General Capillary Endothelial Cells Undergo Reprogramming into Arterial Endothelial Cells in Pulmonary Hypertension through HIF-2α/Notch4 Pathway.

Pulmonary arterial hypertension (PAH) is characterized by a progressive increase of pulmonary vascular resistance and obliterative pulmonary vascular remodeling that result in right heart hypertrophy, failure, and premature death. The underlying mechanisms of loss of distal capillary endothelial cells (ECs) and obliterative vascular lesion formation remain unclear. Our recent single-cell RNA sequencing, spatial transcriptomics analysis, RNASCOPE, and immunostaining analysis showed that arterial ECs accumulation and loss of capillary ECs were evident in human PAH patients and pulmonary hypertension (PH) rodents. Pseudotime trajectory analysis of the single-cell RNA sequencing data suggest that lung capillary ECs transit to arterial ECs during the development of PH. Our study also identified CXCL12 as the marker for arterial ECs in PH. Capillary EC lineage tracing approach using capillary specific-Dre;Tdtomato reporter mice demonstrated that capillary ECs gave rise to arterial ECs during PH development. Genetic deletion of HIF-2a or pharmacological inhibition of Notch4 normalized the arterial programming in PH. In conclusion, our study demonstrates that capillary endothelium transits to arterial endothelium through the HIF-2a-Notch4 pathway during the development of PAH. Thus, targeting arterial EC transition might be a novel approach for treating PAH patients.

Single-cell and Spatial Transcriptomics Identified Fatty Acid-binding Proteins Controlling Endothelial Glycolytic and Arterial Programming in Pulmonary Hypertension.

Pulmonary arterial hypertension (PAH) is a devastating disease characterized by obliterative vascular remodeling and persistent increase of vascular resistance, leading to right heart failure and premature death. Understanding the cellular and molecular mechanisms will help develop novel therapeutic approaches for PAH patients. Single-cell RNA sequencing (scRNAseq) analysis found that both FABP4 and FABP5 were highly induced in endothelial cells (ECs) of Egln1Tie2Cre (CKO) mice, which was also observed in pulmonary arterial ECs (PAECs) from idiopathic PAH (IPAH) patients, and in whole lungs of pulmonary hypertension (PH) rats. Plasma levels of FABP4/5 were upregulated in IPAH patients and directly correlated with severity of hemodynamics and biochemical parameters using plasma proteome analysis. Genetic deletion of both Fabp4 and 5 in CKO mice (Egln1Tie2Cre/Fabp4-5-/- ,TKO) caused a reduction of right ventricular systolic pressure (RVSP) and RV hypertrophy, attenuated pulmonary vascular remodeling and prevented the right heart failure assessed by echocardiography, hemodynamic and histological analysis. Employing bulk RNA-seq and scRNA-seq, and spatial transcriptomic analysis, we showed that Fabp4/5 deletion also inhibited EC glycolysis and distal arterial programming, reduced ROS and HIF-2α expression in PH lungs. Thus, PH causes aberrant expression of FABP4/5 in pulmonary ECs which leads to enhanced ECs glycolysis and distal arterial programming, contributing to the accumulation of arterial ECs and vascular remodeling and exacerbating the disease.

Ferrochrome slag: A critical review of its properties, environmental issues and sustainable utilization.

Ferrochrome slag (FCS) is a by-product of ferrochrome industries and is produced during the extraction of ferrochrome from chromite ore. The chemical composition of FCS comprises of 27-33% SiO2, 15-25% Al2O3, 20-35% MgO, and 10-15% iron-chromium compounds. The high chromium content of FCS and the possibility of its leaching into the environment categorize FCS as hazardous waste material. For each ton of ferrochrome production, nearly 1.2-1.5 tons of FCS is generated, which becomes a significant challenge for the ferrochrome producers while managing this hazardous waste. Therefore, several research attempts have been made to observe the leaching characteristics of chromium (VI) in FCS, its stabilization, and subsequent potential utilization. The high mechanical properties of FCS have led many researchers worldwide to utilize it as a construction material. This review work has undertaken FCS's physical, chemical, and microstructural characteristics and its following utilization as a fine and coarse aggregate in producing green and sustainable concrete. Different methods of stabilizing chromium (VI), including the physical, chemical, and biological methods, are extensively discussed in this review. This article also accommodated FCS as a precursor material in geopolymer and alkali-activated binders. However, the compressive strength achieved with FCS as a binder in geopolymer is very low, and thus more studies are needed to establish the possibility of strength enhancement. The leaching aspects of geopolymers with FCS also need to be studied extensively for their successive application. Lastly, the conclusions and discussion of this study have keenly addressed the significant challenges to the safe utilization of FCS in construction applications. Also, it deliberates on how the emerging research on FCS, such as refractory, composites, and coating material, can be new avenues for its utilization without any potential threat to the environment.

