Human antigen R transfers miRNA to Syntaxin 5 to synergize miRNA export from activated macrophages

Intercellular miRNA exchange acts as a key mechanism to control gene expression post-transcriptionally in mammalian cells. Regulated export of repressive miRNAs allows the expression of inflammatory cytokines in activated macrophages. Intracellular trafficking of miRNAs from the endoplasmic reticulum to endosomes is a rate-determining step in the miRNA export process and plays an important role in controlling cellular miRNA levels and inflammatory processes in macrophages. We have identified the SNARE protein Syntaxin 5 (STX5) to show a synchronized expression pattern with miRNA activity loss in activated mammalian macrophage cells. STX5 is both necessary and sufficient for macrophage activation and clearance of the intracellular pathogen Leishmania donovani from infected macrophages. Exploring the mechanism of how STX5 acts as an immunostimulant, we have identified the de novo RNA-binding property of this SNARE protein that binds specific miRNAs and facilitates their accumulation in endosomes in a cooperative manner with human ELAVL1 protein, Human antigen R. This activity ensures the export of miRNAs and allows the expression of miRNA-repressed cytokines. Conversely, in its dual role in miRNA export, this SNARE protein prevents lysosomal targeting of endosomes by enhancing the fusion of miRNA-loaded endosomes with the plasma membrane to ensure accelerated release of extracellular vesicles and associated miRNAs.

HuR-miRNA complex activates RAS GTPase RalA to facilitate endosome targeting and extracellular export of miRNAs

Extracellular vesicles-mediated exchange of miRNA cargos between diverse types of mammalian cells is a major mechanism of controlling cellular miRNA levels and activity, thus regulating the expression of miRNA-target genes in both donor and recipient cells. Despite tremendous excitement related to extracellular vesicles-associated miRNAs as biomarkers or having therapeutic potential, the mechanism of selective packaging of miRNAs into endosomes and multivesicular bodies for subsequent extracellular export is poorly studied due to the lack of an in vitro assay system. Here, we have developed an in vitro assay with endosomes isolated from mammalian macrophage cells to follow miRNA packaging into endocytic organelles. The synthetic miRNAs, used in the assay, get imported inside the isolated endosomes during the in vitro reaction and become protected from RNase in a time- and concentration-dependent manner. The selective miRNA accumulation inside endosomes requires both ATP and GTP hydrolysis and the miRNA-binding protein HuR. The HuR-miRNA complex binds and stimulates the endosomal RalA GTPase to facilitate the import of miRNAs into endosomes and their subsequent export as part of the extracellular vesicles. The endosomal targeting of miRNAs is also very much dependent on the endosome maturation process that is controlled by Rab5 protein and ATP. In summary, we provide an in vitro method to aid in the investigation of the mechanism of miRNA packaging process for its export from mammalian macrophage cells.

Subcutaneous Administration of Monoclonal Antibodies: Pharmacology, Delivery, Immunogenicity, and Learnings From Applications to Clinical Development

Subcutaneous (s.c.) administration of monoclonal antibodies (mAbs) can reduce treatment burden for patients and healthcare systems compared with intravenous (i.v.) infusion through shorter administration times, made possible by convenient, patient-centric devices. A deeper understanding of clinical pharmacology principles related to efficacy and safety of s.c.-administered mAbs over the past decade has streamlined s.c. product development. This review presents learnings from key constituents of the s.c. mAb development pathway, including pharmacology, administration variables, immunogenicity, and delivery devices. Restricted mAb transportation through the hypodermis explains their incomplete absorption at a relatively slow rate (pharmacokinetic (PK)) and may impact mAb-cellular interactions and/or onset and magnitude of physiological responses (pharmacodynamic). Injection volumes, formulation, rate and site of injection, and needle attributes may affect PKs and the occurrence/severity of adverse events like injection-site reactions or pain, with important consequences for treatment adherence. A review of immunogenicity data for numerous compounds reveals that incidence of anti-drug antibodies (ADAs) is generally comparable across i.v. and s.c. routes, and complementary factors including response magnitude (ADA titer), persistence over time, and neutralizing antibody presence are needed to assess clinical impact. Finally, four case studies showcase how s.c. biologics have been clinically developed: (i) by implementation of i.v./s.c. bridging strategies to streamline PD-1/PD-L1 inhibitor development, (ii) through co-development with i.v. presentations for anti-severe acute respiratory syndrome-coronavirus 2 antibodies to support rapid deployment of both formulations, (iii) as the lead route for bispecific T cell engagers (BTCEs) to mitigate BTCE-mediated cytokine release syndrome, and (iv) for pediatric patients in the case of dupilumab.

Oxygen vacancy-enriched Zn2SnO4 for aliphatic alcohol sensing and enhanced selectivity towards n-butanol

The sensitive detection of toxic flammable volatile organics using low cost efficient sensors is important for ensuring both indoor and outdoor safety. It is essential for chemical sensors to exhibit a significantly stronger response to target analytes compared to equivalent amounts of analogous competing chemicals. In line with this importance, current work evaluated the performance of Zn2SnO4, a n-type semiconducting metal oxide, for sensing n-butanol in comparison to methanol, ethanol, and propanol vapours. These vapours fall within the category of aliphatic alcohols but vary in characteristics such as molecular weight, vapour pressure, volatility, and diffusivity. In this work we have explored the sensor's performance by adjusting the operating temperature over the range of 225-300 °C while detecting 1000 ppm of each of these vapours. Efforts were made to establish a correlation between the sensor's responses with the interactions of these vapours on the sensor's surface. Prior to assessing the sensing characteristics of the solid-state-route-derived Zn2SnO4, its structural characteristics, including phase purity, crystalline structure, bonding patterns, morphology, and defect characteristics, were studied. This comprehensive analysis sheds light on the potential of Zn2SnO4 as an effective sensor for detecting n-butanol.

Probing the p-type Chemiresistive Response of NiFe2 O4 Nanoparticles for Potential Utilization as Ethanol Sensor

Detection of gas molecules and volatile organic compounds (VOCs) using efficient, low cost sensors has fetched significant attention in environmental monitoring, safety measures and medical diagnosis. In the present work, nickel ferrite (NFO) nanoparticles are explored as p-type semiconducting metal oxide (SMO) sensor for detection of five different organic vapors namely methanol, ethanol, n-propanol, iso-propanol and acetone which often cause severe damage to human body under prolonged exposure. The sensing studies in presence of the aforementioned five vapors are carried out by varying the sensor operating temperature (225-300 °C) and vapor concentrations (10-1000 ppm). Developed NFO sensor demonstrated best performance in terms of sensing (~10 ppm), response time (<10 s), excellent repeatability and selectivity towards ethanol among all other considered gas species. The repeatability of the sensor response is verified and the underlying reasons for the variation in the response of NFO sensor due to the change of operating temperature, analyte type and concentrations has been discussed. The synthesis of NFO through auto combustion method and study on their formation behaviour, oxygen vacancy evolution, band gap calculation, crystalline nature as well as microstructural features provides here the comprehensive information about the potential application of NFO nanoparticles as gas sensor.

