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The metal nanoparticles (MNPs) are tremendously being used as growth-promoting agents in agricultural crops. One such MNP is iron nanoparticle (FeNP) as iron is an essential growth element for plants. In the current study, a unique method is employed to recycle kitchen waste (KW) and employ it in the synthesis of FeNPs. Further, the growth-promoting activity of these particles was assessed on Vigna radiata (Mung bean). The FeNPs were prepared using KW extract containing crucial phytocompounds as identified using GC-MS analysis. The synthesized KW-FeNPs were ellipsoidal/spherical in shape (150–185 nm) and had -6.14 mV Z-potential. Nano-priming of the seeds at varying concentrations of FeNPs (50–150 ppm) was done before germination of the seeds along with spraying of FeNPs throughout the growth period of the plantlets. In vitro and in vivo growth parameters were evaluated after the 10th and 21st day respectively. The seedlings sprayed with 150 ppm KW-FeNPs showed a highly significant increase in SL (21.63 ± 2.66 cm), RL (7.21 ± 2.11), and seedling length (28.85 ± 2.41) when compared to the control. The lower values of the S/R ratio (3.40–4.49) and increased number of lateral roots were seen in seedlings treated with Kw-FeNPs. A significant (13.02 ± 0.12 mg/g of leaves) and highly significant (17.01 ± 0.82 mg/g of leaves) increase in chlorophyll content was observed in 100 and 150 ppm KW-FeNPs treated plantlets respectively. The synthesized NPs were able to stimulate seedling and plantlet growth even at lower concentrations. A dose-dependent increase in all the plant growth parameters was observed till 150 ppm KW-FeNPs treatment without any visible sign of oxidative stress. The present research work has successfully utilized kitchen waste in the synthesis of a metal-based nanofertilizer for sustainable agricultural practice. [Display omitted] • The study highlights recycling of kitchen waste in production of iron nanoparticles. • Enhanced growth of Vigna radiata was observed in the presence of KW-FeNPs. • KW-FeNPs treatment showed a significant increase in G%, SL, RL, seedling length and lateral roots of Vigna radiata. • Increased chlorophyll content indicated improved photosynthetic rates after KW-FeNPs treatment. • No doses of KW-FeNPs show oxidative stress in plantlets. [ABSTRACT FROM AUTHOR]

The precise regulation of gene expression is required for the determination of cell fate, differentiation, and developmental programs in eukaryotes. The Polycomb Group (PcG) genes are the key transcriptional regulators that constitute the repressive system, with two major protein complexes, Polycomb Repressive Complex 1 (PRC1) and Polycomb Repressive Complex 2 (PRC2). Previous studies have demonstrated the significance of these proteins in regulation of normal growth and development processes. However, the role of PcG in adaptation of crops to abiotic stress is still not well understood. The present study aimed to a comprehensive genome-wide identification of the PcG gene family in one of the economically important staple crops, Oryza sativa. Here, a total of 14 PcG genes have been identified, which were distributed over eight chromosomes. Protein structure analysis revealed that both the complexes have distinct domain and motifs that are conserved within the complexes. In silico promoter analysis showed that PcG gene promoters have abundance of abiotic stress-responsive elements. RNA-seq based expression analysis revealed that PcG genes are differentially expressed in different tissues and responded variably in different environmental stress. Validation of gene expression by qRT-PCR showed that most of the genes were upregulated at 1-h time point in shoot tissue and at 24-h time point in root tissue under the drought and salinity stress conditions. These findings provide important and extensive information on the PcG family of O. sativa, which will pave the path for understanding their role in stress signaling in plants. [ABSTRACT FROM AUTHOR]