Development of the India COVID-19 vaccine tracker.

COVID-19 was declared a pandemic by the World Health Organization (WHO) on March 11, 2020. Since then, efforts were initiated to develop safe and effective vaccines. Till date, 11 vaccines have been included in the WHO's emergency use list. The emergence and spread of variant strains of SARS-CoV-2 has altered the disease transmission dynamics, thus creating a need for continuously monitoring the real-world effectiveness of various vaccines and assessing their overall impact on disease control. To achieve this goal, the Indian Council of Medical Research (ICMR) along with the Ministry of Health and Family Welfare, Government of India, took the lead to develop the India COVID-19 Vaccination Tracker by synergizing three different public health databases: National COVID-19 testing database, CoWIN vaccination database and the COVID-19 India portal. A Vaccine Data Analytics Committee (VDAC) was constituted to advise on various modalities of the proposed tracker. The VDAC reviewed the data related to COVID-19 testing, vaccination and patient outcomes available in the three databases and selected relevant data points for inclusion in the tracker, following which databases were integrated, using common identifiers, wherever feasible. Multiple data filters were applied to retrieve information of all individuals ≥18 yr who died after the acquisition of COVID-19 infection with or without vaccination, irrespective of the time between vaccination and test positivity. Vaccine effectiveness (VE) against the reduction of mortality and hospitalizations was initially assessed. As compared to the hospitalization data, mortality reporting was found to be much better in terms of correctness and completeness. Therefore, hospitalization data were not considered for analysis and presentation in the vaccine tracker. The vaccine tracker thus depicts VE against mortality, calculated by a cohort approach using person-time analysis. Incidence of COVID-19 deaths among one- and two-dose vaccine recipients was compared with that among unvaccinated groups, to estimate the rate ratios (RRs). VE was estimated as 96.6 and 97.5 per cent, with one and two doses of the vaccines, respectively, during the period of reporting. The India COVID-19 Vaccination Tracker was officially launched on September 9, 2021. The high VE against mortality, as demonstrated by the tracker, has helped aid in allaying vaccine hesitancy, augmenting and maintaining the momentum of India's COVID-19 vaccination drive.

A Comprehensive Overview on COVID-19: Future Perspectives.

The outbreak of COVID-19 has proven to be an unprecedented disaster for the whole world. The virus has inflicted billion of lives across the globe in all aspects-physically, psychologically, as well as socially. Compared to the previous strains of ß-CoV genera- MERS and SARS, SARS-CoV-2 has significantly higher transmissibility and worst post-recovery implications. A frequent mutation in the initial SARS-CoV-2 strain has been a major cause of mortalities (approx. 3 million deaths) and uncontrolled virulence (approx. 1 billion positive cases). As far as clinical manifestations are concerned, this particular virus has exhibited deleterious impacts on systems other than the respiratory system (primary target organ), such as the brain, hematological system, liver, kidneys, endocrine system, etc. with no promising curatives to date. Lack of emergency treatments and shortage of life-saving drugs has promoted the repurposing of existing therapeutics along with the emergence of vaccines with the combined efforts of scientists and industrial experts in this short span. This review summarizes every detail on COVID-19 and emphasizes undermining the future approaches to minimize its prevalence to the remaining lives.

Hypoxia-mediated alterations in pulmonary surfactant protein expressions: Beneficial effects of quercetin prophylaxis.

