N-acetylcysteine reduces the renal oxidative stress and apoptosis induced by hemorrhagic shock

Involvement of CD44 and MAPK14-mediated ferroptosis in hemorrhagic shock

To elucidate the induction of ferroptotic pathways and the transcriptional modulation of pivotal genes in the context of hemorrhagic shock. The R software was used to analyze the GSE64711 dataset, isolating genes relevant to ferroptosis. Enrichment analyses and protein interaction networks were assembled. Using WGCNA hub genes were identified and intersected with ferroptosis-related genes, highlighting hub genes CD44 and MAPK14. In a rat hemorrhagic shock model, cardiac ROS, Fe2+, MDA, and GSH levels were assessed. Key ferroptotic proteins (SLC7A11/GPX4) in myocardial tissues were examined via western blot. Hub genes, CD44 and MAPK14, expressions were confirmed through immunohistochemistry. Analyzing the GSE64711 dataset revealed 337 differentially expressed genes, including 12 linked to ferroptosis. Enrichment analysis highlighted pathways closely related to ferroptosis. Using Genemania, we found these genes mainly affect ROS metabolism and oxidative stress response. WGCNA identified CD44 and MAPK14 as hub genes. Rat myocardial tissue validation showed significant cardiac damage and elevated ROS and MDA levels, and decreased GSH levels in the hemorrhagic shock model. The ferroptotic pathway SLC7A11/GPX4 was activated, and immunohistochemistry showed a significant increase in the expression levels of CD44 and MAPK14 in the hemorrhagic shock rat model. We demonstrated the presence of tissue ferroptosis in hemorrhagic shock by combining bioinformatics analysis with in vivo experimentation. Specifically, we observed the activation of the SLC7A11/GPX4 ferroptotic pathway. Further, CD44 and MAPK14 were identified as hub genes in hemorrhagic shock.

Effects of grape seed-derived proanthocyanidin B2 pretreatment on oxidative stress, endoplasmic reticulum stress and apoptosis of renal tubular epithelial cells in renal ischemia-reperfusion injury model of mice

PURPOSE

To investigate the effect of grape seed-derived proanthocyanidin B2 (GSPB2) pretreatment on acute renal ischemia-reperfusion injury model of mice.

METHODS

50 mice were divided into 5 groups: Sham group: mice were treated with right nephrectomy. GSPB2 group: GSPB2 was injected intraperitoneally 45 min before right nephrectomy. IRI group: right kidney was resected and the left renal arteriovenous vessel was blocked for 45 min. GSPB2 + IRI group: GSPB2 was intraperitoneally injected 45 min before IRI established. GSPB2 + BRU + IRI group: GSPB2 and brusatol (BRU) were injected intraperitoneally 45 min before IRI established. Creatinine and urea nitrogen of mice were detected, and the kidney morphology and pathological changes of each group were detected by HE staining, PAS staining and transmission electron microscopy. Expressions of Nrf2, HO-1, GRP78, CHOP, and cleaved-caspase3 were detected by immunofluorescence staining and western blotting.

RESULTS

Morphology and mitochondrial damages of kidney in GSPB2 + IRI group were significantly alleviated than those in IRI group. Expression levels of Nrf2 and HO-1 were significantly higher in GSPB2 + IRI group than those in IRI group. Expression levels of GRP78, CHOP and cleaved-caspase3 were significantly lower in GSPB2 + IRI group than those in IRI group. However, compared to GSPB2 + IRI group, protective effects of GSPB2 pretreatment were weakened in GSPB2 + BRU + IRI group.

CONCLUSIONS

GSPB2 pretreatment could alleviate oxidative stress damage and reduce apoptosis of renal tubular epithelial cells, which might be related to activating the antioxidant system, up-regulating the expression of Nrf2 and HO-1, inhibiting the expressions of GRP78, CHOP and cleaved-caspase3. However, the protective effect could be reversed by brusatol.

Effects of N-acetylcysteine on the inflammatory response and bacterial translocation in a model of intestinal obstruction and ischemia in rats

PURPOSE

To evaluate effect of N-acetylcysteine (NAC) associated with Ringer lactate or hypertonic saline in inflammation and bacterial translocation on experimental intestinal obstruction (IO).

