Serine 408 phosphorylation is a molecular switch that regulates structure and function of the occludin α-helical bundle.

Occludin is a tetramembrane-spanning tight junction protein. The long C-terminal cytoplasmic domain, which represents nearly half of occludin sequence, includes a distal bundle of three α-helices that mediates interactions with other tight junction components. A short unstructured region just proximal to the α-helical bundle is a phosphorylation hotspot within which S408 phosphorylation acts as molecular switch that modifies tight junction protein interactions and barrier function. Here, we used NMR to define the effects of S408 phosphorylation on intramolecular interactions between the unstructured region and the α-helical bundle. S408 pseudophosphorylation affected conformation at hinge sites between the three α-helices. Further studies using paramagnetic relaxation enhancement and microscale thermophoresis indicated that the unstructured region interacts with the α-helical bundle. These interactions between the unstructured domain are enhanced by S408 phosphorylation and allow the unstructured region to obstruct the binding site, thereby reducing affinity of the occludin tail for zonula occludens-1 (ZO-1). Conversely, S408 dephosphorylation attenuates intramolecular interactions, exposes the binding site, and increases the affinity of occludin binding to ZO-1. Consistent with an increase in binding to ZO-1, intravital imaging and fluorescence recovery after photobleaching (FRAP) analyses of transgenic mice demonstrated increased tight junction anchoring of enhanced green fluorescent protein (EGFP)-tagged nonphosphorylatable occludin relative to wild-type EGFP-occludin. Overall, these data define the mechanisms by which S408 phosphorylation modifies occludin tail conformation to regulate tight junction protein interactions and paracellular permeability.

Optical thickness measurement of occluded samples by lens-less Fourier transform digital holography, thermal loading, and machine learning.

Thickness measurements of objects, especially transparent and semi-transparent objects, are essential for their characterization and identification. However, in the case of occluded objects, the optical thickness determination becomes difficult, and an indirect way must be devised. Thermal loading of the objects changes their opto-thermal properties, which will be reflected as a change in their optical thickness. The key to quantifying such occluded objects lies in collecting these opto-thermal signatures. This could be achieved by imaging the changes occurring to a probe wavefront passing through the object while it is being thermally loaded. Digital holographic interferometry is an ideal tool for observing phase changes, as it can be used to compare wavefronts recorded at different instances of time. Lens-less Fourier transform digital holographic imaging provides the phase information from a single Fourier transform of the recorded hologram and can be used to quantify occluded phase objects. Here we describe a technique for the measurement of change in optical thickness of thermally loaded occluded phase samples using lens-less Fourier transform digital holography and machine learning. The advantage of the proposed technique is that it is a single shot, lens-less imaging modality for quasi-real-time quantification of phase samples behind thin occlusions.

Comparing color match by conventional trial and error method with maxillofacial spectrophotometer method for the skin of Indian participants: A subjective and objective assessment.

STATEMENT OF PROBLEM: The comparative accuracy of different color-matching methods for maxillofacial prostheses is lacking. PURPOSE: This clinical study aimed to compare prosthesis color matching using the conventional trial and error method with that using the maxillofacial spectrophotometer method. MATERIAL AND METHODS: Fifty-four Indian participants were enrolled based on skin color and divided into Light, Medium, and Dark groups (n=18). Silicone specimens of different thicknesses were fabricated using both the conventional trial and error and maxillofacial spectrophotometer coloration methods for all participants. The color match of the specimens with natural skin was assessed subjectively and objectively using expert consensus and fiber optic spectroscopy with the CIELab color difference formula, respectively. Statistical analyzes included the Shapiro-Wilk and independent sample t tests (α=.05). RESULTS: The mean ΔL* (white-black axis) value for the Skin-Conventional color match difference was significantly lower and positive compared with the Skin-Spectrophotometer match (P=.090) for the sample. The mean Δb* (yellow-blue axis) value for the Skin-Conventional color difference was significantly positive compared with the Skin-Spectrophotometer match (P=.020). The mean ΔE* (color difference) for the Skin-Conventional color match was significantly lower than the Skin-Spectrophotometer value (P=.034). Expert opinion as assessed with a visual analog scale found color matching using the conventional method (7.12) to be significantly better than with the spectrophotometer (6.30). A qualitative analysis of expert opinion revealed that conventional color matching should have been less red (34.3%) and that spectrophotometer matching should have been less yellow (30.1%). CONCLUSIONS: Across different thicknesses of silicone and Indian skin shades, color matching was significantly better for the conventional versus the maxillofacial spectrophotometer method, both objectively and subjectively. The spectrophotometer match was significantly yellower and lighter than natural skin.