Leaf senescence represents an active and regulated degeneration process. Leucine-rich repeat receptor-like protein kinase (LRR-RLK) represents a large group of cell surface receptors that play important roles in multiple biological processes, and some are also known to regulate the senescence process. In the present study, we elucidated the involvement of Phytosulfokine Receptor (PSKR) gene in the regulation of leaf senescence. The expression of PSKR1 of Arabidopsis was found to be up-regulated during leaf senescence. The over-expressing lines of AtPSKR1 and its rice homologue OsPSKR10 displayed an early leaf senescent phenotype in Arabidopsis, while the late senescence in mutant line of AtPSKR1 supported the idea that PSKR positively regulate the process of leaf senescence. Furthermore, the leaves of the overexpressing lines displayed increased superoxide accumulation compared to mutant lines, along with higher expression of NADPH oxidases (AtRBOHD and AtRBOHF). Importantly, our findings demonstrates that both AtPSKR1and OsPSKR10 interact with AtRBOHD and AtRBOHF and thereby instigating superoxide accumulation in the leaves through NADPH oxidases. • Expression of PSKR is up-regulated in the senescent leaves. • Over-expressing lines of AtPSKR1 and OsPSKR10 show an early leaf senescence phenotype. • AtPSKR1 and OsPSKR10 trigger superoxides accumulation in leaves. • AtPSKR1 and OsPSKR10 interact with the NADPH oxidases (AtRBOHD and AtRBOHF). [ABSTRACT FROM AUTHOR]

INTRODUCTION Neonatal sepsis (sepsis neonatorum) is a clinical syndrome resulting from the pathophysiologic effects of local or systemic infection. This is a major cause of morbidity and mortality around the world affecting newborns up to one month of age with clinical symptoms and positive blood cultures. This study aimed at examining the risk factors of neonatal sepsis at pediatric tertiary care hospital. MATERIAL AND METHODS This was a hospital based cross-sectional case control study conducted among 350 neonates admitted within April to September 2015 at the Kanti Children's Hospital, Kathmandu Nepal. Cases were neonates who had sepsis and controls were neonates who did not have sepsis with their index mothers. CRP screening tests and blood culture was performed. Data were entered using the SPSS (Version 22). Bivariate and multivariate logistic regression was used to determine the risk of neonatal sepsis. RESULTS A total of 59 (17%) neonates who had sepsis (cases) with their index mothers' and 291 (83%) neonates who had no sepsis (controls) with their index mothers were enrolled. Maternal factors that predicted the occurrence of sepsis among neonates were parity (p<0.027), mode of delivery (p<0.001) and PROM (p<0.001). Neonatal risk factors which predicted the occurrence of sepsis were duration of stay in the facility (p<0.001) and neonatal age on admission (p<0.001). CONCLUSION The study found both maternal and neonatal factors to have a strong association with the risk of developing neonatal sepsis. Encouraging maternal antenatal care utilization would help identify the risk factors during prenatal and postnatal care and appropriate interventions implemented to reduce the likelihood of the neonate developing sepsis. [ABSTRACT FROM AUTHOR]

The first ever homobimetallic catalyst which efficiently catalyzes the reductive amination (RA) reaction of carbonyl compounds in water is described herein. Two new Ru(II) compounds, homobimetallic [(p-cymene)2(RuCl)2L1] (Ru1) and monometallic [(p-cymene)(RuCl)L2] (Ru2) (where L1 = 2,2′-((1E,1′E)-((3,3′,5,5′-tetraisopropyl-[1,1′-biphenyl]-4,4′diyl)bis-(azaneylylidene))bis(methaneylylidene))diphenoxide) and L2 = (2,6-(((diisopropylphenyl)-imino)methyl)phenoxide) incorporating Schiff-base ligands have been synthesized and characterized by various spectroscopic and analytical techniques. Their molecular structures have been deduced by X-ray diffraction measurements. Both complexes, which are water/air stable at room temperature as well as at high temperature, were employed as catalysts for RA in aqueous media using formate buffer as the hydrogen source. Complex Ru1, in the presence of formic acid/formate buffer as the hydrogen source, catalyzes one-pot RA production of secondary amines in ∼99% yield with just 0.05 mol% of the catalyst exhibiting a turnover number (TON) of 1920 and a turnover frequency (TOF) of 480 h−1. When the catalyst loading was further reduced to 0.0001 mol%, the highest reported TON and TOF for any RA reactions were observed (4.3 × 104 and 107 × 103 h−1, respectively), albeit with reduced selectivity. A comparative study between Ru1 and Ru2 reveals that complex Ru1 is more chemo-selective for the formation of a secondary amine, attributable to a cooperative effect. This cooperative effect is further substantiated through extensive computational methodologies involving Density Functional Theory (DFT) calculations on both bimetallic and monometallic Ru(II) complexes along a hybrid-model complex. [ABSTRACT FROM AUTHOR]

