MicroRNA-126 (MiR-126): key roles in related diseases.

In eukaryotes such as humans, some non-coding single-stranded RNAs (ncRNAs) help to regulate the pre- and post-transcriptional expression of certain genes, which in turn control many important physiological processes, such as cell proliferation, distinctions, invasion, angiogenesis, and embryonic development. microRNA-126 is an important member of these miRNAs that can be directly or indirectly involved in the control of angiogenesis. Recently, numerous studies have expounded that microRNA-126 can inhibit or promote angiogenesis as well as attenuate inflammatory responses through complex molecular mechanisms. As such, it serves as a biomarker or potential therapeutic target for the prediction, diagnosis, and treatment of relevant diseases. In this review, we present the advancements in research regarding microRNA-126's role in the diagnosis and treatment of related diseases, aiming to provide innovative therapeutic options for the diagnosis and treatment of clinically relevant diseases.

Wireless, Smart Hemostasis Device with All-Soft Sensing System for Quantitative and Real-Time Pressure Evaluation.

The properly applied pressure between the skin and hemostasis devices is an essential parameter for preventing bleeding and postoperative complications after a transradial procedure. However, this parameter is usually controlled based on the subjective judgment of doctors, which might cause insufficient hemostatic effect or thrombosis. Here this study develops a compact and wireless sensing system for continuously monitoring the pressure applied on the radial artery and wrist skin in clinical practice. A liquid metal (LM)-based all-soft pressure sensor is fabricated to enable conformal attachment between the device and skin even under large deformation conditions. The linear sensitivity of 0.007 kPa-1 among the wide pressure range of 0-100 kPa is achieved and the real-time detection data can be wirelessly transmitted to mobile clients as a reference pressure value. With these devices, detailed pressure data can be collected, analyzed, and stored for medical assistance as well as to improve surgery quality.

CircPTP4A2 Promotes Microglia Polarization in Cerebral Ischemic Stroke via miR-20b-5p/YTHDF1/TIMP2 Axis.

Activated microglia play dual roles in ischemic stroke (IS) according to its polarization states. Herein, we investigated the function of circPTP4A2 in regulating microglia polarization in IS. IS models were established by MACO/R and OGD/R treatment. TTC staining was employed to detect cerebral infarct size. Cell vitality was measured using CCK-8 assay. CD16 and CD206 levels were examined using flow cytometry. The interactions between circPTP4A2, miR-20b-5p, and YTHDF1 were analyzed by dual-luciferase reporter gene, RIP, or RNA pull-down assays. circPTP4A2 was upregulated in IS patients. circPTP4A2 knockdown alleviated MCAO/R-induced cerebral injury in mice. circPTP4A2 knockdown promoted microglia M2 polarization after OGD/R. circPTP4A2 promoted YTHDF1 expression by sponging miR-20b-5p. The promoting effect of circPTP4A2 knockdown on microglia M2 polarization was abrogated by miR-20b-5p inhibition. YTHDF1 activated the NF-κB pathway by increasing TIMP2 mRNA stability and expression. circPTP4A2 downregulation promoted microglia M2 polarization to inhibit IS development by regulating the miR-20b-5p/YTHDF1/TIMP2/NF-κB axis.

YOLOv5s-Fog: An Improved Model Based on YOLOv5s for Object Detection in Foggy Weather Scenarios.

In foggy weather scenarios, the scattering and absorption of light by water droplets and particulate matter cause object features in images to become blurred or lost, presenting a significant challenge for target detection in autonomous driving vehicles. To address this issue, this study proposes a foggy weather detection method based on the YOLOv5s framework, named YOLOv5s-Fog. The model enhances the feature extraction and expression capabilities of YOLOv5s by introducing a novel target detection layer called SwinFocus. Additionally, the decoupled head is incorporated into the model, and the conventional non-maximum suppression method is replaced with Soft-NMS. The experimental results demonstrate that these improvements effectively enhance the detection performance for blurry objects and small targets in foggy weather conditions. Compared to the baseline model, YOLOv5s, YOLOv5s-Fog achieves a 5.4% increase in mAP on the RTTS dataset, reaching 73.4%. This method provides technical support for rapid and accurate target detection in adverse weather conditions, such as foggy weather, for autonomous driving vehicles.

