Role of plasma exchange in a post-partum case of severe thrombotic thrombocytopenic purpura with acute kidney injury.

Thrombotic thrombocytopenic purpura (TTP) is a life-threatening disease present with the classic pentad of microangiopathic hemolytic anemia (MAHA), fever, neurologic changes, thrombocytopenia, and renal dysfunction. In a diagnostic dilemma, therapeutic plasma exchange (TPE) is a choice of life-saving intervention. In this, we assess the efficacy of TPE in a suspected case of post-partum TTP. A 27 years old female was admitted in an emergency on day 8 after a lower segment cesarian section (LSCS) with unresponsive behavior for 3 days and with TTP. She was normal 32 days back with her second, 7-month pregnancy. Ultrasonography (USG) showed an umbilical cord around the neck of the baby. On the fifth post-operative day, she was shifted to emergency with fever, generalized anasarca, gastrointestinal tract (GI) bleeding, low platelet count, and low Hb, with a poor Glasgow coma scale (GCS) of 6. On the bases of serum urea and serum creatinine, she presented acute kidney injury with encephalopathy. At emergency, she was unresponsive to mechanical ventilation and supportive treatment; hence, therapeutic plasma exchange was performed. After eight TPE cycles, the patient presented with an improved hematological and renal profile with good GCS. TPE is helpful and life-saving for suspected TTP patients with AKI.

ORMDL3 regulates NLRP3 inflammasome activation by maintaining ER-mitochondria contacts in human macrophages and dictates ulcerative colitis patient outcome.

Genome-wide association studies in inflammatory bowel disease have identified risk loci in the orosomucoid-like protein 3/ORMDL sphingolipid biosynthesis regulator 3 (ORMDL3) gene to confer susceptibility to ulcerative colitis (UC), but the underlying functional relevance remains unexplored. Here, we found that a subpopulation of the UC patients who had higher disease activity shows enhanced expression of ORMDL3 compared to the patients with lower disease activity and the non-UC controls. We also found that the patients showing high ORMDL3 mRNA expression have elevated interleukin-1ß cytokine levels indicating positive correlation. Further, knockdown of ORMDL3 in the human monocyte-derived macrophages resulted in significantly reduced interleukin-1ß release. Mechanistically, we report for the first time that ORMDL3 contributes to a mounting inflammatory response via modulating mitochondrial morphology and activation of the NLRP3 inflammasome. Specifically, we observed an increased fragmentation of mitochondria and enhanced contacts with the endoplasmic reticulum (ER) during ORMDL3 over-expression, enabling efficient NLRP3 inflammasome activation. We show that ORMDL3 that was previously known to be localized in the ER also becomes localized to mitochondria-associated membranes and mitochondria during inflammatory conditions. Additionally, ORMDL3 interacts with mitochondrial dynamic regulating protein Fis-1 present in the mitochondria-associated membrane. Accordingly, knockdown of ORMDL3 in a dextran sodium sulfate -induced colitis mouse model showed reduced colitis severity. Taken together, we have uncovered a functional role for ORMDL3 in mounting inflammation during UC pathogenesis by modulating ER-mitochondrial contact and dynamics.

CLUH functions as a negative regulator of inflammation in human macrophages and determines ulcerative colitis pathogenesis.

Altered mitochondrial function without a well-defined cause has been documented in patients with ulcerative colitis (UC). In our efforts to understand UC pathogenesis, we observed reduced expression of clustered mitochondrial homolog (CLUH) only in the active UC tissues compared with the unaffected areas from the same patient and healthy controls. Stimulation with bacterial Toll-like receptor (TLR) ligands similarly reduced CLUH expression in human primary macrophages. Further, CLUH negatively regulated secretion of proinflammatory cytokines IL-6 and TNF-α and rendered a proinflammatory niche in TLR ligand-stimulated macrophages. CLUH was further found to bind to mitochondrial fission protein dynamin related protein 1 (DRP1) and regulated DRP1 transcription in human macrophages. In the TLR ligand-stimulated macrophages, absence of CLUH led to enhanced DRP1 availability for mitochondrial fission, and a smaller dysfunctional mitochondrial pool was observed. Mechanistically, this fissioned mitochondrial pool in turn enhanced mitochondrial ROS production and reduced mitophagy and lysosomal function in CLUH-knockout macrophages. Remarkably, our studies in the mouse model of colitis with CLUH knockdown displayed exacerbated disease pathology. Taken together, this is the first report to our knowledge explaining the role of CLUH in UC pathogenesis, by means of regulating inflammation via maintaining mitochondrial-lysosomal functions in the human macrophages and intestinal mucosa.