A multi-model forecasting approach for solid waste generation by integrating demographic and socioeconomic factors: a case study of Prayagraj, India.

Projecting municipal solid waste generation and identifying socioeconomic factors affecting waste generation is crucial for integrated waste management strategies. The present research work focuses on the projection of municipal solid waste (MSW) generation in Prayagraj, India, based on demographics and socioeconomic factors, using long short-term memory (LSTM), autoregressive integrated moving average (ARIMA), and incremental increase models (IIM). The model was integrated with nine socioeconomic variables to improve accuracy. The influence of socioeconomic variables on MSW generation was evaluated using correlation and fuzzy logic approaches. Waste generation data collected from the Central Pollution Control Board (CPCB) from 1997 to 2015 were used to train the models. The results of the correlation study indicate that population growth, employment, and households have a substantial impact on waste generation rates. Root mean squared error (RMSE), mean absolute percent error (MAPE), and coefficient of determination (R2) suggest that LSTM is the best model to forecast MSW generation in Prayagraj, India. The R2 value indicates that the LSTM is more accurate (0.92) than ARIMA (0.72) and IIM (0.70). LSTM projection indicates that the city will have a population of 1.6 million by 2031, and waste generation will increase by 70.6% in 2031.

Clinical profile and microbiological spectrum of patients with continuous ambulatory peritoneal dialysis-associated peritonitis at a tertiary care center.

Background: We present risk factors, clinical profile, and microbiological spectrum of patients with continuous ambulatory peritoneal dialysis (CAPD)-associated peritonitis who were managed at our center. Methods: All consecutive patients with CAPD-associated peritonitis who presented to our center between July 2018 and December 2019 were included in the study. Risk factors, microbiological spectrum, clinical profile, and outcome of patients were studied. Results: Eighty-five patients with CAPD-associated peritonitis and 50 patients who never had peritonitis during the study period were included. Diabetes Mellitus (OR 0.058, 95% CI0.007-0.493, p < 0.05), residence in rural area (OR 3.376, 95% CI 1.084-10.516, p < 0.05), duration of peritoneal dialysis (OR 0.935, 95% CI 0.886-0.987, p < 0.05), mean serum hemoglobin (OR 1.674, 95% CI 1.119-2.502, p < 0.05) and serum albumin (OR 0.148, 95% CI 0.066-0.333, p < 0.05) were associated with higher risk of peritonitis in CAPD patients. Eight-three patients (98.8%) had turbid CAPD fluid and 52 (61.2%) had fever at the time of presentation to the hospital. The mean CAPD fluid TLC on day 1, 3, and 5 were 2034.3 ± 3330.1 cells/cumm, 1049.0 ± 1210.9 cells/cumm, and 605.2 ± 950.5 cells/cumm, respectively. The organisms isolated were two Escherichia coli (2.4%), one Staphylococcus aureus (1.2%), one Klebsiella (1.2%), two Acinetobacter (2.4%), 10 Fungal organisms (11.7%), and in two (2.4%) cases, Mycobacterium tuberculosis (MTB) was detected by polymerase chain reaction (PCR) of CAPD fluid. Thirty-seven (43.5%) patients had a complete cure and 48 (56.5%) patients were refractory to treatment; hence catheter was removed in them (catheter loss). Six (7.0%) patients died during the study period. Conclusion: CAPD-associated peritonitis is an important risk factor for technique failure. The majority of episodes are culture-negative, and PCR can help in detecting fungal and tubercular peritonitis early in the course.

