5% vs. 20.3% and 18.8% vs. 14.2%, respectively). An 8% increase in the prevalence of hypertension and T2DM became more than double compared to the 1995-2010 period. CONCLUSION: Future research should focus on the underlying factors that increase the prevalence of these diseases and prevention strategies to reduce the trend of increasing prevalence.

Association Among Cystic Volume, Intracystic Pressure, and Histopathological Changes in the Liver in Patients With Choledochal Cyst.

Background Choledochal cyst is a congenital cystic dilatation of the biliary tree. Various aspects of pathophysiology are unclear, particularly with reference to intracholedochal cystic pressure (ICCP) and liver histopathology. This study aimed to determine the relationship among cystic volume, ICCP, and histopathological changes in the liver in patients with choledochal cysts. Methods This cross-sectional study was carried out among 21 patients diagnosed with choledochal cysts, who attended the Department of Pediatric Surgery at Bangabandhu Sheikh Mujib Medical University (BSMMU) from April 2021 to August 2022. Cystic volume was measured pre-operatively using ultrasonography, while ICCP was measured per-operatively with a pressure gauge. Liver histology was assessed through an intraoperative liver biopsy and graded using the meta-analysis of histological data in viral hepatitis (METAVIR) scoring system. The data were analyzed using SPSS version 25.0 (IBM Corporation, Armonk, New York). Frequency and percentages were calculated to present categorical variables, and for quantitative variables, mean, standard deviation (SD), median, and interquartile range (IQR) were calculated. Fisher's exact tests were performed to determine the association between cystic volume, ICCP, and the grading of hepatic fibrosis. A p-value of <0.05 was considered statistically significant. Results The age of the patients ranged from 1 to 12 years, with a mean of 5.0±3.4 years. The male-to-female ratio was 1:4.3. Type I cysts were the most prevalent (71.4%). The median and IQR for cystic volume were 3.4 ml and 1.1-8.2 ml, respectively. The median and IQR for ICCP were 7.46 mmHg and 4.67-9.33 mmHg, respectively. The most frequent grade of fibrosis was F1 (38.1%), followed by F2 (23.8%) and F3 (23.8%). A negative relationship between cystic volume and ICCP was observed, which was statistically significant (p=0.008). A positive relationship was also observed between ICCP and the grading of liver fibrosis, which was statistically significant (p=0.002). Although a negative correlation between cystic volume and grading of liver fibrosis was noted, it was not statistically significant (p=0.198). Conclusions This study reveals significant associations between cystic volume, ICCP, and the grading of liver fibrosis in patients with choledochal cysts. Smaller volume cysts may exhibit higher ICCP, resulting in more pronounced fibrotic changes in the liver.

Regulation of the (pro)renin-renin receptor in cardiac remodelling.

The (pro)renin-renin receptor [(P)RR] was discovered as an important novel component of the renin-angiotensin system (RAS). The functional significance of (P)RR is widely studied in renal and vascular pathologies and has sparked interest for a potential role in cardiovascular disease. To investigate the role of (P)RR in cardiac pathophysiology, we aimed to assess (P)RR regulation in adverse cardiac remodelling of the failing heart. In particular, we evaluated the expression of (P)RR in different models of heart failure and across different species. Significantly increased levels of (P)RR mRNA were found in post-myocardial infarcted (MI) hearts of rats (1.6-fold, P < 0.05) and mice (5-fold, P < 0.01), as well as in transgenic rats with overexpression of the mouse renin gene (Ren2) (2.2-fold, P < 0.01). Moreover, we observed a strong increase of (P)RR expression in hearts of dilated cardiomyopathy (DCM) patients (5.3-fold, P < 0.001). Because none of the tested commercially available antibodies appeared to detect endogenous (P)RR, a (P)RR-specific polyclonal antibody was generated to study (P)RR protein levels. (P)RR protein levels were significantly increased in the post-MI rat heart (1.4-fold, P < 0.05) as compared to controls. Most interestingly in DCM patients, a significant 8.7-fold (P < 0.05) increase was observed. Thus, protein expression paralleled gene expression. These results demonstrate that (P)RR expression is strongly up-regulated both in rodent models of heart failure and in the failing human heart, hinting to a potential role for (P)RR in cardiac pathophysiology.

Enhanced suicidal erythrocyte death in mice carrying a loss-of-function mutation of the adenomatous polyposis coli gene.

