Molecular Epidemiology and Risk Factors of Carbapenem-Resistant Klebsiella Pneumoniae Bloodstream Infections in Wuhan, China.

OBJECTIVE: The clinical characteristics and microbiological data of patients with K. pneumoniae bloodstream infections (BSI) from January 2018 to December 2020 were retrospectively analyzed to study the molecular epidemiology of Carbapenem-resistant Klebsiella pneumoniae (CRKP). We also aimed to identify the risk factors for the development of CRKP BSI. METHODS: This retrospective study was conducted at Renmin Hospital of Wuhan University from January 2018 to December 2020. The date of non-duplicate K. pneumoniae isolates isolated from blood samples was identified using the microbiology laboratory database. The data from patients diagnosed with K. pneumoniae BSI were collected and analyzed. RESULTS: From 2018 to 2020, there were 510 non-duplicated K. pneumoniae blood isolates, mainly distributed in the intensive care unit (ICU) (28.4%), that were identified in our research. These cases included 77 strains of CRKP and 433 strains of carbapenem-susceptible K. pneumoniae (CSKP). The resistance rate of K. pneumoniae to meropenem and imipenem increased from 11.2% in 2018 to 27.1% in 2020. Moreover, Compared with CSKP, all CRKP isolates showed multi-resistance to tested antibiotics. The phylogenetic analysis showed that the CRKP isolates could be grouped into four major clades, and multilocus sequence typing revealed that the isolates had considerable clonality. Overall, 8 sequence types (STs) of CRKP were detected, of which ST11 comprised the majority and clustered into clade 3. The most prevalent carbapenemase gene was blaKPC (87%) among the CRKP isolates, followed by blaNDM (9.1%) and blaIMP (1.3%). A total of 74 (16.6%) patients with CRKP BSI and 373 (83.4%) patients with CSKP BSI were categorized as the case and control groups. The mortality in the CRKP group was 44.6%, and 11.5% in CSKP group (P<0.001). A multivariate analysis that a long hospital stay before BSI (OR=1.42, 95% CI 1.02-4.31, P=0.011), ICU hospitalization history (OR=3.30, 95% CI 1.35-8.05, P=0.002), and prior use of carbapenems (OR=3.33, 95% CI 1.29-7.27, P=0.001) and antifungals (OR=2.81, 95% CI 1.24-6.04, P<0.001) were independent risk factors for CRKP BSI. CONCLUSION: ST11 is the predominant type of CRKP mediating inter-hospital transmission, and blaKPC is the main carbapenemase gene harboured by CRKP blood isolates. ICU stay, prolonged hospitalization before BSI, and prior use of carbapenems and antifungals were independent risk factors for acquiring CRKP BSI. Our study may provide insights into early infection control practices.

L-Carnitine protects against tacrolimus-induced renal injury by attenuating programmed cell death via PI3K/AKT/PTEN signaling.

Reducing immunosuppressant-related complications using conventional drugs is an efficient therapeutic strategy. L-carnitine (LC) has been shown to protect against various types of renal injury. In this study, we investigated the renoprotective effects of LC in a rat model of chronic tacrolimus (TAC) nephropathy. SD rats were injected with TAC (1.5 mg · kg-1 · d-1, sc) for 4 weeks. Renoprotective effects of LC were assessed in terms of renal function, histopathology, oxidative stress, expression of inflammatory and fibrotic cytokines, programmed cell death (pyroptosis, apoptosis, and autophagy), mitochondrial function, and PI3K/AKT/PTEN signaling. Chronic TAC nephropathy was characterized by severe renal dysfunction and typical histological features of chronic nephropathy. At a molecular level, TAC markedly increased the expression of inflammatory and fibrotic cytokines in the kidney, induced oxidative stress, and led to mitochondrial dysfunction and programmed cell death through activation of PI3K/AKT and inhibition of PTEN. Coadministration of LC (200 mg · kg-1 · d-1, ip) caused a prominent improvement in renal function and ameliorated histological changes of kidneys in TAC-treated rats. Furthermore, LC exerted anti-inflammatory and antioxidant effects, prevented mitochondrial dysfunction, and modulated the expression of a series of apoptosis- and autophagy-controlling genes to promote cell survival. Human kidney proximal tubular epithelial cells (HK-2 cells) were treated with TAC (50 µg/mL) in vitro, which induced production of intracellular reactive oxygen species and expression of an array of genes controlling programmed cell death (pyroptosis, apoptosis, and autophagy) through interfering with PI3K/AKT/PTEN signaling. The harmful responses of HK-2 cells to TAC were significantly attenuated by cotreatment with LC and the PI3K inhibitor LY294002 (25 µM). In conclusion, LC treatment protects against chronic TAC nephropathy through interfering the PI3K/AKT/PTEN signaling.