On the Coupled Thermal and Hydrodynamic Interaction of Adjacently Located Vapor Bubbles on Highly Wetting Surfaces.

Spatio-temporally resolved IR measurements coupled with high-speed videography have been made to propose the regime map of the interaction between two adjacently located vapor bubbles on high-wettability surfaces. The modes of interaction (thermal and/or hydrodynamic) have been studied as a function of distance between the two nucleation sites under saturated nucleate pool boiling conditions with water as the working fluid, and their effects on the wall heat-transfer rates have been quantified. Based on the comprehensive observations and analyses of the simultaneously mapped vapor bubble dynamics, substrate surface temperature, and the associated wall heat flux distributions, the possible regimes of bubble interactions have been identified. Experiments revealed three dominant mechanisms of bubble interactions: hydrodynamic interaction (HI), thermal interaction (TI), and horizontal coalescence (C). Depending on the relative spacing of the two nucleation sites, a regime map has been prepared wherein various possible bubble interactions (and/or their combinations) have been classified as HI + TI + C, HI + C, and HI. The IR thermography-based measurements revealed a strong dependence of bubble base evaporation-driven heat transfer on the possible bubble interaction mechanism(s) encountered in each regime. The dependence of microlayer formation beneath the growing vapor bubble(s) and its evaporation on HI is further corroborated through thin-film interferometric measurements. Plausible explanation(s) for mechanisms through which bubble interactions influence heat transfer have been discussed. A trend of variation of wall heat-transfer performance with bubble interaction regimes has been deduced and discussed.

Extraction and characterization of microalgae-derived phenolics for pharmaceutical applications: A systematic review.

Microalgae are regarded as a rich trove of diverse secondary metabolites that exert remarkable biological activities. In particular, microalgae-derived bioactive phenolic compounds (MBPCs) are a boon to biopharmaceutical and nutraceutical industries due to their diverse bioactivities, including antimicrobial, anticancer, antiviral, and immunomodulatory activities. The state-of-the-art green technologies for extraction and purification of MBPCs, along with the modern progress in the identification and characterization of MBPCs, have accelerated the discovery of novel active pharmaceutical compounds. However, several factors regulate the production of these bioactive phenolic compounds in microalgae. Furthermore, some microalgae species produce toxic phenolic compounds that negatively impact the aquatic ecosystem, animal, and human life. Therefore, the focus of this review paper is to bring into light the current innovations in bioprospection, extraction, purification, and characterization of MBPCs. This review is also aimed at a better understanding of the physicochemical factors regulating the production of MBPCs at an industrial scale. Finally, the present review covers the recent advances in toxicological evaluation, diverse applications, and future prospects of MBPCs in biopharmaceutical industries.

Nanodroplet Oligomers (NanDOs) of Aß40.

Using atomic force microscopy (AFM) and nuclear magnetic resonance (NMR), we describe small Aß40 oligomers, termed nanodroplet oligomers (NanDOs), which form rapidly and at Aß40 concentrations too low for fibril formation. NanDOs were observed in putatively monomeric solutions of Aß40 (e.g., by size exclusion chromatography). Video-rate scanning AFM shows rapid fusion and dissolution of small oligomer-sized particles, of which the median size increases with peptide concentration. In NMR (13C HSQC), a small number of chemical shifts changed with a change in peptide concentration. Paramagnetic relaxation enhancement NMR experiments also support the formation of NanDOs and suggest prominent interactions in hydrophobic domains of Aß40. Addition of Zn2+ to Aß40 solutions caused flocculation of NanDO-containing solutions, and selective loss of signal intensity in NMR spectra from residues in the N-terminal domain of Aß40. NanDOs may represent the earliest aggregated form of Aß40 in the aggregation pathway and are akin to premicelles in solutions of amphiphilies.

