Dynamic expression analysis of peripheral blood derived small extracellular vesicle miRNAs in sepsis progression.

Immune disorders caused by sepsis have recently drawn much attention. We sought to dynamically monitor the expression of small extracellular vesicle (sEV) miRNAs in peripheral blood during sepsis to explore these miRNAs as potential biomarkers for monitoring immune function in sepsis patients. This study included patients with sepsis. Blood samples were obtained from 10 patients on the first through 10th days, the 12th day and the 14th day since sepsis onset, resulting in 120 collected samples. Serum sEVs were extracted from peripheral venous blood, and levels of MIR497HG, miR-195, miR-497, and PD-L1 in serum sEVs were detected by qPCR, and clinical information was recorded. Our study revealed that the levels of MIR497HG, miR-195, miR-497 and PD-L1 in serum sEVs showed periodic changes; the time from peak to trough was approximately 4-5 days. The levels of sEV MIR497HG and miR-195 had a positive linear relationship with SOFA score (r values were -0.181 and -0.189; p values were 0.048 and 0.039, respectively). The recorded quantities of sEV MIR497HG, miR-195 and PD-L1 showed a substantial correlation with ARDS. ROC curve analysis revealed that sEV MIR497HG, miR-195 and miR-497 could predict the 28-day mortality of sepsis patients with an AUC of 0.66, 0.68 and 0.72, respectively. Levels of sEVs MIR497HG, miR-195, miR-497 and PD-L1 showed periodic changes with the immune status of sepsis, which provides a new exploration direction for immune function biomarkers and immunotherapy timing in sepsis patients.

Diabetes and aortic dissection: unraveling the role of 3-hydroxybutyrate through mendelian randomization.

BACKGROUND: In observational and experimental studies, diabetes has been reported as a protective factor for aortic dissection. 3-Hydroxybutyrate, a key constituent of ketone bodies, has been found to favor improvements in cardiovascular disease. However, whether the protective effect of diabetes on aortic dissection is mediated by 3-hydroxybutyrate is unclear. We aimed to investigate the causal effects of diabetes on the risk of aortic dissection and the mediating role of 3-hydroxybutyrate in them through two-step Mendelian randomization. MATERIALS AND METHODS: We performed a two-step Mendelian randomization to investigate the causal connections between diabetes, 3-hydroxybutyrate, and aortic dissection and calculate the mediating effect of 3-hydroxybutyrate. Publicly accessible data for Type 1 diabetes, Type 2 diabetes, dissection of aorta and 3-hydroxybutyrate were obtained from genome-wide association studies. The association between Type 1 diabetes and dissection of aorta, the association between Type 2 diabetes and dissection of aorta, and mediation effect of 3-hydroxybutyrate were carried out separately. RESULTS: The IVW method showed that Type 1 diabetes was negatively associated with the risk of aortic dissection (OR 0.912, 95% CI 0.836-0.995), The weighted median, simple mode and weighted mode method showed consistent results. The mediated proportion of 3-hydroxybutyrate on the relationship between Type 1 diabetes and dissection of aorta was 24.80% (95% CI 5.12-44.47%). The IVW method showed that Type 2 diabetes was negatively associated with the risk of aortic dissection (OR 0.763, 95% CI 0.607-0.960), The weighted median, simple mode and weighted mode method showed consistent results. 3-Hydroxybutyrate does not have causal mediation effect on the relationship between Type 2 diabetes and dissection of aorta. CONCLUSION: Mendelian randomization study revealed diabetes as a protective factor for dissection of aorta. The protective effect of type 1 diabetes on aortic dissection was partially mediated by 3-hydroxybutyrate, but type 2 diabetes was not 3-hydroxybutyrate mediated.

Cell-type-specific labeling and profiling of glycans in living mice.