Inhibition of HDAC6 attenuates LPS-induced inflammation in macrophages by regulating oxidative stress and suppressing the TLR4-MAPK/NF-κB pathways.

BACKGROUND: Histone deacetylase 6 (HDAC6) has been considered as an important regulator in the development of inflammatory diseases. However, the mechanism of HDAC6 in regulating inflammatory responses has not been fully determined. In the present study, we aim to investigate the role and mechanisms of HDAC6 in regulating inflammation in lipopolysaccharide (LPS)-activated macrophages. METHODS: Flow cytometry was used to determine a suitable treatment dosage of ACY-1215 on lipopolysaccharide (LPS)-activated macrophages for the present study. The RAW264.7 macrophages were divided into normal, LPS-treated, and ACY-1215 treated groups, respectively. For the ACY-1215 group, ACY-1215 (10 µM) was added to the medium 2 h prior to treatment with LPS (1 µg/ml) for 24 h. In this study, ROS, inflammatory cytokines, the ultrastructure of mitochondria, mitochondrial membrane potential, RNA and protein expression assay were detected respectively. Subsequently, the effect of HDAC6 knockdown on inflammatory response in LPS-activated RAW264.7 macrophages was also detected. RESULTS: Inhibition of HDAC6 inhibited the overproduction of ROS and suppressed the expression of pro-inflammatory cytokines such as TNF-α, IL-1ß, and IL-6 in LPS-activated RAW264.7 cells. Pretreatment with ACY-1215 could normalize the ultrastructure of mitochondria and mitochondrial membrane potential in LPS-activated macrophages. Moreover, the protein expression of TLR4, Nrf2, HO-1 and the activation of MAPK and NF-κB signaling pathways were normalized by the inhibition of HDAC6. CONCLUSIONS: Inhibition of HDAC6 exhibited protective role against LPS-induced inflammation in RAW264.7 cells by regulating oxidative stress and suppressing the activation of TLR4- MAPK/NF-κB signaling pathway.

Quantitative Proteomic Analysis Reveals the Sites Related to Acetylation and Mechanism of ACY-1215 in Acute Liver Failure Mice.

Background: ACY-1215 is a well-known selective histone deacetylase 6 (HDAC6) inhibitor, and it has been considered as a potential therapeutic drug in inflammatory diseases, including acute liver failure (ALF). However, little is known about the impact of ACY-1215 treatment on histone lysine acetylation and proteome in ALF. In this study, we aim to investigate whether ACY-1215 has inhibitory effects and mechanism on the necrosis of hepatocytes; moreover, the impact of ACY-1215 treatment on histone lysine acetylation still needs further elucidation. Methods: Male C57/BL6 mice were divided into normal, model, and ACY-1215 groups. ACY-1215 (25 mg/kg) and same amounts of saline were injected intraperitoneally to the mice before the establishment of ALF model induced by lipopolysaccharide (LPS) (100 µg/kg) combined with D-gal (400 mg/kg). All animals were sacrificed after 24 h. In this study, detection programs, including quantitative proteomic analysis, transmission electron microscopy (TEM) micrographs, pathological staining, protein expression, the detection of reactive oxygen species (ROS) as well as glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) measurement. Results: The function of liver and the necrosis of hepatocytes in ALF mice were significantly normalized by ACY-1215 pretreatment. The quantitative proteomic analysis revealed that ACY-1215-restrained oxidative phosphorylation normalized the function respiratory electron-transport chain in the mitochondria. Moreover, pretreatment of ACY-1215 not only normalized the structure of mitochondria but also inhibited the generation of reactive oxygen species (ROS). Conclusions: ACY-1215 was able to inhibit necrosis of hepatocytes in ALF mice through regulating the mitochondrial-mediated oxidative stress, and we identified the common sites related to acetylation level.