Bisphenols (BPs) are recognized as emerging contaminants because of their estrogenic properties and frequent occurrence in environmental matrices. Here, we evaluated the toxic effects of five common BPs on freshwater microalga Chlamydomonas mexicana and removal of the BPs by the alga. Bisphenols -AF (BPAF), -B (BPB), and -Z (BPZ) (96 h, EC 50 1.78–12.09 mg·L−1) exhibited higher toxicity to C. mexicana compared to bisphenol -S (BPS) and -F (BPF) (96 h, EC 50 30.53–85.48 mg·L−1). In contrast, the mixture of BPs exhibited acute toxicity (96 h, EC 50 8.07 mg·L−1). After 14 days, C. mexicana had effectively removed 61%, 99%, 55%, 87%, and 89% of BPS, BPF, BPAF, BPB, and BPZ, respectively, at 1 mg L−1. The biotransformed products of all five BPs were analyzed using UHPLC QTOF, and their toxicity was predicted. All biotransformed products were observed to be less toxic than the parent compounds. The fatty acid composition of C. mexicana after exposure to the BP mixture was predominantly palmitic acid (34.14%), followed by oleic acid (18.9%), and γ-linolenic acid (10.79%). The results provide crucial information on the ecotoxicity of these five BPs and their removal by C. mexicana ; the resulting biomass is a potential feedstock for producing biodiesel. [Display omitted] • Bisphenol-AF exhibited the highest toxicity to C. mexicana. • C. mexicana effectively removed 99–61% of 1 mg L−1 bisphenols in 14 days. • Biotransformed products of bisphenols in C. mexicana were analyzed. • Palmitic acid in C. mexicana increased significantly after bisphenols exposure. [ABSTRACT FROM AUTHOR]

[Display omitted] • I. pseudacorus completely removed BPS at 0.2 mg/L in 10 days. • Twelve BPS metabolites were identified by high-resolution mass spectrometry. • Developed continuous flow phytoreactor effectively treated BPS spiked wastewater. • Degradation pathways of BPS in aquatic macrophytes are firstly reported. Bisphenol-S (BPS) is recognized as an emerging contaminant due to its potential estrogenic properties and is frequently detected in aquatic environment. The safety and environmental behavior of BPS is controversial. Furthermore, the removal studies of BPS from aqueous environment are scarce. In this study, we assessed the phytoremediation potential of three aquatic macrophytes (Iris pseudacorus, Ipomoea aquatica, and Typha angustifolia) for BPS removal from secondary wastewater effluent. BPS at environmentally relevant concentration (0.005 mg/L) was removed 100 %, 97 % and 97.5 % with I. pseudacorus, I. aquatica and T. angustifolia respectively. Twelve biotransformed products of BPS were identified through gas chromatography mass spectrophotometry. The enzymatic analysis showed induction of both phase I (laccase, 315 %; peroxidase, 739 %, superoxide dismutase, 881 %; aminopyrine N demethylase, 60 %) and phase II enzymes (glutathione S-transferase, 592 %) in the plant roots after 7 days of BPS exposure. A lab-scale vertical phytoreactor was constructed with PVC tubes that completely removed BPS in 14 days along with nutrients (phosphorus and nitrogen) and inorganic (heavy metals) contaminants from the secondary wastewater effluent. An analysis of the microbial diversity in the phytoreactor effluent showed an enhanced relative abundance of the phyla Bacteroidetes (20 %) and Proteobacteria (44 %) after BPS exposure. This study is the first report highlighting the removal of BPS by aquatic macrophyte and its fate in aquatic environments. [ABSTRACT FROM AUTHOR]