Microbial Brazil nut effect.

The Brazil nut effect (BNE) is a counter-intuitive process of segregation of a large object inside a vibrated granular medium (GM), which has been studied widely by subjecting GMs to various kinds of shears and vibrations. In this article, we report a new kind of BNE which occurs as a consequence of granular fluctuations induced by microbe-generated gas bubbles. We call it the 'microbial Brazil nut effect'. The paper demonstrates microbial BNE for a bidisperse granular mixture as well as for intruder segregation. Furthermore, using X-ray µCT and a simple scaling argument for segregation velocity, the paper clarifies the transport mechanics of an intruder inside a bubbly granular bed. We think the reported phenomenon should be ubiquitous in the microbe-populated wet sandy floors of waterbodies and may have some implication on the distribution of material near the floors.

A versatile method for producing labeled or unlabeled Aß55, Aß40, and other ß-amyloid family peptides.

We present a straightforward, versatile method for expressing and purifying ß-amyloid (Aß40) and transmembrane peptides derived from ß-amyloid precursor protein (Aß55). In principle, these methods should be applicable to other types of strongly aggregating peptides. We start with a DNA plasmid encoding a HexaHis tag with a flexible, hydrophilic linker sequence, followed by a cleavage site, and then Aß peptides. The HexaHis tag rather than a protein fusion partner (e.g., GST) obviates the need for a folded protein in affinity purification. Second, we present two cleavage methods, using either Factor Xa or BNPS-Skatole. Although the latter procedure requires subsequent reduction of the product, we describe methods for minimizing side reactions. Because the use of BNPS-Skatole obviates the need for a folded protein in the cleavage reaction, it is compatible with harsh conditions (e.g., inclusion of detergents and denaturants) needed to solubilize the fusion proteins; such conditions tend to inactivate Factor Xa. Finally, we also describe purification strategies for Aß40 and Aß55 using FPLC and/or reverse phase HPLC. Yields of peptide after these BNPS-Skatole cleavage and peptide reduction, though subquantitative, greatly exceed those obtained using Factor Xa cleavage, as the reaction of BNPS-Skatole is insensitive to the presence of detergents and denaturants, and therefore can be used to produce highly aggregative and low solubility peptides such as Aß55. Trp is a low abundance amino acid in proteins generally, and for peptides like Aß55, and other transmembane peptides lacking Trp in relevant positions, this cleavage method remains a useful option.

Numerical analysis of thermal response of tissues subjected to high intensity focused ultrasound.

The present work is concerned with the numerical investigation of the thermal response of tissue-mimicking biological phantom(s) subjected to high intensity focused ultrasound (HIFU). Simulations have been performed on the 3-dimensional physical domain for two-layered as well as multi-layered medium consisting of water and liver tissue. Local pressure distribution within the body of the phantom has been calculated by solving the complete full-wave nonlinear form of Westervelt equation. The solution of the pressure wave equation has been coupled with Pennes bioheat transfer equation to determine the full field temperature distribution. Results in the form of pressure fields, temperature distributions and the corresponding thermal dosage in the targeted region of the tissue domain have been presented. Magnitudes of the maximum pressure (and hence the resultant temperature levels) in the focal region as obtained using the nonlinear form of Westervelt equation are found to be significantly higher than that determined based on the linear form of the equation. Compared to water, wherein the acoustic intensity is maximum, the addition of sub-layers of skin, fat, and muscle into water resulted in the reduction of the peak intensity and also shifted the intensity profiles along the direction of propagation of the acoustic waves. However, addition of liver tissue into water led to the shifting of intensity profile in the opposite direction i.e., towards the transducer. The results further reveal that due to the dependence of attenuation coefficient on the source frequency, the temperature at the focal region increases with an increase in the transducer frequency. The work is further extended from single lesion to multiple lesion generation through controlled movement of the transducer and the resultant transient full field temperature distribution has been presented. The concerned observations highlight the need of optimizing the thermal energy for each lesion, the inter spatial distance between different lesions and the delay time so as to ensure minimal thermal damage to the surrounding healthy cells as well as to reduce the total treatment duration.

