Protective role of nitric oxide donors on endothelium in ischemia-reperfusion injury: a meta-analysis of randomized controlled trials.

BACKGROUND: Decreased bioavailability of nitric oxide (NO) under hypoxic conditions can lead to endothelial dysfunction. NO supplementation may protect endothelial function in ischemia-reperfusion (IR) injury. Therefore, a meta-analysis of randomized controlled trials (RCTs) was performed to verify the protective effect of NO donors on endothelium in IR injury. METHODS: Medline, Embase, Cochrane Library, and Web of Science databases were searched from inception to April 1, 2023. The specific inclusion criteria were as follows: (1) RCTs; (2) trials comparing NO donors with placebo control groups; and (3) trials reporting the effects of these interventions on vascular endothelial functional outcomes in IR injury. Random-effects models were used to assess pooled effect sizes, which were expressed as standardized mean differences (SMD). RESULTS: Seven studies satisfied the inclusion criteria and consisted of a total of 149 participants. NO donors were protective of endothelial function in IR injury (SMD: - 1.60; 95% confidence interval [CI]: - 2.33, - 0.88, P < 0.0001; heterogeneity [I2 = 66%, P = 0.001]). Results of the subgroup analysis showed the following: absence of protective effect of NO donor use following ischemia on endothelial function in IR injury - 1.78 (95% CI: - 2.50, - 1.07) and loss of protective effect on endothelial function after prolonged NO donor use - 0.89 (95% CI: - 2.06, 0.28). CONCLUSION: The short-period use of NO donors before the onset of ischemia can protect endothelial function in IR injury.

Inhibition of the NADPH Oxidase Pathway Reduces Ferroptosis during Septic Renal Injury in Diabetic Mice.

Background: Obesity and type 2 diabetes mellitus (DM) contribute to a higher mortality rate in patients with septic acute kidney injury (AKI) during sepsis. Reactive oxygen species (ROS) is the major injury factor for sepsis. This study was aimed at exploring the potential therapeutic drug for septic AKI targeting on ROS. Methods: A murine septic AKI model was established in both wild-type and high-fat diet-fed (HFD) mice. NADPH oxidase inhibitor Vas2870 was used in vivo to explore the role of NADPH oxidase in ROS release in septic AKI in diabetic mice. Ferrostatin-1 was administered to investigate the role of ferroptosis in ROS accumulation during NADPH oxidase activating in septic AKI in diabetic mice. Results: Compared to chow diet-fed mice, HFD diabetic mice which were subjected to LPS exhibited aggravated renal function (blood urea nitrogen, creatinine clearance, and serum cystatin C) and oxidative stress (malondialdehyde, 4-HNE, ROS, 8-OHdG, and NADPH oxidase), thus resulting in a higher mortality rate. Septic renal injury was significantly attenuated by the ferroptosis inhibitor Fer-1 in HFD-challenged mice. Furthermore, ferroptosis accumulation and related protein expression (ASCL4, FTH1, and GPX4) were altered by LPS stimulation in HFD-challenged mice and suppressed by NADPH oxidase inhibition via Vas2870 in vivo. In summary, NADPH inhibition restored septic renal function from injury by suppressing ferroptosis accumulation in HFD-challenged mice. Conclusion: These results suggest that targeting NADPH-mediated ROS release and ferroptosis accumulation is a novel therapeutic strategy to protect the kidney from septic injury in patients with obesity and type 2 DM.

Ultrasound-guided transmuscular quadratus lumborum block reduced postoperative opioids consumptions in patients after laparoscopic hepatectomy: a three-arm randomized controlled trial.

BACKGROUND: To investigate whether transmuscular quadratus lumborum block (TQLB) combined with oxycodone-based patient-controlled intravenous analgesia (PCIA) compared with sufentanil-based patient-controlled intravenous analgesia could reduce postoperative pain and opioid consumption in patients undergoing laparoscopic hepatectomy. METHODS: Eighty patients undergoing laparoscopic hepatectomy surgery were randomly divided into Group S (Sufentanil for PCIA group), Group O (Oxycodone for PCIA group) and Group QO (transmuscular quadratus lumborum block + oxycodone for PCIA group). Primary outcome was Numerical Rating Scale (NRS) pain score when coughing at 6th hour after the operation. We summarized opioid consumption and recorded complications, opioid drug adverse reaction and analgesia satisfaction. RESULTS: NRS pain scores were significantly lower in Group QO while patients coughing at 6th hour after the operation compared with Group S and Group O (median (interquartile range [IQR]):Group S vs. Group O vs. Group QO 4.0 [3.0, 5.0] vs. 4.0[3.0,5.0]vs.3.0 [2.0, 3.0], p < 0.05). Within 24 h after surgery, the bolus times of PCIA (patient controlled intravenous analgesia) in the QO group was reduced which was compared with the Group S and Group O (median (interquartile range [IQR]):Group S vs. Group O vs. Group QO 13.0 [10.3, 19.5] vs. 11.5 [7.8, 18.3]vs.6.5[3.5,12.0], p < 0.05). The proportion of patients in the three groups who required additional analgesia was ranked as Group QO < Group O < Group S(p < 0.05). The analgesic satisfaction of patients in Group QO was higher than the Group S (p = 0.001) and Group O (p = 0.012). CONCLUSIONS: TQLB combined with oxycodone-based PCIA provided satisfactory postoperative analgesia and reduced oxycodone consumption in patients following laparoscopic hepatectomy. TRIAL REGISTRATION: ChiCTR1900028467 (22/12/2019).

High-fat diet increased NADPH-oxidase-related oxidative stress and aggravated LPS-induced intestine injury.