We have compared the prophylactic efficacies of quercetin and salbutamol in preventing pulmonary surfactants oxidation under hypoxia. Male SD rats supplemented orally with quercetin (50 mg/Kg BW) and salbutamol (2 mg/Kg BW) were exposed to hypobaric hypoxia (7,620 m for 6 h). Hypoxia-mediated elevation in oxidative stress, inflammation, and extravasations of LDH & albumin content in BALF of rats were assessed. Western blotting and mRNA studies determined the differential expressions of Nrf-2, HO-1, and associated surfactant proteins (SP-A, SP-B, SP-C, & SP-D) in rat lungs. Later, the lung configuration under hypoxia was assessed histopathologically. Quercetin and salbutamol pretreatment considerably restored the expressions of Nrf-2, HO-1, and surfactant proteins to normal by attenuating the increase in oxidative stress, inflammation, and extravasations of plasma proteins in the animals under hypoxia. The histopathology has also evidenced the protective effect of quercetin in retaining normal lung architecture under hypoxia over salbutamol. The present study indicates the effectiveness of quercetin prophylaxis in preventing pulmonary surfactants oxidation under hypoxia over salbutamol.

Quercetin: a savior of alveolar barrier integrity under hypoxic microenvironment.

High altitude pulmonary edema (HAPE) is generally characterized by the loss of alveolar epithelial barrier integrity. The current study was undertaken to assess the noninvasive approaches of HAPE diagnosis and to evaluate the prophylactic potential of quercetin in preventing alveolar junction impairments. Male SD rats fed with quercetin 1 h prior to hypoxia (7,620 m, for 6 h) were selected. PET/CT imaging was performed to visualize the lung uptake of 18F-FDG in animals under hypoxia. Further, oxidant status, catalase activity, hematological & blood gas parameters were evaluated. Moreover, tight junction (TJ) proteins (ZO-1, JAM-C, Claudin-4, and occludin) expression analysis was accomplished using immune-blotting. The structural differences in lung epithelia were noted by TEM imaging. Quercetin prophylaxis has significantly reduced the FDG uptake in rat lungs under hypoxia. It has also dramatically alleviated the protein oxidation followed by an elevation in catalase activity in the lungs under hypoxia. The TJ protein expression in the lungs has also been restored to normal upon quercetin pre-treatment. Concomitantly, the quercetin preconditioning has elicited the stable blood gas and hematological parameters under hypoxia. The observations from TEM imaging have also implicated the normal lung epithelial structures in the quercetin pretreated animals under hypoxia. Quercetin prophylaxis has significantly restored alveolar epithelium integrity by abating oxidative stress in the lungs under hypoxia.Abbreviations: CT- Computed Tomography18F-FDG- Fluorodeoxyglucose (18FHAPE- High Altitude Pulmonary EdemaHb- HemoglobinHCT- HematocritHCO3- BicarbonateJAM- Junctional Adhesion MoleculeKBq- Killo BecquerelPaO2- Partial pressure of arterial oxygenPaCO2- Partial pressure of arterial carbon di-oxidePET- Positron Emission TomographyRBC- Red Blood CorpusclesSD- Sprague DawleyTJ- Tight JunctionsTEM- Transmission Electron MicroscopyWBC- White Blood CorpusclesZO- Zona Occludin.

Efficacy of Quercetin as a potent sensitizer of ß2-AR in combating the impairment of fluid clearance in lungs of rats under hypoxia.

BACKGROUND: Hypoxia reportedly increases free radical generation in the body, causing oxidative stress and inhibiting ß2-AR signaling. The present study correlates the prophylactic potential of quercetin and salbutamol in ameliorating fluid clearing capacity of lungs by re-sensitizing ß2-AR signaling under hypoxia. METHODS: Male SD rats supplemented orally with quercetin (50 mg/Kg BW), and salbutamol (2 mg/Kg BW) were exposed to hypobaric hypoxia at 7620 m for 6 h. Western blotting and ELISA quantitated NFĸB and related genes and GPCR pathway proteins. The binding affinities of drugs with receptor were determined by SPR spectroscopy and further confirmed insilico. RESULTS: Quercetin and salbutamol pre-treatment significantly up-regulated the expressions of ß2-AR, GPR-1, GPR-10, GCSα, cAMP content, and down-regulated GRK-2, ß-arrestin, ROS, NFκB (p < 0.001), thus, enhancing alveolar fluid clearance (AFC). SPR and insilico findings revealed a higher binding affinity of ß2-AR with quercetin over salbutamol. CONCLUSION: Results indicated quercetin to be a better prophylactic that augmented AFC in rats exposed to hypoxia by attenuating inflammation and stimulating ß2-AR.