Metabolic labeling of glycans with clickable unnatural sugars has enabled glycan analysis in multicellular systems. However, cell-type-specific labeling of glycans in vivo remains challenging. Here we develop genetically encoded metabolic glycan labeling (GeMGL), a cell-type-specific strategy based on a bump-and-hole pair of an unnatural sugar and its matching engineered enzyme. N-pentynylacetylglucosamine (GlcNAl) serves as a bumped analog of N-acetylglucosamine (GlcNAc) that is specifically incorporated into glycans of cells expressing a UDP-GlcNAc pyrophosphorylase mutant, AGX2F383G. GeMGL with the 1,3-di-O-propionylated GlcNAl (1,3-Pr2GlcNAl) and AGX2F383G pair was demonstrated in cell cocultures, and used for specific labeling of glycans in mouse xenograft tumors. By generating a transgenic mouse line with AGX2F383G expressed under a cardiomyocyte-specific promoter, we performed specific imaging of cardiomyocyte glycans in the heart and identified 582 cardiomyocyte O-GlcNAcylated proteins with no interference from other cardiac cell types. GeMGL will facilitate cell-type-specific glycan imaging and glycoproteomics in various tissues and disease models.

1,2-Dichloroethane causes anxiety and cognitive dysfunction in mice by disturbing GABA metabolism and inhibiting the cAMP-PKA-CREB signaling pathway.

1,2-Dichloroethane (1,2-DCE) is a powerfully toxic neurotoxin, which is a common environmental pollutant. Studies have indicated that 1,2-DCE long-term exposure can result in adverse effects. Nevertheless, the precise mechanism remains unknown. In this study, behavioral results revealed that 1,2-DCE long-term exposure could cause anxiety and learning and memory ability impairment in mice. The contents of γ-aminobutyric acid (GABA) and glutamine (Gln) in mice's prefrontal cortex decreased, whereas that of glutamate (Glu) increased. With the increase in dose, the activities of glutamate decarboxylase (GAD) decreased and those of GABA transaminase (GABA-T) increased. The protein and mRNA expressions of GABA transporter-3 (GAT-3), vesicular GABA transporter (VGAT), GABA A receptor α2 (GABAARα2), GABAARγ2, K-Cl cotransporter isoform 2 (KCC2), GABA B receptor 1 (GABABR1), GABABR2, protein kinase A (PKA), cAMP-response element binding protein (CREB), p-CREB, brain-derived neurotrophic factor (BDNF), c-fos, c-Jun and the protein of glutamate dehydrogenase (GDH) and PKA-C were decreased, while the expression levels of GABA transporter-1 (GAT-1) and Na-K-2Cl cotransporter isoform 1 (NKCC1) were increased. However, there was no significant change in the protein content of succinic semialdehyde dehydrogenase (SSADH). The expressions of adenylate cyclase (AC) and cyclic adenosine monophosphate (cAMP) contents were also reduced. In conclusion, the results of this study show that exposure to 1,2-DCE could lead to anxiety and cognitive impairment in mice, which may be related to the disturbance of GABA metabolism and its receptors along with the cAMP-PKA-CREB pathway.

Facile Synthesis of Clickable Unnatural Sugars in the Unprotected and 1,6-Di-O-Acylated Forms for Metabolic Glycan Labeling.

Clickable unnatural sugars have been widely used in studying glycosylation in living systems via the metabolic glycan labelling (MGL) strategy. Partial protection of unnatural sugars by 1,6-di-O-acylation increases the labelling efficiency while avoiding the non-specific S-glyco-modification. Herein, we report the facile synthesis of a series of clickable unnatural sugars in both the unprotected and 1,6-di-O-acylated forms at the ten-gram scale. By evaluation of the labelling specificity, efficiency, and biocompatibility of various 1,6-di-O-acylated sugars for MGL in cell lines and living mice, we demonstrate that 1,6-di-O-propionylated unnatural sugars are optimal chemical reporters for glycan labelling. The synthetic routes developed in this work should facilitate the widespread use of MGL with no artificial S-glyco-modification for investigating the functional roles of glycans.

Implementation of Tele-Intensive Care Unit Services During the COVID-19 Pandemic: A Systematic Literature Review and Updated Experience from Shandong Province.