Modulations in human neutrophil metabolome and S-glutathionylation of glycolytic pathway enzymes during the course of extracellular trap formation.

Neutrophil extracellular trap formation (NETosis) has been irrefutably referred to as a distinct and unique form of active cell death with the purpose to counteract invading pathogens or augmenting the inflammatory cascade. Since the discovery, consistent efforts have been made to understand the various aspects of the initiation and sustenance of NETosis. In this study, using a global metabolomics approach during the phorbol 12-myristate 13-acetate (PMA) induced NETosis in human neutrophils, various metabolic pathways were found to be altered which includes intermediates related to, carbohydrate metabolism, and redox related metabolites, nucleic acid metabolism, and amino acids metabolism. Enrichment analysis of the metabolite sets highlighted the importance of the pentose phosphate pathway (PPP) and glutathione metabolism PMA-induced NETotic neutrophils. Further, analysis of the glutathyniolation status of neutrophil proteins by Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) indicated six different glutathionylated proteins: among them, two metabolically important proteins were α-enolase and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) with MALDI score 166 and 70 respectively. Other proteins were lactoferrin, ß-actin, c-myc promoter-binding protein, and uracil DNA glycosylase with MALDI scores of 96, 167, 104, and 68 respectively. Besides, activation of signalling proteins involved in metabolic regulation is also correlated with NETosis. Altogether, a balance between reactive oxygen species-glutathione metabolism seems to regulate the activity of glycolytic enzymes such as GAPDH and α-enolase during PMA-induced NETosis in a time-dependent manner.

An Imaging and Computational Algorithm for Efficient Identification and Quantification of Neutrophil Extracellular Traps.

Neutrophil extracellular traps (NETs) are associated with multiple disease pathologies including sepsis, asthma, rheumatoid arthritis, cancer, systemic lupus erythematosus, acute respiratory distress syndrome, and COVID-19. NETs, being a disintegrated death form, suffered inconsistency in their identification, nomenclature, and quantifications that hindered therapeutic approaches using NETs as a target. Multiple strategies including microscopy, ELISA, immunoblotting, flow cytometry, and image-stream-based methods have exhibited drawbacks such as being subjective, non-specific, error-prone, and not being high throughput, and thus demand the development of innovative and efficient approaches for their analyses. Here, we established an imaging and computational algorithm using high content screening (HCS)-cellomics platform that aid in easy, rapid, and specific detection as well as analyses of NETs. This method employed membrane-permeable and impermeable DNA dyes in situ to identify NET-forming cells. Automated algorithm-driven single-cell analysis of change in nuclear morphology, increase in nuclear area, and change in intensities provided precise detection of NET-forming cells and eliminated user bias with other cell death modalities. Further combination with Annexin V staining in situ detected specific death pathway, e.g., apoptosis, and thus, discriminated between NETs, apoptosis, and necrosis. Our approach does not utilize fixation and permeabilization steps that disturb NETs, and thus, allows the time-dependent monitoring of NETs. Together, this specific imaging-based high throughput method for NETs analyses may provide a good platform for the discovery of potential inhibitors of NET formation and/or agents to modulate neutrophil death, e.g., NETosis-apoptosis switch, as an alternative strategy to enhance the resolution of inflammation.

A preliminary experience of plasma exchange in liver failure.