METHODS

Wistar rats was subjected to IO. Six or 24 hours after, rats were subjected to enterectomy and fluid resuscitation: IO, RL (subjected to the same procedures but with fluid resuscitation using Ringer's lactate solution); RLNAC (added NAC to Ringer's solution); and HSNAC (surgical procedure + fluid reposition with 7.5% hypertonic saline and NAC). After 24 h, tissues were collected to cytokines, bacterial translocation, and histological assessments.

RESULTS

In kidney, interleukin-1beta (IL-1beta) was lower in the groups with fluid resuscitation compared to IO group. The RLNAC showed lower levels compared to the RL. Interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-alpha), and (IFN-gamma) were lower in the treatment groups than in IO. In lung, IL-1beta and IL-6 were lower in RLNAC compared to IO. IL-10 was lower in RL, RLNAC and HSNAC compared to IO. TNF-alpha was higher in HSNAC compared to both RL and RLNAC. Bacterial translocation was observed in all animals of IO group. In kidneys, inflammation and congestion degrees were lower in HSNAC compared to RL. In lungs, inflammation levels were higher in RLNAC compared with the sham group.

CONCLUSIONS

The data indicates that NAC associated with RL can promote a decrease in the inflammatory process in the kidneys and lungs in rats, following intestinal obstruction and ischemia in rats.

N-Acetyl-L-Cysteine Protects Organ Function After Hemorrhagic Shock Combined With Seawater Immersion in Rats by Correcting Coagulopathy and Acidosis

Background

The mortality of trauma combined with seawater immersion is higher than that of land injury, however, research on how to treat this critical case and which treatments to adopt is lacking.

Methods

The effect of the thiol compound, N-acetyl-L-Cysteine (NAC), on survival, acidosis, coagulopathy, vital signs, oxidative stress, and mitochondrial and multi-organ function was assessed in a rat model of hemorrhagic shock combined with seawater immersion (Sea-Shock).

Results

Hemorrhagic shock combined with seawater immersion caused a severe lethal triad: multi-organ impairment, oxidative stress, and mitochondrial dysfunction. NAC (30 mg/kg) with lactated Ringer’s (LR) solution (2 × blood volume lost) significantly improved outcomes compared to LR or hetastarch (HES 130/0.4) alone. NAC significantly prolonged survival time to 52.48 ± 30.09 h and increased 72 h survival rate to 11/16 (68%). NAC relieved metabolic acidosis and recovered the pH back to 7.33. NAC also restored coagulation, with APTT, PT, and PT-INR decreased by 109.31, 78.09, and 73.74%, respectively, while fibrinogen level increased 246.23% compared with untreated Sea-Shock. Administration of NAC markedly improved cardiac and liver function, with some improvement of kidney function.

Conclusion

The addition of NAC to crystalloid resuscitation fluid alleviated oxidative stress, restored redox homeostasis, and provided multi-organ protection in the rats after Sea-Shock. NAC may be an effective therapeutic measure for hemorrhagic shock combined with seawater immersion.

Shen-fu injection alleviates acute renal injury by reducing cytokine levels and modulating apoptosis in a porcine hemorrhagic shock model

PURPOSE

Shen-fu injection (SFI) was used to intervene in the resuscitation of porcine hemorrhagic shock (HS) model to study its protective effects on acute kidney injury.

METHODS

After 60 min of HS, 28 animals were randomly assigned into four groups. The groups were as follows: hemorrhagic shock group (HS); HS resuscitation with shed-blood group (HSR); HS resuscitation with shed-blood and SFI (1 mL·kg-1) group (HSR-SFI); and the sham operation group (Sham). The bloods were analyzed for serum creatinine (sCr), cystatin C (CysC) and neutrophil gelatinase-associated lipocalin (NGAL). BAX, Bcl-2, and caspase-3 protein expressions by Western blot analysis and immunohistochemical staining. The renal tissues were removed and pathologic changes were observed.