The D2D3 form of uPAR acts as an immunotoxin and may cause diabetes and kidney disease

Soluble urokinase plasminogen activator receptor (suPAR) is a risk factor for kidney diseases. In addition to suPAR, proteolysis of membrane-bound uPAR results in circulating D1 and D2D3 proteins. We showed that when exposed to a high-fat diet, transgenic mice expressing D2D3 protein developed progressive kidney disease marked by microalbuminuria, elevated serum creatinine, and glomerular hypertrophy. D2D3 transgenic mice also exhibited insulin-dependent diabetes mellitus evidenced by decreased levels of insulin and C-peptide, impaired glucose-stimulated insulin secretion, decreased pancreatic β cell mass, and high fasting blood glucose. Injection of anti-uPAR antibody restored β cell mass and function in D2D3 transgenic mice. At the cellular level, the D2D3 protein impaired β cell proliferation and inhibited the bioenergetics of β cells, leading to dysregulated cytoskeletal dynamics and subsequent impairment in the maturation and trafficking of insulin granules. D2D3 protein was predominantly detected in the sera of patients with nephropathy and insulin-dependent diabetes mellitus. These sera inhibited glucose-stimulated insulin release from human islets in a D2D3-dependent manner. Our study showed that D2D3 injures the kidney and pancreas and suggests that targeting this protein could provide a therapy for kidney diseases and insulin-dependent diabetes mellitus.

Accelerated export of Dicer1 from lipid-challenged hepatocytes buffers cellular miRNA-122 levels and prevents cell death

Hepatocytes on exposure to high levels of lipids reorganize the metabolic program while fighting against the toxicity associated with elevated cellular lipids. The mechanism of this metabolic reorientation and stress management in lipid-challenged hepatocytes has not been well explored. We have noted the lowering of miR-122, a liver-specific miRNA, in the liver of mice fed with either a high-fat diet or a methionine-choline-deficient diet that is associated with increased fat accumulation in mice liver. Interestingly, low miR-122 levels are attributed to the enhanced extracellular export of miRNA processor enzyme Dicer1 from hepatocytes in the presence of high lipids. Export of Dicer1 can also account for the increased cellular levels of pre-miR-122-the substrate of Dicer1. Interestingly, restoration of Dicer1 levels in the mouse liver resulted in a strong inflammatory response and cell death in the presence of high lipids. Increasing death of hepatocytes was found to be caused by increased miR-122 levels in hepatocytes restored for Dicer1. Thus, the Dicer1 export by hepatocytes seems to be a key mechanism to combat lipotoxic stress by shunting out miR-122 from stressed hepatocytes. Finally, as part of this stress management, we determined that the Ago2-interacting pool of Dicer1, responsible for mature microribonucleoprotein formation in mammalian cells, gets depleted. miRNA-binder and exporter protein HuR is found to accelerate Ago2-Dicer1 uncoupling to ensure export of Dicer1 via extracellular vesicles in lipid-loaded hepatocytes.

Evidence of charge susceptibility and multiplef-chybridization configurations with the La doping in CeGe: a DFT + DMFT study

Kondo coupling has been extensively investigated in several Ce-based systems. However, the search for materials showing the interplay between the Kondo effect, spin-orbit interaction, and crystal-field effect along with the presence of local charge susceptibility; remains a challenge for the condensed matter community. Actually, in Ce-based systems, the strong coupling of the conduction electrons to the local magnetic moments usually hides these properties. Here, we present a detailed investigation of Ce_0.6La_0.4Ge through a combined density functional theory and dynamic mean-field theory study. Our investigations give evidence of the significant charge susceptibility and the multiple differentf-chybridization configurations. The weakening of the magnetization owing to the dilution of the Ce-site is the main cause for the appearance of such properties, which is believed to occur due to the presence of the relevant local moment andf-chybridization over the competition with the on-site Coulomb interaction.

Evidence of multi-band superconductivity in non-centrosymmetric full Heusler alloy LuPd2Sn

In this work, evidence of multi-band superconductivity and presence of mixed parity states in full Heusler alloy LuPd₂Sn is investigated using the x-ray diffraction, temperature and field dependent resistivity, temperature dependent magnetization, and heat capacity measurements. Our studies reveal that LuPd₂Sn is a type II superconductor and undergoes superconducting transition below 2.5 K. Above 2.5 K, the temperature and field dependence of resistivity indicate to the presence of multiple bands and inter-band phonon assisted scattering. The upper critical field,H_C2(T) exhibits linear behaviour and deviates from Werthamer, Helfand and Hohenberg model over the measured temperature range. Additionally, the Kadowaki-Woods ratio plot supports the unconventional superconductivity in this alloy. Moreover, a significant deviation from the s-wave behaviour is noted, which is studied using phases fluctuation analysis. It indicates the presence of spin triplet along with spin singlet component arising due to antisymmetric spin orbit coupling.

A plausible investigation of low dimensional magnetism in a 3D spin system PrVO4

3D spin systems provide an important platform to investigate the novel magnetic behaviors, which arise due to the complex network of spins in such materials. In this context, we have studied a rare-earth orthovanadate PrVO₄, in which the distorted PrO₈ polyhedral results in complex spin geometries made by the near neighbor Pr atoms. The fourth near neighbor Pr atoms form linear chains, which are separated by non-magnetic VO₄ tetrahedra. DC magnetic susceptibility reveals a broad maximum and its position remains unaltered under applied magnetic field. The magnetic heat capacity shows a broad maximum with almost zero value at low temperatures. This indicates the presence of spin gap in the excitation spectra and hints toward the possibility of low dimensional magnetism. Our investigations reveal that PrVO₄ can be a potential candidate to study low dimensional magnetism in rare-earth-based systems.

Evolution of field induced magnetic phase attributed to higher order magnetic moments in TbVO4

Study of quantum magnetism in rare earth orthovanadates (RVO₄, R = rare earth) is a topic which is currently being investigated by the condensed matter physicists. In this work, through both experimental and theoretical tools, we report the presence of field induced magnetic phase, attributed to fifth order susceptibility, in TbVO₄, at low temperatures. The structural transition reported around 31 K, results in the formation of pseudospin-[Formula: see text] doublet ground state separated by an energy δ. Temperature dependent heat capacity indicates toward an increment in δ, on application of magnetic fields. Above 10 kOe, the Zeeman energy associated with magnetic anisotropy strengthens, resulting in an enhanced splitting of the pseudo-doublet ground state. This increased splitting stabilizes the magnetic phase associated with higher order moments. These observations are further supported by our theoretical model to evaluate δ, as a function of applied field. Our study provides a platform to study the possible presence of higher order moments in other Jahn-Teller systems.

Possible realization of three-dimensional quantum spin liquid behavior in HoVO4

The study of geometrically frustrated magnetic systems with unusual crystal field ground states offers a possibility of realizing the new aspects of physics of disordered systems. In this study, we report our results of structural, magnetic susceptibility, heat capacity measurements, along with density functional theory (DFT) calculations on HoVO₄; a compound in which the presence of a distorted kind of HoO₈polyhedral leads to multiple magnetic interaction paths. The observed broad maximum below 10 K in the temperature response of DC susceptibility curves implies the presence of short-range correlations. AC susceptibility rules out the possibility of any kind of spin freezing. Temperature dependent heat capacity measurement at zero field indicate towards the absence of long-range ordering, along with the presence of a broad maximum centered around 14 K. The residual heat capacity exhibits a characteristic power-law (T^α) behavior with the exponentαnearly equal to 2, which is analogous to that observed for other three-dimensional (3D) quantum spin liquid (QSL) systems. The DFT calculations signify the presence of dominant second and third nearest neighbor interactions, which in turn lead to magnetic frustration in our system. Our investigations suggest that HoVO₄can be a candidate for realizing a 3D QSL state.