AIMS: Lipopolysaccharide (LPS)-induced intestinal injury is a common clinical feature of sepsis. Aggravated inflammation and higher sensitivity to infection are associated with high-fat diet (HFD) in patients with type 2 diabetes and/or obesity. However, the mechanism by which HFD exacerbates LPS-induced intestinal injury has not been elucidated. This study aims to examine the effects of HFD on intestinal injury induced by LPS and the underlying mechanism. MAIN METHODS: Mice were fed with HFD or regular chow for 12weeks and were then challenged with LPS. Vas2870 was administered to mice that received HFD before the initiation of the diet. The levels of tight junction protein expression, oxidative stress, organ injury, and nicotinamide adenine dinucleotide phosphate (NADPH)-associated proteins were assessed periodically. KEY FINDINGS: LPS treatment resulted in severe intestinal pathological injury and increased oxidative stress, evidenced by significantly increased serum diamine oxidase, reactive oxygen species, malondialdehyde, and intestinal fatty acid binding protein contents. Additionally, a decrease in tight junction protein expression was observed, indicating a loss of tight junction integrity. LPS treatment induced the expression of Nox2 and Nox4. All the effects were more severe in HFD mice. Treatment with vas2870 conferred protection against LPS-induced intestinal injury in HFD-fed mice, partially reduced oxidative stress, and rescued the expression of tight junction proteins. CONCLUSION: HFD aggravated LPS-induced intestine injury through exacerbating intestinal Nox-related oxidative stress, which led to a loss of the integrity of tight junctions and consequently increased intestinal permeability.

Distinct Geographical Distribution of the Miscanthus Accessions with Varied Biomass Enzymatic Saccharification.

Miscanthus is a leading bioenergy candidate for biofuels, and it thus becomes essential to characterize the desire natural Miscanthus germplasm accessions with high biomass saccharification. In this study, total 171 natural Miscanthus accessions were geographically mapped using public database. According to the equation [P(H/L| East) = P(H/L∩East)/P(East)], the probability (P) parameters were calculated on relationships between geographical distributions of Miscanthus accessions in the East of China, and related factors with high(H) or low(L) values including biomass saccahrification under 1% NaOH and 1% H2SO4 pretreatments, lignocellulose features and climate conditions. Based on the maximum P value, a golden cutting line was generated from 42°25' N, 108°22' E to 22°58' N, 116°28' E on the original locations of Miscanthus accessions with high P(H|East) values (0.800-0.813), indicating that more than 90% Miscanthus accessions were originally located in the East with high biomass saccharification. Furthermore, the averaged insolation showed high P (H|East) and P(East|H) values at 0.782 and 0.754, whereas other climate factors had low P(East|H) values, suggesting that the averaged insolation is unique factor on Miscanthus distributions for biomass saccharification. In terms of cell wall compositions and wall polymer features, both hemicelluloses level and cellulose crystallinity (CrI) of Miscanthus accessions exhibited relative high P values, suggesting that they should be the major factors accounting for geographic distributions of Miscanthus accessions with high biomass digestibility.

Lignin extraction distinctively enhances biomass enzymatic saccharification in hemicelluloses-rich Miscanthus species under various alkali and acid pretreatments.

In this study, one- and two-step pretreatments with alkali and acid were performed in the three Miscanthus species that exhibit distinct hemicelluloses levels. As a result, one-step with 4% NaOH or two-step with 2% NaOH and 1% H2SO4 was examined to be optimal for high biomass saccharification, indicating that alkali was the main effecter of pretreatments. Notably, both one- and two-step pretreatments largely enhanced biomass digestibility distinctive in hemicelluloses-rich samples by effectively co-extracting hemicelluloses and lignin. However, correlation analysis further indicated that the effective lignin extraction, other than the hemicelluloses removals, predominately determined biomass saccharification under various alkali and acid pretreatments, leading to a significant alteration of cellulose crystallinity. Hence, this study has suggested the potential approaches in bioenergy crop breeding and biomass process technology.

Hemicelluloses negatively affect lignocellulose crystallinity for high biomass digestibility under NaOH and H2SO4 pretreatments in Miscanthus.

BACKGROUND: Lignocellulose is the most abundant biomass on earth. However, biomass recalcitrance has become a major factor affecting biofuel production. Although cellulose crystallinity significantly influences biomass saccharification, little is known about the impact of three major wall polymers on cellulose crystallization. In this study, we selected six typical pairs of Miscanthus samples that presented different cell wall compositions, and then compared their cellulose crystallinity and biomass digestibility after various chemical pretreatments. RESULTS: A Miscanthus sample with a high hemicelluloses level was determined to have a relatively low cellulose crystallinity index (CrI) and enhanced biomass digestibility at similar rates after pretreatments of NaOH and H2SO4 with three concentrations. By contrast, a Miscanthus sample with a high cellulose or lignin level showed increased CrI and low biomass saccharification, particularly after H2SO4 pretreatment. Correlation analysis revealed that the cellulose CrI negatively affected biomass digestion. Increased hemicelluloses level by 25% or decreased cellulose and lignin contents by 31% and 37% were also found to result in increased hexose yields by 1.3-times to 2.2-times released from enzymatic hydrolysis after NaOH or H2SO4 pretreatments. The findings indicated that hemicelluloses were the dominant and positive factor, whereas cellulose and lignin had synergistic and negative effects on biomass digestibility. CONCLUSIONS: Using six pairs of Miscanthus samples with different cell wall compositions, hemicelluloses were revealed to be the dominant factor that positively determined biomass digestibility after pretreatments with NaOH or H2SO4 by negatively affecting cellulose crystallinity. The results suggested potential approaches to the genetic modifications of bioenergy crops.