RESULTS

Mean aortic pressure (MAP) in HSR-SFI groups were higher than that in HSR groups after shock. At the 6th hour after shock, the urine volume per hour in the HSR-SFI groups was more than that in the HSR groups. The sCr, NGAL, CysC and cytokine levels of HSR-SFI groups were lower. The Bcl-2 expression was increased in the HSR-SFI groups. The BAX and caspase-3 expressions were reduced. The histopathologic score in the HSR-SFI was lower.

CONCLUSIONS

SFI may reduce the risk of acute kidney injury (AKI) following hemorrhagic shock by attenuating systemic inflammatory responses, and regulating the expression of apoptosis-related proteins.

Efficacy and Safety of N-acetylcysteine for the Management of Chronic Pain in Adults: A Systematic Review & Meta-analysis

OBJECTIVE

To assess the efficacy and safety of N-acetylcysteine in the treatment of chronic pain.

METHODS

A systematic search was carried out until April 2020 for clinical studies of N-acetylcysteine in the management of any persistent or recurrent chronic pain condition for adults ≥ 18 years old. Risk of Bias was assessed using the validated risk of bias tools. When appropriate, a meta-analysis using a random-effects model was performed, with a fixed-effect model for sensitivity analysis.

RESULTS

Nine studies (n = 863) were included (5 randomized controlled trials [RCTs], 2 open-label non-comparative studies and 2 comparative studies), that evaluated patients with sickle cell disease (3), complex regional pain syndrome (1), pelvic pain/endometriosis (2), rheumatoid arthritis (1), diabetic neuropathy (1), and chronic neuropathic pain (1). In the pooled analysis of 3 RCTs, N-acetylcysteine did not reduce pain intensities (SMD -0.21, 95% CI -0.33 to 0.75, random-effects), improve functional outcomes (SMD 0.21, 95% CI -0.33 to 0.75) or quality of life (SMD 0.60, 95% CI -4.44 to 5.64); however, sensitivity analysis with a fixed effect model demonstrated an effect for pain intensities and function. Due to adverse events being inconsistently reported, no conclusion could be made regarding safety of N-acetylcysteine in chronic pain.

CONCLUSIONS

While there is some evidence to indicate N-acetylcysteine may provide analgesic efficacy for certain pain conditions, there is insufficient evidence to provide definitive evidence on NAC in chronic pain management. Larger-size RCTs spanning a variety of chronic pain conditions are needed to determine N-acetylcysteine's role, if any, in pain medicine.

Effect of Triiodothyronine Administration on the Kidney During Haemorrhagic Shock and Resuscitation

Objective

Apoptosis, measured via caspase activity, can be used to assess renal tissue damage in haemorrhagic shock. We investigated whether Triiodothyronine could attenuate apoptosis and protect against haemorrhagic shock-induced renal injury.

Methods

Haemorrhagic shock was induced in swine until the mean arterial pressure (MAP) was 35–40 mmHg for 40 minutes. Animals were randomly assigned to a control group (n=5), Group-F (Fluid resuscitation, n=6), and Group-T3 (Fluid plus Triiodothyronine, n=6). The swine were resuscitated for 1 hour aiming to MAP restoration (±10% from baseline) and were followed up for another 360 minutes. Haemodynamic parameters, fluids, acid-base status, plasma urea nitrogen, creatinine levels and caspase activity in the kidney were measured.

Results

Haemodynamic parameters did not differ significantly amongst the three groups. Group-T3 required less normal saline (Group-T3: 1083±204 mL versus F: 2500±547 mL, p=0.001) and hydroxyethyl starch (Group-T3: 558±102 mL versus F: 916±204 mL, p=0.004) during resuscitation. Additionally, Group-T3 swine experienced less acidosis following haemorrhage/resuscitation with a pH of 7.39 versus a pH of 7.26 in Group-F (p=0.004) at 360 minutes. Urea remained within normal limits in all groups, but creatinine levels were elevated at 6 hours in Group-F as compared to Group-T3 (p=0.019). Apoptosis, assessed by renal caspase-3 activity, was increased in Group-T3 (132±174 pmol minute⁻¹ g⁻¹) and reduced in Group-F (32±18 pmol minute⁻¹ g⁻¹) as compared to the control group, but without statistical significance (p=0.245 between Group-T3 and Group-F).