IKK1 aggravates ischemia-reperfusion kidney injury by promoting the differentiation of effector T cells.

Ischemia-reperfusion injury (IRI) is one of the major causes of acute kidney injury (AKI), and experimental work has revealed detailed insight into the inflammatory response in the kidney. T cells and NFκB pathway play an important role in IRI. Therefore, we examined the regulatory role and mechanisms of IkappaB kinase 1 (IKK1) in CD4+T lymphocytes in an experimental model of IRI. IRI was induced in CD4cre and CD4IKK1Δ mice. Compared to control mice, conditional deficiency of IKK1 in CD4+T lymphocyte significantly decreased serum creatinine, blood urea nitrogen (BUN) level, and renal tubular injury score. Mechanistically, lack in IKK1 in CD4+T lymphocytes reduced the ability of CD4 lymphocytes to differentiate into Th1/Th17 cells. Similar to IKK1 gene ablation, pharmacological inhibition of IKK also protected mice from IRI. Together, lymphocyte IKK1 plays a pivotal role in IRI by promoting T cells differentiation into Th1/Th17 and targeting lymphocyte IKK1 may be a novel therapeutic strategy for IRI.

Machine learning prediction models and nomogram to predict the risk of in-hospital death for severe DKA: A clinical study based on MIMIC-IV, eICU databases, and a college hospital ICU.

AIM: To establish a prediction model and assess the risk factors for severe diabetic ketoacidosis (DKA) in adult patients during the ICU. INTRODUCTION: With DKA hospitalization rates consistently increasing, in-hospital mortality has become a growing concern. METHODS: DKA patients aged >18 years old in the US-based critical care database (Medical Information Mart for Intensive Care (MIMIC-IV)) were considered. Independent risk factors for in-hospital mortality were screened using extreme gradient boosting (XGBoost) and the Bayesian information criterion (BIC) optimal subset regression. One predictive model was developed using machine learning extreme gradient boosting (XGBoost), and the other one was a nomogram based on logistic regression to estimate risks of in-hospital mortality with severe DKA. Established models were assessed by using internal validation and external validation. The MIMIC-IV was split into training and testing samples in a 7:3 ratio. The eICU Collaborative Research Database and admissions data from the department of critical care medicine of the first affiliated hospital of Harbin medical university were used for independent validation. The discriminatory ability of the model was determined by illustrating a receiver operating curve (ROC) and calculating the C-index. Meanwhile, the calibration plot and Hosmer-Lemeshow goodness-of-fit test (HL test) was conducted to evaluate the performance of our new build model. Decision curve analysis (DCA) was performed to assess the clinical net benefit. Net Reclassification Improvement (NRI) was used to compare the predictive power of the two models. RESULTS: A multivariable model that included acute physiology score III (APS III), the highest levels of blood plasma osmolality (osmolarity_max), minimum osmolarity (osmolarity_min)/osmolarity _max, vasopressor, and the highest levels of blood lactate was represented as the nomogram. The C- index of the nomogram model was 0.915 (95% CI: 0.966-0.864) in the training dataset and 0.971 (95% CI: 0.992-0.950) in the internal validation. The nomogram's sensitivity was well according to all data's HL test (P > 0.05). DCA showed that our model was clinically valuable. The XGB (extreme gradient boosting) model achieved an AUC (area under the curve) of 0.950 (95% CI, 0.920-0.980); however, the nomogram model made was more effective than XGB based on NRI. CONCLUSION: The predictive XGB and nomogram models for predicting in-hospital patient deaths with DKA were effective. The forecast models can help clinical physicians promptly identify patients at high risk of DKA, prevent in-hospital deaths, and promptly intervene.

Flexible integrated sensor with asymmetric structure for simultaneously 3D tactile and thermal sensing.

