Evaluation of Clan CD C11 peptidase PNT1 and other Leishmania mexicana cysteine peptidases as potential drug targets

Leishmania mexicana is one of the causative agents of cutaneous leishmaniasis in humans. There is anurgent need to identify new drug targets to combat the disease. Cysteine peptidases play crucial role inpathogenicity and virulence in Leishmania spp. and are promising targets for developing new antileishmanialdrugs. Genetic drug target validation has been performed on a number of cysteinepeptidases, but others have yet to be characterized. We targeted 16 L. mexicana cysteine peptidasesfor gene deletion and tagging using CRISPR-Cas9 in order to identify essential genes and ascertaintheir cellular localization. Our analysis indicates that two clan CA, family C2 calpains (LmCAL27.1,LmCAL31.6) and clan CD, family C11 PNT1 are essential for survival in the promastigote stage. Theother peptidases analysed, namely calpains LmCAL4.1, LmCAL25.1, and members of clan CA C51,C78, C85 and clan CP C97 were found to be non-essential. We generated a gene deletion mutant(Δpnt1) which was severely compromised in its cell growth and a conditional gene deletion mutant ofPNT1 (Δpnt1:: PNT1flox/Δ pnt1::HYG [SSU DiCRE]). PNT1 localizes to distinct foci on the flagellumand on the surface of the parasite. The conditional gene deletion of PNT1 induced blebs and pits onthe cell surface and eventual cell death. Over-expression of PNT1, but not an active site mutantPNT1C134A, was lethal, suggesting that active PNT1 peptidase is required for parasite survival.Overall, our data suggests that PNT1 is an essential gene and one of a number of cysteine peptidasesthat are potential drug targets in Leishmania

Pulmonary Edema in Myasthenic Crisis

We report a previously asymptomatic 50-year-old lady who came with myasthenic crisis as initial presentation of myasthenia gravis. She developed pulmonary edema following intravenous immunoglobulin administration and had ischemic changes in ECG and left ventricular dysfunction on echocardiography. She improved with diuretics, dobutamine, and fluid restriction alone. This is the first report in English-language medical literature describing the association between myasthenic crisis and likely takotsubo cardiomyopathy-related pulmonary edema following intravenous immunoglobulin administration.</jats:p

The Nlrp3 inflammasome regulates acute graft-versus-host disease

The success of allogeneic hematopoietic cell transplantation is limited by acute graft-versus-host disease (GvHD), a severe complication accompanied by high mortality rates. Yet, the molecular mechanisms initiating this disease remain poorly defined. In this study, we show that, after conditioning therapy, intestinal commensal bacteria and the damage-associated molecular pattern uric acid contribute to Nlrp3 inflammasome-mediated IL-1β production and that gastrointestinal decontamination and uric acid depletion reduced GvHD severity. Early blockade of IL-1β or genetic deficiency of the IL-1 receptor in dendritic cells (DCs) and T cells improved survival. The Nlrp3 inflammasome components Nlrp3 and Asc, which are required for pro-IL-1β cleavage, were critical for the full manifestation of GvHD. In transplanted mice, IL-1β originated from multiple intestinal cell compartments and exerted its effects on DCs and T cells, the latter being preferentially skewed toward Th17. Compatible with these mouse data, increased levels of active caspase-1 and IL-1β were found in circulating leukocytes and intestinal GvHD lesions of patients. Thus, the identification of a crucial role for the Nlrp3 inflammasome sheds new light on the pathogenesis of GvHD and opens a potential new avenue for the targeted therapy of this severe complication

Effect of CO2 driven ocean acidification on calcification, physiology and ovarian cells of tropical sea urchin Salmacis virgulata – A microcosm approach

In the present study, we depict the structural modification of test minerals, physiological response and ovarian damage in the tropical sea urchin Salmacis virgulata using microcosm CO2 (Carbon dioxide) perturbation experiment. S. virgulata were exposed to hypercapnic conditions with four different pH levels using CO2 gas bubbling method that reflects ambient level (pH 8.2) and elevated pCO(2) scenarios (pH 8.0, 7.8 and 7.6). The variations in physical strength and mechanical properties of S. virgulata test were evaluated by thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction analysis and scanned electron microscopy analysis. Biomarker enzymes such as glutathione-S-transferase, catalase, acetylcholine esterase, lipid peroxidase and reduced glutathione showed physiological stress and highly significant (p < 0.01) towards pH 7.6 and 7.8 treatments. Ovarian cells were highly damaged at pH 7.6 and 7.8 treatments. This study proved that the pH level 7.6 and 7.8 drastically affect calcification, physiological response and ovarian cells in S. virgulata.University Grants Commission: India - New Zealand Educational Council 101-3/2014(IC