Non-Native Metal Ion Reveals the Role of Electrostatics in Synaptotagmin 1-Membrane Interactions.

C2 domains are independently folded modules that often target their host proteins to anionic membranes in a Ca2+-dependent manner. In these cases, membrane association is triggered by Ca2+ binding to the negatively charged loop region of the C2 domain. Here, we used a non-native metal ion, Cd2+, in lieu of Ca2+ to gain insight into the contributions made by long-range Coulombic interactions and direct metal ion-lipid bridging to membrane binding. Using X-ray crystallography, NMR, Förster resonance energy transfer, and vesicle cosedimentation assays, we demonstrate that, although Cd2+ binds to the loop region of C2A/B domains of synaptotagmin 1 with high affinity, long-range Coulombic interactions are too weak to support membrane binding of individual domains. We attribute this behavior to two factors: the stoichiometry of Cd2+ binding to the loop regions of the C2A and C2B domains and the impaired ability of Cd2+ to directly coordinate the lipids. In contrast, electron paramagnetic resonance experiments revealed that Cd2+ does support membrane binding of the C2 domains in full-length synaptotagmin 1, where the high local lipid concentrations that result from membrane tethering can partially compensate for lack of a full complement of divalent metal ions and specific lipid coordination in Cd2+-complexed C2A/B domains. Our data suggest that long-range Coulombic interactions alone can drive the initial association of C2A/B with anionic membranes and that Ca2+ further augments membrane binding by the formation of metal ion-lipid coordination bonds and additional Ca2+ ion binding to the C2 domain loop regions.

Numerical investigation of thermal response of laser-irradiated biological tissue phantoms embedded with gold nanoshells.

The work presented in this paper focuses on numerically investigating the thermal response of gold nanoshells-embedded biological tissue phantoms with potential applications into photo-thermal therapy wherein the interest is in destroying the cancerous cells with minimum damage to the surrounding healthy cells. The tissue phantom has been irradiated with a pico-second laser. Radiative transfer equation (RTE) has been employed to model the light-tissue interaction using discrete ordinate method (DOM). For determining the temperature distribution inside the tissue phantom, the RTE has been solved in combination with a generalized non-Fourier heat conduction model namely the dual phase lag bio-heat transfer model. The numerical code comprising the coupled RTE-bio-heat transfer equation, developed as a part of the current work, has been benchmarked against the experimental as well as the numerical results available in the literature. It has been demonstrated that the temperature of the optical inhomogeneity inside the biological tissue phantom embedded with gold nanoshells is relatively higher than that of the baseline case (no nanoshells) for the same laser power and operation time. The study clearly underlines the impact of nanoshell concentration and its size on the thermal response of the biological tissue sample. The comparative study concerned with the size and concentration of nanoshells showed that 60nm nanoshells with concentration of 5×1015mm-3 result into the temperature levels that are optimum for the irreversible destruction of cancer infected cells in the context of photo-thermal therapy. To the best of the knowledge of the authors, the present study is one of the first attempts to quantify the influence of gold nanoshells on the temperature distributions inside the biological tissue phantoms upon laser irradiation using the dual phase lag heat conduction model.

Mapping the Hydrogen Bond Networks in the Catalytic Subunit of Protein Kinase A Using H/D Fractionation Factors.