Conclusion

Administration of Triiodothyronine in a swine model of haemorrhagic shock seems to interfere with renal cell apoptosis. The exact mechanism needs to be further investigated in future research.

Bisphenol A aggravates renal ischemia-reperfusion injury by disrupting mitochondrial homeostasis and N-acetylcysteine mitigates the injurious outcomes

Exposure to bisphenol A (BPA), a chemical generally used in consumer products, becomes a global public health concern, as humans are increasingly exposed through their daily consuming activities. Renal ischemia-reperfusion (RIR) is the major cause of acute kidney injury with high prevalence and increased long-term risks for multiple comorbidities and mortality. As the kidney is susceptible to these conditions, we explored whether the outcomes following the RIR episode could be influenced by BPA exposure, and investigated the therapeutic possibility by N-acetylcysteine (NAC) including the mechanisms involved. Three groups of male Wistar rats were fed with vehicle, BPA 5, and 50 mg/kg, respectively, for five consecutive weeks then underwent the sham operation. Three other groups with identical treatment underwent bilateral renal IR induction (45-min ischemia followed by 24-hr reperfusion). An additional RIR group was treated with BPA 50 plus NAC 100 mg/kg. BPA-exposed rats that encountered RIR episode showed dose-dependent worsening of RIR injury as evidenced by augmentations of renal dysfunction and histopathological abnormalities, oxidative stress, apoptosis, mitochondrial functional impairment, mitochondrial dynamic, and mitophagy disproportion compared with the vehicle-exposed RIR group. The NAC therapy considerably attenuated the exacerbated effects of BPA, which was associated with increased AMP-activated protein kinase (AMPK), PGC-1α, silent information regulator 3 or sirtuin 3 (SIRT3), and mitofusin 2 (MFN2) expressions but decreased Phosphorylated dynamin-related protein 1 (p-DRP1)/Dynamin-related protein 1 (DRP1), PTEN-induced putative kinase (PINK), and PARKIN expressions. These findings reveal the detrimental effect of repeated BPA exposure on the renal outcomes following the IR episode, and further demonstrate the protective efficacy of NAC by maintaining mitochondrial homeostasis, which is, partly, mediated through the AMPK-PGC-1α-SIRT3 axis.

MLN4924 Exerts a Neuroprotective Effect against Oxidative Stress via Sirt1 in Spinal Cord Ischemia-Reperfusion Injury

Oxidative stress is a leading contributor to spinal cord ischemia-reperfusion (SCIR) injury. Recently, MLN4924, a potent and selective inhibitor of the NEDD8-activating enzyme, was shown to exert a neuroprotective effect against oxidative stress in vitro. However, it is unknown whether MLN4924 plays a protective role against SCIR injury. In the present study, we found that MLN4924 treatment significantly attenuated oxidative stress and neuronal cell death induced by H₂O₂ in SH-SY-5Y neural cells and during rat SCIR injury. Furthermore, MLN4924 administration restored neurological and motor functions in rats with SCIR injury. Mechanistically, we found that MLN4924 protects against H₂O₂- and SCIR injury-induced neurodegeneration by regulating sirtuin 1 (Sirt1) expression. Collectively, these findings demonstrate the neuroprotective role of MLN4924 against oxidative stress in SCIR injury via Sirt1.

N-Acetylcysteine Attenuates Cisplatin-Induced Acute Kidney Injury by Inhibiting the C5a Receptor

N-acetylcysteine has been widely used as a nutritional supplement and drug in humans for its antioxidant properties. The complement activation fragment C5a is a strong proinflammatory molecule that mediates cell adhesion, chemotaxis, and the complex biological functions. However, the effect of NAC on the C5a, and the relationship of those two with cisplatin-induced acute kidney injury are unknown. In cisplatin induced AKI mouse model, mice with NAC administration had a marked improvement in renal function (BUN and Cr), decreased pathological damage, reduced inflammation, and alleviated renal oxidative stress. Furthermore, C5a and C5aR expression in the cisplatin-treated group was notably increased compared with the control group, and this increase could be significantly inhibited by NAC. In addition, neutrophils coexpressed distinctly with C5aR, and the number of infiltrating neutrophils (MPO⁺ly6G⁺) and inflammatory factors decreased with NAC treatment in the cisplatin-treated group. Overall, these data demonstrate that NAC could ameliorate cisplatin-induced nephrotoxicity in mice and the protective effects may be conducted by inhibiting the activation of kidney inflammation and the complement system.