The potential of Iris pseudacorus and the associated periphytic biofilm for biodegradation of two common pharmaceutical contaminants (PCs) in urban wastewater was assessed individually and in consortium. An enhanced removal for sulfamethoxazole (SMX) was achieved in consortium (59%) compared to individual sets of I. pseudacorus (50%) and periphytic biofilm (7%) at concentration of 5 mg L−1. Conversely, individual sets of periphytic biofilm (77%) outperformed removal of doxylamine succinate (DOX) compared to individual sets of I. pseudacorus (59%) and consortium (67%) at concentration of 1 mg L−1. Enhanced relative abundance of microflora containing microalgae (Sellaphora , Achnanthidium), rhizobacteria (Acidibacter , Azoarcus , Thioalkalivibrio), and fungi (Serendipita) in periphytic biofilm was observed after treatment. SMX treatment for five days elevated cytochrome P450 enzymes' expressions, including aniline hydroxylase (48%) and aminopyrine N-demethylase (54%) in the periphytic biofilm. Nevertheless, I. pseudacorus showed 175% elevation of aniline hydroxylase along with other biotransformation enzymes, such as peroxidase (629%), glutathione S-transferase (514%), and dichloroindophenol reductase (840%). A floating bed phytoreactor planted with I. pseudacorus and the periphytic biofilm consortium removed 67% SMX and 72% DOX in secondary wastewater effluent. Thus, the implementation of this strategy in constructed wetland-based treatment could be beneficial for managing effluents containing PCs. [Display omitted] • I. pseudacorus and associated biofilm synergistically improved removal of contaminants. • Acidibacter , Serendipita , Sellaphora in biofilm promotes plant growth. • Induction of phase I/II enzymes indicates their role in contaminants degradation. • Developed phytoreactor facilitated effective treatment of wastewater. [ABSTRACT FROM AUTHOR]

Since the discovery of penicillin, antibiotics have been a cornerstone in modern medicine and significantly improved global health. And while decades of overuse, misuse and abuse of antibiotics in hospitals, and in general population, at an ever increasing rate, both when they are needed and when they are not, in human beings and animals have accelerated the emergence and spread of resistant bacteria. Indiscriminate use of antibiotics in veterinary practice, and in animal feeds led to emergence of drug resistant strains, that are transferred to humans. This emergence of drug resistance is a major problem worldwide in antibiotic therapy. Infections caused by resistant microorganisms often fail to respond to the standard treatment, resulting in prolonged illness, longer hospital stays, higher healthcare expenditures, and greater risk of death. This article reviews and focuses on various aspects of development and mechanisms of antibiotic resistance in bacteria, and preventive measures to fight the emerging antibiotic resistance threat. [ABSTRACT FROM AUTHOR]

• A unique was approach adopted for managing solid biodegradable wastes and fly ash. • Potential use of GE with FA on composting of organic waste was evaluated. • Combination of 20% FA, 70.4% BW and 9.6% HW in Vessel 5 showed maximum degradation. • Mature compost sample in vessel 5 showed maximum reduced C: N ratio of 13.68. • FTIR results revealed increased shifting trends from aromatic to aliphatic compounds. The aim of the present work was to study the synergic effect of fly ash (FA) and garbage enzymes (GE) on biotransformation of organic wastes in in-vessel composting system. In-vessel composting of organic waste (household + brown in vessel 1) was performed with fly ash (mixed 5% in vessel 2; 10% in vessel 3; 15% in vessel 4; and 20% in vessel 5) by addition of extra carbon source (5%) and garbage enzyme in a fixed-dose (5%) for 15 days and changes in chemical properties (C: N ratio, nitrates, sulphates, phosphates and macro-elements) were analyzed at maturity. Vessel 5 showed better results in terms of organic matter degradability and C: N ratio (13.68) of mature compost. Principal Component Analysis (PCS) also confirmed vessel 5 as the best performing among other vessels. FTIR analysis indicated a major shift in chemical structure of organic waste due to the composting action. [ABSTRACT FROM AUTHOR]

