Structurally distinct bacterial TBC-like GAPs link Arf GTPase to Rab1 inactivation to counteract host defenses.

Rab GTPases are frequent targets of vacuole-living bacterial pathogens for appropriate trafficking of the vacuole. Here we discover that bacterial effectors including VirA from nonvacuole Shigella flexneri and EspG from extracellular Enteropathogenic Escherichia coli (EPEC) harbor TBC-like dual-finger motifs and exhibits potent RabGAP activities. Specific inactivation of Rab1 by VirA/EspG disrupts ER-to-Golgi trafficking. S. flexneri intracellular persistence requires VirA TBC-like GAP activity that mediates bacterial escape from autophagy-mediated host defense. Rab1 inactivation by EspG severely blocks host secretory pathway, resulting in inhibited interleukin-8 secretion from infected cells. Crystal structures of VirA/EspG-Rab1-GDP-aluminum fluoride complexes highlight TBC-like catalytic role for the arginine and glutamine finger residues and reveal a 3D architecture distinct from that of the TBC domain. Structure of Arf6-EspG-Rab1 ternary complex illustrates a pathogenic signaling complex that rewires host Arf signaling to Rab1 inactivation. Structural distinctions of VirA/EspG further predict a possible extensive presence of TBC-like RabGAP effectors in counteracting various host defenses.

Trehalose along with ABA promotes the salt tolerance of Avicennia marina by regulating Na+ transport.

Mangroves grow in tropical/subtropical intertidal habitats with extremely high salt tolerance. Trehalose and trehalose-6-phosphate (T6P) have an alleviating function against abiotic stress. However, the roles of trehalose in the salt tolerance of salt-secreting mangrove Avicennia marina is not documented. Here, we found that trehalose was significantly accumulated in A. marina under salt treatment. Furthermore, exogenous trehalose can enhance salt tolerance by promoting the Na+ efflux from leaf salt gland and root to reduce the Na+ content in root and leaf. Subsequently, eighteen trehalose-6-phosphate synthase (AmTPS) and 11 trehalose-6-phosphate phosphatase (AmTPP) genes were identified from A. marina genome. Abscisic acid (ABA) responsive elements were predicted in AmTPS and AmTPP promoters by cis-acting elements analysis. We further identified AmTPS9A, as an important positive regulator, that increased the salt tolerance of AmTPS9A-overexpressing Arabidopsis thaliana by altering the expressions of ion transport genes and mediating Na+ efflux from the roots of transgenic A. thaliana under NaCl treatments. In addition, we also found that ABA could promote the accumulation of trehalose, and the application of exogenous trehalose significantly promoted the biosynthesis of ABA in both roots and leaves of A. marina. Ultimately, we confirmed that AmABF2 directly binds to the AmTPS9A promoter in vitro and in vivo. Taken together, we speculated that there was a positive feedback loop between trehalose and ABA in regulating the salt tolerance of A. marina. These findings provide new understanding to the salt tolerance of A. marina in adapting to high saline environment at trehalose and ABA aspects.

NADPH oxidase-dependent H2O2 production mediates salicylic acid-induced salt tolerance in mangrove plant Kandelia obovata by regulating Na+/K+ and redox homeostasis.

Salicylic acid (SA) is known to enhance salt tolerance in plants. However, the mechanism of SA-mediated response to high salinity in halophyte remains unclear. Using electrophysiological and molecular biological methods, we investigated the role of SA in response to high salinity in mangrove species, Kandelia obovata, a typical halophyte. Exposure of K. obovata roots to high salinity resulted in a rapid increase in endogenous SA produced by phenylalanine ammonia lyase pathway. The application of exogenous SA improved the salt tolerance of K. obovata, which depended on the NADPH oxidase-mediated H2O2. Exogenous SA and H2O2 increased Na+ efflux and reduced K+ loss by regulating the transcription levels of Na+ and K+ transport-related genes, thus reducing the Na+/K+ ratio in the salt-treated K. obovata roots. In addition, exogenous SA-enhanced antioxidant enzyme activity and its transcripts, and the expressions of four genes related to AsA-GSH cycle as well, then alleviated oxidative damages in the salt-treated K. obovata roots. However, the above effects of SA could be reversed by diphenyleneiodonium chloride (the NADPH oxidase inhibitor) and paclobutrazol (a SA biosynthesis inhibitor). Collectively, our results demonstrated that SA-induced salt tolerance of K. obovata depends on NADPH oxidase-generated H2O2 that affects Na+/K+ and redox homeostasis in response to high salinity.