Emergence of low-temperature glassy dynamics in Ru substituted non-magnetic insulator CaHfO3

Non-magnetic insulators/semiconductors with induced magnetism introduced via transition metal substitution are one of the promising materials in the field of spintronics, magnetoelectronics and magneto-optical devices. In this context, here, we focus on magnetism induced in a non-magnetic insulator CaHfO₃, by the substitution of 4d element Ru, at Hf-site. Structural investigations indicate that substitution of Ru⁴⁺(up to 50%) does not affect the original crystal structure of the parent compound. Magnetic studies divulge a crossover from a diamagnetic to paramagnetic state with 20% Ru substitution. Further replacement of Hf results in a glassy magnetic state in CaHf_1-xRu_xO₃(0.3 ⩽x⩽ 0.5). The nature of the low temperature glassiness (below 20 K) in these compositions is confirmed through Vogel-Fulcher and Power law, along with, magnetic memory effect and relaxation dynamics. The observed glassiness is explained through the phenomenological 'hierarchical model'. Our studies indicate that the presence of competing short range interactions among randomly arranged Ru cations in non-magnetic insulator CaHfO₃are responsible for the observed low temperature magnetic state in this series with compositions >0.25.

Unravelling the signatures of effective spin1/2moments in CeVO4: magnetization and heat capacity study

The realization of an effective spin (J_eff) ½ state at low temperatures offers a platform to study the enthralling physics behind the disordered states in certain systems. Here, we report the signatures of magnetic ground state associated withJ_eff= ½ in CeVO₄. Our studies confirm the absence of any ordering or freezing down to 1.8 K. In the low temperature region, the Curie-Weiss fit of the inverse DC susceptibility indicate towards the presence of antiferromagnetic correlations among the Ce³⁺spins. The calculated value of effective moment (∼1.16μB) corresponds toJ= ½ withg_J∼ 1.20. Further, the field dependent magnetization curve at 2 K follows a behaviour corresponding toJ= ½ Brillouin function withg_J∼ 1.13. Magnetic field dependent heat capacity fits very well with two-level Schottky scheme. Our investigations suggest that CeVO₄can be a promising candidate to realiseJ_eff= ½ properties among 3D spin systems.

Simultaneous stabilization of actin cytoskeleton in multiple nephron-specific cells protects the kidney from diverse injury

Chronic kidney diseases and acute kidney injury are mechanistically distinct kidney diseases. While chronic kidney diseases are associated with podocyte injury, acute kidney injury affects renal tubular epithelial cells. Despite these differences, a cardinal feature of both acute and chronic kidney diseases is dysregulated actin cytoskeleton. We have shown that pharmacological activation of GTPase dynamin ameliorates podocyte injury in murine models of chronic kidney diseases by promoting actin polymerization. Here we establish dynamin's role in modulating stiffness and polarity of renal tubular epithelial cells by crosslinking actin filaments into branched networks. Activation of dynamin's crosslinking capability by a small molecule agonist stabilizes the actomyosin cortex of the apical membrane against injury, which in turn preserves renal function in various murine models of acute kidney injury. Notably, a dynamin agonist simultaneously attenuates podocyte and tubular injury in the genetic murine model of Alport syndrome. Our study provides evidence for the feasibility and highlights the benefits of novel holistic nephron-protective therapies.

Leishmania survives by exporting miR-146a from infected to resident cells to subjugate inflammation

Leishmania donovani, the causative agent of visceral leishmaniasis, infects and resides within tissue macrophage cells. It is not clear how the parasite infected cells crosstalk with the noninfected cells to regulate the infection process. During infection, Leishmania adopts a dual strategy for its survival by regulating the intercellular transport of host miRNAs to restrict inflammation. The parasite, by preventing mitochondrial function of host cells, restricts the entry of liver cell derived miR-122-containing extracellular vesicles in infected macrophages to curtail the inflammatory response associated with miR-122 entry. On contrary, the parasite up-regulates the export of miR-146a from the infected macrophages. The miR-146a, associated with the extracellular vesicles released by infected cells, restricts miR-122 production in hepatocytes while polarizing neighbouring naïve macrophages to the M2 state by affecting the cytokine expression. On entering the recipient macrophages, miR-146a dominates the miRNA antagonist RNA-binding protein HuR to inhibit the expression of proinflammatory cytokine mRNAs having HuR-interacting AU-rich elements whereas up-regulates anti-inflammatory IL-10 by exporting the miR-21 to polarize the recipient cells to M2 stage.

Large magnetodielectric coupling in the vicinity of metamagnetic transition in 6Hperovskite Ba3GdRu2O9

The 6H-perovskites Ba₃RRu₂O₉(R = rare earth element) demonstrate the magnetodielectric (MD) coupling as a manifestation of 4d-4fmagnetic interactions. Here, a detailed study of the structural, magnetic, heat capacity, and MD properties of the 6H-perovskite Ba₃GdRu₂O₉is reported. The signature of long-range antiferromagnetic (AFM) ordering ∼14.8 K (T_N) is evident from the magnetization and heat capacity studies. TheT_Nshifts towards the lower temperature side, apart from splitting in two with the application of the magnetic field. Field-dependent magnetization at 2 K shows three metamagnetic transitions with the opening of small hysteresis in different regions. A new transition atT₁emerges after the onset of the first metamagnetic transition. Complex magnetic behavior is observed in different magnetic field regions whereas these field regions themselves vary with the temperature. Dielectric response recorded at zero and 80 kOe field exhibits the development of MD coupling well aboveT_N. The MD coupling (∼4.5% at 10 K) is enhanced by 25% as compared to the Dy counterpart. Effect of complex magnetic behavior is also conveyed in the MD results where the maximum value of MD coupling is observed in the vicinity of 10 K (onset ofT₁) and near the second metamagnetic transition. Our investigation suggests that both Gd and Ru moments align simultaneously atT_N. Short-range magnetic ordering is possibly responsible for MD coupling aboveT_N.

Entropic topography associated with field-induced quantum criticality in a magnetic insulator DyVO4

Exploration of low temperature phase transitions associated with quantum critical point is one of the most mystifying fields of research which is under intensive focus in recent times. In this work, through comprehensive experimental evidences, we report the possibility of achieving quantum criticality in the neighborhood of a magnetic field-tuned tricritical point separating paramagnetic, antiferromagnetic and metamagnetic phases in a magnetic insulator, DyVO4. Magnetic susceptibility and heat capacity indicate to the presence of a long-range second order antiferromagnetic transition at TN ~ 3.2 K. Field variation of Magnetic susceptibility and heat capacity, along with differential magnetic susceptibility and DC field dependent AC susceptibility gives evidence of the modification of the antiferromagnetic structure below the tricritical point; implying the presence of a field-induced first order metamagnetic transition which persists down to 1.8 K. Further, the magnetic field dependence of the thermodynamic quantity - dM/dT, which is related to magnetic Gruneisen parameter, approaches a minimum, followed by a crossover near 5 kOe to a maximum; along with a hyperbolic divergence in temperature response of dM/dT in the critical field regime. Temperature response of heat capacity at 5 kOe also shows a deviation from the conventional behavior. Entropic topography phase diagram allows tracking of the variation of the entropy, which indicates towards the emergence of the peak at quantum critical point into a V-shaped region at high temperatures. Our studies yield an inimitable phase diagram describing a tricritical point at which the second-order antiferromagnetic phase line terminates followed by a first order line of metamagnetic transition, as the temperature is lowered, leading to metamagnetic quantum critical end point.