INTRODUCTION: Plasma exchange (PLEX) is one of the experimental modalities of treatment for liver failure. We report our experience of PLEX in patients with acute-(ALF) or acute-on-chronic (ACLF) liver failure. METHODS: Hemodynamically stable adult patients with ALF or ACLF, encephalopathy, model for end-stage liver disease (MELD) score ≥ 15, and clinical worsening/no improvement after 72-h of inpatient care were included. PLEX cycles repeated every 48 h, each of 2.5-4.0 h duration with 1-1.5 times of estimated plasma volume, were given. PLEX cycle was repeated till either of the end-points were achieved (i) MELD < 20 for 48 h or reaches below the baseline, whichever is lower, (ii) completed three PLEX cycles, (iii) hemodynamic instability, (iv) or outcome achieved. Outcome of interest was categorized as favorable (discharged in stable condition) or unfavorable (death or discharge in moribund condition). Data are expressed as median (interquartile range). RESULTS: Sixteen patients (age 35 [27-48] years; male 8; ALF 5, ACLF 11; MELD 33 [27-37]; CLIF-SOFA 10 [8.5-12]) were included. Participants received 2 (1-3) cycles of PLEX during 13 (11-25) days of hospitalization. Overall, serum bilirubin, INR, creatinine, MELD, and CLIF-SOFA scores were significantly improved after PLEX. Five patients (5/16, 31%) had complete resolution of HE. Eight patients (50%) had a favorable outcome. Those with favorable outcome had significant improvement in serum bilirubin, INR, and CLIF-SOFA scores as compared to those with unfavorable outcome. CONCLUSION: PLEX may be effective in patients with ALF or ACLF. More data are needed to establish its role in the management of liver failure.

Therapeutic plasma exchange an emerging treatment modality: A 3-year retrospective analysis of patients admitted in a multispecialty hospital of North India.

BACKGROUND AND AIMS: Therapeutic plasma exchange (TPE) is increasingly used throughout the medical field. We aimed to analyze the various aspects of TPE practices at our hospital in terms of clinical indications, technical feasibility, safety, outcome as well as complications associated with the procedures. MATERIALS AND METHODS: The data included demographic profiles, clinical parameters, and technical characteristics of each TPE procedure. All the information was noted in data spread sheet (Microsoft Excel 2013) for further analysis. RESULTS: This is a 3-year retrospective study of total 266 TPE procedures carried out on 92 patients with different clinical conditions. Out of them, 55 (59.8%) were male and 37 (40.2%) were female patients. There were six major categories such as (1) neurological, (2) hematological, (3) gastrological, (4) renal, (5) rheumatic, and (6) others. The TPE treatment was highest in neurology group (60.2%), followed by gastrology group (24.4%). Most of the procedures (82.6%) were according to the American society of apheresis 2016 I or II categories (76/92 patients). CONCLUSION: TPE is beneficial and used as primary or secondary adjunctive therapy for a wide spectrum of various diseases and syndromes. TPE is considered as safe, cost-effective, and life-saving treatment modality in various diseases.

Expression of inducible NOS is indispensable for the antiproliferative and proapoptotic effect of imatinib in BCR-ABL positive cells.

Chronic myeloid leukemia (CML) is characterized by constitutive BCR-ABL kinase activity, an aggressive proliferation of immature cells, and reduced differentiation. Targeting tyrosine kinase activity of BCR-ABL with imatinib is an effective therapy for the newly diagnosed CML patients; however, 20%-30% of the patients initially treated with imatinib eventually experience treatment failure. Therefore, early identification of these patients is of high clinical relevance. In the present study, we by undertaking a direct comparison of inducible NOS (iNOS) status in neutrophils from healthy volunteers, newly diagnosed, imatinib responder, and resistant CML patients as well as by conducting in vitro studies in K562 cells demonstrated that inhibition of BCR-ABL by imatinib or siRNA significantly enhanced NO generation and iNOS expression. Indeed, patients exhibiting treatment failure or imatinib resistance were less likely to induce NO generation/iNOS expression. Our findings further demonstrated that imatinib mediated antiproliferative and proapoptotic effect in BCR-ABL+ cells associated with enhanced iNOS expression, and it was significantly prevented in the presence of L-NAME, 1400W, or iNOS siRNA. Overexpression of iNOS in K562 cells expectedly enhanced imatinib sensitivity on cytostasis and apoptosis, even at lower concentration (0.1 µM) of imatinib. Mechanistically, imatinib or BCR-ABL siRNA following deglutathionylation of NF-κB, enhanced its binding to iNOS promoter and induced iNOS transcription. Deglutathionylation of procaspase-3 however associated with increased caspase-3 activity and cell apoptosis. Taken together, results obtained suggest that monitoring NO/iNOS level could be useful to identify patients likely to be responsive or resistant to imatinib and can be used to personalized alternative therapy.