Putative role of STING-mitochondria associated membrane crosstalk in immunity.

Stimulator of interferon genes (STING) has emerged as a key regulator of innate immunity, recognizing intracellular exogenous and endogenous DNA. Recent findings reveal that STING has multiple cell-specific immune functions in various pathological settings, including pathogenic infections, cancer, and autoimmune diseases. Here, we hypothesize that this unique location of STING in the mitochondria-associated membrane (MAM) might lead to the specificity of the cellular functions of STING mediated by mitochondria-ER communication. This new insight suggests that STING on the MAM might act as a hub that translates multiple cues on MAM into distinct cellular responses. This innovative view of STING biology might impart insights for future putative treatments in cancer and immune diseases that have been attributed to STING dysfunction.

Wavelength-Resolved Janus Biosensing Interface for Ratiometric Electrochemical Analysis.

The Janus interface, comprising multiple functional heterointerfaces with contrasting functionalities within a single interface, has recently garnered widespread research interest. Herein, a Janus biosensing interface is obtained via wavelength-resolved laser illumination. Deoxyribonucleic acid bridges the electrochemical probe of methylene blue (MB) and plasmonic gold nanoparticles (AuNPs), achieving a sensitive detection performance. MB shows differential electrochemical signals under front (I532front) and back (I650back) laser illumination at 532 and 650 nm, respectively, owing to the selective wavelength-resolved effect. Thus, the presence of a wavelength-resolved laser enabled the design of a biosensing interface with Janus properties. The change in the distance between MB and AuNPs induced by aflatoxin B1 (AFB1) indicates that a sensitive response of the Janus biosensing interface can be achieved. A ratiometric strategy is introduced to describe the electrochemical signals of the I532front and I650back for improved robustness. The obtained linear range is 0.0005-50 ng mL-1, with a detection limit of 0.175 pg mL-1. Our study demonstrated that the wavelength-resolved Janus interface enables an electrochemical biosensor with excellent sensitivity. This finding provides an efficient approach for improving biosensor performance.

Brassinosteroid enhances salt tolerance via S-nitrosoglutathione reductase and nitric oxide signaling pathway in mangrove Kandelia obovata.

Brassinosteroid (BR) has been shown to modulate plant tolerance to various stresses. S-nitrosoglutathione reductase (GSNOR) is involved in the plant response to environment stress by fine-turning the level of nitric oxide (NO). However, whether GSNOR is involved in BR-regulated Na+ /K+ homeostasis to improve the salt tolerance in halophyte is unknown. Here, we firstly reported that high salinity increases the expression of BR-biosynthesis genes and the endogenous levels of BR in mangrove Kandelia obovata. Then, salt-induced BR triggers the activities and gene expressions of GSNOR and antioxidant enzymes, thereafter decrease the levels of malondialdehyde, hydrogen peroxide. Subsequently, BR-mediated GSNOR negatively regulates NO contributions to the reduction of reactive oxygen species generation and induction of the gene expression related to Na+ and K+ transport, leading to the decrease of Na+ /K+ ratio in the roots of K. obovata. Finally, the applications of exogenous BR, NO scavenger, BR biosynthetic inhibitor and GSNOR inhibitor further confirm the function of BR. Taken together, our result provides insight into the mechanism of BR in the response of mangrove K. obovata to high salinity via GSNOR and NO signaling pathway by reducing oxidative damage and modulating Na+ /K+ homeostasis.

Oleanolic acid attenuates hydrogen peroxide-induced apoptosis of IPEC-J2 cells through suppressing c-Jun and MAPK pathway.