Inhibition of extracellular vesicle-associated MMP2 abrogates intercellular hepatic miR-122 transfer to liver macrophages and curtails inflammation

Hepatic miRNA, miR-122, plays an important role in controlling metabolic homeostasis in mammalian liver. Intercellular transfer of miR-122 was found to play a role in controlling tissue inflammation. miR-122, as part of extracellular vesicles released by lipid-exposed hepatic cells, are taken up by tissue macrophages to activate them and produce inflammatory cytokines. Matrix metalloprotease 2 or MMP2 was found to be essential for transfer of extracellular vesicles and their miRNA content from hepatic to non-hepatic cells. MMP2 was found to increase the movement of the extracellular vesicles along the extracellular matrix to enhance their uptake in recipient cells. Inhibition of MMP2 restricts functional transfer of hepatic miRNAs across the hepatic and non-hepatic cell boundaries, and by targeting MMP2, we could reduce the innate immune response in mammalian liver by preventing intra-tissue miR-122 transfer. MMP2 thus could be a useful target to restrict high-fat-diet-induced obesity-related metaflammation.

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Hepatocytes on exposure to high lipid export proinflammatory miR-122 in mouse liver

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Uptake of extracellular miR-122 induces inflammatory signals in liver macrophages

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MMP2 on extracellular vesicles is essential for intercellular transfer of miRNA

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Inhibition of MMP2 prevents miR-122 transfer and stops activation of macrophages

Unravelling the phonon scattering mechanism in half-Heusler alloys ZrCo1-xIrxSb (x0, 0.1 and 0.25)

Insight about the scattering mechanisms responsible for reduction in the lattice thermal conductivity (κ_L) in half-Heusler alloys (HHA) is imperative. In this context, we have thoroughly investigated the temperature response of thermal conductivity of ZrCo_1-xIr_xSb (x= 0, 0.1 and 0.25). For ZrCoSb,κ_Lis found to be ∼15.13 W m^-1 K^-1at 300 K, which is drastically reduced to ∼4.37 W m^-1 K^-1in ZrCo_0.9Ir_0.1Sb. This observed reduction is ascribed to softening of acoustic phonon modes and point defect scattering, on substitution of heavier mass. However, no further reduction inκ_Lis observed in ZrCo_0.75Ir_0.25Sb, because of identical scattering parameter. This has been elucidated based on the Klemen's Callaway model. Also, in the parent alloy, phonon-phonon scattering mechanism plays a significant role in heat conduction process, whereas in Ir substituted alloys, point defect scattering (below 500 K) and phonon-phonon scattering (above 750 K) are the dominant scattering mechanisms. The minimumκ_Lis found to be ∼1.73 W m^-1 K^-1(at 950 K) in ZrCo_0.9Ir_0.1Sb, which is the lowest reported value till now, for n-type Zr based HHA. Our studies indicate that partial substitution of heavier mass element Ir at Co-site effectively reduces theκ_Lof n-type ZrCoSb, without modifying the nature of charge carriers.

Unconventional critical behaviour in weak ferromagnets Fe2-xMnxCrAl (0 ≤ x < 1)

Recent investigation on weak ferromagnets Fe2-xMnxCrAl (0 ≤ x < 1) reveal the existence of a cluster glass phase (CGP) and a Griffiths-like phase (GP) below and above the ferromagnetic transition temperature (TC), respectively [(2019) Sci. Rep. 9 15888]. In this work, the influence of these inhomogeneous phases on the critical behaviour (around TC) of the above-mentioned series of alloys has been investigated in detail. For the parent alloy Fe2CrAl, the critical exponent γ is estimated as ~ 1.34, which lies near to the ordered 3D Heisenberg class, whereas the obtained value of the critical exponent β ~ 0.273 does not belong to any universality class. With increment in Mn concentration, both exponents γ and β increase, where γ and β approach the disordered and ordered 3D Heisenberg class, respectively. The observed deviation of γ and unconventional value of δ can be ascribed to the increment of GP with Mn-concentration. The trend noted for β can be attributed to the increment in CGP regime with an increase in Mn-content. The estimated critical exponents are consistent and reliable as corroborated using the scaling law and equations of state. Our studies indicate that the critical phenomenon of Fe2-xMnxCrAl (0 ≤ x < 1) alloys possibly belong to a separate class, which is not described within the framework of any existing universal model.

Spontaneous Formation of Star-Shaped Surface Patterns in a Driven Bose-Einstein Condensate

We observe experimentally the spontaneous formation of star-shaped surface patterns in driven Bose-Einstein condensates. Two-dimensional star-shaped patterns with l-fold symmetry, ranging from quadrupole (l=2) to heptagon modes (l=7), are parametrically excited by modulating the scattering length near the Feshbach resonance. An effective Mathieu equation and Floquet analysis are utilized, relating the instability conditions to the dispersion of the surface modes in a trapped superfluid. Identifying the resonant frequencies of the patterns, we precisely measure the dispersion relation of the collective excitations. The oscillation amplitude of the surface excitations increases exponentially during the modulation. We find that only the l=6 mode is unstable due to its emergent coupling with the dipole motion of the cloud. Our experimental results are in excellent agreement with the mean-field framework. Our work opens a new pathway for generating higher-lying collective excitations with applications, such as the probing of exotic properties of quantum fluids and providing a generation mechanism of quantum turbulence.

Anomalous magnetoresistance and magneto-thermal properties of the half-Heuslers,RPdSi (RY, Gd-Er)

Here, we present a detailed study on the magnetic, magneto-transport, and magneto-thermal properties of the equiatomic half-Heusler compounds with the general formula,RPdSi (R= Y and rare-earth, Gd-Er). These materials crystallize in two different superstructures of the TiNiSi-type orthorhombic unit cell with the space groupsPnmaandPmmn. Our magnetic and heat capacity measurements reveal the onset of an antiferromagnetic (AFM) ordering in the temperature range 3-16 K for all the local moments bearingRPdSi compounds, while the non-magnetic analog, YPdSi exhibits a Pauli-paramagnetic behaviour. The AFM state of these compounds can be tuned by magnetic field and temperature as demonstrated by the magnetic measurements below the Neel temperature (T_N). Most importantly, this tuning of the magnetic structure is well documented in the complex temperature and field dependence of magnetoresistance (MR) and magnetocaloric effect (MCE). Our study establishes a striking correlation of the commensurate/incommensurate AFM structure with that of positive/negative MR and MCE in this series of compounds. We emphasize that such a framework applies to a large number of AFM intermetallic systems.

Stochastic pausing at latent HIV-1 promoters generates transcriptional bursting

Promoter-proximal pausing of RNA polymerase II is a key process regulating gene expression. In latent HIV-1 cells, it prevents viral transcription and is essential for latency maintenance, while in acutely infected cells the viral factor Tat releases paused polymerase to induce viral expression. Pausing is fundamental for HIV-1, but how it contributes to bursting and stochastic viral reactivation is unclear. Here, we performed single molecule imaging of HIV-1 transcription. We developed a quantitative analysis method that manages multiple time scales from seconds to days and that rapidly fits many models of promoter dynamics. We found that RNA polymerases enter a long-lived pause at latent HIV-1 promoters (>20 minutes), thereby effectively limiting viral transcription. Surprisingly and in contrast to current models, pausing appears stochastic and not obligatory, with only a small fraction of the polymerases undergoing long-lived pausing in absence of Tat. One consequence of stochastic pausing is that HIV-1 transcription occurs in bursts in latent cells, thereby facilitating latency exit and providing a rationale for the stochasticity of viral rebounds.