The human body detects tactile stimuli through a combination of pressure force and temperature signals via various cutaneous receptors. The development of a multifunctional artificial tactile perception system has potential benefits for future robotic technologies, human-machine interfaces, artificial intelligence, and health monitoring devices. However, constructing systems beyond simple pressure sensing capabilities remains challenging. Here, we propose an artificial flexible and ultra-thin (50 µ m) skin system to simultaneously capture 3D tactile and thermal signals, which mimics the human tactile recognition process using customized sensor pairs and compact peripheral signal-converting circuits. The 3D tactile sensors have a flower-like asymmetric structure with 5-ports and 4 capacitive elements in pairs. Differential and average signals would reveal the curl and amplitude values of the fore field with a resolution of 0.18/mm. The resistive thermal sensors are fabricated with serpentine lines and possess stable heat-sensing performance (165 mV/°C) under shape deformation conditions. Real-time monitoring of the skin stimuli is displayed on the user interface and stored on mobile clients. This work offers broad capabilities relevant to practical applications ranging from assistant prosthetics to artificial electronic skins.

circ-Katnal1 Enhances Inflammatory Pyroptosis in Sepsis-Induced Liver Injury through the miR-31-5p/GSDMD Axis.

Background: Sepsis is a systemic inflammatory response that can elicit organ dysfunction as well as circulatory diseases in serious cases. When inflammatory responses are especially dysregulated, severe complications can arise, including sepsis-induced liver injury. Various microRNAs along with circular (circ) RNAs are involved in inflammatory responses; nevertheless, their functions in regulating sepsis-induced liver injury remain unknown. The cecal ligation and puncture (CLP) procedure can induce liver injury as well as polymicrobial sepsis. Methods: In this study, CLP was used to induce liver injury as well as polymicrobial sepsis. Then, liver function, inflammatory cytokine expression, and hepatic histopathology were evaluated. High-throughput sequencing was employed to investigate the abnormal hepatic circRNA expression after CLP. Raw264.7 cells were utilized to simulation an in vitro sepsis inflammation model with LPS induce. The relative mRNA as well as protein levels of TNF-α, IL-1ß, and IL-6 was explored by quantitative polymerase chain reaction (PCR) and enzyme-linked immunosorbent assays. We explored functional connections among circRNAs, miR-31-5p, and gasdermin D (GSDMD) using dual-luciferase reporter assays. Western blot was employed to test GSDMD, caspase-1, and NLRP3 expression in mice and cell models. Results: Our results showed that CLP-induced sepsis promoted liver injury via increasing inflammatory pyroptosis. The abnormal expression of circ-Katnal1 played an important role in CLP-induced sepsis. Downregulating circ-Katnal1 suppressed LPS-induced inflammatory pyroptosis in Raw264.7 cells. Bioinformatics and luciferase reporter results confirmed that miR-31-5p and GSDMD were downstream targets of circ-Katnal1. Inhibiting miR-31-5p or upregulating GSDMD reversed the protective effects of silencing circ-Katnal1. Conclusion: Taken together, circ-Katnal1 enhanced inflammatory pyroptosis in sepsis-induced liver injury through the miR-31-5p/GSDMD axis.

Role of carnitine in adaptation of Chromohalobacter salexigens DSM 3043 and its mutants to osmotic and temperature stress in defined medium.

L-Carnitine is widespread in nature, but little information is available on its metabolism and physiological functions in moderate halophiles. In this study, we found that Chromohalobacter salexigens DSM 3043 could utilize carnitine not only as a nutrient, but also as an osmolyte. When grown at 37 °C under salt-stress conditions, the strain utilized carnitine as an osmoprotectant by enzymatically converting it into GB. When grown at low and high temperature, both carnitine and its metabolic intermediate GB were simultaneously accumulated intracellularly, serving as cryoprotectants and thermoprotectants. The genes (csal_3172, csal_3173, and csal_3174) which were predicted to participate in L-carnitine degradation to GB were deleted to construct the corresponding mutants. The effects of salinity and temperature on the growth rates and cytoplasmic solute pools of the C. salexigens wild-type and mutant strains were investigated. 13C-NMR analysis revealed that GB was still detected in the Δcsal_3172Δcsal_3173Δcsal_3174 mutant grown in a defined medium with added DL-carnitine, but not with L-carnitine, indicating that an unidentified D-carnitine degradation pathway exists in C. salexigens. Taken together, the data presented in this study expand our knowledge on carnitine metabolism and its physiological functions in C. salexigens exposed to single or multiple environmental abiotic stress.