Background: Help-seeking behaviors are poor in medical professionals and understudied in mental health professions. Beliefs and perceived stigma influence such behavior. Hence, this study was undertaken to assess, compare, and find associations between these factors among medical and mental health professionals. Methods: This cross-sectional online questionnaire-based study was conducted among 150 medical and mental health professionals practicing in Mumbai using Treatment Seeking Behaviour Scale (TSB), Beliefs toward Mental Illness Scale (BTMI), Self-stigma of Seeking Help (SSOSH), and perception of stigmatization by others for Seeking Help (PSOSH) Scales. Google Forms were sent to the consenting participants through social media platforms and WhatsApp. We had a 40% response rate from the participants. Results: Mean BTMI was 76.76 ± 27.40, which was poor, SSOSH (12.96 ± 4.81) was found to be low, but PSOSH (12.46 ± 5.22) was found to be high. Professional TSB (4.24 ± 0.76) was significantly higher than traditional TSB (2.8 ± 0.81). Mental health professionals had significantly lower scores of BTMI (P = 0.001), SSOSH (P = 0.050), PSOSH (P = 0.044), and traditional TSB (P = 0.002) as compared to medical professionals. Scores of BTMI, SSOSH, and PSOSH were positively correlated with traditional TSB and negatively correlated with professional TSB (P < 0.01). Conclusion: BTMIs are poor and the perception of stigmatization by others for seeking help is high among doctors. Mental health professionals fared significantly better on all their beliefs. [ABSTRACT FROM AUTHOR]

Objective: Neonatal sepsis is a major cause of morbidity and mortality of newborns (< 1 month of age). Septicemia and drug resistance is a predominant issue for neonatal death in Nepal. This study is intended to find bacteriological profile of neonatal sepsis and antibiotic susceptibility pattern of the isolates from neonates at Kanti Children's Hospital, Kathmandu, Nepal. Results: Out of 350 suspected cases of neonatal sepsis, 59 (16.9%) cases showed positive blood culture. The prevalent of positive blood culture with different neonatal risk factors (sex, age, birth weight, gestational age, and delivery mode) showed highest positive bacterial growth in male (52.3%); 3 or above 3 days age (71.2%); low birth weight (62.7%); preterm gestational age (31.4%); and caesarean delivery mode (63.3%). Among positive cases, the bacteriological profile was found highest for Staphylococcus aureus (35.6%) followed by Klebsiella pneumoniae (15.3%). The most sensitive and resistive antibiotics among Gram-positive isolates were gentamicin (93%) and ampicillin (78%), respectively. Meropenem and imipenem showed highest 100% effective and cefotaxime was least (28%) sensitive among Gram-negative isolates. This concludes broad ranges of bacteria are associated with neonatal sepsis and revealed variation in antibiotic susceptibility pattern among bacterial isolates. [ABSTRACT FROM AUTHOR]

Acute kidney injury (AKI) leads to acute cardiac injury and dysfunction in cardiorenal syndrome Type 3 (CRS3) through oxidative stress (OS). The stress-inducible Sestrin2 (Sesn2) protein reduces reactive oxygen species (ROS) accumulation and activates AMP-dependent protein kinase (AMPK) to regulate cellular metabolism and energetics during OS. Sesn2 levels and its protective effects decline in the aged heart. Antidiabetic drug metformin upregulates Sesn2 levels in response to ischemia–reperfusion (IR) stress. However, the role of metformin in CRS3 remains unknown. This study seeks to explore how the age-related decrease in cardiac Sesn2 levels contributes to cardiac intolerance to AKI-induced insults, and how metformin ameliorates CRS3 through Sesn2. Young (3–5 months) and aged (21–23 months) C57BL/6J wild-type mice along with cardiomyocyte-specific knockout (cSesn2−/−) and their wild type of littermate (Sesn2f/f) C57BL/6J mice were subjected to AKI for 15 min followed by 24 h of reperfusion. Cardiac and mitochondrial functions were evaluated through echocardiograms and seahorse mitochondria respirational analysis. Renal and cardiac tissue was collected for histological analysis and immunoblotting. The results indicate that metformin could significantly rescue AKI-induced cardiac dysfunction and injury via Sesn2 through an improvement in systolic and diastolic function, fibrotic and cellular damage, and mitochondrial function in young, Sesn2f/f, and especially aged mice. Metformin significantly increased Sesn2 expression under AKI stress in the aged left-ventricular tissue. Thus, this study suggests that Sesn2 mediates the cardioprotective effects of metformin during post-AKI. [ABSTRACT FROM AUTHOR]