Oleanolic acid (OA) is a natural triterpenoid with therapeutic potential for a multitude of diseases. However, the precise mechanism by which OA influences stress-induced apoptosis of intestinal epithelial cells remains elusive. Therefore, the effect of OA on intestinal diseases under stressful conditions and its possible mechanisms have been investigated. In a hydrogen peroxide (H2 O2 )-induced oxidative stress model, OA attenuated H2 O2 -induced apoptosis in a concentration-dependent manner. To investigate the underlying mechanisms, the gene expression profile of OA on IPEC-J2 cells was analyzed using an RNA sequencing system. Results from gene ontology and Kyoto encyclopedia of genes and genomes analysis confirmed that OA may mitigate the cytotoxic effects of H2 O2 by downregulating gene expression through the MAPK signaling pathway. Furthermore, Quantitative real-time polymerase chain reaction results validated the differentially expressed genes data. Western blot analysis further demonstrated that OA effectively suppressed the expression level of c-Jun protein induced by H2 O2 in IPEC-J2 cells. Collectively, our results indicate that OA pretreatment significantly attenuated H2 O2 -induced apoptosis in intestinal epithelial cells through suppressing c-Jun and MAPK pathway.

E2F1-driven histone demethylase KDM6B enhances thyroid malignancy via manipulating TFEB-dependent autophagy axis.

Aberrant epigenetic modifications or events regulate autophagy to influence tumor progression, which has gained increasing attention. KDM6B is an essential histone demethylase that participates in multiple processes of tumors, but its role in thyroid carcinoma (THCA) remains to be unknown. Here, in this study, we used the MTT assay to screen and validate that KDM6B is an essential demethylase for THCA. KDM6B promotes THCA proliferation, migration, invasion in vitro and in vivo. Transcriptional factor E2F1 directly binds to the promoter region of KDM6B and regulates its mRNA levels in THCA. E2F1 partially depended on KDM6B to exert its oncogenic functions. Mechanistically, KDM6B binds to TFEB promoter region and mediates the demethylation of H3K27me3. KDM6B depended on TFEB to activate a series of lysosomal-related genes. KDM6B enhances autophagy process, as evidenced by elevated p62 and Beclin-1 proteins. KDM6B depended on TFEB-driven autophagy activity to accelerate THCA progression. Lastly, targeting autophagy with 3-MA could notably abrogate growth of KDM6Bhigh THCA, but has mild influence on KDM6Blow THCA. Together, this study identified KDM6B as an essential epigenetic regulator for THCA, functioning as an autophagy regulator. The fundamental mechanisms underlying E2F1/KDM6B/TFEB axis provided novel vulnerabilities for THCA treatment.

Alpha-kinase 1 is a cytosolic innate immune receptor for bacterial ADP-heptose.

Immune recognition of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors often activates proinflammatory NF-κB signalling1. Recent studies indicate that the bacterial metabolite D-glycero-ß-D-manno-heptose 1,7-bisphosphate (HBP) can activate NF-κB signalling in host cytosol2-4, but it is unclear whether HBP is a genuine PAMP and the cognate pattern recognition receptor has not been identified. Here we combined a transposon screen in Yersinia pseudotuberculosis with biochemical analyses and identified ADP-ß-D-manno-heptose (ADP-Hep), which mediates type III secretion system-dependent NF-κB activation and cytokine expression. ADP-Hep, but not other heptose metabolites, could enter host cytosol to activate NF-κB. A CRISPR-Cas9 screen showed that activation of NF-κB by ADP-Hep involves an ALPK1 (alpha-kinase 1)-TIFA (TRAF-interacting protein with forkhead-associated domain) axis. ADP-Hep directly binds the N-terminal domain of ALPK1, stimulating its kinase domain to phosphorylate and activate TIFA. The crystal structure of the N-terminal domain of ALPK1 and ADP-Hep in complex revealed the atomic mechanism of this ligand-receptor recognition process. HBP was transformed by host adenylyltransferases into ADP-heptose 7-P, which could activate ALPK1 to a lesser extent than ADP-Hep. ADP-Hep (but not HBP) alone or during bacterial infection induced Alpk1-dependent inflammation in mice. Our findings identify ALPK1 and ADP-Hep as a pattern recognition receptor and an effective immunomodulator, respectively.

Extracellular production of antifungal peptides from oxidative endotoxin-free E. coli and application.