Whole Blood Redox Potential Correlates With Progressive Accumulation of Oxygen Debt and Acts as A Marker of Resuscitation in A Swine Hemorrhagic Shock Model

INTRODUCTION

Oxidation-reduction reactions involve electron exchanges that require optimal balance for proper cell function. This balance is measured via redox potential and reflects oxidative stress. Despite the critical role of oxidative stress in critical illness and injury, little is known regarding redox potential. We hypothesize redox potential measurements will correlate with accumulation of O2 debt produced by hemorrhage over time.

METHODS

Ten swine were studied using a polytrauma hemorrhagic shock model. Whole blood and plasma redox potential measures were obtained at defined stages of O2 debt (20 mL/kg, 40 mL/kg, 60 mL/kg, 80 mL/kg), and through resuscitation. Redox potential was determined by measuring open circuit potential using novel gold nanoporous electrodes with Ag/AgCl reference.

RESULTS

Whole blood redox potential showed negative change as O2 debt accumulated, exhibiting positive response during resuscitation, and correlated with O2 debt across all animals (P < 0.001). Redox potential changes throughout O2 debt accrual were significant compared with baseline (P≤0.05), and at end resuscitation compared with O2 debt 60 mL/kg (P = 0.05) and 80 mL/kg (P = 0.02). Whole blood redox potential measures also correlated with oxygen extraction ratio, ScvO2, and lactic acid, appearing very sensitive to acute changes. Plasma redox potential showed no correlation with O2 debt.

CONCLUSIONS

Whole blood redox potential demonstrates significant correlation to O2 debt at all stages in this model. These results set the stage for further study of redox potential as a direct measure of oxidative stress and potential clinical tool. Given redox potential plasma performance, these measures should be made in whole blood versus plasma.

Hypertonic saline and pentoxifylline enhance survival, reducing apoptosis and oxidative stress in a rat model of strangulated closed loop small bowel obstruction

OBJECTIVES

Intestinal obstruction has a high mortality rate when therapeutic treatment is delayed. Resuscitation in intestinal obstruction requires a large volume of fluid, and fluid combinations have been studied. Therefore, we evaluated the effects of hypertonic saline solution (HS) with pentoxifylline (PTX) on apoptosis, oxidative stress and survival rate.

METHODS

Wistar rats were subjected to intestinal obstruction and ischemia through a closed loop ligation of the terminal ileum and its vessels. After 24 hours, the necrotic bowel segment was resected, and the animals were randomized into four groups according to the following resuscitation strategies: Ringer's lactate solution (RL) (RL-32 ml/kg); RL+PTX (25 mg/kg); HS+PTX (HS, 7.5%, 4 ml/kg), and no resuscitation (IO-intestinal obstruction and ischemia). Euthanasia was performed 3 hours after resuscitation to obtain kidney and intestine samples. A malondialdehyde (MDA) assay was performed to evaluate oxidative stress, and histochemical analyses (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling [TUNEL], Bcl-2 and Bax) were conducted to evaluate kidney apoptosis. Survival was analyzed with another series of animals that were observed for 15 days.

RESULTS

PTX in combination with RL or HS reduced the MDA levels (nmol/mg of protein), as follows: kidney IO=0.42; RL=0.49; RL+PTX=0.31; HS+PTX=0.34 (p<0.05); intestine: IO=0.42; RL=0.48; RL+PTX=0.29; HS+PTX=0.26 (p<0.05). The number of labeled cells for TUNEL and Bax was lower in the HS+PTX group than in the other groups (p<0.05). The Bax/Bcl-2 ratio was lower in the HS+PTX group than in the other groups (p<0.05). The survival rate on the 15th day was higher in the HS+PTX group (77%) than in the RL+PTX group (11%).