Background: While the use of telemedicine had been expanding before the initial outbreak of COVID-19, the pandemic has dramatically accelerated its implementation and expanded its usage in many hospitals. Tele-intensive care unit (ICU) is a specialized type of telemedicine that adapts available technologies to the unique needs of critically ill patients. We published an editorial in 2020 describing our initial experiences of Tele-ICU application in Shandong Province. Here, we update our insights gained over the past 2 years, and we provide a systematic review of the literature to compare our perspectives with those from other institutions. Methods: We performed a systematic literature review of publications describing the use of telemedicine in an ICU setting during COVID-19. The PubMed database was searched for studies published after January 1, 2020, which offered detailed descriptions of tele-ICU usage. Extracted data included details regarding tele-ICU technologies, descriptions of the institution, usage cases, assessments of tele-ICU effectiveness, and site-reported opinions (e.g., advantages, disadvantages). Results: We screened 162 studies resulting from the PubMed literature search, along with one expert recommendation. Of the 112 full-text articles retrieved, 11 were selected for inclusion in this qualitative summary. All were retrospective descriptions of tele-ICU experiences at a single site. Some pairs of included articles reported results from the same institution, with seven unique sites being described. Three sites employed centralized models of tele-ICU, while four allowed staff to participate from distant locations. Five sites collected user-reported feedback regarding tele-ICU. While the advantages and disadvantages described rarely overlapped directly between sites, many reported positive opinions of tele-ICU use overall. Conclusions: The potential applications of tele-ICU technologies vary widely, making them highly adaptable to the needs of individual institutions. Tele-ICU has proven invaluable to some hospitals during COVID-19 due to its effectiveness at aiding patient care while mitigating risk to health care workers.

Dynamic Zn/Electrolyte Interphase and Enhanced Cation Transfer of Sol Electrolyte for All-Climate Aqueous Zinc Metal Batteries.

Zn metal as one of the promising anodes of aqueous batteries possesses notable advantages, but it faces severe challenges from severe side reactions and notorious dendrite growth. Here, ultrathin nanosheets of α-zirconium phosphate (ZrP) are explored as an electrolyte additive. The nanosheets not only create a dynamic and reversible interphase on Zn but also promote the Zn2+ transportation in the electrolyte, especially in the outer Helmholtz plane near ZrP. Benefited from the enhanced kinetics and dynamic interphase, the pouch cells of Zn||LiMn2 O4 using this electrolyte remarkably improve electrochemical performance under harsh conditions, i.e. Zn powders as the Zn anode, high mass loading, and wide temperatures. The results expand the materials available for this dynamic interphase, provide an insightful understanding of the enhanced charge transfer in the electrolyte, and realize the combination of dynamic interphase and enhanced kinetics for all-climate performance.

Micronutrient Level Is Negatively Correlated with the Neutrophil-Lymphocyte Ratio in Patients with Severe COVID-19.

Aim: To explore the potential relationship between NLR and micronutrient deficiency in patients with severe COVID-19 infection. Methods: Sixteen patients were categorized into the mild group (mild COVID-19) and severe group (severe COVID-19) based on the guideline of the management of COVID-19. The lactate dehydrogenase (LDH); superoxide dismutase (SOD), the inflammatory markers (neutrophil lymphocyte ratio (NLR)), erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), selenium (Se), iron (Fe), zinc (Zn), nickel (Ni), copper (Cu), chromium (Cr), cadmium (Cd), arsenic (As), and manganese (Mn) were measured in the blood. Results: Compared to the mild group, the NLR (P < 0.05) and the level of Se (P < 0.01), Fe (P < 0.05), and Zn (P < 0.05) were significantly decreased in the severe group. The level of Se, Fe, and Zn was significantly correlated to NLR levels. Furthermore, close positive correlation was found between NLR and severity of COVID-19. Conclusion: The micronutrient deficiency in the blood is associated with NLR in the severity of COVID-19 patients.

In Situ Formation of Nitrogen-Rich Solid Electrolyte Interphase and Simultaneous Regulating Solvation Structures for Advanced Zn Metal Batteries.

Zn metal as one of promising anode materials for aqueous batteries suffers from notorious dendrite growth, serious Zn corrosion and hydrogen evolution. Here, a bifunctional electrolyte additive, N-methyl pyrrolidone (NMP), is developed to improve the electrochemical performance of Zn anode. NMP not only alters the solvation structure of Zn2+ , but also in situ produces a dense N-rich solid-electrolyte-interphase layer on Zn foils. This layer protects Zn foils from corrosive electrolytes and benefits the uniform plating/stripping of Zn. Hence, the asymmetrical cells with NMP in the electrolyte retain a high coulombic efficiency of 99.8 % over 1000 cycles. The symmetric cells survive ≈200 h for 10 mAh cm-2 at a high Zn utilization of 85.6 %. The full cells of Zn||MnO2 show an impressive cumulative capacity even with lean electrolyte (E/C ratio=10 µL mAh-1 ), limited Zn supply (N/P ratio=2.3) and high areal capacity (5.0 mAh cm-2 ).