Antifungal peptides (AFPs) can be used as novel preservatives, but achieving large-scale production and application remains a long-term challenge. In this study, we developed a hybrid peptide MD (metchnikowin-drosomycin fusion) secreted into Escherichia coli supernatant, demonstrating strong inhibitory activity against Aspergillus flavus and Botrytis cinerea. The fusion tag did not impact its activity. Moreover, an endotoxin-free and oxidative leaky strain was developed by knocking out the trxB, gor, and lpp genes of endotoxin-free E. coli ClearColi-BL21(DE3). This strain facilitates the proper folding of multi-disulfide bond proteins and promotes the extracellular production of recombinant bioactive AFP MD, achieving efficient production of endotoxin-free MD. In addition, temperature control replaces chemical inducers to further reduce production costs and circumvent the toxicity of inducers. This extracellularly produced MD exhibited favorable effectiveness in inhibiting fruit mold growth, and its safety was preliminarily established by gavage testing in mice, suggesting that it can be developed into a green and sustainable fruit fungicide. In conclusion, this study provides novel approaches and systematic concepts for producing extracellularly active proteins or peptides with industrial significance. KEY POINTS: • First report of extracellular production of bioactive antifungal peptide in Escherichia coli. • The hybrid antifungal peptide MD showed strong inhibitory activity against Aspergillus flavus and Botrytis cinerea, and the activity was not affected by the fusion tag. • Endotoxin-free oxidative Escherichia coli suitable for the expression of multi-disulfide bond proteins was constructed.

Analysis of Imprecision for Internal Quality Control of Newborn Screening by Tandem Mass Spectrometry in China, 2015 - 2021.

BACKGROUND: This study aimed to assess the performance of the newborn screening laboratories in China through retrospective analysis of the coefficient of variation (CV) of the internal quality control (IQC) data in the national tandem mass spectrometry screening for inherited metabolic disorders in newborns. METHODS: From 2015 to 2021, the IQC data of amino acid and acylcarnitine test were collected twice each year. CVmonthly in-control was calculated by excluding outliers for the current month and its discrete distribution and changes in trend were comprehensively evaluated for both normal and high concentration levels. The proportion of laboratories meeting both 1/3 and 1/4 quality criteria of the total error allowable (TEa), based on the CVmonthly in-control for each testing item, was calculated. RESULTS: The analysis of CVmonthly in-control for the two concentration levels for the amino acids and acylcarnitine parameters showed that CVmonthly in-control for the normal concentration levels were more discrete before 2018, while CVmonthly in-control for the high concentration levels were less discrete than the normal concentration levels, but there were relatively more outliers. More than 80% of laboratories were able to meet the 1/3 TEa standard for each test at the high concentration level, while the pass rate for the 1/4 TEa standard was significantly lower than 80% (except for C2). CONCLUSIONS: According to the current status of testing in China, it is recommended to use 1/3TEa as the imprecision level standard; for laboratories with relatively high precision, the 1/4TEa standard can be used.

Obstructive sleep apnea affects cognition: dual effects of intermittent hypoxia on neurons.

Obstructive sleep apnea (OSA) is a common respiratory disorder. Multiple organs, especially the central nervous system (CNS), are damaged, and dysfunctional when intermittent hypoxia (IH) occurs during sleep for a long time. The quality of life of individuals with OSA is significantly impacted by cognitive decline, which also escalates the financial strain on their families. Consequently, the development of novel therapies becomes imperative. IH induces oxidative stress, endoplasmic reticulum stress, iron deposition, and neuroinflammation in neurons. Synaptic dysfunction, reactive gliosis, apoptosis, neuroinflammation, and inhibition of neurogenesis can lead to learning and long-term memory impairment. In addition to nerve injury, the role of IH in neuroprotection was also explored. While causing neuron damage, IH activates the neuronal self-repairing mechanism by regulating antioxidant capacity and preventing toxic protein deposition. By stimulating the proliferation and differentiation of neural stem cells (NSCs), IH has the potential to enhance the ratio of neonatal neurons and counteract the decline in neuron numbers. This review emphasizes the perspectives and opportunities for the neuroprotective effects of IH and informs novel insights and therapeutic strategies in OSA.

Photoelectrochemical aptasensing with methylene blue filled Ni-MOFs nanocomposite by spatial confinement for microcystin-LR detection.