Protein kinase A is a prototypical phosphoryl transferase, sharing its catalytic core (PKA-C) with the entire kinase family. PKA-C substrate recognition, active site organization, and product release depend on the enzyme's conformational transitions from the open to the closed state, which regulate its allosteric cooperativity. Here, we used equilibrium nuclear magnetic resonance hydrogen/deuterium (H/D) fractionation factors (φ) to probe the changes in the strength of hydrogen bonds within the kinase upon binding the nucleotide and a pseudosubstrate peptide (PKI5-24). We found that the φ values decrease upon binding both ligands, suggesting that the overall hydrogen bond networks in both the small and large lobes of PKA-C become stronger. However, we observed several important exceptions, with residues displaying higher φ values upon ligand binding. Notably, the changes in φ values are not localized near the ligand binding pockets; rather, they are radiated throughout the entire enzyme. We conclude that, upon ligand and pseudosubstrate binding, the hydrogen bond networks undergo extensive reorganization, revealing that the open-to-closed transitions require global rearrangements of the internal forces that stabilize the enzyme's fold.

Conformational propensities and dynamics of a ßγ-crystallin, an intrinsically disordered protein.

The three-dimensional folded structure of a protein has been considered essential for its function. However, recently many proteins have been identified to function without having a definite structure and they have been classified as intrinsically disordered proteins (IDPs). Recently, we have identified a ßγ-crystallin domain in the genome of a marine bacterium called Hahella chejuensis on the basis of known sequence signatures. This protein, called Hahellin, was characterized by NMR spectroscopy as an IDP, which upon Ca(2+)-binding was shown to undergo a large conformational transformation and acquires a typical ßγ-crystallin fold. In this paper, we have characterized this IDP by a combined use of NMR and Replica Exchange Molecular Dynamics simulation and found it to be in a highly dynamic, inter-converting population having a molten globular state with the C-terminal Greek key motif relatively more flexible as compared to its N-terminal counterpart. Network analysis and clustering on the observed conformational ensemble showed a heterogeneous mixture of eleven distinct clusters, classified into near-native and far-native populations, which are not in equilibrium. Several conformational clusters display an increased propensity for helical conformation(s) and a decreased ß-strand propensity, which is consistent with the NMR observations made on this protein. The negatively charged Ca(2+)-coordinating residues form parts of the highly flexible polypeptide stretches, and thus act as seeds for the origin of different conformational clusters observed. This study thus helps us to understand the relationship between the role of conformational dynamics and the structural propensities of the intrinsically disordered state of apo-Hahellin.

Application of the windowed-Fourier-transform-based fringe analysis technique for investigating temperature and concentration fields in fluids.

The present work is concerned with the development and application of a novel fringe analysis technique based on the principles of the windowed-Fourier-transform (WFT) for the determination of temperature and concentration fields from interferometric images for a range of heat and mass transfer applications. Based on the extent of the noise level associated with the experimental data, the technique has been coupled with two different phase unwrapping methods: the Itoh algorithm and the quality guided phase unwrapping technique for phase extraction. In order to generate the experimental data, a range of experiments have been carried out which include cooling of a vertical flat plate in free convection conditions, combustion of mono-propellant flames, and growth of organic as well as inorganic crystals from their aqueous solutions. The flat plate and combustion experiments are modeled as heat transfer applications wherein the interest is to determine the whole-field temperature distribution. Aqueous-solution-based crystal growth experiments are performed to simulate the mass transfer phenomena and the interest is to determine the two-dimensional solute concentration field around the growing crystal. A Mach-Zehnder interferometer has been employed to record the path-integrated quantity of interest (temperature and/or concentration) in the form of interferometric images in the experiments. The potential of the WFT method has also been demonstrated on numerically simulated phase data for varying noise levels, and the accuracy in phase extraction have been quantified in terms of the root mean square errors. Three levels of noise, i.e., 0%, 10%, and 20% have been considered. Results of the present study show that the WFT technique allows an accurate extraction of phase values that can subsequently be converted into two-dimensional temperature and/or concentration distribution fields. Moreover, since WFT is a local processing technique, speckle patterns and the inherent noise in the interferometric data do not affect the resultant phase values. Brief comparisons of the accuracy of the WFT with other standard techniques such as conventional Fourier-filtering methods are also presented.