An epigenome-wide DNA methylation study of patients with COVID-19.

In the early 2000s, emerging SARS-CoV-2, which is highly pathogenic, posed a great threat to public health. During COVID-19, epigenetic regulation is deemed to be an important part of the pathophysiology and illness severity. Using the Illumina Infinium Methylation EPIC BeadChip (850 K), we investigated genome-wide differences in DNA methylation between healthy subjects and COVID-19 patients with different disease severities. We conducted a combined analysis and selected 35 "marker" genes that could indicate a SARS-CoV-2 infection, including 12 (ATHL1, CHN2, CHST15, CPLX2, CRHR2, DCAKD, GNAI2, HECW1, HYAL1, MIR510, PDE11A, and SMG6) situated in the promoter region. The functions and pathways of differentially methylated genes were enriched in biological processes, signal transduction, and the immune system. In the "Severe versus Mild" group, differentially methylated genes, after eliminating duplicates, were used for PPI analyses. The four hub genes (GNG7, GNAS, PRKCZ, and PRKAG2) that had the highest degree of nodes were identified and among them, GNG7 and GNAS genes expressions were also downregulated in the severe group in sequencing results. Above all, the results suggest that GNG7 and GNAS may play a non-ignorable role in the progression of COVID-19. In conclusion, the identified key genes and related pathways in the current study can be used to study the molecular mechanisms of COVID-19 and may provide possibilities for specific treatments.

Critical Care Bed Capacity in Asian Countries and Regions.

OBJECTIVE: To assess the number of adult critical care beds in Asian countries and regions in relation to population size. DESIGN: Cross-sectional observational study. SETTING: Twenty-three Asian countries and regions, covering 92.1% of the continent's population. PARTICIPANTS: Ten low-income and lower-middle-income economies, five upper-middle-income economies, and eight high-income economies according to the World Bank classification. INTERVENTIONS: Data closest to 2017 on critical care beds, including ICU and intermediate care unit beds, were obtained through multiple means, including government sources, national critical care societies, colleges, or registries, personal contacts, and extrapolation of data. MEASUREMENTS AND MAIN RESULTS: Cumulatively, there were 3.6 critical care beds per 100,000 population. The median number of critical care beds per 100,000 population per country and region was significantly lower in low- and lower-middle-income economies (2.3; interquartile range, 1.4-2.7) than in upper-middle-income economies (4.6; interquartile range, 3.5-15.9) and high-income economies (12.3; interquartile range, 8.1-20.8) (p = 0.001), with a large variation even across countries and regions of the same World Bank income classification. This number was independently predicted by the World Bank income classification on multivariable analysis, and significantly correlated with the number of acute hospital beds per 100,000 population (r = 0.19; p = 0.047), the universal health coverage service coverage index (r = 0.35; p = 0.003), and the Human Development Index (r = 0.40; p = 0.001) on univariable analysis. CONCLUSIONS: Critical care bed capacity varies widely across Asia and is significantly lower in low- and lower-middle-income than in upper-middle-income and high-income countries and regions.

Telemedicine Technologies and Tuberculosis Management: A Randomized Controlled Trial.