Continuous Renal Replacement Therapy With oXiris Filter May Not be an Effective Resolution to Alleviate Cytokine Release Syndrome in Non-AKI Patients With Severe and Critical COVID-19.

In this study, we aimed to determine whether continuous renal replacement therapy (CRRT) with oXiris filter may alleviate cytokine release syndrome (CRS) in non-AKI patients with severe and critical coronavirus disease 2019 (COVID-19). A total of 17 non-AKI patients with severe and critical COVID-19 treated between February 14 and March 26, 2020 were included and randomly divided into intervention group and control group according to the random number table. Patients in the intervention group immediately received CRRT with oXiris filter plus conventional treatment, while those in the control group only received conventional treatment. Demographic data were collected and collated at admission. During ICU hospitalization, the concentrations of circulating cytokines and inflammatory chemokines, including IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ, were quantitatively measured daily to reflect the degree of CRS induced by SARS-CoV-2 infection. Clinical data, including the severity of COVID-19 white blood cell count (WBC), neutrophil proportion (NEUT%), lymphocyte count (LYMPH), lymphocyte percentage (LYM%), platelet (PLT), C-reaction protein (CRP), high sensitivity C-reactive protein (hs-CRP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TB), albumin (ALB), serum creatinine (SCr), D-Dimer, fibrinogen (FIB), IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ, number of hospital days and sequential organ failure assessment (SOFA) score were obtained and collated from medical records, and then compared between the two groups. Age, and SCr significantly differed between the two groups. Besides the IL-2 concentration that was significantly lower on day 2 than that on day 1 in the intervention group, and the IL-6 concentrations that were significantly higher on day 1, and day 2 in the intervention group compared to the control group, similar to the IL-10 concentration on day 5, there were no significant differences between the two groups. To sum up, CRRT with oXiris filter may not effectively alleviate CRS in non-AKI patients with severe and critical COVID-19. Thus, its application in these patients should be considered with caution to avoid increasing the unnecessary burden on society and individuals and making the already overwhelmed medical system even more strained (IRB number: IRB-AF/SC-04).

Clinical characteristics and severity of beta and delta variants of SARS-CoV-2 and the effect of vaccine on delta variants.

Background: The Delta variant of concern (VOC) is rapidly becoming the dominant strain globally. We report the clinical characteristics and severity of hospitalized patients infected with Delta and Beta VOCs during the local outbreak in Harbin, Heilongjiang Province, China, and the effect of vaccines on the Delta variant. Methods: We collected a total of 735 COVID-19 patients from the First Affiliated Hospital of Harbin Medical University, including 96 cases infected with the Delta VOC and 639 cases infected with the Beta VOC. Demographic, clinical characteristic and laboratory findings were collected and compared. Results: Differences in viral shedding, IgG and IgM levels, and the neutrophil-to-lymphocyte ratio were noted between the Delta and Beta VOCs (p < 0.05). Survival analysis of the two groups revealed longer viral shedding of the Delta VOC (p < 0.05). For the Delta VOC, the longer the vaccination period, the lower the IgG and IgM levels. IgM levels were higher in the convalescent plasma group, whereas lymphocyte counts were lower. Conclusions: Delta VOC virus shedding was longer compared with Beta VOC shedding. Vaccination with inactivated vaccines can reduce the severe illness rate of the Delta VOC. IgG and IgM levels are reduced as the time period between the first and second vaccine doses increases.

Melatonin Exerts Cardioprotective Effects by Inhibiting NLRP3 Inflammasome-Induced Pyroptosis in Mice following Myocardial Infarction.