Loss-of-function mutations in human adenomatous polyposis coli (APC) lead to multiple colonic adenomatous polyps eventually resulting in colonic carcinoma. Similarly, heterozygous mice carrying defective APC (apc(Min/+)) suffer from intestinal tumours. The animals further suffer from anaemia, which in theory could result from accelerated eryptosis, a suicidal erythrocyte death triggered by enhanced cytosolic Ca(2+) activity and characterized by cell membrane scrambling and cell shrinkage. To explore, whether APC-deficiency enhances eryptosis, we estimated cell membrane scrambling from annexin V binding, cell size from forward scatter and cytosolic ATP utilizing luciferin-luciferase in isolated erythrocytes from apc(Min/+) mice and wild-type mice (apc(+/+)). Clearance of circulating erythrocytes was estimated by carboxyfluorescein-diacetate-succinimidyl-ester labelling. As a result, apc(Min/+) mice were anaemic despite reticulocytosis. Cytosolic ATP was significantly lower and annexin V binding significantly higher in apc(Min/+) erythrocytes than in apc(+/+) erythrocytes. Glucose depletion enhanced annexin V binding, an effect significantly more pronounced in apc(Min/+) erythrocytes than in apc(+/+) erythrocytes. Extracellular Ca(2+) removal or inhibition of Ca(2+) entry with amiloride (1 mM) blunted the increase but did not abrogate the genotype differences of annexin V binding following glucose depletion. Stimulation of Ca(2+) -entry by treatment with Ca(2+) -ionophore ionomycin (10 µM) increased annexin V binding, an effect again significantly more pronounced in apc(Min/+) erythrocytes than in apc(+/+) erythrocytes. Following retrieval and injection into the circulation of the same mice, apc(Min/+) erythrocytes were more rapidly cleared from circulating blood than apc(+/+) erythrocytes. Most labelled erythrocytes were trapped in the spleen, which was significantly enlarged in apc(Min/+) mice. The observations point to accelerated eryptosis and subsequent clearance of apc(Min/+) erythrocytes, which contributes to or even accounts for the enhanced erythrocyte turnover, anaemia and splenomegaly in those mice.

The experiences of children and adolescents undergoing forced separation from their parents during migration: A systematic review.

Globally, the migration of unaccompanied minors is increasing, however, the experiences of these children have not been examined. We systematically synthesised the existing qualitative literature to examine the experiences of children undergoing forced separation from their parents during migration. The review was structured based on the PRISMA statement. A systematic search of Ovid MEDLINE, EMBASE, PsychINFO and Scopus databases from inception to November 23, 2020 was conducted to retrieve eligible studies. Only qualitative studies of children aged ≤18 years were reviewed. The data analysis and synthesis were informed by the intersectionality framework. The search yielded 10,956 studies of which eight were included in this review. Thematic analysis identified the following themes: unaccompanied minors experience a deep sense of loss; anxiety over the uncertainty of the migration process; difficulty adjusting to their new life in the host country and adverse health effects. These experiences were heightened by children's exposure to violence during migration. The intersectionality framework suggests that unaccompanied minors experience separation from their parents during migration in ways that marginalise them and widen inequalities. Migration processes need to be streamlined to provide integrated health, emotional, legal and educational supports for unaccompanied children with particular attention given to treating the trauma of past violence. More research is needed to explore how to facilitate the integration of unaccompanied children into host communities in ways that are healing and empowering.

Refreshable Braille Display With Adjustable Cell Size for Learners With Different Tactile Sensitivity.

Braille is one of the most popular mediums of education for the blind. However, learning braille requires trainers and a lot of practice. Additionally, different individuals have different levels of tactile sensitivity at their fingertips. The tactile components get often overlooked in most braille learning devices and related studies. Our solution is a single cell refreshable braille display with six custom-made electromechanical flapper actuators. It incorporates speech functionalities to facilitate self-learning and independent operation. The cell size can be adjusted according to the learner's preference by moving the actuators. The device can provide standard braille cell dimensions and elevation as well. It is designed to help learners with different tactile perceptions improve themselves through practice and adapt to standard size braille. The operational conditions and force analysis of the braille dots were performed. Two tests were also performed with two different cell sizes to evaluate the device with several blind students. The device is very affordable and easy to maintain. It can also be used to teach braille to the sighted.