A Novel Fluorogenic Assay for the Detection of Nephrotoxin-Induced Oxidative Stress in Live Cells and Renal Tissue

Drug-induced kidney injury frequently leads to aborted clinical trials and drug withdrawals. Sufficiently sensitive sensors capable of detecting mild signs of chemical insult in cell-based screening assays are critical to identifying and eliminating potential toxins in the preclinical stage. Oxidative stress is a common early manifestation of chemical toxicity, and biomolecule carbonylation is an irreversible repercussion of oxidative stress. Here, we present a novel fluorogenic assay using a sensor, TFCH, that responds to biomolecule carbonylation and efficiently detects modest forms of renal injury with much greater sensitivity than standard assays for nephrotoxins. We demonstrate that this sensor can be deployed in live kidney cells and in renal tissue. Our robust assay may help inform preclinical decisions to recall unsafe drug candidates. The application of this sensor in identifying and analyzing diverse pathologies is envisioned.

Metabolomic and transcriptomic analysis reveals endogenous substrates and metabolic adaptation in rats lacking Abcg2 and Abcb1a transporters

Abcg2/Bcrp and Abcb1a/Pgp are xenobiotic efflux transporters limiting substrate permeability in the gastrointestinal system and brain, and increasing renal and hepatic drug clearance. The systemic impact of Bcrp and Pgp ablation on metabolic homeostasis of endogenous substrates is incompletely understood. We performed untargeted metabolomics of cerebrospinal fluid (CSF) and plasma, transcriptomics of brain, liver and kidney from male Sprague Dawley rats (WT) and Bcrp/Pgp double knock-out (dKO) rats, and integrated metabolomic/transcriptomic analysis to identify putative substrates and perturbations in canonical metabolic pathways. A predictive Bayesian machine learning model was used to predict in silico those metabolites with greater substrate-like features for either transporters. The CSF and plasma levels of 169 metabolites, nutrients, signaling molecules, antioxidants and lipids were significantly altered in dKO rats, compared to WT rats. These metabolite changes suggested alterations in histidine, branched chain amino acid, purine and pyrimidine metabolism in the dKO rats. Levels of methylated and sulfated metabolites and some primary bile acids were increased in dKO CSF or plasma. Elevated uric acid levels appeared to be a primary driver of changes in purine and pyrimidine biosynthesis. Alterations in Bcrp/Pgp dKO CSF levels of antioxidants, precursors of neurotransmitters, and uric acid suggests the transporters may contribute to the regulation of a healthy central nervous system in rats. Microbiome-generated metabolites were found to be elevated in dKO rat plasma and CSF. The altered dKO metabolome appeared to cause compensatory transcriptional change in urate biosynthesis and response to lipopolysaccharide in brain, oxidation-reduction processes and response to oxidative stress and porphyrin biosynthesis in kidney, and circadian rhythm genes in liver. These findings present insight into endogenous functions of Bcrp and Pgp, the impact that transporter substrates, inhibitors or polymorphisms may have on metabolism, how transporter inhibition could rewire drug sensitivity indirectly through metabolic changes, and identify functional Bcrp biomarkers.

Structure driven magnetic correlations and magnetodielectric coupling in 6H-perovskite Ba3DyRu2O9

The 6H-perovskites Ba₃(R/M)Ru₂O₉(R= rare Earth,M= transition metal) exhibit complex magnetism and have been extensively studied recently for their magnetodielectric (MD) properties. Here, we present a detailed study of structural, magnetic, thermodynamic and MD properties of a 6H-perovskite Ba₃DyRu₂O₉. This compound is found to undergo long range antiferromagnetic ordering below ∼5.8 K (T_N), along with the presence of metamagnetic transition at low temperatures. The heat capacity shows two additional anomalies at ∼28 K (T₁) and ∼33 K (T₂), besides the anomaly atT_N. Signature of these anomalies is also visible in the derivative of magnetization curve. The dielectric response also shows weak anomalies aroundT₁andT₂at zero field whereas anomaly atT₂gets suppressed at 80 kOe. The observed MD coupling of ∼2%-4% at 80 kOe field below ∼30 K temperature range, is among the highest values observed for the compounds of this family. Low temperature crystal structures of the compound show sharp distortion of Ru₂O₉octahedra nearT₂. Our study points toward the emergence of structurally driven spin correlations of Ru moments resulting in the observed MD coupling in this compound.

Testosterone Metabolite 6β-Hydroxytestosterone Contributes to Angiotensin II-Induced Abdominal Aortic Aneurysms in Apoe-/- Male Mice

Background

Sex is a prominent risk factor for abdominal aortic aneurysms (AAAs), and angiotensin II (Ang II) induces AAA formation to a greater degree in male than in female mice. We previously reported that cytochrome P450 1B1 contributes to the development of hypertension, as well as AAAs, in male mice. We also found that a cytochrome P450 1B1‐generated metabolite of testosterone, 6β‐hydroxytestosterone (6β‐OHT), contributes to Ang II‐induced hypertension and associated cardiovascular and renal pathogenesis in male mice. The current study was conducted to determine the contribution of 6β‐OHT to Ang II‐induced AAA development in Apoe^–/– male mice.

Methods and Results

Intact or castrated Apoe^–/–/Cyp1b1^+/+ and Apoe^–/–/Cyp1b1^–/– male mice were infused with Ang II or its vehicle for 28 days, and administered 6β‐OHT every third day for the duration of the experiment. Abdominal aortas were then evaluated for development of AAAs. We observed a significant increase in the incidence and severity of AAAs in intact Ang II‐infused Apoe^–/–/Cyp1b1^+/+ mice, compared with vehicle‐treated mice, which were minimized in castrated Apoe^–/–/Cyp1b1^+/+ and intact Apoe^–/–/Cyp1b1^–/– mice infused with Ang II. Treatment with 6β‐OHT significantly restored the incidence and severity of AAAs in Ang II‐infused castrated Apoe^–/–/Cyp1b1^+/+ and intact Apoe^–/–/Cyp1b1^–/– mice. However, administration of testosterone failed to increase AAA incidence and severity in Ang II‐infused intact Apoe^–/–/Cyp1b1^–/– mice.

Conclusions

Our results indicate that the testosterone‐cytochrome P450 1B1‐generated metabolite 6β‐OHT contributes to Ang II‐induced AAA development in Apoe^–/– male mice.

Bootstrapping M-estimators in generalized autoregressive conditional heteroscedastic models

We consider the weighted bootstrap approximation to the distribution of a class of M-estimators for the parameters of the generalized autoregressive conditional heteroscedastic model. We prove that the bootstrap distribution, given the data, is a consistent estimate in probability of the distribution of the M-estimator, which is asymptotically normal. We propose an algorithm for the computation of M-estimates which at the same time is useful for computing bootstrap replicates from the given data. Our simulation study indicates superior coverage rates for various weighted bootstrap schemes compared with the rates based on the normal approximation and existing bootstrap methods for the generalized autoregressive conditional heteroscedastic model, such as percentile $t$-subsampling schemes. Since some familiar bootstrap schemes are special cases of the weighted bootstrap, this paper thus provides a unified theory and algorithm for bootstrapping in generalized autoregressive conditional heteroscedastic models.