CONCLUSION

PTX in combination with HS enhanced survival and attenuated oxidative stress and apoptosis. However, when combined with RL, PTX did not reduce apoptosis or mortality.

l-Cysteine and l-Serine Modified Dendrimer with Multiple Reduced Thiols as a Kidney-Targeting Reactive Oxygen Species Scavenger to Prevent Renal Ischemia/Reperfusion Injury

l-cysteine (Cys)- and l-serine (Ser)-modified, third-generation polyamidoamine (PAMAM) dendrimer with multiple reduced thiols (Ser-PAMAM-Cys) was synthesized as a kidney-targeting reactive oxygen species (ROS) scavenger to help prevent renal ischemia/reperfusion injury. Ser-PAMAM-Cys effectively scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and ROS (hydrogen peroxide and hydroxyl radical) in phosphate-buffered saline (PBS). In addition, ~64% of ¹¹¹In-labeled Ser-PAMAM-Cys accumulated in mouse kidney 3 h after intravenous administration. An in vivo imaging system (IVIS) study indicated that near-infrared fluorescence dye (NIR)-labeled Ser-PAMAM-Cys specifically accumulated in the kidney. In a mouse renal ischemia/reperfusion injury model, increases in the kidney damage markers creatinine (Cre) and blood urea nitrogen (BUN) were significantly inhibited by intravenous Ser-PAMAM-Cys administration. In contrast, Cys injection had no statistically significant effect of preventing Cre or BUN elevation relative to the control. Ser-PAMAM-Cys also effectively downregulated the inflammatory factors NGAL, IL-18, ICAM-1, and VCAM-1 in the renal ischemia/reperfusion injury model. These results indicate that Ser-PAMAM-Cys is a promising kidney-targeting ROS scavenger which could prevent ischemia/reperfusion-induced renal failure.

Protective Effect of N-Acetylcysteine against Oxidative Stress Induced by Zearalenone via Mitochondrial Apoptosis Pathway in SIEC02 Cells

Zearalenone (ZEN), a nonsteroidal estrogen mycotoxin, is widely found in feed and foodstuffs. Intestinal cells may become the primary target of toxin attack after ingesting food containing ZEN. Porcine small intestinal epithelial (SIEC02) cells were selected to assess the effect of ZEN exposure on the intestine. Cells were exposed to ZEN (20 µg/mL) or pretreated with (81, 162, and 324 µg/mL) N-acetylcysteine (NAC) prior to ZEN treatment. Results indicated that the activities of glutathione peroxidase (Gpx) and glutathione reductase (GR) were reduced by ZEN, which induced reactive oxygen species (ROS) and malondialdehyde (MDA) production. Moreover, these activities increased apoptosis and mitochondrial membrane potential (ΔΨm), and regulated the messenger RNA (mRNA) expression of Bax, Bcl-2, caspase-3, caspase-9, and cytochrome c (cyto c). Additionally, NAC pretreatment reduced the oxidative damage and inhibited the apoptosis induced by ZEN. It can be concluded that ZEN-induced oxidative stress and damage may further induce mitochondrial apoptosis, and pretreatment of NAC can degrade this damage to some extent.

N-Acetyl Cysteine Restores Limb Function, Improves Mitochondrial Respiration, and Reduces Oxidative Stress in a Murine Model of Critical Limb Ischaemia

OBJECTIVE/BACKGROUND

The aim of this study was to investigate whether antioxidant therapy might decrease oxidative stress related deleterious effects in the setting of critical limb ischaemia (CLI).

METHODS

Twenty Swiss mice were submitted to sequential right femoral and iliac ligatures; the left limb served as control. The mice were assigned to two groups: in the first group (no-treatment group, n = 10) no treatment was administered; in the second group (N-acetyl cysteine [NAC] group, n = 10) NAC was administered by dissolution in drinking water for 4 weeks, starting on day 7, when CLI was effective. Clinical and functional scores were assessed by two blinded investigators. Mice were killed on day 40 and mitochondrial respiratory chain complex activities, calcium retention capacity, oxidative stress, and histological analysis were analysed.