Protective role of AGK2 on thioacetamide-induced acute liver failure in mice.

AIMS: The aim of the present study was to investigate the protective effects of AGK2 as a selective SIRT2 inhibitor on thioacetamide (TAA)-induced acute liver failure (ALF) in mice and its potential mechanism. MAIN METHODS: All male C57BL/6 mice were separated into control, TAA, AGK2 + TAA, and AGK2 groups. The histological changes were observed by hematoxylin and eosin (HE) staining. The apoptosis cells of liver tissues were detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were used to evaluate the damage of liver function. The inflammatory cytokines of iNOS, TNF-α, IL-1ß was detected by Western blotting and RT-PCR assay. The expression of mitogen-activated protein kinase (MAPK), NF-κB, and apoptosis pathways was determined by Western blotting. KEY FINDINGS: AGK2 improved the damage of TAA-induced liver pathology and function. AGK2 pretreatment also reduced the levels of pro-inflammatory cytokines in ALF liver tissues. AGK2 improved the TAA-induced survival rate. Moreover, AGK2 administration suppressed the increase of phosphorylation NF-κB-p65 and the activation of MAPK pathway. In addition, pretreatment alleviated TAA-induced the liver cells apoptosis. SIGNIFICANCE: AGK2 improve TAA-induced survival rate in mice with ALF, suppress the inflammatory responses by inhibition of MAPK and NF-κB signaling pathways, and decrease the hepatocyte necrosis by inhibition of apoptosis. Pharmacologic inhibition of SIRT2 may be a promising approach for the treatment of ALF.

Histone deacetylases and acetylated histone H3 are involved in the process of hepatitis B virus DNA replication.

AIMS: The aim of this study was to investigate the relationship between anti-HBV treatment and the regulation of HDACs during HBV DNA replication. METHODS: HDAC activities and HBV DNA levels in CHB patients' sera were measured and correlation analysis was made. The changes of HDAC2, HDAC6, AH3 and histone H3 levels in normal control and 4 CHB patient liver tissue samples before and after antiviral treatment were examined. The HDAC inhibitor, TSA, anti-HBV agents, ETV and IFN-α were used to stimulate HepG2.2.15 cells. The levels of HBV DNA, pgRNA in supernatants, and cccDNA in the cells were determined by PCR. The HDAC activity, HDAC6, HDAC2, AH3 and H3 protein levels in cells were tested at days 3, 6, and 9 after treatments. KEY FINDINGS: HDAC activity was positively correlated with HBV DNA in the HBV patients' sera. The levels of HDAC2, HDAC6 and AH3 were notably decreased after antiviral treatment. When compared with antiviral treatment group, the normal liver tissue showed obviously decreased HDAC2, HDAC6 and AH3 protein levels. In vitro study, the level of HBV DNA, the HDAC activity, and the HDAC2, HDAC6 and AH3 protein levels decreased in the ETV, IFN-α and TSA groups compared with the control group. The pgRNA level in supernatants was declined in the IFN-α group and increased in the ETV and TSA groups. cccDNA expression was suppressed by IFN-α. SIGNIFICANCE: The changes of HBV replicative products during antiviral treatment are associated with histone deacetylation. Acetylated histone H3 is involved in the process of hepatitis B virus DNA replication.

Histone Deacetylase 2 Inhibitor CAY10683 Alleviates Lipopolysaccharide Induced Neuroinflammation Through Attenuating TLR4/NF-κB Signaling Pathway.