Background: Since 1990s, directly observed therapy (DOT) has been the standard-of-care for tuberculosis (TB), although it is cumbersome for patients as well as service providers. For raising implementation, an alternative delivery method with good potential is telehealth. The current study assessed the clinical and cost benefit of video directly observed therapy (VDOT), compared with DOT service. Methods: This prospective randomized controlled trial randomized adults with bacteriologically confirmed pulmonary TB to the intervention (VDOT) or control (DOT) group. The observation data for DOT and VDOT were updated by observers until the end of treatment or until the study concluded. The primary outcome was the TB treatment result defined by the World Health Organization (WHO) as used in some other studies conducted in North India and England as follows: good (cured and treatment completed), poor (death and failure), relocation, and lost to follow-up and others (refused, adverse reaction, not a TB case). Other secondary measures were treatment adherence, patient satisfaction, time and cost spent on DOT or VDOT. Results: On analyzing the results from 405 participants from each study arm, we found very high rates of treatment completion (96.1% with VDOT vs. 94.6% with DOT). The two observed treatment methods had no statistical differences, and all could accomplish their tasks well. Average time per dose observed was 16.5 min (standard deviation [SD] 12.1) for VDOT, while 44.1 min (SD 3.7) for DOT (including travel time), p < 0.01. And the cost incurred on VDOT was ï¿¥34.3 (SD 3.8) manmo, which was statistically lower compared with ï¿¥71.6 (SD 49.7) manmo in the DOT group, p < 0.01. Most of the patients in both groups believed that observed treatment (VDOT/DOT) helped them not to miss doses (185 [93.0%] vs. 171 [86.7%], p = 0.057). Patients in the VDOT group had a better experience compared with those in DOT group. They thought the way was convenient and comfortable (191 [96.0%] vs. 111 [56.6%], p < 0.001), would choose the original way if necessary (191 [96.0%] vs. 113 [57.7%], p < 0.001), and would recommend the method to other patients (191 [96.0%] vs. 113 [57.7%], p < 0.001). Conclusion: The study showed that VDOT enabled meaningful direct observation for TB patients through mobile devices, which was highly acceptable to patients and health care providers. It also saved time and is a cost-effective method, enabling the use of the saved money to other much-needed areas for TB.

Proteomic Analysis of Peri-Wounding Tissue Expressions in Extracorporeal Shock Wave Enhanced Diabetic Wound Healing in a Streptozotocin-Induced Diabetes Model.

Our former studies have demonstrated that extracorporeal shock wave therapy (ESWT) could enhance diabetic wound healing but the bio-mechanisms remain elusive. This study investigated the changes of topical peri-wounding tissue expressions after ESWT in a rodent streptozotocin-induced diabetic wounding model by using the proteomic analysis and elucidated the molecular mechanism. Diabetic rats receiving ESWT, normal control, and diabetic rats receiving no therapy were analyzed. The spots of interest in proteome analysis were subjected to mass spectrometry to elucidate the peptide mass fingerprints. Protein expression was validated using immunohistochemical staining and related expression of genes were analyzed using real-time RT-PCR. The proteomic data showed a significantly higher abundance of hemopexin at day 3 of therapy but down-regulation at day 10 as compared to diabetic control. In contrast, the level of serine proteinase inhibitor (serpin) A3N expression was significantly decreased at day 3 therapy but expression was upregulated at day 10. Using real-time RT-PCR revealed that serpin-related EGFR-MAPK pathway was involved in ESWT enhanced diabetic wound healing. In summary, proteome analyses demonstrated the expression change of hemopexin and serpin with related MAPK signaling involved in ESWT-enhanced diabetic wound healing. Modulation of hemopexin and serpin related pathways are good strategies to promote wound healing.

LINC00520 targeting miR-27b-3p regulates OSMR expression level to promote acute kidney injury development through the PI3K/AKT signaling pathway.

BACKGROUND: Acute kidney injury (AKI) shows several kinds of disorders, which acutely harm the kidney. However, the current medical methods have limited therapeutic effects. The present study aimed to find out the molecular mechanism of AKI pathogenesis, which may provide new insights for future therapy. METHODS: Bioinformatic analysis was conducted using the R language (AT&T BellLaboratories, University of Auckland, New Zealand) to acquire the differentially expressed long noncoding RNAs (lncRNAs) and messenger RNAs (mRNAs) in AKI. The expression levels of RNAs and related proteins in tissues and cells were detected by quantitative real-time PCR (qRT-PCR) and western blot. Dual-luciferase reporter gene assays were performed to verify the target relationship between microRNA (miRNA) and lncRNA as well as miRNA and mRNA. Flow cytometry and tunnel assay were used to detect the cell apoptotic rate in AKI. RESULTS: LINC00520, miR-27b-3p, and OSMR form an axis to regulate AKI. Knockdown of LINC00520 reduced acute renal injury both in vitro and in vivo. LINC00520 activated the PI3K/AKT pathway to aggravate renal ischemia/reperfusion injury, while upregulation of miR-27b-3p or downregulation of OSMR could accelerate the recovery of AKI. CONCLUSION: Overexpression of LINC00520 contributes to the aggravation of AKI by targeting miR-27b-3p/ OSMR.

Modulation of vascular endothelial growth factor and mitogen-activated protein kinase-related pathway involved in extracorporeal shockwave therapy accelerate diabetic wound healing.