Purpose: The primary objective of the study was to assess the macular retinal vessel density, subfoveal choroidal thickness, and retinal layer metrics by optical coherence tomography angiography (OCTA), enhanced-depth imaging optical coherence tomography (EDI-OCT), and spectral domain optical coherence tomography (SD-OCT), respectively, in recovered COVID-19 patients and its comparison with the same in control subjects. The secondary objective was to evaluate differences in OCTA parameters in relation with the severity of COVID-19 disease and administration of corticosteroids. Methods: A case–control study was performed that included patients who had recovered from COVID-19 and age-matched healthy controls. Complete ocular examination including OCTA, SD-OCT, and EDI-OCT were performed three months following the diagnosis. Results: Three hundred sixty eyes of 180 subjects were enrolled between the two groups. A decreased mean foveal avascular zone area in both superficial capillary plexuses (P = 0.03) and deep capillary plexuses (P < 0.01), reduced average ganglion cell layer-inner plexiform layer thickness (P = 0.04), and increased subfoveal choroidal thickness (P < 0.001) were observed among cases in comparison to the control group. A significant correlation was found between sectoral macular vessel density in relation to disease severity and a decrease in vessel density with greater severity of the disease. Conclusion: OCTA detected retinal microvascular alterations following SARS-CoV-2 infection in subjects with the absence of any clinical ocular manifestation or systemic thrombotic events. These parameters could be used to help identify patients with a higher incidence of systemic thromboembolism on longer follow-ups and identify the impact of corticosteroids on retinal architecture. [ABSTRACT FROM AUTHOR]

This study aimed to review the current literature for epidemiology, pathogenesis, clinical spectrum and management of rhino-orbito-cerebral-mucormycosis (ROCM), especially highlighting the association between ROCM and COVID-19 disease and factors resulting in its resurgence during the pandemic. Mucormycosis is a rare, but an important emerging opportunistic fungal infection, often associated with high morbidity and mortality. ROCM is the commonest and also the most aggressive clinical form occurring in debilitated patients in conjunction with sinus or para-sinus involvement due to the propensity for contiguous spread. Recently ROCM has shown an unprecedented resurgence during the current pandemic. Reports from different parts of the world indicated an increased risk and incidence of ROCM in patients who had required hospital admission and have recovered from moderate-to-severe COVID-19 disease. A majority of mucormycosis cases have been reported from India. The presence of diabetes mellitus (DM) and use of corticosteroids for COVID-19 pneumonia were found to be the key risk factors, resulting in higher mortality. Amidst the ongoing pandemic, with the third wave already having affected most of the world, it becomes imperative to adopt a risk-based approach toward COVID-19 patients predisposed to developing ROCM. This could be based on the most recently published literature and emerging data from centers across the world. The present review intended to elucidate the causes that brought about the current spike in ROCM and the importance of its early detection and management to reduce mortality, loss of eye, and the need for mutilating debridement. [ABSTRACT FROM AUTHOR]