Neuroinflammation involves in the progression of many central nervous system diseases. Several studies have shown that histone deacetylase (HDAC) inhibitors modulated inflammatory responses in lipopolysaccharide (LPS) stimulated microglia. While, the mechanism is still unclear. The aim of present study was to investigate the effect of HDAC2 inhibitor CAY10683 on inflammatory responses and TLR4/NF-κB signaling pathways in LPS activated BV2 microglial cells and LPS induced mice neuroinflammation. The effect of CAY10683 on cell viability of BV2 microglial cells was detected by CCK-8 assay. The expressions of inflammatory cytokines were analyzed by western blotting and RT-PCR respectively. The TLR4 protein expression was measured by western blotting, immunofluorescence, immunohistochemistry respectively. The protein expressions of MYD88, phospho-NF-κB p65, NF-κB-p65, acetyl-H3 (AH3), H3, and HDAC2 were analyzed by western blotting. We found that CAY10683 could inhibit expression levels of inflammatory cytokine TNF-α and IL-1ß in LPS activated BV2 microglial cells and LPS induced mice neuroinflammation. It could induce TLR4, MYD88, phospho-NF-κB p65, and HDAC2 expressions. Moreover, CAY10683 increased the acetylation of histones H3 in LPS activated BV2 microglial cells and LPS induced mice neuroinflammation. Taken together, our findings suggested that HDAC2 inhibitor CAY10683 could suppress neuroinflammatory responses and TLR4/NF-κB signaling pathways by acetylation after LPS stimulation.

Histone deacetylase 6 inhibitor ACY-1215 protects against experimental acute liver failure by regulating the TLR4-MAPK/NF-κB pathway.

Histone deacetylase 6 (HDAC6) is considered a new target for anticancer, anti-inflammatory, and neurodegenerative treatment. ACY-1215 is a selective histone deacetylase 6 inhibitor, and it has been recognized as a potential anticancer and anti-inflammation drug. The aim of our study was to investigate whether ACY-1215 has protective effects on acute liver failure (ALF) in mice and explore its potential mechanism. Male C57/BL6 mice were divided into normal, model, and ACY-1215 groups. ACY-1215 (25mg/kg) and same amounts of saline were given to mice. After 2h, the ALF models were induced by lipopolysaccharide (LPS, 100µg/kg) combined with D-galactosamine (D-gal, 400mg/kg). All animals were killed after 24h. The expressions of HDAC6 were determined by western blotting and RT-PCR assay. The expression levels of inflammatory cytokines were detected by ELISA and RT-PCR. The protein expression of Toll-like receptor 4 (TLR4), mitogen-activated protein kinase (MAPK), and nuclear factor κB (NF-κB) species were determined by western blot. The mortality of mice with ALF induced by LPS and D-gal was significantly decreased by ACY-1215 pretreatment. Procedures to manage ALF caused adversely affected liver histology and function; this damage was repaired by pretreatment of ACY-1215. ACY-1215 treatment also attenuated the serum and messenger RNA levels of the proinflammatory cytokines. Pretreatment of ACY-1215 significantly decreased the protein expression of TLR4 and the activation of MAPK and NF-κB signalling pathways. ACY-1215 has potential therapeutic value in mice with ALF by directly inhibiting inflammatory response via regulation of the TLR4-MAPK/NF-kB pathway.

Glutamine ameliorates lipopolysaccharide-induced cardiac dysfunction by regulating the toll-like receptor 4/mitogen-activated protein kinase/nuclear factor-kB signaling pathway.