Locking CBL TKBD in its native conformation presents a novel therapeutic opportunity in mutant CBL-dependent leukemia

Casitas B-lineage lymphoma (CBL) is an E3 ubiquitin ligase critical for negatively regulating receptor protein tyrosine kinases (RTKs). Deleterious CBL mutants lose E3 activity, but act as adaptors that gain function to cause myeloproliferative neoplasms. Currently, there is no targeted treatment available for patients with CBL mutant-dependent disorders. By combining phage-display technology and structure-based optimization, we discovered CBLock, a nanomolar affinity peptide inhibitor, that binds the substrate-binding site of CBL's tyrosine kinase binding domain (TKBD). CBLock disrupts the interaction between CBL mutants and RTKs, thereby impairing RTK-mediated priming of adaptor function of CBL mutants and downstream signaling. Notably, CBLock binds TKBD without inducing conformational changes, thereby preserving its ligand-free native conformation. In contrast, when CBL binds RTK substrates, TKBD undergoes a conformational change. Maintaining the native CBL TKBD conformation was crucial for CBLock to inhibit proliferation, induce cell-cycle arrest, and promote apoptosis in leukemia cells harboring CBL mutations. In a mouse xenograft model of acute myeloid leukemia (AML), CBLock reduced tumor burden and improved survival rate. Moreover, CBLock inhibited the proliferation of cells derived from patients with CBL mutations. Therefore, inhibiting CBL TKBD in its native state presents a promising therapeutic opportunity in targeting mutant CBL-dependent leukemia

Spatial regulation of the glycocalyx component podocalyxin is a switch for prometastatic function

The glycocalyx component and sialomucin podocalyxin (PODXL) is required for normal tissue development by promoting apical membranes to form between cells, triggering lumen formation. Elevated PODXL expression is also associated with metastasis and poor clinical outcome in multiple tumor types. How PODXL presents this duality in effect remains unknown. We identify an unexpected function of PODXL as a decoy receptor for galectin-3 (GAL3), whereby the PODXL-GAL3 interaction releases GAL3 repression of integrin-based invasion. Differential cortical targeting of PODXL, regulated by ubiquitination, is the molecular mechanism controlling alternate fates. Both PODXL high and low surface levels occur in parallel subpopulations within cancer cells. Orthotopic intraprostatic xenograft of PODXL-manipulated cells or those with different surface levels of PODXL define that this axis controls metastasis in vivo. Clinically, interplay between PODXL-GAL3 stratifies prostate cancer patients with poor outcome. Our studies define the molecular mechanisms and context in which PODXL promotes invasion and metastasis

Hard Real-Time Delay (RTD) Estimation and Analysis for Safety-Critical System

Avionics embedded systems encapsulate the greater number of processing units that are completely under its control and with respect to the functional requirement very often they have strict timing analysis. The purpose of this work is to capture the timing analysis of the system-level data transfer using the AFDX format sending to the Multi-functional display computer, which has an IMA architecture. In the most recent years due to the strong partition of integrated modular avionics (IMA) architecture, they have been widely adopted in the field of avionics. In the development of avionics systems, although the architecture of IMA can achieve an effective reduction in cost and enhancement in reliability it results in less scheduling difficulty. So, even under the worst-case situations the deadlines of the IMA system should be meet and evaluation of the latency period has to obtain. The methodology involved for timing analysis is presented based on the case study carried out using visualsim simulation platform

Estimation of Macro-financial Linkages for the Indian Economy

The widespread impacts of global financial crisis (2008-09) reinstate the need for better assessment of the macro-financial linkages for forecasting and policy evaluation. Our paper contributes to the relevant literature with evidence from the Indian financial sector. Following Castelnuovo (2013), a New Keynesian model with macro-financial linkages is estimated by the Bayesian technique for the sample period 2004: Q3 to 2019: Q1. We find that, in an Emerging Market Economy like India, business cycle leads financial cycle through the channel of expectations. Further, our results show that the linkages are heterogeneous in size depending on the financial market segment and market-specific shocks. JEL Codes: C11, E44, G10 </jats:p