Evaluation of the ethanolic ultrasound-assisted extraction from clove (Syzygium aromaticum) leaves and chemical characterization of the extracts.

In this study, clove leaves (Syzygium aromaticum) were subjected to ultrasound-assisted extraction (UAE) with ethanol as the solvent, following a central composite design to evaluate the effects of time, amplitude, solvent/sample ratio, and temperature on the yield, eugenol content, and antioxidant capacity of the extracts. The results were compared with those obtained using the conventional method of maceration (ME). The optimum conditions for extract yield were achieved with an extraction time of 25 min,amplitude of 85%, solvent/sample ratio of 35 mL g-1, and temperature of 70 °C, and the result (14.63 wt%) was three times higher than that of conventional extraction. Eugenol was detected in the extracts obtained by both methods, with the highest yield of 2.94 g eugenol kg leaves-1obtained in the UAE method, while the ME method achieved 1.36 g eugenol kg leaves-1.In general, the extracts exhibited high antioxidant capacities.

Idelalisib activates AKT via increased recruitment of PI3Kδ/PI3Kß to BCR signalosome while reducing PDK1 in post-therapy CLL cells.

Idelalisib targets PI3Kδ in the BCR pathway generating only a partial response in CLL patients, indicating that the leukemic cells may have evolved escape signals. Indeed, we detected increased activation of AKT accompanied by upregulation of MYC/BCL2 in post-therapy CLL cells from patients treated with idelalisib/ofatumumab. To unravel the mechanism of increased AKT-activation, we studied the impact of idelalisib on a CLL-derived cell line, MEC1, as a model. After an initial inhibition, AKT-activation level was restored in idelalisib-treated MEC1 cells in a time-dependent manner. As BCAP (B-cell adaptor for PI3K) and CD19 recruit PI3Kδ to activate AKT upon BCR-stimulation, we examined if idelalisib-treatment altered PI3Kδ-recruitment. Immunoprecipitation of BCAP/CD19 from idelalisib-treated MEC1 cells showed increased recruitment of PI3Kδ in association with PI3Kß, but not PI3Kα or PI3Kγ and that, targeting both PI3Kδ with PI3Kß inhibited AKT-reactivation. We detected similar, patient-specific recruitment pattern of PI3K-isoforms by BCAP/CD19 in post-idelalisib CLL cells with increased AKT-activation. Interestingly, a stronger inhibitory effect of idelalisib on P-AKT (T308) than S473 was discernible in idelalisib-treated cells despite increased recruitment of PI3Kδ/PI3Kß and accumulation of phosphatidylinositol-3,4,5-triphosphate; which could be attributed to reduced PDK1 activity. Thus, administration of isoform-specific inhibitors may prove more effective strategy for treating CLL patients.

Sphingosine but not sphingosine-1-phosphate stimulates suicidal erythrocyte death.

Sphingosine kinase 1 phosphorylates sphingosine, which is converted to ceramide by ceramide synthetase. Ceramide triggers eryptosis, the suicidal erythrocyte death characterized by cell shrinkage and phosphatidylserine (PS) exposure at the erythrocyte surface. Erythrocytes lack sphingosine phosphate-degrading enzymes and thus store large quantities of sphingosine phosphate. The present study explored the influence of sphingosine and sphingosine phosphate on eryptosis. [Ca(2+)](i), was estimated from Fluo3 fluorescence, cell volume from forward scatter and PS exposure from annexin V-binding in FACS analysis. Sphingosine (0.1 - 10 µM) but not sphingosine-1- phosphate (0.1 - 10 µM) increased [Ca(2+)](i), decreased cell volume and increased PS-exposure. The observations disclose sphingosine, but not sphingosine-1-phosphate, as a strong inducer of eryptosis.

Endothelin B receptor stimulation inhibits suicidal erythrocyte death.