The inflammatory response of sepsis induced by lipopolysaccharide (LPS) may result in irreversible cardiac dysfunction. Glutamine (GLN) has a multitude of pharmacological effects, including anti-inflammatory abilities. Previous studies have reported that GLN attenuated LPS-induced acute lung injury and intestinal mucosal injury. The present study investigated whether GLN exerts potential protective effects on LPS-induced cardiac dysfunction. Male Sprague-Dawley rats were divided into three groups (15 rats per group), including the control (saline-treated), LPS and LPS+GLN groups. Pretreatment with 1 g/kg GLN was provided via gavage for 5 days in the LPS+GLN group, while the control and LPS groups received the same volume of normal saline. On day 6, a cardiac dysfunction model was induced by administration of LPS (10 mg/kg). After 24 h, the cardiac functions of the rats that survived were detected by echocardiography and catheter-based measurements. The serum levels of tumor necrosis factor α (TNF-α), interleukin (IL)-1ß and IL-6 were detected by enzyme-linked immunosorbent assay, while the mRNA levels of toll-like receptor (TLR)4, TNF-α, IL-1ß and IL-6 were examined by reverse transcription-quantitative polymerase chain reaction. The protein expression of TLR4, mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) were also determined by western blot analysis. The results of echocardiography and catheter-based measurements revealed that GLN treatment attenuated cardiac dysfunction. GLN treatment also attenuated the serum and mRNA levels of the pro-inflammatory cytokines. In addition, the protein levels of TLR4, phosphorylated (p-)extracellular signal-regulated kinase, p-c-Jun N-terminal kinase and p-P38 were reduced upon GLN pretreatment. Furthermore, GLN pretreatment resulted in decreased activation of the NF-κB signaling pathway. In conclusion, GLN has a potential therapeutic effect in the protection against cardiac dysfunction mediated by sepsis through regulating the TLR4/MAPK/NF-κB signaling pathway.

[Study on the Distinguishment of Camouflage Paints Based on Depolarization Characteristics].

As an important part in the modern warfare, camouflage technology plays a critical role in the battlefield, and the results of detection of camouflage target directly affect the results of war. However, there is little paper to detect camouflage paint by depolarization characteristics, so it is of great significance to use the depolarization technology to study the distinguishment of camouflage paints. To address this issue, we studied the mechanism of the scattering of electromagnetic wave, and analysed the relationship between the characteristics of depolarization and mechanism of scattering. Jones Matrix and Mueller Matrix were used to set up the physical model, and the Mueller-Jones Matrix was decomposed with the characteristics of polarization, then the depolarization coefficients(ωd) of the surfaces of the samples was acquired. In this experiment, we measured soil and three kinds of camouflage yellow paints in seven different incident angles to analyze the characteristics of depolazation of the soil and three kinds of camouflage yellow paints' surfaces. Finally, we applied the theory of Fresnel formulas to verify the theoretical model. The results showed that: the depolarization coefficients of the samples' surfaces were related to the scattering, and with the increase of the incident angles, the depolarization coefficients were decline. But in the whole measurement process, the depolarization coefficients of the soil were far above the camouflage paints'. Research indicated that: this article was the first paper which used the depolarization coefficients as an important parameter to identify the camouflage targets, and could identify the camouflage yellow paints in the soil-background accurately and effectively. The processes of the experiments were simpler, and the time was shorter. In modern battlefield, it could identify the camouflage targets quickly and easily, and furnish the precious time for the victory of the war. Therefore, the depolarization technology had a great application value, and the paper had very important significance on the development of camouflage recognition technology.

Trichostatin A protects against intestinal injury in rats with acute liver failure.

BACKGROUND: Histone deacetylase (HDAC) inhibitors have been widely applied in the clinic as anticancer drugs against multiple neoplasms and proved their anti-inflammation under different pathology recently. Trichostatin A (TSA) is an HDAC inhibitor specific in class I and II HDAC enzymes. The aim of the present study was to elucidate the protective effects of TSA on acute liver failure (ALF) in rats and its potential mechanism. METHODS: A total of 18 female Sprague-Dawley rats were separated into control, model, and TSA groups. We used Western blotting to determine the expression of HDACs, inflammatory cytokines, and acetylation of histone in liver and small intestine. The gene expression of inflammatory factors and Cox-2 was detected by a polymerase chain reaction. Colonic motility was assessed by spatiotemporal mapping. Histologic analysis and immunohistochemistry were performed. Intestinal permeability examination and levels of alanine aminotransferase, aspartate aminotransferase, and total bilirubin were also observed. RESULTS: ALF procedure caused harm to histology of liver and small intestine, increased the intestinal permeability and serum levels of alanine aminotransferase, aspartate aminotransferase, and total bilirubin. It also interrupted the normal organization of colonic motor patterns by hurting enteric nervous system and pacemaker cells. Along with the decrease of inflammatory factors in ALF rats by TSA administration, all the damage to the liver, the small intestine, and the colon was repaired. CONCLUSIONS: TSA alleviates the lesion in liver, as well as in small intestine and colon in ALF rats by directly inhibiting inflammatory response.