Microcystin LR (MC-LR) is a hazardous cyanotoxin produced by cyanobacteria during freshwater eutrophication, which can cause liver cancer. Here, a photoelectrochemical (PEC) aptasensor based on methylene blue (MB)-loaded Ni-MOF composite (Ni-MOF/MB) with spatial confinement was constructed for the sensitive detection of MC-LR. Ni-MOF with two-dimensional sheet structure was prepared via a liquid-liquid interface synthesis method with environmental-friendly solvent and milder reaction conditions. Benefiting from the uniform pore size, Ni-MOF acted as reaction platform to anchor the photosensitive molecule MB. The electron donor, ascorbic acid (AA), was produced by alkaline phosphatase (ALP) loaded on DNA strand catalyzing ascorbic acid phosphate. The generated AA was absorbed by Ni-MOF/MB, thereby effectively improving the utilization of AA and avoiding the external environment interferences to enlarge the photocurrent of MB. For analysis, ALP-labeled aptamer can specifically recognize MC-LR by forming a complex to strip from aptasensor, thus leading to a  decreased photocurrent. The developed PEC aptasensor offered a linear range of 10 fM-100 pM with a detection limit of 6 fM. It was successfully employed for detecting MC-LR in farm water and fish meat, and the results were validated by ultrahigh-performance liquid chromatography-mass spectrometry. This method presents a new idea of MOF-limited domain for PEC aptasensing.

Effects of bile acid metabolism on intestinal health of livestock and poultry.

Bile acids are synthesised in the liver and are essential amphiphilic steroids for maintaining the balance of cholesterol and energy metabolism in livestock and poultry. They can be used as novel feed additives to promote fat utilisation in the diet and the absorption of fat-soluble substances in the feed to improve livestock performance and enhance carcass quality. With the development of understanding of intestinal health, the balance of bile acid metabolism is closely related to the composition and growth of livestock intestinal microbiota, inflammatory response, and metabolic diseases. This paper systematically reviews the effects of bile acid metabolism on gut health and gut microbiology in livestock. In addition, our paper summarised the role of bile acid metabolism in performance and disease control.

The N-end rule ubiquitin ligase UBR2 mediates NLRP1B inflammasome activation by anthrax lethal toxin.

Anthrax lethal toxin (LT) is known to induce NLRP1B inflammasome activation and pyroptotic cell death in macrophages from certain mouse strains in its metalloprotease activity-dependent manner, but the underlying mechanism is unknown. Here, we establish a simple but robust cell system bearing dual-fluorescence reporters for LT-induced ASC specks formation and pyroptotic lysis. A genome-wide siRNA screen and a CRISPR-Cas9 knockout screen were applied to this system for identifying genes involved in LT-induced inflammasome activation. UBR2, an E3 ubiquitin ligase of the N-end rule degradation pathway, was found to be required for LT-induced NLRP1B inflammasome activation. LT is known to cleave NLRP1B after Lys44. The cleaved NLRP1B, bearing an N-terminal leucine, was targeted by UBR2-mediated ubiquitination and degradation. UBR2 partnered with an E2 ubiquitin-conjugating enzyme UBE2O in this process. NLRP1B underwent constitutive autocleavage before the C-terminal CARD domain. UBR2-mediated degradation of LT-cleaved NLRP1B thus triggered release of the noncovalent-bound CARD domain for subsequent caspase-1 activation. Our study illustrates a unique mode of inflammasome activation in cytosolic defense against bacterial insults.

Portable Visual Photoelectrochemical Biosensor Based on a MgTi2O5/CdSe Heterojunction and Reversible Electrochromic Supercapacitor for Dual-Modal Cry1Ab Protein Detection.