SARS-CoV-2 IgG Surveillance in Asymptomatic Blood Donors and Health Workers.

MATERIALS AND METHODS: 2085 blood donors were allowed to donate blood only after fulfilling all the criteria laid down by the FDA of India with additional history of excluding COVID-19 suspects. IgG antibody testing was performed by chemiluminescence, and results were noted along with their reactive status. Their reactive status was analyzed with donor information to get an idea of the risk parameters for COVID-19. Medical healthcare workers in whom the study was carried out were 560, out of which 114 had worked in COVID-19 duties and 446 had worked in non-COVID-19 emergencies areas. COVID-19 area duties were further subdivided into triage, holding area, isolation, and COVID-19-related duties. The samples were run on architect i2000 and evaluated for their plasma immunoglobulin G. RESULTS: Amongst the asymptomatic blood donors, 1.9% was found to be COVID-19 IgG antibody positive. It was observed that maximum COVID-19 IgG positivity (57.1%) was seen in the age group 18-29 years followed by 26.2% in the age group 30-39 years. Donors in the age group 40-49 years showed antibody positivity of 16.7%, and no antibody-positive donors were found above 50 years of age. COVID-19 IgG positivity was maximum in replacement donors (61.9%) followed by family donors (28.6%) and least involuntary donors (0.6%) Blood donors who showed high IgG positivity were mainly of labor class. Antibody IgG testing on medical healthcare workers showed 2.3% positivity. The healthcare workers who were posted in COVID-19 duties showed 4.8% positivity in the holding area (waiting area with the treatment of patients till their RT PCR report comes) and 5.7% in other COVID-19 areas related to laboratory work. Healthcare workers doing duties in COVID-19 areas showed 2.7% positivity, while those doing duties in non-COVID-19 emergency areas showed a positivity of 2.2%. CONCLUSION: Our study shows that the prevalence of detectable antibodies was low in the general population in India and many patients were asymptomatic as seen in the blood donors, especially the labor class. Maximum exposure was present in young healthy males of labor class who remained asymptomatic. The healthcare workers were more exposed to COVID-19 as compared to the general population probably due to lack of precaution and awareness. Those doing non-COVID-19 duties were also exposed appreciably and needed to take all the precautions required for COVID-19 duties.

Prevalence and predictors of adverse reactions in plateletpheresis donors with the perspective of donor safety in a tertiary care hospital of Northern India.

BACKGROUND: Plateletpheresis procedures are generally safe and associated with low adverse reactions. Although donor reactions and injuries are self-limited events, they may discourage donors from future platelet donations. AIM: The purpose of this study was to determine the prevalence and predictors of adverse donor reactions in plateletpheresis donors, which could serve as targets for interventions to reduce reactions. MATERIALS AND METHODS: The study included 106 platelet donors over a period of 2 years. The demographic, biometric, and clinical parameters were noted. The data were analyzed for predictors of adverse donor reactions. STATISTICAL ANALYSIS USED: The data were analyzed using independent sample t-test to correlate donor variables such as gender. To correlate other variables such as age, weight, and whole blood processed, Chi-square test was used. RESULTS: A total of 106 plateletpheresis donations were performed and 13.2% of vasovagal reactions were observed. The significant predictive factors for reactions were young female donors with low body weight in which more than 2.5 L volume of whole blood was processed and more than 250 ml of acid, citrate, and dextrose-A was infused and with single venous access procedures. CONCLUSIONS: The results of this study are encouraging and helpful in identifying donors at risk for developing adverse reactions during plateletpheresis so that proper and close observation during and after donation as well as timely intervention can prevent most of the unpleasant events of plateletpheresis donors.

Prevalence of red blood cell antibodies in whole blood donors: A single-centre experience in north India.