Extracorporeal shockwave therapy (ESWT) has a significant positive effect to accelerate chronic wound healing. This study investigated whether the vascular endothelial growth factor (VEGF)-related pathway has involved in ESWT enhancement of diabetic wound healing. A dorsal skin defect (area, 6 × 5 cm) in a streptozotocin-induced diabetes rodent model was used. Thirty-two male Wistar rats were divided into four groups. Group I consisted of nondiabetic control; group II, diabetic control without treatment; group III, diabetic rats received ESWT; and group IV, rats received Avastin (a VEGF monoclonal antibody) on day 0 (post-wounding immediately) to day 7 and ESWT on day 3 and day 7. The wound healing was assessed clinically. The VEGF, endothelial nitric oxide synthase (eNOS), and Ki-67 were analyzed with immunohistochemical staining. The mRNA expression of mitogen-activated protein kinase-related genes was measured by real-time quantitative real-time polymerase chain reaction. The results revealed wound size was significantly reduced in the ESWT-treated rats as compared to the diabetic control (p < 0.01). The positive effect of ESWT-increasing wound healing was significantly suppressed in pretreatment of the Avastin group. Histological findings revealed significant increase in neo-vessels in the ESWT group as compared to the control. In immunohistochemical stain, significant increases in VEGF, eNOS, and Ki-67 expressions were noted in the ESWT group as compared to that in controls. However, Avastin suppressed the shockwave effect and down-regulation of VEGF, eNOS, and Ki-67 expressions in the Avastin-ESWT group as compared to that in the ESWT alone group. We found that highly mRNA expression of Kras, Raf1, Mek1, Jnkk, Jnk, and Jun at early stage in the ESWT group, as compared to the diabetic control. These evidences indicated treatment with multiple sessions of ESWT significantly enhanced diabetic wound healing associated with increased neovascularization and tissue regeneration. The bio-mechanism of ESWT-enhanced wound healing is correlated with VEGF and mitogen-activated protein kinase-mediated pathway.

Smoking Attenuates Efficacy of Penehyclidine Hydrochloride in Acute Respiratory Distress Syndrome Induced by Lipopolysaccharide in Rats.

BACKGROUND Penehyclidine hydrochloride is a novel drug for acute respiratory distress syndrome. The aim of the study was to reveal the impact of smoking on the efficacy of the drug in rats with acute respiratory distress syndrome. MATERIAL AND METHODS A 132 Sprague-Dawley rats were used in this study; 72 rats were used in the smoking models. Penehyclidine hydrochloride (3 mg/kg) was injected to induce acute respiratory distress syndrome. Rats were divided into the smoking group and the non-smoking group; these 2 groups were subdivided according to different treatments. The arterial blood gas analysis (PaO2/FiO2) and extent of pneumonedema (wet-to-dry weight ratio) was analyzed to evaluate disease severity. Expressions of mitogen-activated protein kinases (p-p38MAPK, p38MAPK, p-ERK, ERK, p-JNK, and JNK) in lung tissue were measured using western blot assay. RESULTS Penehyclidine hydrochloride improved the pneumonedema (wet-to-dry weight ratio) and hyoxemia (PaO2/FiO2) of the disease in non-smoking group (P<0.001, P<0.001 respectively), but not in smoking group (P=0.244, P=0.424 respectively). The drug inhibited the expressions of phospho-p38MAPK and phospho-ERK in non-smoking group (P<0.001, P<0.001 respectively), but not in smoking group (P=0.350, P=0.507 respectively). In the smoking group, blocking the phospho-p38MAPK or phospho-ERK signal pathway by their inhibitors showed a better therapeutic effect on the pneumonedema and hyoxemia compared with the use of penehyclidine hydrochloride (phospho-p38MAPK: P=0.004, P=0.010 respectively; phospho-ERK: P=0.022, P=0.004 respectively). CONCLUSIONS The study confirmed the protective effect of penehyclidine hydrochloride in acute respiratory distress syndrome, mainly in the non-smoking group, which might be explained by the fact that phospho-p38MAPK and phospho-ERK signal pathways were difficult to inhibit by the drug in the smoking group.

Suppression of Oxygen Radicals Protects Diabetic Endothelium Damage and Tissue Perfusion in a Streptozotocin-Induced Diabetes Rodent Model.