Reversible electrochromic supercapacitors (ESCs) have attracted considerable interest as visual display screens. The use of ESCs in combination with a photoelectrochemical (PEC) biosensor promises to improve the detection efficiency. Herein, a visual PEC biosensor is developed by introducing a circuit module between a PEC-sensing platform (PSP) and a reversible ESC for Cry1Ab protein detection. In PSP, a type II MgTi2O5/CdSe heterojunction effectively drives charge separation by their cross-matched band gap structures, generating an amplified photocurrent. Next, the circuit module is designed to connect the PSP and ESC, realizing the signal conversion from photocurrent to voltage. ESC, as a visual display screen, produces reversible color changes with different voltages. As the concentration of Cry1Ab increases, the photocurrent decreases due to the specific binding between the aptamer and Cry1Ab in PSP, while the color of the reversible ESC changes from green to blue. To improve the integrity of the device, a portable PEC biosensor is further constructed via three-dimensional printing for dual-modal Cry1Ab protein detection, thus collecting both PEC and visual signals. The linear ranges are 0.3-3000 ng mL-1 for PEC mode and 1-1000 ng mL-1 for visual mode. This work presents a portable, efficient, sensitive, and visualized detection system, providing an important reference for practical visualization applications.

1,5-Anhydroglucitol promotes pre-B acute lymphocytic leukemia progression by driving glycolysis and reactive oxygen species formation.

BACKGROUND: Precursor B-cell acute lymphoblastic leukemia (pre-B ALL) is the most common hematological malignancy in children. Cellular metabolic reorganization is closely related to the progression and treatment of leukemia. We found that the level of 1,5-anhydroglucitol (1,5-AG), which is structurally similar to glucose, was elevated in children with pre-B ALL. However, the effect of 1,5-AG on pre-B ALL was unclear. Here, we aimed to reveal the roles and mechanisms of 1,5-AG in pre-B ALL progression. METHODS: The peripheral blood plasma level of children with initial diagnosis of pre-B ALL and that of healthy children was measured using untargeted metabolomic analysis. Cell Counting Kit-8 assay, RNA sequencing, siRNA transfection, real-time quantitative PCR, and western blot were performed using pre-B ALL cell lines Reh and HAL-01. Cell cycle, cell apoptosis, ROS levels, and the positivity rate of CD19 were assessed using flow cytometry. Oxygen consumption rates and extracellular acidification rate were measured using XFe24 Extracellular Flux Analyzer. The lactate and nicotinamide adenine dinucleotide phosphate levels were measured using kits. The effect of 1,5-AG on pre-B ALL progression was verified using the In Vivo Imaging System in a xenotransplantation leukemia model. RESULTS: We confirmed that 1,5-AG promoted the proliferation, viability, and intracellular glycolysis of pre-B ALL cells. Mechanistically, 1,5-AG promotes glycolysis while inhibiting mitochondrial respiration by upregulating pyruvate dehydrogenase kinase 4 (PDK4). Furthermore, high levels of intracellular glycolysis promote pre-B ALL progression by activating the reactive oxygen species (ROS)-dependent mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway. Conversely, N-acetylcysteine or vitamin C, an antioxidant, effectively inhibited 1,5-AG-mediated progression of leukemia cells. CONCLUSIONS: Our study reveals a previously undiscovered role of 1,5-AG in pre-B ALL, which contributes to an in-depth understanding of anaerobic glycolysis in the progression of pre-B ALL and provides new targets for the clinical treatment of pre-B ALL.

Integration of eQTL and GWAS analysis uncovers a genetic regulation of natural ionomic variation in Arabidopsis.

KEY MESSAGE: This study provided important insights into the genetic architecture of variations in A. thaliana leaf ionome in a cell-type-specific manner. The functional interpretation of traits associated variants by expression quantitative trait loci (eQTL) analysis is usually performed in bulk tissue samples. While the regulation of gene expression is context-dependent, such as cell-type-specific manner. In this study, we estimated cell-type abundances from 728 bulk tissue samples using single-cell RNA-sequencing dataset, and performed cis-eQTL mapping to identify cell-type-interaction eQTL (cis-eQTLs(ci)) in A. thaliana. Also, we performed Genome-wide association studies (GWAS) analyses for 999 accessions to identify the genetic basis of variations in A. thaliana leaf ionome. As a result, a total of 5,664 unique eQTL genes and 15,038 unique cis-eQTLs(ci) were significant. The majority (62.83%) of cis-eQTLs(ci) were cell-type-specific eQTLs. Using colocalization, we uncovered one interested gene AT2G25590 in Phloem cell, encoding a kind of plant Tudor-like protein with possible chromatin-associated functions, which colocalized with the most significant cis-eQTL(ci) of a Mo-related locus (Chr2:10,908,806:A:C; P = 3.27 × 10-27). Furthermore, we prioritized eight target genes associated with AT2G25590, which were previously reported in regulating the concentration of Mo element in A. thaliana. This study revealed the genetic regulation of ionomic variations and provided a foundation for further studies on molecular mechanisms of genetic variants controlling the A. thaliana ionome.