Prophylactic efficacy of Quercetin in ameliorating the hypoxia induced vascular leakage in lungs of rats.

The objective of the study was to find out the prophylactic efficacy of Quercetin in ameliorating the hypoxia induced vascular leakage in lungs of rats. Male SD rats received different doses of quercetin @ 25mg, 50mg, 100mg and 200mg/Kg BW, 1h prior to hypobaric hypoxia exposure (7,620m, for 6h). Quercetin 50 mg/kg BW supplemented orally 1h prior to hypoxia exposure was considered to be the optimum dose, due to significant reduction (p<0.001) in lung water content and lung transvascular leakage compared to control (hypoxia, 6h). Further, biochemical analysis (ROS, MDA, GSH, GPx, LDH, and albumin) and differential expressions of proteins (IKK-α/ß, NFĸB, Nrf-2,TNF-α, ICAM-1, VCAM, P-selectin, Hif-1α, VEGF, TNF-α, TGF-ß, INF-γ and IL-4) were determined by western blotting and ELISA. Changes in lung parenchyma were assessed by histopathology. Quercetin (50 mg/kg BW) prophylaxis under hypoxia showed significant reduction in oxidative stress (ROS and MDA), concomitant increase in antioxidants (GSH, GPx and SOD) followed by decreased LDH and albumin extravasation in BAL fluid over hypoxia. Quercetin prophylaxis significantly down regulated hypoxia induced increase in IKKα/ß and NFĸB expressions leading to reduction in the levels of pro-inflammatory cytokines (TNF-α and INF-γ) followed by up regulation of anti-inflammatory cytokines (IL-4 and INF-γ) in lungs. Further, hypoxia mediated increase in HIF-1α was stabilized and VEGF levels in lungs were significantly down regulated by quercetin supplementation, leading to reduction in vascular leakage in lungs of rats under hypoxia. However, Quercetin has also enacted as Nrf-2 activator which significantly boosted up the synthesis of GSH under hypoxic condition compared to hypoxia. Histopathological observations further confirmed that quercetin preconditioning has an inhibitory effect on progression of oxidative stress and inflammation via attenuation of NFκB and stabilization HIF-1α in lungs of rats under hypoxia.These studies indicated that quercetin prophylaxis abrogates the possibility of hypobaric hypoxia induced pulmonary edema in rats.

Docking studies on novel alkaloid tryptanthrin and its analogues against enoyl-acyl carrier protein reductase (InhA) of Mycobacterium tuberculosis.

Isoniazid resistance is a serious threat in the battle against the treatment of multi-drug resistant tuberculosis (MDR-TB) and extremely drug-resistant tuberculosis (XDR-TB). Isoniazid is an inhibitor of enoyl-acyl carrier protein reductase (InhA) of Mycobacterium tuberculosis, which is an important and functional enzyme of the type II fatty acid synthesis system and important therapeutic target. Natural alkaloid tryptanthrin and its analogues have shown anti-tubercular activity against MDR-TB, but their cellular target is unknown. In this work, in silico molecular docking was performed using docking server in order to see the interaction of tryptanthrin and its 15 analogues with InhA of M. tuberculosis. Results showed that among tryptanthrin and its 15 analogues, tryptanthrin and its two analogues exhibited good affinity to the binding site of InhA with free binding energy of -7.94 kcal/mol and inhibition constant (Ki) of 1.50 microm. Active site residues of InhA interacting with tryptanthrin were Ser13, Thr39, Phe41, Leu63, Asp64, Val65, Ile95, Phe97 and Ile122. In binding mode, polar bond were found between O1 (1) with Asp64 of bond length (3.34 A) and hydrophobic bonds were found between Leu63 with C15 and C12, Val65 with C7, Val65 with C12 and C4, Ile95 with C6 and C7, Ile95 with C10, C12 and C14. Important pi-pi bonds were found between Phe41 with C2, C5, C7, C12, C4, C6, C8, C9, C13 and Phe97 with C9. These interactions indicated stability of tryptanthrin in active residue and suggested it as a potential drug candidate. Thus, good affinity of tryptanthrin to binding site of InhA may lead to synthesis of anti-tubercular drug capable of combating MDR strains of M. tuberculosis.