Endothelins (ETs), potent endothelium-derived mediators, stimulate formation of nitric oxide, which, in turn, protects against suicidal erythrocyte death or eryptosis, characterized by phosphatidylserine exposure at the erythrocyte surface and triggered by increase in cytosolic Ca(2+) ([Ca(2+)](i)). The present study explored whether the ET1-receptor ETB influences suicidal erythrocyte death. To this end, [Ca(2+)](i) (Fluo3-fluorescence) and phosphatidylserine exposure (annexin V-binding) were determined utilizing FACS analysis. Energy depletion increased [Ca(2+)](i) and phosphatidylserine-exposure, effects significantly blunted by ET1 (IC(50) approximately 100 nM) and the ETB receptor-agonist sarafotoxin 6c (IC(50) approximately 10 nM) but not by ET2 and ET3. ET1 and sarafotoxin significantly delayed the kinetics of suicidal erythrocyte death following energy depletion. ETB stimulation did not blunt the effect of Ca(2+)-ionophore ionomycin (1 microM) on phosphatidylserine exposure. The in vivo significance was tested using rescued ETB-knockout (etb(-/-)) and wild-type (etb(+/+)) mice. The number of phosphatidylserine-exposing erythrocytes, of reticulocytes and spleen size were significantly larger in etb(-/-) mice than in etb(+/+)-mice. The etb(-/-) erythrocytes were more susceptible to the eryptotic effect of oxidative stress and more rapidly cleared from circulating blood than etb(+/+) erythrocytes. Finally, the spleens from etb(-/-) mice were enlarged and contained markedly more phosphatidylserine-exposing erythrocytes than spleens from etb(+/+) mice. The observations disclose a novel function of ET1, i.e., protection from suicidal erythrocyte death.

SIRT3 overexpression and epigenetic silencing of catalase regulate ROS accumulation in CLL cells activating AXL signaling axis.

Mitochondrial metabolism is the key source for abundant ROS in chronic lymphocytic leukemia (CLL) cells. Here, we detected significantly lower superoxide anion (O2-) levels with increased accumulation of hydrogen peroxide (H2O2) in CLL cells vs. normal B-cells. Further analysis indicated that mitochondrial superoxide dismutase (SOD)2, which converts O2- into H2O2 remained deacetylated in CLL cells due to SIRT3 overexpression resulting its constitutive activation. In addition, catalase expression was also reduced in CLL cells suggesting impairment of H2O2-conversion into water and O2 which may cause H2O2-accumulation. Importantly, we identified two CpG-islands in the catalase promoter and discovered that while the distal CpG-island (-3619 to -3765) remained methylated in both normal B-cells and CLL cells, variable degrees of methylation were discernible in the proximal CpG-island (-174 to -332) only in CLL cells. Finally, treatment of CLL cells with a demethylating agent increased catalase mRNA levels. Functionally, ROS accumulation in CLL cells activated the AXL survival axis while upregulated SIRT3, suggesting that CLL cells rapidly remove highly reactive O2- to avoid its cytotoxic effect but maintain increased H2O2-level to promote cell survival. Therefore, abrogation of aberrantly activated cell survival pathways using antioxidants can be an effective intervention in CLL therapy in combination with conventional agents.

Trispecific CD19-CD20-CD22-targeting duoCAR-T cells eliminate antigen-heterogeneous B cell tumors in preclinical models.

A substantial number of patients with leukemia and lymphoma treated with anti-CD19 or anti-CD22 monoCAR-T cell therapy relapse because of antigen loss or down-regulation. We hypothesized that B cell tumor antigen escape may be overcome by a chimeric antigen receptor (CAR) design that simultaneously targets three B cell leukemia antigens. We engineered trispecific duoCAR-T cells with lentiviral vectors encoding two CAR open reading frames that target CD19, CD20, and CD22. The duoCARs were composed of a CAR with a tandem CD19- and CD20-targeting binder, linked by the P2A self-cleaving peptide to a second CAR targeting CD22. Multiple combinations of intracellular T cell signaling motifs were evaluated. The most potent duoCAR architectures included those with ICOS, OX40, or CD27 signaling domains rather than those from CD28 or 4-1BB. We identified four optimal binder and signaling combinations that potently rejected xenografted leukemia and lymphoma tumors in vivo. Moreover, in mice bearing a mixture of B cell lymphoma lines composed of parental triple-positive cells, CD19-negative, CD20-negative, and CD22-negative variants, only the trispecific duoCAR-T cells rapidly and efficiently rejected the tumors. Each of the monoCAR-T cells failed to prevent tumor progression. Analysis of intracellular signaling profiles demonstrates that the distinct signaling of the intracellular domains used may contribute to these differential effects. Multispecific duoCAR-T cells are a promising strategy to prevent antigen loss-mediated relapse or the down-regulation of target antigen in patients with B cell malignancies.