BACKGROUND: Oxygen free radicals play a central role in diabetic angiopathy. This study investigated whether suppression of oxygen radicals could decrease endothelial damage and increase peripheral tissue circulation in a diabetic rodent model. METHODS: Sprague-Dawley rats were treated using streptozotocin to induce diabetes. The experiments were performed 4 weeks after diabetes induction: group 1: control, consisted of normal rats; group 2: diabetes, did not receive treatment; groups III (SOD10) and IV (SOD50): diabetes, received polyethylene glycol-conjugated superoxide dismutase (SOD), an antioxidant, 10 and 50 U/kg per day intraperitoneally for 4 weeks. Each subgroup consisted of 10 rats. Oxygen radicals in blood mononuclear cells were detected by flow cytometry. The blood lipid peroxidation byproduct malondialdehyde was measured. Tissue perfusion of hind limb was examined by laser Doppler. The expressions of oxygen radicals, as demonstrated by 8-hydroxyguanosine (8-OG), and constitutive endothelial nitric oxide synthase in distal femoral vessels were examined by immunohistochemical staining. RESULTS: Oxygen radicals, as demonstrated by H2O2 with 2',7'-dichlorofluorescin diacetate-conjugated expression, were significantly increased in diabetic rats. However, the SOD treatment groups significantly suppressed the H2O2 reaction. Diabetic-induced high malondialdehyde levels were significantly suppressed in the SOD50 group. The topical tissue blood perfusion was significantly increased as detected by laser Doppler in SOD10 and SOD50 groups, as compared with that in diabetes without treatment group (P < 0.05). The expression of 8-OG was markedly increased in the diabetic endothelium and subintima compared with that in normal vessels. Polyethylene glycol-conjugated SOD significantly suppressed 8-OG expression and protected endothelial nitric oxide synthase expression. CONCLUSIONS: Suppression of oxygen radicals, particularly with the higher dosage of polyethylene glycol-conjugated SOD at 50 U/kg per day, could have a positive effect to protect against endothelial damage and enhance peripheral perfusion in diabetes.

Hfq, a RNA Chaperone, Contributes to Virulence by Regulating Plant Cell Wall-Degrading Enzyme Production, Type VI Secretion System Expression, Bacterial Competition, and Suppressing Host Defense Response in Pectobacterium carotovorum.

Hfq is a RNA chaperone and participates in a wide range of cellular processes and pathways. In this study, mutation of hfq gene from Pectobacterium carotovorum subsp. carotovorum PccS1 led to significantly reduced virulence and plant cell wall-degrading enzyme (PCWDE) activities. In addition, the mutant exhibited decreased biofilm formation and motility and greatly attenuated carbapenem production as well as secretion of hemolysin coregulated protein (Hcp) as compared with wild-type strain PccS1. Moreover, a higher level of callose deposition was induced in Nicotiana benthamiana leaves when infiltrated with the mutant. A total of 26 small (s)RNA deletion mutants were obtained among a predicted 27 sRNAs, and three mutants exhibited reduced virulence in the host plant. These results suggest that hfq plays a key role in Pectobacterium virulence by positively impacting PCWDE production, secretion of the type VI secretion system, bacterial competition, and suppression of host plant responses.

The Ribosomal Protein RplY Is Required for Pectobacterium carotovorum Virulence and Is Induced by Zantedeschia elliotiana Extract.

Pectobacterium carotovorum subsp. carotovorum strain PccS1, a bacterial pathogen causing soft rot disease of Zantedeschia elliotiana (colored calla), was investigated for virulence genes induced by the host plant. Using a promoter-trap transposon (mariner), we obtained 500 transposon mutants showing kanamycin resistance dependent on extract of Z. elliotiana. One of these mutants, PM86, exhibited attenuated virulence on both Z. elliotiana and Brassica rapa subsp. pekinensis. The growth of PM86 was also reduced in minimal medium (MM), and the reduction was restored by adding plant extract to the MM. The gene containing the insertion site was identified as rplY. The deletion mutant ΔrplY, exhibited reduced virulence, motility and plant cell wall-degrading enzyme production but not biofilm formation. Analysis of gene expression and reporter fusions revealed that the rplY gene in PccS1 is up-regulated at both the transcriptional and the translational levels in the presence of plant extract. Our results suggest that rplY is induced by Z. elliotiana extract and is crucial for virulence in P. carotovorum subsp. carotovorum.