Background & objectives: Blood transfusion therapy involves multiple steps to ensure selection of safe blood component for transfusion. This includes testing for infectious markers, full ABO compatibility, free from any clinically significant red cell antibodies and acceptable donor's red cell survival rates without destruction of recipient's red cells. The red cell antibodies present in healthy blood donors can cause severe haemolytic transfusion reaction, especially in massive blood transfusion recipients and paediatric patients. Hence, screening of red cell antibodies in donor blood is important to provide compatible blood products and to avoid haemolytic transfusion reactions in susceptible patient population. This study was planned to assess prevalence, aetiology and type of unexpected red cell antibodies in a large number of whole blood donor population in north India. Methods: This three-year prospective observational study included blood donor samples for antibody screening from January 2015 to December 2017. A total of 166,803 healthy blood donors including 156,128 (93.6%) males and 10,675 (6.4%) females were screened. Results: The prevalence of red cell antibodies was 0.17 per cent in our donor population. Of the total 286 donors with red cell antibodies, 248 (86.7%) had alloantibodies, 30 (10.5%) had autoantibodies and eight donors (2.8%) showed positive antibody screening with inconclusive results. Interpretation & conclusions: Alloimmunization to red cell antigens is a challenging task for current transfusion practices. The antibody screening in blood donors may improve the quality and safety of blood transfusion in the recipients. It also reduces the risk of complications from incompatible blood transfusions.

Role of pyruvate kinase M2 in oxidized LDL-induced macrophage foam cell formation and inflammation.

Pyruvate kinase M2 (PKM2) links metabolic and inflammatory dysfunction in atherosclerotic coronary artery disease; however, its role in oxidized LDL (Ox-LDL)-induced macrophage foam cell formation and inflammation is unknown and therefore was studied. In recombinant mouse granulocyte-macrophage colony-stimulating factor-differentiated murine bone marrow-derived macrophages, early (1-6 h) Ox-LDL treatment induced PKM2 tyrosine 105 phosphorylation and promotes its nuclear localization. PKM2 regulates aerobic glycolysis and inflammation because PKM2 shRNA or Shikonin abrogated Ox-LDL-induced hypoxia-inducible factor-1α target genes lactate dehydrogenase, glucose transporter member 1, interleukin 1ß (IL-1ß) mRNA expression, lactate, and secretory IL-1ß production. PKM2 inhibition significantly increased Ox-LDL-induced ABCA1 and ABCG1 protein expression and NBD-cholesterol efflux to apoA1 and HDL. PKM2 shRNA significantly inhibited Ox-LDL-induced CD36, FASN protein expression, DiI-Ox-LDL binding and uptake, and cellular total cholesterol, free cholesterol, and cholesteryl ester content. Therefore, PKM2 regulates lipid uptake and efflux. DASA-58, a PKM2 activator, downregulated LXR-α, ABCA1, and ABCG1, and augmented FASN and CD36 protein expression. Peritoneal macrophages showed similar results. Ox-LDL induced PKM2- SREBP-1 interaction and FASN expression in a PKM2-dependent manner. Therefore, this study suggests a role for PKM2 in Ox-LDL-induced aerobic glycolysis, inflammation, and macrophage foam cell formation.

Therapeutic plasma exchange: A life-saving modality in Wegener's granulomatosis.

We report a case of Wegener's granulomatosis (WG) who very well responded to the combination strategy of therapeutic plasma exchange (TPE) and immunosuppression. The patient was a 38-year-old female, diagnosed with severe form of WG. A total of seven cycles was performed with 1.3 total plasma volumes (TPVs) on every alternate day. Standard induction therapy was also started that comprised of a combination of 500 mg intravenous (i.v.) cyclophosphamide and methylprednisolone 1 g slow i.v. daily for 3 days followed by oral prednisolone 60 mg daily for 4 weeks. After seven cycles of TPE, the patient improved and hence TPE was stopped.

Catalase S-Glutathionylation by NOX2 and Mitochondrial-Derived ROS Adversely Affects Mice and Human Neutrophil Survival.

Neutrophil survival and oxidative stress during inflammatory conditions are linked to tissue damage. The present study explores less understood role of catalase, the enzyme catalysing hydrogen peroxide decomposition, in neutrophil survival/death. Importantly, inhibition of catalase activity following S-glutathionylation in the PMA, NO, or zymosan-activated neutrophils or treatment with catalase inhibitor led to neutrophil death. On the contrary, introducing reducing environment by TCEP rescued catalase activity and significantly improved neutrophil survival. Furthermore, augmentation in ROS generation by NOX-2 activation or induction of mitochondrial ROS by Antimycin-A induced catalase S-glutathionylation and cell death, which was prevented in the neutrophil cytosolic factor1 (NCF-1-/-) cells or was rescued by MitoTEMPO, a mitochondrial ROS scavenger, thus, suggesting a correlation between catalase S-glutathionylation/activity inhibition and reduced neutrophil survival. Altogether, enhanced NOX2 activation/mitochondrial dysfunction led to reduced survival of human and mice neutrophils, due to H2O2 accumulation, S-glutathionylation of catalase, and reduction in its enzymatic activity. The present study thus demonstrated mitigation of catalase activity under oxidative stress-impacted neutrophil survival.