Probing the molecular mechanism of aggressive infection by antimony resistant Leishmania donovani

The disease visceral leishmaniasis (VL) or kala azar is caused by the protozoan parasite, Leishmania donovani (LD). For many decades the pentavalent antimonial drugs countered the successive epidemics of the disease in the Indian sub-continent and elsewhere. With time, antimony resistant LD (LD^R) developed and the drug in turn lost its efficacy. Infection of mammals with LD^R gives rise to aggressive infection as compared to its sensitive counterpart (LD^S) coupled with higher surge of IL-10 and TGF-β. The IL-10 causes upregulation of multidrug resistant protein-1 which causes efflux of antimonials from LD^R infected cells. This is believed to be a key mechanism of antimony resistance. MicroRNAs (miRNAs) are tiny post-transcriptional regulators of gene expression in mammalian cells and in macrophage play a pivotal role in controlling the expression of cytokines involved in infection process. Therefore, a change in miRNA profiles of macrophages infected with LD^S or LD^R could explain the differential cytokine response observed. Interestingly, the outcome of LD infection is also governed by the critical balance of pro- and anti-inflammatory cytokines which is inturn regulated by miRNA-Ago2 or miRNP complex and its antagonist RNA binding protein HuR. Here Ago2 plays the fulcrum whose phosphorylation and de-phosphorylation dictates the process; which in turn is controlled by PP2A and HuR. LD^S and LD^R upregulate PP2A and downregulate HuR at different magnitude leading to various levels of anti-inflammatory to proinflammatory cytokine production and resulting pathology in the host. While ectopic HuR expression alone is sufficient to clear LD^S infection, simultaneous upregulation of HuR and inhibition of PP2A is required to inhibit LD^R mediated infection. Therefore, tampering with miRNA pathway could be a new strategy to control infection caused by LD^R parasite.

Allyl piperidine-1-carbodiothioate and benzyl 1H-imidazole 1 carbodithioate: two potential agents to combat against mycobacteria

AIMS

The emergence of multidrug resistant strains of Mycobacterium tuberculosis has made tuberculosis more difficult to manage clinically. With the aim of obtaining new and effective anti-mycobacterial agent(s), this study investigated the anti-mycobacterial activity of several imidazole and piperidine derivatives.

METHODS AND RESULTS

Towards obtaining new anti-mycobacterial agents, Mycobacterium smegmatis cells were treated with different compounds for their growth inhibitory activity. Among these, benzyl 1H-imidazole-1-carbodithioate and allyl piperidine-1-carbodiothioate exhibited better inhibition than the others. Thereafter, anti-biofilm property of these two was examined by treating M. smegmatis with these agents before and after the formation of biofilm. The result showed that both the compounds at their sublethal dose inhibited the formation of biofilm as well as dispersed preformed biofilm. Consistently, they augmented the activity of isoniazid or rifampicin against biofilm-encapsulated cells. MTT assay was performed to examine the toxic effects of this combinatorial therapy on different cell lines. Results exhibited a low cytotoxicity for this combinatorial treatment. The activity of these two was also verified against dormant mycobacterial cells and was found to be effective.

CONCLUSION

The present study identified two compounds that exhibited anti-mycobacterial activities against both planktonic and dormant cells. These two also exhibited anti-biofilm activity at their sublethal dose and augmented the activity of isoniazid and rifampicin against biofilm encapsulated cells.

SIGNIFICANCE AND IMPACT OF THE STUDY

The current study provides two new agents that have the potential to be used in anti-mycobacterial therapy and may help in public health management.

Visualization of oxidative stress-induced carbonylation in live mammalian cells

Oxidative stress (OS) is associated with a wide variety of diseases and disorders. Detection of oxidative stress in living systems typically relies on fluorescent probes for reactive oxygen species (ROS), which is challenging because of their short life span and high reactivity. Oxidative damage caused by OS produces a more stable signal, but these biomarkers are usually detected using techniques that are not compatible with live cells. OS-induced biomolecule carbonylation is a stable modification that also possesses a chemically reactive functional group, and its detection typically employs a chemical reaction with a hydrazine-containing probe within the process. These hydrazone-forming reactions require strong acid catalysis or nucleophilic catalysis with an aromatic amine when performed on isolated biomaterial or on fixed cells. In live cells, however, hydrazone-forming reactions are surprisingly facile. Fluorophores possessing hydrazine or hydrazide functional groups can undergo reaction with carbonylated biomolecules in live cells, and these products can be observed using fluorescence microscopy. In this chapter, standard methods for detection of biomolecule carbonylation in cell lysate and in intact cells are enumerated. Protocols for fluorescently labeling biomolecule carbonylation in live cells are provided for commercially available fluorophores. Also described is a one-step protocol that employs one of the hydrazine-modified fluorophores developed in our lab, which are designed to be live-cell compatible and to undergo a spectral change upon hydrazone formation. Finally, a procedure for observing both biomolecule carbonylation and ROS production simultaneously is provided.

Taurine Is Covalently Incorporated into Alpha-Tubulin

Taurine is the most abundant free amino acid in the human body. It is found in relatively high concentrations (1-10 mM) in many animal tissues but not in plants. It has been studied since the early 1800s but has not been found to be covalently incorporated into proteins in any animal tissue. Taurine has been found in only one macromolecular complex as a post-transcriptional modification to mitochondrial tRNA. Tubulin is the subunit of microtubules found in all eukaryotic species and almost all eukaryotic cells and subject to numerous post-translational modifications (PTMs). An important PTM on α-tubulin is the removal and re-ligation of the final carboxyl residue, tyrosine. We here demonstrate that taurine can be covalently incorporated at the C-terminal end of alpha-tubulin in avian erythrocytes in a reaction that requires the de-tyrosination PTM and prevents the re-tyrosination PTM. Further, this is, to our knowledge, the first instance of taurine incorporation into a large protein.

Haploinsufficiency of X-linked intellectual disability gene CASK induces post-transcriptional changes in synaptic and cellular metabolic pathways

Heterozygous mutations in the X-linked gene CASK are associated with intellectual disability, microcephaly, pontocerebellar hypoplasia, optic nerve hypoplasia and partially penetrant seizures in girls. The Cask^+/- heterozygous knockout female mouse phenocopies the human disorder and exhibits postnatal microencephaly, cerebellar hypoplasia and optic nerve hypoplasia. It is not known if Cask^+/- mice also display seizures, nor is known the molecular mechanism by which CASK haploinsufficiency produces the numerous documented phenotypes. 24-h video electroencephalography demonstrates that despite sporadic seizure activity, the overall electrographic patterns remain unaltered in Cask^+/- mice. Additionally, seizure threshold to the commonly used kindling agent, pentylenetetrazol, remains unaltered in Cask^+/- mice, indicating that even in mice the seizure phenotype is only partially penetrant and may have an indirect mechanism. RNA sequencing experiments on Cask^+/- mouse brain uncovers a very limited number of changes, with most differences arising in the transcripts of extracellular matrix proteins and the transcripts of a group of nuclear proteins. In contrast to limited changes at the transcript level, quantitative whole-brain proteomics using iTRAQ quantitative mass-spectrometry reveals major changes in synaptic, metabolic/mitochondrial, cytoskeletal, and protein metabolic pathways. Unbiased protein-protein interaction mapping using affinity chromatography demonstrates that CASK may form complexes with proteins belonging to the same functional groups in which altered protein levels are observed. We discuss the mechanism of the observed changes in the context of known molecular function/s of CASK. Overall, our data indicate that the phenotypic spectrum of female Cask^+/- mice includes sporadic seizures and thus closely parallels that of CASK haploinsufficient girls; the Cask^+/- mouse is thus a face-validated model for CASK-related pathologies. We therefore surmise that CASK haploinsufficiency is likely to affect brain structure and function due to dysregulation of several cellular pathways including synaptic signaling and cellular metabolism.