Inhibiting SIRT-2 by AK-7 restrains airway inflammation and oxidative damage promoting lung resurgence through NF-kB and MAP kinase signaling pathway.

Introduction: Chronic obstructive pulmonary disease (COPD) is a major global cause of mortality with limited effective treatments. Sirtuins (SIRT) are histone deacetylases that are involved in the regulation of redox and inflammatory homeostasis. Hence, the present study aims to investigate the role of SIRT-2 in modulating inflammation in a murine model of COPD. Methods: COPD in mice was established by cigarette smoke (CS) exposure for 60 days, and AK-7 was used as the specific SIRT-2 inhibitor. AK-7 (100 µg/kg and 200 µg/kg body weight) was administered intranasally 1 h before CS exposure. Molecular docking was performed to analyze the binding affinity of different inflammatory proteins with AK-7. Results: Immune cell analysis showed a significantly increased number of macrophages (F4/80), neutrophils (Gr-1), and lymphocytes (CD4+, CD8+, and CD19+) in the COPD, group and their population was declined by AK-7 administration. Total reactive oxygen species, total inducible nitric oxide synthase, inflammatory mediators such as neutrophil elastase, C-reactive protein, histamine, and cytokines as IL4, IL-6, IL-17, and TNF-α were elevated in COPD and declined in the AK-7 group. However, IL-10 showed reverse results representing anti-inflammatory potency. AK-7 administration by inhibiting SIRT-2 decreased the expression of p-NF-κB, p-P38, p-Erk, and p-JNK and increased the expression of Nrf-2. Furthermore, AK-7 also declined the lung injury by inhibiting inflammation, parenchymal destruction, emphysema, collagen, club cells, and Kohn pores. AK-7 also showed good binding affinity with inflammatory proteins. Discussion: The current study reveals that SIRT-2 inhibition mitigates COPD severity and enhances pulmonary therapeutic interventions, suggesting AK-7 as a potential therapeutic molecule for COPD medication development.

Blocking µ-opioid receptor by naltrexone exaggerates oxidative stress and airway inflammation via the MAPkinase pathway in a murine model of asthma.

Opioids regulate various physiological and pathophysiological functions, including cell proliferation, immune function, obesity, and neurodegenerative disorders. They have been used for centuries as a treatment for severe pain, binding to opioid receptors a specific G protein-coupled receptor. Common opioids, like ß-endorphin, [D-Ala2, N-MePhe4, Gly-ol]-enkephalin (DAMGO), and dynorphins, have analgesic effects. The use of a potent antagonist, like naltrexone hydrochloride, to block the effects of mu Opioid Receptor (µOR) may result in the withdrawal of physiological effects and could potentially impact immune responses in many diseases including respiratory disease. Asthma is a respiratory disease characterized by airway hyperresponsiveness, inflammation, bronchoconstriction, chest tightness, stress generation and release of various cytokines. Airway inflammation leads recruitment and activation of immune cells releasing mediators, including opioids, which may modulate inflammatory response by binding to their respective receptors. The study aims to explore the role of µOR antagonist (naltrexone) in regulating asthma pathophysiology, as the regulation of immune and inflammatory responses in asthma remains unclear. Balb/c mice were sensitized intranasally by 1% TDI and challenged with 2.5% TDI. Naltrexone hydrochloride (1 mg/kg body weight) was administered through intraperitoneal route 1 h before TDI induction. Blocking µOR by naltrexone exacerbates airway inflammation by recruiting inflammatory cells (lymphocytes and neutrophils), enhancing intracellular Reactive oxygen species in bronchoalveolar lavage fluid (BALF), and inflammatory mediator (histamine, Eosinophil peroxidase and neutrophil elastase) in lungs. Naltrexone administration modulated inflammatory cytokines (TNF-α, IL-4, IL-5, IL-6, IL-10, and IL-17A), and enhanced IgE and CRP levels. Naltrexone administration also increased the expression of NF-κB, and phosphorylated p-P38, p-Erk, p-JNK and NF-κB by inhibiting the µOR. Docking study revealed good binding affinity of naltrexone with µOR compared to δ and κ receptors. In future it might elucidate potential therapeutic against many respiratory pathological disorders. In conclusion, µOR blocking by naltrexone regulates and implicates inflammation, bronchoconstriction, and lung physiology.