Myocardial infarction- (MI-) induced myocardial damage is mainly attributed to the loss of cardiomyocytes. Pyroptosis is a newly recognized form of programmed cell necrosis that is associated with the progression of MI. Melatonin has been shown to exert cardioprotective effects against cardiac damage in multiple cardiovascular diseases. However, the effect of melatonin on pyroptosis-induced cardiac injury in MI has not been elucidated. Herein, we found that melatonin administration ameliorated cardiac dysfunction and reduced cardiomyocyte death both in mice following coronary artery ligation and in H9C2 cells exposed to hypoxia. The results also showed that pyroptosis was induced both in vivo and in vitro, as evidenced by increased NLRP3, cleaved caspase-1, GSDMD-N, and mature IL-1ß and IL-18 levels, and these changes were decreased by melatonin treatment. Furthermore, we observed that TLR4 and NF-κB levels were increased by MI or hypoxia, and these increases were reversed by melatonin. The antipyroptotic action of melatonin was abrogated by treatment with an agonist of the TLR4/NF-κB signaling pathway. Our results indicate that melatonin can exert cardioprotective effects by inhibiting NLRP3 inflammasome-induced pyroptosis through modulation of the TLR4/NF-κB signaling pathway and provide strong evidence for the utility of melatonin in the treatment of MI.

COVID-19 patient with an incubation period of 27 d: A case report.

BACKGROUND: As a highly contagious disease, coronavirus disease 2019 (COVID-19) is wreaking havoc around the world due to continuous spread among close contacts mainly via droplets, aerosols, contaminated hands or surfaces. Therefore, centralized isolation of close contacts and suspected patients is an important measure to prevent the transmission of COVID-19. At present, the quarantine duration in most countries is 14 d due to the fact that the incubation period of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is usually identified as 1-14 d with median estimate of 4-7.5 d. Since COVID-19 patients in the incubation period are also contagious, cases with an incubation period of more than 14 d need to be evaluated. CASE SUMMARY: A 70-year-old male patient was admitted to the Department of Respiratory Medicine of The First Affiliated Hospital of Harbin Medical University on April 5 due to a cough with sputum and shortness of breath. On April 10, the patient was transferred to the Fever Clinic for further treatment due to close contact to one confirmed COVID-19 patient in the same room. During the period from April 10 to May 6, nucleic acid and antibodies to SARS-CoV-2 were tested 7 and 4 times, respectively, all of which were negative. On May 7, the patient developed fever with a maximum temperature of 39℃, and his respiratory difficulties had deteriorated. The results of nucleic acid and antibody detection of SARS-CoV-2 were positive. On May 8, the nucleic acid and antibody detection of SARS-CoV-2 by Heilongjiang Provincial Center for Disease Control were also positive, and the patient was diagnosed with COVID-19 and reported to the Chinese Center for Disease Control and Prevention. CONCLUSION: This case highlights the importance of the SARS-CoV-2 incubation period. Further epidemiological investigations and clinical observations are urgently needed to identify the optimal incubation period of SARS-CoV-2 and formulate rational and evidence-based quarantine policies for COVID-19 accordingly.

Standardization of critical care management of non-critically ill patients with COVID-19.

The large global outbreak of coronavirus disease 2019 (COVID-19) has seriously endangered the health care system in China and globally. The sudden surge of patients with severe acute respiratory syndrome coronavirus 2 infection has revealed the shortage of critical care medicine resources and intensivists. Currently, the management of non-critically ill patients with COVID-19 is performed mostly by non-intensive care unit (ICU) physicians, who lack the required professional knowledge, training, and practice in critical care medicine, especially in terms of continuous monitoring of the respiratory function, intervention, and feedback on treatment effects. This clinical problem needs an urgent solution. Therefore, here, we propose a series of clinical strategies for non-ICU physicians aimed at the standardization of the management of non-critically ill patients with COVID-19 from the perspective of critical care medicine. Isolation management is performed to facilitate the implementation of hierarchical monitoring and intervention to ensure the reasonable distribution of scarce critical care medical resources and intensivists, highlight the key patients, timely detection of disease progression, and early and appropriate intervention and organ function support, and thus improve the prognosis. Different management objectives are also set based on the high-risk factors and the severity of patients with COVID-19. The approaches suggested herein will facilitate the timely detection of disease progression, and thus ensure the provision of early and appropriate intervention and organ function support, which will eventually improve the prognosis.