Initially dismissed as 'junk DNA', genomic progress highlights the essential role of non-coding regulatory RNAs (ncRNAs) in gene expression. Long non-coding RNA (lncRNAs) and microRNA (miRNAs) play a vital role in regulating diverse plant biological processes. Despite extensive identification and characterization through bioinformatics and RNA-seq, only a limited subset of lncRNAs has been functionally studied. In this particular research, a total of twenty-six drought induced lncRNAs were selected from RNA-seq dataset of Oryza sativa for in depth analysis including in silico promoter analysis and the examination of their expression patterns under abiotic stress conditions, with the aim of unravelling their intricate regulatory mechanisms. Promoter analysis revealed their responsiveness to both ABA-independent and dependent pathways, indicating potential roles in pathway-regulated responses. Notably, three lncRNAs- OsDlnc12, OsDlnc22, and OsDlnc24 found to act as ceRNA (competing endogenous RNAs) for Osa-miR169 family members , Osa-miR2864.2, and Osa-miR1437b-3p respectively. Subsequent target prediction revealed that Osa-miR169 family members target OsNF-YA3, OsNF-YA7, and HAP2 , Osa- miR2864.2 targets OsERD-15, and Osa-miR1437b-3p targets OsCYP450, OsAQP, and OsPRX precursor genes. Furthermore, qRT-PCR was employed to investigate the expression patterns and target mimicry mechanisms of selected lncRNAs under various abiotic stresses, revealing temporally regulated expressions. This finding provides insights into plant regulatory mechanisms under environmental stress, emphasizing the potential importance of lncRNAs in these processes. • 26 drought-responsive lncRNAs were characterized to unravel their intricate regulatory mechanisms in O. sativa. • Abiotic stress-responsive elements were prevalent in promoter of all OsDlncs , indicating their role in abiotic stress. • In rice, Dlncs 12, 22 and 24 were identified as target mimics for miR169f.1, g, r , miR2864.2 , and miR1437b-3p , respectively. • Temporal qRT-PCR analysis provide valuable insights into the dynamic responses of OsDlncs under abiotic stress conditions. [ABSTRACT FROM AUTHOR]

R3217 --> 863.4 --> The regulation of renin release from juxtaglomerular (JG) cells at the systemic or local level has been extensively investigated and well understood. It includes three primary mechanisms: intrarenal baroreceptor, salt feedback via macula densa, and β1‐adrenergic receptor activation. However, further understanding of the control of renin synthesis and secretion in JG cells at the cellular or molecular level is limited. Additionally, JG cells are generally considered to be derived from the smooth muscle (SM) cells in the afferent arterioles via a reversible metaplastic transformation. The number of JG cells could be significantly increased under specific conditions, which is also known as the process of JG cells recruitment. Nevertheless, the similarities and differences at the molecular level between JG cells and SM cells as well as the intracellular mechanisms underlying the JG cells recruitment have not been fully clarified. An emerging technique, the single‐cell RNA sequencing, provides a new tool to precisely investigate the molecular characterization of JG cells. In the present study, we isolated and sequenced a total of 9815 cells from a single‐cell stock derived from the renal cortex of C57BL/6J mice (~20 mg cortical tissue per mouse, n=5). Using stringent quality controls, we further analyzed 7557 cells. Unbiased clustering analysis demonstrated 16 distinct cell clusters in the t‐distributed stochastic neighbor embedding (tSNE) map, and each cell cluster was defined based on the expression level of the representative cell type‐specific marker genes. In particular, a cluster consisting of 284 cells was identified as smooth muscle (SM) cells by the high and distinct expression of both Acta2 (α‐smooth muscle actin) and Tagln (Transgelin). Moreover, on the basis of the expression level of the marker gene Ren1 (Renin), 34 JG cells were further distinguished from this cluster of SM cells. We profiled the whole‐transcriptome of these JG cells and correlated it with the transcriptional level of Ren1. The top 5 genes that were most positively correlated with the Ren1 expression were Nr2f1 (R=0.79), Akr1b7 (R=0.68), Smim15 (R=0.64), Gng11 (R=0.60) and Sdc1 (R=0.59). We also compared the whole‐transcriptome between these JG cells and SM cells. The top 5 genes with the largest difference in the normalized transcript count were Ren1 (+4.28), Akr1b7 (+1.53), Sfrp2 (+1.01), Fam46a (+0.88), and Sdc1 (+0.75). Thus, aldo‐keto reductase 1B7 (Akr1b7) and syndecan‐1 (Sdc1) could be two potential candidates that may participate in the control of renin release from JG cells. However, previous studies using the Akr1b7‐deficient mice have shown that aldo‐keto reductase 1B7 is not of major relevance for the modulation of renin production and secretion. Therefore, we speculate that syndecan‐1 (Sdc1), a transmembrane heparan sulfate proteoglycan, may play a role in the regulation of renin release as well as JG cells recruitment, especially through the mechanism of intrarenal baroreceptor. This hypothesis will be tested with the Sdc1‐deficient mouse model in our future studies. [ABSTRACT FROM AUTHOR]