Local incomplete combustion emissions define the PM2.5 oxidative potential in Northern India.

The oxidative potential (OP) of particulate matter (PM) is a major driver of PM-associated health effects. In India, the emission sources defining PM-OP, and their local/regional nature, are yet to be established. Here, to address this gap we determine the geographical origin, sources of PM, and its OP at five Indo-Gangetic Plain sites inside and outside Delhi. Our findings reveal that although uniformly high PM concentrations are recorded across the entire region, local emission sources and formation processes dominate PM pollution. Specifically, ammonium chloride, and organic aerosols (OA) from traffic exhaust, residential heating, and oxidation of unsaturated vapors from fossil fuels are the dominant PM sources inside Delhi. Ammonium sulfate and nitrate, and secondary OA from biomass burning vapors, are produced outside Delhi. Nevertheless, PM-OP is overwhelmingly driven by OA from incomplete combustion of biomass and fossil fuels, including traffic. These findings suggest that addressing local inefficient combustion processes can effectively mitigate PM health exposure in northern India.

ß-Endorphin (an endogenous opioid) inhibits inflammation, oxidative stress and apoptosis via Nrf-2 in asthmatic murine model.

Asthma, a chronic respiratory disease is characterized by airway inflammation, remodelling, airflow limitation and hyperresponsiveness. At present, it is considered as an umbrella diagnosis consisting several variable clinical presentations (phenotypes) and distinct pathophysiological mechanisms (endotypes). Recent evidence suggests that oxidative stress participates in airway inflammation and remodelling in chronic asthma. Opioids resembled by group of regulatory peptides have proven to act as an immunomodulator. ß-Endorphin a natural and potent endogenous morphine produced in the anterior pituitary gland play role in pain modulation. Therapeutic strategy of many opioids including ß-Endorphin as an anti­inflammatory and antioxidative agent has not been yet explored despite its promising analgesic effects. This is the first study to reveal the role of ß-Endorphin in regulating airway inflammation, cellular apoptosis, and oxidative stress via Nrf-2 in an experimental asthmatic model. Asthma was generated in balb/c mice by sensitizing with 1% Toulene Diisocyanate on day 0, 7, 14 and 21 and challenging with 2.5% Toulene Diisocyanate from day 22 to 51 (on every alternate day) through intranasal route. ß-Endorphin (5 µg/kg) was administered through the nasal route 1 h prior to sensitization and challenge. The effect of ß-Endorphin on pulmonary inflammation and redox status along with parameters of oxidative stress were evaluated. We found that pre-treatment of ß-Endorphin significantly reduced inflammatory infiltration in lung tissue and cell counts in bronchoalveolar lavage fluid. Also, pre-treatment of ß-Endorphin reduced reactive oxygen species, Myeloperoxidase, Nitric Oxide, Protein and protein carbonylation, Glutathione Reductase, Malondialdehyde, IFN-γ, and TNF-α. Reversely, ß-Endorphin significantly increased Superoxide dismutase, Catalase, glutathione, Glutathione-S-Transferase, and activation of NF-E2-related factor 2 (Nrf-2) via Kelch-like ECH-associated protein 1 (Keap1), independent pathway in the lung restoring architectural alveolar and bronchial changes. The present findings reveal the therapeutic potency of ß-END in regulating asthma by Keap-1 independent regulation of Nrf-2 activity. The present findings reveal the therapeutic potency of ß-Endorphin in regulating asthma.