Knockdown CD44 promote the inflammatory response through the autophagy pathway in mouse models of pulmonary contusion.

BACKGROUND: The effects of CD44, via the anti-inflammatory functions of autophagy, on lung injuries following pulmonary contusion (PC) and cell apoptosis were investigated. METHODS: Acute lung injury (ALI) mouse models were established by inducing lung injury via PC. This injury was verified using hematoxylin and eosin (H&E) staining, following which bronchoalveolar lavage fluid (BALF) was collected from these mice for analysis and further experimentation. CD44, LC3 I/II ratio, Beclin-1, and p62 expression levels in A549 cells were determined using immunohistochemistry, and western blot assays. CCK-8, flow cytometry, and acridine orange/ethidium bromide (AO/EB) fluorescence staining were used to quantify cell growth induced by BALF. LC3 II and LC3 I expression was determined through immunofluorescence. CD44-knockdown mice were used to demonstrate lung function after PC. RESULTS: The successful establishment of the ALI mouse models, created via PC was confirmed by an enhanced inflammatory response in the lung tissue, markers of cell autophagy. The ALI mice were found to have elevated CD44 expression. The viability of A549 cells exposed to BALF was downregulated, while the knockdown of CD44 promoted this effect. AO/EB and flow cytometry also indicated that the knockdown of CD44 promoted the cell apoptosis induced by BALF. Western blot analysis showed that knockdown of CD44 can inhibit LC3 I/II, p62, and Beclin-1 expression induced by BALF exposure. Additionally, knockdown of CD44 in mice was found to promote PC-induced lung injury through the attenuation of autophagy. CONCLUSIONS: Knockdown CD44 was shown to inhibit cell growth and induced cell apoptosis via autophagy signaling pathways, promote mice with ALI induced by PC in vivo and in vitro.

Functional Metabolomics Analysis Elucidating the Metabolic Biomarker and Key Pathway Change Associated With the Chronic Glomerulonephritis and Revealing Action Mechanism of Rhein.

Chronic glomerulonephritis (CGN) as the culprit of kidney failure can increase the mortality of critically ill patients and seriously threatens people's health all over the world. This study using metabolomics strategy is to reveal the potential therapeutic mechanism-related targets to evaluate the effects of rhein (RH) on CGN rats. Changes of serum metabolites and pathways were analyzed by non-targeted metabolomic method based on liquid chromatography-mass spectrometry (LC-MS) combined with ingenuity pathway analysis. In addition, the levels of biochemical indicators were also detected. A total of 25 potential biomarkers were identified to express serum metabolic turbulence in CGN animal model, and then 16 biomarkers were regulated by RH trending to the normal states. From metabolite enrichment and pathway analysis, pharmacological activity of RH on CGN were mainly involved in six vital metabolic pathways including phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism, arachidonic acid metabolism, tricarboxylic acid cycle (TCA cycle), alanine, aspartate, and glutamate metabolism, arginine and proline metabolism. It suggested CGN treatment with RH, which may be mediated via interference with metabolic pathway such as amino acid metabolism, arachidonic acid metabolism, and TCA cycle to regulating inflammation, oxidation response and immune regulation against CGN. It showed that metabolomics method offer deeply insight into the therapeutic mechanisms of natural product.

Lycorine attenuates lipopolysaccharide-induced acute lung injury through the HMGB1/TLRs/NF-κB pathway.