R3418 --> 726.3 --> Increased NaCl at the macula densa, the same stimulus of the tubuloglomerular feedback (TGF), also induces intracellular alkalinization (pH: from 7.4 to 7.8) and enhances nitric oxide (NO) generation. Neuronal NO synthase (NOS1) is the primary isoform of NOS expressed in the macula densa and its activity is strongly pH‐dependent. Nevertheless, the impact of pH on the catalytic capacity of NOS1 remains controversial with inconsistent observations. A potential explanation for this discrepancy may be due to the presence of different splice variants of NOS1 (NOS1α and NOS1β). Therefore, we hypothesized that the macula densa intracellular alkalinization during TGF activates NOS1β but suppresses NOS1α, which modulates the NO production and thus the TGF responsiveness. To test this hypothesis, we measured the NOS activity of purified NOS1α and NOS1β proteins in various pH environments using the Griess method. The pH‐dependent NO production curves of NOS1α and NOS1β were different. The optimal pH was ~6.5 for NOS1α, but ~8.5 for NOS1β. The maximum activities of NOS1α and NOS1β were similar at their optimal pH of 6.5 and 8.5, respectively. Then, we measured and compared the renal cortical NOS1 expression, macula densa NO generation, TGF response in vitro and in vivo, renal vascular resistance (RVR), and mean arterial pressure (MAP) in the Sprague Dawley (SD) rats and the spontaneously hypertensive rats (SHRs). While the total NOS1 expression was not significantly different between SD rats and SHRs, the alternative splicing patterns were contradictory. The ratio of NOS1α/NOS1β was greater in SHRs than SD rats (2.94±0.48 vs 0.36±0.07; n=6, p<0.01 vs SD), which was associated with the reduced NO production (21.6±4.5 vs 38.3±5.6 units/min; n=8, p<0.01 vs SD), enhanced TGF in vitro (4.9±0.4 vs 3.5±0.5 µm; n=10, p<0.05 vs SD) and in vivo (12.8±2.1 vs 9.1±1.7 mmHg; n=9, p<0.01 vs SD), increased RVR (23.9±1.3 vs 17.8±1.5 mmHg.ml‐1.min‐1.g kidney wt‐1; n=6, p<0.05 vs SD), and elevated MAP (127.3±6.6 vs 101.7±4.2 mmHg; n=6, p<0.05 vs SD). We also measured and compared the NOS1 expression in the renal biopsy (cortex) tissues of Caucasians (CAs) and African Americans (AAs). There was no significant difference in the total NOS1 expression between CAs and AAs, whereas the ratio of NOS1α/NOS1β was greater in AAs than CAs (3.53±1.64 vs 0.43±0.31; n=10‐11, p<0.01 vs CAs), which was associated with the higher serum creatinine level (1.25±0.08 vs 1.03±0.12 mg/dl; n=10‐11, p<0.05 vs CAs). Lastly, we determined the effects of pH on the macula densa NO generation as well as the TGF responsiveness in SD rats and SHRs. When the pH of the tubular perfusate was switched from 7.4 to 8.0, the macula densa NO production increased by 29.5±6.9% (from 39.7±4.5 to 51.4±5.7 units/min) in SD rats, whereas it decreased by 26.2±4.3% (from 22.5±3.4 to 16.6±4.2 units/min) in SHRs (n=7, p<0.05 vs 7.4); the TGF response in vitro decreased by 24.3±5.4% (from 3.7±0.4 to 2.8±0.6 µm) in SD rats, while it increased by 19.1±3.9% (from 4.7±0.4 to 5.6±0.5 µm) in SHRs (n=7, p<0.05 vs 7.4). In conclusion, the present study demonstrates that the macula densa intracellular alkalinization during TGF activates NOS1β but suppresses NOS1α, which regulates the NO generation, the TGF response and potentially the renal hemodynamics. [ABSTRACT FROM AUTHOR]