[Geochemical Characteristics of Lateral Hyporheic Zone Between the River Water and Groundwater, a Case Study of Maanxi in Chongqing].

The hyporheic zone is a place where river water and groundwater mutually exchange and mix. It plays an important role in protecting the ecology and water quality of river water and groundwater. In order to study the geochemical characteristics of lateral hyporheic zone in river and ground water, water temperature, dissolved oxygen, pH, electrical conductivity were measured automatically at the hyporheic zone of Maanxi in Chongqing. The concentrations of ions in water and elements in sediment within the hyporheic zone were also analyzed. The results showed that the hydrochemical species of lateral hyporheic zone in Maanxi was HCO3-Ca·Mg. Affected by the infiltration of river water, the coefficient variations of water temperature, dissolved oxygen, pH and electrical conductivity in the hyporheic zone were lower than those observed in the river under the buffer action. Along with the farther distance from the riverbank, an anoxia redox environment was formed in the hyporheic zone due to a physical, chemical and biological interactions. An acid and alkali environment was also formed with a decreasing pH trend near the riverbank and hyporheic zone. Under its influence, concentrations of K+, NH4+-N, NO3- and SO42- decreased. Mn, electrical conductivity, and the concentrations of Ca2+, Mg2+, Ba2+ and Sr2+ firstly increased and then decreased, while the concentrations of Fe, Al3+ were elevated. Affected by the long-time interaction of river water and groundwater, the elementary concentrations in the sediment were relatively high at the place of about 30 cm away from the riverbank. This consequently formed a hydrogeochemical gradient in the hyporheic zone. The boundary of the hyporheic zone was inferred at 30 to 50 cm away from the riverbank, whereas the boundary of shallow hyporheic zone was located at 10 cm away from the riverbank. In the process of river water recharging groudnwater, hyporheic zone of river and groundwater played an important role in the purification of water quality.

[Comparison on the Hydrogeochemical Characteristics of Typical Karst Groundwater System in Southwest China, a Case of Qingmuguan and Laolongdong in Chongqing].

To study the hydrogeochemical characteristics of southwestern typical karst underground river influenced by different land-use types and human activities, underground rivers of Qingmuguan and Laolongdong, which have similar geological background in Chongqing, were contrastively analyzed from the scale of monthly and rainfall event variation. By the means of independent t-test and principal component analysis(PCA), the results showed that ions of Ca2+, HCO3-, Mg2+, K+, NO3-, Na+, SO42-, Cl- and conductivity were distinctly different at the outlet of the two observed underground rivers, Jiangjia spring and Laolongdong. Compared with Laolongdong, Jiangjia spring showed larger monthly variation range and mean concentrations of K+, NO3-, but ions of Na+, SO42-, Cl- showed an opposite trend. Water-rock interaction played an important role in the hydrogeochemical characteristics and variations of two observed karst underground rivers. Qingmuguan underground river was mainly affected by agricultural activities, while Laolongdong underground river was dominantly influenced by urban and industrial activities. Owing to the difference in manner and intensity of human activities, the two observed karst underground river systems responded differently during a single rainfall event. The variation of water chemical indicators that highly corresponded to discharge at Jiangjia spring were relatively disordered at Laolongdong. It was shown that the hydrogeochemical characteristic of Qingmuguan was primarily influenced by soil erosion and agricultural activities, followed by water-rock interaction, while the hydrochemical characteristic of Laolongdong was dominantly influenced by water-rock interaction, followed by urban activities, industrial activities and soil erosion.