MicroRNA exporter HuR clears the internalized pathogens by promoting pro-inflammatory response in infected macrophages

HuR is a miRNA derepressor protein that can act as miRNA sponge for specific miRNAs to negate their action on target mRNAs. Here we have identified how HuR, by inducing extracellular vesicles‐mediated export of miRNAs, ensures robust derepression of miRNA‐repressed cytokines essential for strong pro‐inflammatory response in activated mammalian macrophages. Leishmania donovani, the causative agent of visceral leishmaniasis, on the contrary alters immune response of the host macrophage by a variety of complex mechanisms to promote anti‐inflammatory response essential for the survival of the parasite. We have found that during Leishmania infection, the pathogen targets HuR to promote onset of anti‐inflammatory response in mammalian macrophages. In infected macrophages, Leishmania also upregulate protein phosphatase 2A that acts on Ago2 protein to keep it in dephosphorylated and miRNA‐associated form. This causes robust repression of the miRNA‐targeted pro‐inflammatory cytokines to establish an anti‐inflammatory response in infected macrophages. HuR has an inhibitory effect on protein phosphatase 2A expression, and mathematical modelling of macrophage activation process supports antagonistic miRNA‐modulatory roles of HuR and protein phosphatase 2A which mutually balances immune response in macrophage by targeting miRNA function. Supporting this model, ectopic expression of the protein HuR and simultaneous inhibition of protein phosphatase 2A induce strong pro‐inflammatory response in the host macrophage to prevent the virulent antimonial drug‐sensitive or drug‐resistant form of L. donovani infection. Thus, HuR can act as a balancing factor of immune responses to curtail the macrophage infection process by the protozoan parasite.

6β-Hydroxytestosterone, a metabolite of testosterone generated by CYP1B1, contributes to vascular changes in angiotensin II-induced hypertension in male mice

Background

Previously, we showed that 6β-hydroxytestosterone (6β-OHT), a cytochrome P450 1B1 (CYP1B1)-derived metabolite of testosterone, contributes to angiotensin II (Ang II)-induced hypertension in male mice. This study was conducted to test the hypothesis that 6β-OHT contributes to increased vascular reactivity, endothelial dysfunction, vascular hypertrophy, and reactive oxygen species production associated with Ang II-induced hypertension.

Methods

Eight- to 10-week-old intact or castrated C57BL/6 J (Cyp1b1^+/+ and Cyp1b1^−/−) mice were anesthetized for implantation of a micro-osmotic pump which delivered Ang II (700 ng/kg/day) or saline for 14 days. Mice were injected with 6β-OHT (15 μg/g b.w every third day), flutamide (8 mg/kg every day), or its vehicle. Blood pressure was measured via tail-cuff. Vascular reactivity, endothelial-dependent and endothelial-independent vasodilation, media to lumen ratio, fibrosis by collagen deposition, and reactive oxygen species production by dihydroethidium staining were determined in the isolated thoracic aorta.

Results

The response of thoracic aorta to phenylephrine and endothelin-1 was increased in Ang II-infused Cyp1b1^+/+ mice compared to intact Cyp1b1^−/− or castrated Cyp1b1^+/+ and Cyp1b1^−/− mice; these effects of Ang II were restored by treatment with 6β-OHT. Ang II infusion caused endothelial dysfunction, as indicated by decreased relaxation of the aorta to acetylcholine in Cyp1b1^+/+ but not Cyp1b1^−/− or castrated Cyp1b1^+/+ and Cyp1b1^−/− mice. 6β-OHT did not alter Ang II-induced endothelial dysfunction in Cyp1b1^+/+ mice but restored it in Cyp1b1^−/− or castrated Cyp1b1^+/+ and Cyp1b1^−/− mice. Ang II infusion increased media to lumen ratio and caused fibrosis and reactive oxygen species production in the aorta of Cyp1b1^+/+ mice. These effects were minimized in the aorta of Cyp1b1^−/− or castrated Cyp1b1^+/+ and Cyp1b1^−/− mice and restored by treatment with 6β-OHT. Treatment with the androgen receptor antagonist flutamide reduced blood pressure and vascular hypertrophy in castrated Ang II-infused mice injected with 6β-OHT.

Conclusions

6β-OHT is required for the action of Ang II to increase vascular reactivity and cause endothelial dysfunction, hypertrophy, and increase in oxygen radical production. The effect of 6β-OHT in mediating Ang II-induced hypertension and associated hypertrophy is dependent on the androgen receptor. Therefore, CYP1B1 could serve as a novel target for the development of therapeutics to treat vascular changes in hypertensive males.

Possibility of a new order parameter driven by multipolar moment and Fermi surface evolution in CeGe

Polycrystalline CeGe is investigated by means of DC and AC susceptibility, non-linear DC susceptibility, electrical transport and heat capacity measurements in the low temperature regime. This compound shows two peaks at low magnetic field around T^I ~ 10.7 and T^II ~ 7.3 K due to antiferromagnetic ordering and subsequent spin rearrangement respectively. Investigation of non-linear DC susceptibility reveals a presence of higher order magnetization which results in the development of a new order parameter around T^I. This leads to a lowering of symmetry of the magnetic state. The order parameter increases with decreasing temperature and stabilizes around T^II. Consequently, the symmetry of the magnetic state is preserved below this transition. Heat capacity and resistivity results indicate the presence of a gap opening around T^I on portion of Fermi surface, due to evolution of the Fermi surface. Magnetoresistance behavior and violation of Kohler’s rule suggest that the evolution of Fermi surface changes the symmetry of magnetic state. The observation of new order parameter (which is of second order) is also confirmed from the Landau free energy theory.

Assessment of healthcare measures, healthcare resource use, and cost of care among severe hemophilia A patients in Mumbai region of India

Background

In India, the low public health priority given to rare disorders such as hemophilia hinders their management and optimal care, leading to relatively poor health outcomes. This study aims to profile the multidimensional health status of patients with severe hemophilia A, and its association with the use of healthcare resources and the cost of care in Mumbai region of India.

Subjects and Methods

A cross-sectional, single-center study was conducted during January-May 2011, among 160 patients diagnosed with severe hemophilia A in Mumbai region of India. Their health status was documented using the Hemophilia Utilization Group Study's validated instrument of Functional Health Status Measure (FHS) and a single item of Self-care Measure.

Results

Of 160 patients, 55% (n = 88) scored on the lower side on the FHS, with an average score of 6.65 ± 2.85. The use of healthcare resources and cost of treatment were considerable for patients with a lower mean rank score on the FHS and a higher mean rank score on the self-care measure. The consumption of clotting factor concentrates (CFCs), number of visits to a health facility and incidence of inpatient episodes were significantly associated with a relatively low score on the FHS. Similarly, a higher cost of treatment, in terms of the cost of CFCs, direct cost, emergency room cost, and indirect cost, were significantly associated with a lower score on the FHS.

Conclusion

The health status of patients with severe hemophilia A is compromised and has a significant impact on the use of healthcare resources and the cost of treatment.