Lung injury associated with systemic inflammatory response is a common problem affecting human health. Previous studies have shown that lycorine exerts a anti-inflammatory effect. However, whether lycorine alleviates lung injury remains unclear. To explore this issue, BALB/c mice and MLE-12 cells were treated with lipopolysaccharide (LPS) to establish lung injury mouse model and cell model, respectively. Glycyrrhizic acid, known as an inhibitor of ALI, was also used to study the effects of lycorine in vitro. Our results showed that after LPS treatment, the lung injury score, lung wet-to-dry weight ratio, and malondialdehyde (MDA) production in the lung tissues and the expression levels of tumor necrosis factor-α, interleukin-1ß, and interleukin-6 in bronchoalveolar lavage fluid were significantly increased, whereas their levels were decreased by lycorine. Additionally, LPS injection activated the high-mobility group box 1 (HMGB1)/Toll-like receptors (TLRs)/NF-κB pathway. However, lycorine treatment attenuated the activity of the HMGB1/TLRs/NF-κB pathway in the lung tissues. In vitro studies showed that lycorine administration significantly decreased the levels of inflammatory cytokines and MDA and attenuated the activity of the HMGB1/TLRs/NF-κB pathway in LPS-treated cells. Moreover, the inhibitory effects of lycorine on the inflammatory response and oxidative stress in LPS-treated lung cells were similar with that of glycyrrhizic acid, and this inhibition was intensified by both lycorine and glycyrrhizic acid treatment. We suggest that lycorine could alleviate LPS-induced lung injury of inflammation and oxidative stress by blocking the HMGB1/TLRs/NF-κB pathway, which gives a new perspective for ALI therapy to treat lycorine as a potential treatment clinically.

Role of N,N-Dimethylglycine and Its Catabolism to Sarcosine in Chromohalobacter salexigens DSM 3043.

Chromohalobacter salexigens DSM 3043 can grow on N,N-dimethylglycine (DMG) as the sole C, N, and energy source and utilize sarcosine as the sole N source under aerobic conditions. However, little is known about the genes and enzymes involved in the conversion of DMG to sarcosine in this strain. In the present study, gene disruption and complementation assays indicated that the csal_0990, csal_0991, csal_0992, and csal_0993 genes are responsible for DMG degradation to sarcosine. The csal_0990 gene heterologously expressed in Escherichia coli was proven to encode an unusual DMG dehydrogenase (DMGDH). The enzyme, existing as a monomer of 79 kDa with a noncovalently bound flavin adenine dinucleotide, utilized both DMG and sarcosine as substrates and exhibited dual coenzyme specificity, preferring NAD+ to NADP+ The optimum pH and temperature of enzyme activity were determined to be 7.0 and 60°C, respectively. Kinetic parameters of the enzyme toward its substrates were determined accordingly. Under high-salinity conditions, the presence of DMG inhibited growth of the wild type and induced the production and accumulation of trehalose and glucosylglycerate intracellularly. Moreover, exogenous addition of DMG significantly improved the growth rates of the four DMG- mutants (Δcsal_0990, Δcsal_0991, Δcsal_0992, and Δcsal_0993) incubated at 37°C in S-M63 synthetic medium with sarcosine as the sole N source. 13C nuclear magnetic resonance (13C-NMR) experiments revealed that not only ectoine, glutamate, and N-acetyl-2,4-diaminobutyrate but also glycine betaine (GB), DMG, sarcosine, trehalose, and glucosylglycerate are accumulated intracellularly in the four mutants.IMPORTANCE Although N,N-dimethylglycine (DMG) dehydrogenase (DMGDH) activity was detected in cell extracts of microorganisms, the genes encoding microbial DMGDHs have not been determined until now. In addition, to our knowledge, the physiological role of DMG in moderate halophiles has never been investigated. In this study, we identified the genes involved in DMG degradation to sarcosine, characterized an unusual DMGDH, and investigated the role of DMG in Chromohalobacter salexigens DSM 3043 and its mutants. Our results suggested that the conversion of DMG to sarcosine is accompanied by intramolecular delivery of electrons in DMGDH and intermolecular electron transfer between DMGDH and other electron acceptors. Moreover, an unidentified methyltransferase catalyzing the production of glycine betaine (GB) from DMG but sharing no homology with the reported sarcosine DMG methyltransferases was predicted to be present in the cells. The results of this study expand our understanding of the physiological role of DMG and its catabolism to sarcosine in C. salexigens.

TLR5 participates in the TLR4 receptor complex and promotes MyD88-dependent signaling in environmental lung injury.