RESULTS

Ischaemic muscles in the no-treatment group showed significantly impaired mitochondrial respiration and calcium retention capacity, with increased production of reactive oxygen species; but no statistical difference was noticed when comparing ischaemic muscles in the NAC group (n = 10) to contralateral muscles (n = 10) and to control muscles in the no-treatment group (n = 10). Ischaemic muscles in the no-treatment group exhibited myopathic features such as wider range in fibre size, rounded shape, centrally located nuclei, and smaller cross sectional areas, but none of these features were observed in contralateral muscles or in NAC-group muscles (ischaemic or controls).

CONCLUSION

Targeting inhibition of oxidative stress may be a potential therapeutic strategy for muscle protection in CLI and might be considered as potential adjunctive therapy to revascularisation procedures.

Acute kidney injury in trauma patients

PURPOSE OF REVIEW

To review epidemiology and pathophysiology of acute kidney injury (AKI) in trauma patients and propose strategies that aim at preventing AKI after trauma.

RECENT FINDINGS

AKI in trauma patients has been reported to be as frequent as 50% with an association to a prolonged length of stay and a raise in mortality. Among the specific risk factors encountered in trauma patients, hemorrhagic shock, rhabdomyolysis severity, age, and comorbidities are independently associated with AKI occurrence. Resuscitation with balanced solutes seems to have beneficial effects on renal outcome compared with NaCl 0.9%, particularly in the context of rhabdomyolysis. However, randomized clinical studies are needed to confirm this signal. Abdominal compartment syndrome (ACS) is rare but has to be diagnosed to initiate a dedicated therapy.

SUMMARY

The high incidence of AKI in trauma patients should lead to early identification of those at risk of AKI to establish a resuscitation strategy that aims at preventing AKI.

Curcumin-carrying nanoparticles prevent ischemia-reperfusion injury in human renal cells

Renal ischemia-reperfusion injury (IRI) is a major complication in clinical practice. However, despite its frequency, effective preventive/treatment strategies for this condition are scarce. Curcumin possesses antioxidant properties and is a promising potential protective agent against renal IRI, but its poor water solubility restricts its application. In this study, we constructed curcumin-carrying distearoylphosphatidylethanolamine-polyethylene glycol nanoparticles (Cur-NPs), and their effect on HK-2 cells exposed to IRI was examined in vitro. Curcumin encapsulated in NPs demonstrated improved water solubility and slowed release. Compared with the IRI and Curcumin groups, Cur-NP groups displayed significantly improved cell viability, downregulated protein expression levels of caspase-3 and Bax, upregulated expression of Bcl-2 protein, increased antioxidant superoxide dismutase level, and reduced apoptotic rate, reactive oxygen species level, and malondialdehyde content. Results clearly showed that Cur-NPs demonstrated good water solubility and slow release, as well as exerted protective effects against oxidative stress in cultured HK-2 cells exposed to IRI.

Hydrogen Sulfide Inhibits Autophagic Neuronal Cell Death by Reducing Oxidative Stress in Spinal Cord Ischemia Reperfusion Injury

Autophagy is upregulated in spinal cord ischemia reperfusion (SCIR) injury; however, its expression mechanism is largely unknown; moreover, whether autophagy plays a neuroprotective or neurodegenerative role in SCIR injury remains controversial. To explore these issues, we created an SCIR injury rat model via aortic arch occlusion. Compared with normal controls, autophagic cell death was upregulated in neurons after SCIR injury. We found that autophagy promoted neuronal cell death during SCIR, shown by a significant number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling- (TUNEL-) positive cells colabeled with the autophagy marker microtubule-associated protein 1 light chain 3, while the autophagy inhibitor 3-methyladenine reduced the number of TUNEL-positive cells and restored neurological and motor function. Additionally, we showed that oxidative stress was the main trigger of autophagic neuronal cell death after SCIR injury and N-acetylcysteine inhibited autophagic cell death and restored neurological and motor function in SCIR injury. Finally, we found that hydrogen sulfide (H₂S) inhibited autophagic cell death significantly by reducing oxidative stress in SCIR injury via the AKT-the mammalian target of rapamycin (mTOR) pathway. These findings reveal that oxidative stress induces autophagic cell death and that H₂S plays a neuroprotective role by reducing oxidative stress in SCIR.