Site-Specific Bioconjugation and Multi-Bioorthogonal Labeling via Rapid Formation of a Boron-Nitrogen Heterocycle

Precise control of covalent bond formation in the presence of multiple functional groups is pertinent in the development of many next-generation bioconjugates and materials. Strategies derived from bioorthogonal chemistries are contributing greatly in that regard; however, the gain of chemoselectivity is often compromised by the slow rates of many of these existing chemistries. Recent work on a variation of the classical aldehyde/ketone condensation based on ortho-carbonylphenylboronic acids has uncovered markedly accelerated rates compared to those of the simple carbonyl counterparts. The products of these reactions are distinct, often in the form of boron-nitrogen heterocycles. In particular, we have shown that 2-formylphenylboronic acid (2fPBA), when coupled with an α-amino-hydrazide, produces a unique zwitterionic and stable 2,3,1-benzodiazaborine derivative. In this work, we apply this chemistry to generate chemically defined and functional bioconjugates, herein illustrated with immunoconjugates. We show that an antibody and a fluorophore (as payload) equipped with the relevant reactive handles undergo rapid conjugation at near-stoichiometric ratios, displaying a reaction half-life of only ∼5 min with 2 equiv of the linker payload. Importantly, the reaction can be extended to multicomponent labeling by partnering with the popular strain-promoted azide-alkyne cycloaddition and tetrazine- trans-cyclooctene (Tz-TCO) ligation. The mutual orthogonality to both of these chemistries allows simultaneous triple bioorthogonal conjugations, a rare feat thus far that will widen the scope of various multilabeling applications. Further collaboration with the Tz-TCO reaction enables rapid one-pot synthesis of a site-specific dual-payload antibody conjugate. Altogether, we envision that the 2fPBA-α-amino-hydrazide ligation will facilitate efficient assembly of diverse bioconjugates and materials, enabling access to more complex modalities via partnership with other orthogonal chemistries.

Nonimmune cell-derived ICOS ligand functions as a renoprotective αvβ3 integrin-selective antagonist

Soluble urokinase receptor (suPAR) is a circulatory molecule that activates αvβ3 integrin on podocytes, causes foot process effacement, and contributes to proteinuric kidney disease. While active integrin can be targeted by antibodies and small molecules, endogenous inhibitors haven't been discovered yet. Here we report what we believe is a novel renoprotective role for the inducible costimulator ligand (ICOSL) in early kidney disease through its selective binding to podocyte αvβ3 integrin. Contrary to ICOSL's immune-regulatory role, ICOSL in nonhematopoietic cells limited the activation of αvβ3 integrin. Specifically, ICOSL contains the arginine-glycine-aspartate (RGD) motif, which allowed for a high-affinity and selective binding to αvβ3 and modulation of podocyte adhesion. This binding was largely inhibited either by a synthetic RGD peptide or by a disrupted RGD sequence in ICOSL. ICOSL binding favored the active αvβ3 rather than the inactive form and showed little affinity for other integrins. Consistent with the rapid induction of podocyte ICOSL by inflammatory stimuli, glomerular ICOSL expression was increased in biopsies of early-stage human proteinuric kidney diseases. Icosl deficiency in mice resulted in an increased susceptibility to proteinuria that was rescued by recombinant ICOSL. Our work identified a potentially novel role for ICOSL, which serves as an endogenous αvβ3-selective antagonist to maintain glomerular filtration.

Cation-specific interactions of protein surface charges in dilute aqueous salt solutions: a combined study using dielectric relaxation spectroscopy and Raman spectroscopy

We exploited glycine as a zwitterionic model system to experimentally probe the cation specific interaction of protein surface charges in dilute (≤0.25 mol L-1) aqueous solutions of four biologically relevant inorganic salts, NaCl, KCl, MgCl2 and CaCl2, via dielectric relaxation spectroscopy (DRS) and Raman spectroscopy. Glycine is the simplest building block of proteins and it exposes the same charged groups (carboxylate and ammonium) to the solvent that dominate the protein-water interface. As a counter ion, we selected Cl- due to its biological importance. For all systems, we performed simultaneous fitting of the real (ε') and imaginary (ε″) parts of the dielectric functions, assuming a multimodal relaxation model, obtained from concentration dependent dielectric measurements at ∼293 K. We observe a reduction of the dielectric amplitude for the glycine relaxation while the corresponding time constant shows only small (<7%) deviations compared to aqueous glycine solutions. We propose that the observed reduction in dielectric amplitude is due to a reduction of the effective dipole moment (µeff) of zwitterionic glycine caused by the interaction of glycine with the ion even at very low (0.05 M) salt concentrations. The interaction between divalent metal ions and zwitterionic glycine is increased compared to the monovalent cation-zwitterion interaction; a finding that is also supported by Raman spectroscopy. Our combined dielectric relaxation and Raman spectroscopic study indicates that ion-glycine interactions are weak and mediated by the solvent. Cation-specificity of protein surface charges is also observed in dilute salt solutions (≤0.25 mol L-1), where electrostatic interactions dominate.

Cytochrome P450 1B1 Is Critical for Neointimal Growth in Wire-Injured Carotid Artery of Male Mice

Background We have reported that cytochrome P450 1B1 ( CYP 1B1), expressed in cardiovascular tissues, contributes to angiotensin II -induced vascular smooth muscle cell ( VSMC ) migration and proliferation and development of hypertension in various experimental animal models via generation of reactive oxygen species. This study was conducted to determine the contribution of CYP 1B1 to platelet-derived growth factor-BB-induced VSMC migration and proliferation in vitro and to neointimal growth in vivo. Methods and Results VSMC s isolated from aortas of male Cyp1b1 +/+ and Cyp1b1 -/- mice were used for in vitro experiments. Moreover, carotid arteries of Cyp1b1 +/+ and Cyp1b1 -/- mice were injured with a metal wire to assess neointimal growth after 14 days. Platelet-derived growth factor- BB -induced migration and proliferation and H2O2 production were found to be attenuated in VSMC s from Cyp1b1 -/- mice and in VSMC s of Cyp1b1 +/+ mice treated with 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl, a superoxide dismutase and catalase mimetic. In addition, wire injury resulted in neointimal growth, as indicated by increased intimal area, intima/media ratio, and percentage area of restenosis, as well as elastin disorganization and adventitial collagen deposition in carotid arteries of Cyp1b1 +/+ mice, which were minimized in Cyp1b1 -/- mice. Wire injury also increased infiltration of inflammatory and immune cells, as indicated by expression of CD 68+ macrophages and CD 3+ T cells, respectively, in the injured arteries of Cyp1b1 +/+ mice, but not Cyp1b1 -/- mice. Administration of 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl attenuated neointimal growth in wire-injured carotid arteries of Cyp1b1 +/+ mice. Conclusions These data suggest that CYP 1B1-dependent oxidative stress contributes to the neointimal growth caused by wire injury of carotid arteries of male mice.

Complex magnetic behaviour and evidence of a superspin glass state in the binary intermetallic compound Er5Pd2

The binary intermetallic compound Er₅Pd₂ has been investigated using dc and ac magnetic susceptibilities, magnetic memory effect, isothermal magnetization, non-linear dc susceptibility, heat capacity and magnetocaloric effect studies. Interestingly, even though the compound does not show geometrical frustration it undergoes glassy magnetic phase transition below 17.2 K. Investigation of dc magnetization and heat capacity data divulged absence of long-ranged magnetic ordering. Through the magnetic memory effect, time dependent magnetization and ac susceptibility studies it was revealed that the compound undergoes glass-like freezing below 17.2 K. Analysis of frequency dependence of this transition temperature through scaling and Arrhenius law; along with the Mydosh parameter indicate, that the dynamics in Er₅Pd₂ are due to the presence of strongly interacting superspins rather than individual spins. This phase transition was further investigated by non-linear dc susceptibility and was characterized by static critical exponents γ and δ. Our results indicate that this compound shows the signature of superspin glass at low temperature. Additionally, both conventional and inverse magnetocaloric effect was observed with a large value of magnetic entropy change and relative cooling power. Our results suggest that Er₅Pd₂ can be classified as a superspin glass system with large magnetocaloric effect.