Regulatory mechanism of downregulation of SOD1 expression on cardiomyocyte function.

BACKGROUND: Many diseases are clinically related to oxidative stress. Obstructive sleep apnea (OSA) is a common disease with oxidative stress in clinical practice, which is mostly associated with cardio-cerebrovascular diseases. It has been shown that the level of oxidative stress increases and the level of antioxidant copper zinc superoxide dismutase (SOD1) decreases in intermittent hypoxia (IH). SOD1 is one of the key antioxidant enzymes in organisms, and it can also be used as a signal transmission controller. Its abnormal expression further affects organ functions, but the specific mechanism is not yet fully clear. METHODS: We downregulated the SOD1 gene in H9C2 cell line, using high-throughput RNA sequencing (RNA-seq) to find differentially expressed genes (DEGs) related to cardiomyocyte function by using GO and KEGG databases to annotate, enrich and analyze the metabolic pathways of DEGs. RESULTS: Through the analysis of these functional gene changes, we can understand the regulation of SOD1 downregulation on cardiomyocyte function. The results found 213 DEGs, of which 135 genes were upregulated and 78 genes were downregulated. The upregulated DEGs were mainly enriched in biological processes such as transcriptional regulation and metabolism. The expression levels of EGR1 and NR1D1 exceeded 1 in the samples. EGR1 was reported to be involved in oxidative stress and cardiac hypertrophy, and NR1D1 played an important regulatory role in regulating inflammatory responses and reducing ROS production. The biological processes involved in downregulated DEGs mainly involve metabolism and redox processes. Among them, SCD1 and CCL2 genes were highly expressed among the genes involved in the redox process involved in SOD1. SCD1 is an important player in the regulation of cardiometabolic processes; downregulation of CCL2 reduces atherosclerosis. We found that the TNF signaling pathway, NOD-like receptor signaling pathway, and chemokine signaling pathway, which were enriched in KEGG analysis, were all associated with inflammation, and the CXCL1 and CCL7 genes are all related to inflammation. CONCLUSION: The gene and signaling pathways involved in oxidative stress and inflammatory response process regulated by SOD1 were demonstrated. SOD1 may affect the function of the heart by affecting myocardial contraction, inflammation, lipid metabolism, and other pathways. It is inferred that they may also play a role in the process of OSA-related myocardial injury, which is worthy of attention and further study.

Effects of Emodin on Protein Expression Related to Autophagy of Interstitial Cells of Cajal in Diabetic Rats.

This work aims to investigate the effects and mechanism of emodin in treating diabetic gastroenteropathy and colonic dysmotility in STZ + HS/HF diet induced diabetic gastroenteropathy rats. Diabetic colonic dysmotility model was established by high-fat/high-glucose (HS/HF) feeding combined with streptozotocin (STZ). Emodin was divided into high, medium and low dose groups. After eight weeks of intervention, fasting blood glucose (FBG) and body weight were measured. Gastrointestinal transmission time was evaluated. Serum vasoactive intestinal peptide (VIP) and substance P (SP) were detected. Colonic protein expression of selective autophagy adaptor proteins p62 and beclin1 were detected by immunohistochemistry. Colonic protein expression of beclin1, autophagy related gene 5 (Atg5), C-kit and p62 were detected by Western blot. After treating with emodin, gastrointestinal transmission rate was improved. The expression of serum SP was increased and serum VIP was decreased. Colonic c-kit and p62 were up-regulated. The expressions of beclin1 and Atg5 were down-regulated. Emodin can improve colonic dysmotility and promote the recovery of colonic motility and intestinal defecation in diabetic rats. Its mechanism may involved with up-regulating the expression of C-kit and P62, down-regulating the expression of Beclin1 and Atg5 in colon, which are associated with colon over-autophagy of Cajal interstitial cell (ICC).