Lung disease causes significant morbidity and mortality, and is exacerbated by environmental injury, for example through lipopolysaccharide (LPS) or ozone (O3). Toll-like receptors (TLRs) orchestrate immune responses to injury by recognizing pathogen- or danger-associated molecular patterns. TLR4, the prototypic receptor for LPS, also mediates inflammation after O3, triggered by endogenous hyaluronan. Regulation of TLR4 signaling is incompletely understood. TLR5, the flagellin receptor, is expressed in alveolar macrophages, and regulates immune responses to environmental injury. Using in vivo animal models of TLR4-mediated inflammations (LPS, O3, hyaluronan), we show that TLR5 impacts the in vivo response to LPS, hyaluronan and O3. We demonstrate that immune cells of human carriers of a dominant negative TLR5 allele have decreased inflammatory response to O3 exposure ex vivo and LPS exposure in vitro. Using primary murine macrophages, we find that TLR5 physically associates with TLR4 and biases TLR4 signaling towards the MyD88 pathway. Our results suggest an updated paradigm for TLR4/TLR5 signaling.

Immune cells in the lung help guard against infections. On the surface of these cells are proteins called TLR receptors that recognize dangerous molecules or DNA from disease-causing microbes such as bacteria. When the immune cells detect these invaders, the TLR receptors spring into action and trigger an inflammatory response to destroy the microbes. This inflammation usually helps the lung clear infections. But it can also be harmful and damage the lung, for example when inflammation is caused by non-infectious substances such as pollutants in the atmosphere. There are several TLR receptors that each recognize a specific molecule. In 2010, researchers showed that the receptor TLR4 is responsible for causing inflammation in the lung after exposure to pollution. Another receptor called TLR5 also helps activate the immune response in the lung. But it was unclear whether this receptor also plays a role in pollution-linked lung damage. Now, Hussain, Johnson, Sciurba et al. ­ including one of the researchers involved in the 2010 study ­ have investigated the role of TLR5 in immune cells from the lungs of humans and mice. The experiments showed that TLR5 works together with TLR4 and helps trigger an inflammatory response to both pollutants and bacteria. Hussain et al. found that people lacking a working TLR5 receptor (which make up 3­10% of the population) are less likely to experience lung inflammation when exposed to pollution or bacterial proteins that activate TLR4. These findings suggest that people without TLR5 may be protected from pollution-induced lung injury. Further research into the role of TLR5 could help develop genetic tests for identifying people who are more sensitive to damage from pollution. This information could then be used to determine the likelihood of a patient experiencing certain lung diseases.

Fibronectin (FN) cooperated with TLR2/TLR4 receptor to promote innate immune responses of macrophages via binding to integrin ß1.

Macrophages could adhere to extracellular matrix molecules(ECM) to induce the expression of pro-inflammatory mediators and phagocytosis that contribute to the pathogenesis of pulmonary infection diseases. Fibronectin (FN) is a large glycoprotein capable of interacting with various ECM molecules produced by a variety of cell types and involved in cell attachment and chemotaxis. However, it is unknown whether FN regulates the expression of pro-inflammatory mediators and phagocytosis of macrophages in the injured lung tissue. Here, we investigated the interaction between FN and integrin ß1 in macrophages, which promotes toll-like receptor 2/4 (TLR2/TLR4) signaling pathways to enhance expression of pro-inflammatory mediators and phagocytosis by macrophages. Our results show that lipopolysaccharide (LPS), lipoteichoic acid (LTA) and peptidoglycan (PGN) significantly increase FN expression of macrophages; FN substantially enhances interleukin 6 (IL-6), tumor necrosis factor-α (TNFα), ras-related C3 botulinum toxin substrate 1/2 (Rac1/2), and cell division control protein 42 homolog (Cdc42) expression and phagocytosis of macrophages. However, FN could not enhance pro-inflammatory cytokines and phagocytosis of macrophages induced by LPS and PGN in integrin ß1-/- macrophages. Furthermore, applied integrin ß1 blocking peptide abrogated the effects that FN promotes innate immune responses of macrophages to LPS and PGN. Those data indicated that the enhanced pro-inflammatory mediators and phagocytosis of macrophages by FN-integrin ß1 signal was through co-operating with TLR2/TLR4 signaling. This study suggests that FN play an essential role in the pathogenesis of pulmonary infection disease.