Glycolysis dependent lactate formation in neutrophils: A metabolic link between NOX-dependent and independent NETosis.

Neutrophil extracellular traps (NETs) play a pivotal role in the innate immune defense, as well as in the pathophysiology of various inflammatory disease conditions. Two major types of NETosis have been described - NOX-dependent and independent. The present study was undertaken to assess metabolic requirements of NETs formation by using PMA and A23187 as the inducers of NOX-dependent and NOX-independent NETosis respectively. Both these inducers caused an increase in ECAR, lactate dehydrogenase (LDH) activity, PKM2 dimerization and reduction in pyruvate kinase M2 (PKM2) activity, promoting lactate formation through Warburg effect. Interestingly exogenous treatment with lactate also induced NETs formation in human neutrophils, while inhibition of LDH activity significantly reduced NETosis by both the pathways. Moreover, NETosis and lactate accumulation during LPS induced sepsis in mice was inhibited by sodium oxamate, LDH inhibitor, demonstrating the importance of lactate in an experimental model of NETosis. Present study thus confirms importance of glycolysis in NETosis and also reveals role of lactate in NETs formation. It also reports sharing of the common metabolic pathway by NOX-dependent and independent NETosis.

Correction to: The IRAK-ERK-p67phox-Nox-2 axis mediates TLR4, 2-induced ROS production for IL-1ß transcription and processing in monocytes.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Level of hyperlipidemia in blood donors: A correlative study in North Indian population.

BACKGROUND: Hyperlipidemia can be caused by abnormal elevation of lipids and lipoproteins in the blood. This increased can lead to heart disease. Risks which can be controlled include alcohol intake, physical activity, smoking, high blood pressure and genetic factors. Markers of increased cardiovascular risk appear to be lower in regular blood donor compared with single time donors as reflected by significantly lower total cholesterol and LDL levels. And it has been thought that there will be a direct relationship between lower risks of Heart diseases with repeated blood donation. AIM: The aim of the present study is to determine the effect of blood donation on single time and repeat donors by assessing their lipid levels and their family history of heart diseases. MATERIAL & METHODS: This cross-sectional study was carried out on (n = 80) random blood donors from the department of Transfusion Medicine KGMU. RESULTS: A significant correlation was found amongst hyperlipidemic level in single time donor & repeat donors and in donors with family history of heart diseases (p < 0.05). A positive association was found between hyperlipidemia with donor's weight (p < 0.05). CONCLUSION: Screening random donor platelets for hyperlipidemia and correlating the condition with other donor criteria like family history of heart diseases, types of donors, donors weight age and gender will help in making the patients safe as well as the donor deferral criteria more stringent to improve the quality of blood supply and will enable blood bankers to supply safe blood and improve the guidelines for blood safety.

L-Arginine and tetrahydrobiopterin supported nitric oxide production is crucial for the microbicidal activity of neutrophils.

Recent report from this lab has shown role of Rac2 in the translocation of inducible nitric oxide synthase (iNOS) to the phagosomal compartment of polymorphonuclear leukocytes (PMNs) following phagocytosis of beads. This study was undertaken to further assess the status and role of tetrahydrobiopterin (BH4), a redox-sensitive cofactor, L-arginine, and the substrate of nitric oxide synthase (NOS) in sustained nitric oxide (˙NO) production in killing of phagocytosed microbes (Escherichia coli) by human PMNs. Time-dependent study revealed consistent NO and reactive oxygen species (ROS) production in the PMNs following phagocytosis of beads. In addition, levels of L-arginine and BH4 were maintained or increased simultaneously to support the enzymatic activity of NOS in the bead activated PMNs. Moreover, translocation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) subunits along with iNOS was reconfirmed in the isolated phagosomes. We demonstrate that increase in the level of NO was supported by L-arginine and BH4 to kill E. coli, by using PMNs from NOS2-/- mice, human PMNs treated with biopterin inhibitor, N-acetyl serotonin (NAS), or by suspending human PMNs in L-arginine deficient medium. Altogether, this study demonstrates that following phagocytosis, sustained. NO production in the PMNs was well-maintained by redox sensitive cofactor, BH4 and substrate, and L-arginine to enable microbial killing. Further results suggest NO production in the human PMNs, along with ROS and myeloperoxidase (MPO) is important to execute antimicrobial activity.

Effectiveness of bone marrow-derived mononuclear stem cells for neurological recovery in participants with spinal cord injury: A randomized controlled trial.

BACKGROUND: Complete lesion after spinal cord injury (SCI) remains irreversible with little hope of neurological recovery. Newer interventions such as re-stimulation of damaged neurons using artificial agents and the use of stem cells for neuronal regeneration have shown promising results. AIM: This study was undertaken for evaluating the neurological status of acute SCI participants after stem cell augmentation and comparing them with other treatment methods. SETTING AND DESIGN: Randomized controlled trial in the northern Indian population. MATERIALS AND METHODS: A total 193 SCI participants of complete paraplegia with unstable T4-L2 injury having thoracolumbar injury severity score ≥4 were enrolled in this study. Participants were randomly allocated for three different treatment modalities, namely, conventional with stem cell augmentation (Group-1), conventional (Group-2), and conservative (Group-3). Neurological recovery after 1 year was evaluated through the ASIA Impairment Scale (AIS)-grading, sensory, and motor scores. STATISTICAL ANALYSIS: T-test for sensory-motor score analysis of each group and analysis of variance for comparison of same variables between the groups. RESULTS: After 1-year significant difference was observed in the AIS-grade, sensory and motor scores in-Group 1 (P < 0.001). In Group-1 versus 2, the mean difference at 1 year for AIS grade, sensory and motor scores were 0.40 (P = 0.010, 95% confidence interval [CI] 0.075-0.727), 8.52 (P = 0.030, 95% CI 0.619-16.419), and 4.55(P = 0.003, 95% CI 1.282-7.815), respectively. In Group-1 versus 3, 1.03, 19.02 and 7.22 (P < 0.001 for each of the parameters) and in Group-2 versus 3, 0.63 (P < 0.001), 10.49 (P = 0.009), and 2.68 (P = 0.019), respectively. CONCLUSIONS: Significant motor neurological recovery and AIS-grade promotion was observed in Group-1 as compared to Group-2 and 3.

S-Glutathionylation of p47phox sustains superoxide generation in activated neutrophils.

Post-translational modifications (PTMs) induced conformational changes of proteins can cause their activation or inactivation. Neutrophils clear pathogen through phagocytosis and oxidative burst generation, while participate in inflammation through sustained and uncontrolled generation of ROS. In activated PMNs, cytosolic NOX-2 subunit p47phox following phosphorylation interacts with p67phox, p40phox and along with Rac2 translocate to the membrane. Phosphorylation of p47phox subunit occurs in both short spurts as well as sustained ROS generation, suggesting towards the unidentified molecular mechanism(s) driving these two diverse outcomes by various stimuli. The present study demonstrates that in PMA or NO treated neutrophils a subunit of NOX2, p47phox gets glutathionylated to sustain ROS generation along with a decrease in catalase, Grx-1 activity and change in GSH/GSSG ratio. Surprisingly, fMLP treated cells neither showed sustained ROS production nor glutathionylation of p47phox. S-Glutathionylation was always secondary to phosphorylation of p47phox and inhibition of glutathionylation did not alter phosphorylation but specifically impaired sustained ROS production. Interestingly, forced S-glutathionylation of p47phox converted the fMLP induced ROS generation into sustained release of ROS. We then identified the glutathionylation susceptible cysteine residues of p47phox by LC-MS/MS with IAM switch mapping. Site-directed mutagenesis of cysteine residues further mitigated p47phox S-glutathionylation. Thus, we demonstrate that p47phox S-glutathionylation plays an essential key role in the sustained ROS generation by human neutrophils.