Oxidative stress influence on renal dysfunction in patients with obstructive jaundice: A case and control prospective study

Phosphatidylserine induce thrombotic tendency and liver damage in obstructive jaundice

INTRODUCTION

Hypercoagulability contributes to the majority of deaths and organ failure associated with obstructive jaundice (OJ). However, the exact mechanism of the coagulopathy in OJ remains elusive. Our objectives were to demonstrate whether phosphatidylserine (PS) exposure on blood cells (BCs), microparticles (MPs), and endothelial cells (ECs) can account for the hypercoagulability and liver damage in OJ patients.

METHODS

We evaluated OJ patients at two time point, which before (Day 0) and 7 days (Day 7) after the endoscopic retrograde cholangiopancreatography procedure (ERCP), and compared with healthy controls. Lactadherin was used to quantify PS exposure on BCs, MPs and ECs. Human umbilical vein endothelial cells (HUVECs) were incubated with serum of OJ patients and the expression of PS were evaluated. Meanwhile, healthy BCs and HUVECs were treated with 0, 25, 50 or 100µM unconjugated bilirubin (UCB) and PS exposure on cells were evaluated. Procoagulant activity was evaluated by purified coagulation complex assays, clotting time, and fibrin turbidity. In addition, we established a cholestatic mouse model by bile duct ligation to determine the potential role of PS in intrahepatic coagulation and liver damage.

RESULTS

Using flow cytometry, we found that OJ patients exhibited elevated levels of PS + BCs and associated MPs compared to the controls. Furthermore, the number of PS + BCs and MPs in patients at Day 0 were significantly higher than in patients at Day 7. Similarly, we observed markedly elevated PS exposure on HUVECs cultured with serum from patients at Day 0 versus serum from patients at Day 7. In vitro assays, PS exposure on BCs and HUVECs progressively increased with the concentration of UCB. Moreover, PS + BCs and MPs contributed to greatly shortened coagulation time and markedly enhanced coagulation factor Xa, thrombin, and fibrin generation. This procoagulant activity could be blocked approximately 80%, by the addition of lactadherin. Moreover, cholestatic mice exhibited significantly increased levels of liver tissue necrosis, fibrin deposition, and thrombophilia compared to sham mice. The enhanced intrahepatic coagulation and liver injury could be reversed by inhibiting PS with lactadherin.

CONCLUSIONS

These results highlight the pathogenic activity of PS + cells and MPs in promoting a prothrombotic environment and liver damage in OJ. As such, lactadherin, a PS blockade, may be a viable therapeutic strategy for treating such patients.

The correlation between blood lipids and intrahepatic cholestasis syndrome during pregnancy

BACKGROUND

To analyse changes in lipid levels during the development of intrahepatic cholestasis of pregnancy (ICP) and identify new biomarkers for predicting ICP.

METHODS

A retrospective case-control study was conducted to analyse 473 pregnant women who underwent regular prenatal examinations and delivered at the Women and Children's Hospital, School of Medicine, Xiamen University, between June 2020 and June 2023, including 269 normal pregnancy controls and 204 pregnant women with cholestasis.

RESULTS

Patients with ICP with gestational diabetes mellitus (GDM) have lower high-density lipoprotein (HDL) levels than in those without GDM. Total bile acid (TBA) levels were significantly higher in pregnant women with GDM than those without. The apolipoprotein A (APOA) level was lower in patients with ICP and hypothyroidism than those without hypothyroidism. TBA levels were significantly higher in pregnant women with hypothyroidism than those without. Triglyceride (TG) levels were significantly higher in patients with preeclampsia (PE) than those without. HDL and APOA levels were lower in women with ICP complicated by preterm delivery than those with normal delivery. The AUC (area under the curve) of the differential diagnosis of cholestasis of pregnancy for the APOA/APOB (apolipoprotein B) ratio was 0.727, with a sensitivity of 85.9% and specificity of 47.5%.

CONCLUSIONS

The results suggested that dyslipidaemia is associated with an increased risk of ICP and its complications. The timely detection of blood lipid and bile acid levels can assist in the diagnosis of ICP and effectively prevent ICP and other complications.

Neutrophil extracellular traps induce intrahepatic thrombotic tendency and liver damage in cholestatic liver disease

BACKGROUND

Cholestatic liver diseases induce local and systemic hypercoagulation, with neutrophil extracellular traps (NETs) serving as major drivers. These NETs have been linked to decreased liver function in patients with obstructive jaundice. However, the impact of NETs on liver hypercoagulation in cholestatic liver disease remains unknown.

METHODS

We utilized bile duct ligation to create experimental mice and analyzed NETs formation in the liver. Fibrin deposition, tissue factor expression, and inflammation in the liver were visualized through western blot and immunohistochemical techniques. LSECs were incubated with isolated NETs, and we detected endothelial procoagulant activity using coagulation protein production assays and measuring endothelial permeability. In both in vivo and in vitro settings, DNase I was applied to clarify the effect of NETs on intrahepatic hypercoagulability, hepatotoxicity, LSEC, and macrophage activation or injury.

RESULTS

Bile duct ligation mice exhibited significantly increased levels of NETs in liver tissue, accompanied by neutrophil infiltration, tissue necrosis, fibrin deposition, and thrombophilia compared to sham mice. Notably, NETs resulted in phosphatidylserine and tissue factor exposure on LSEC, enhancing coagulation Factor Xa and thrombin production. The enhanced procoagulant activity could be reversed by degrading NETs with DNase I. Additionally, NETs-induced permeability changes in LSECs, characterized by increased VE-cadherin expression and F-actin retraction, which could be rescued by DNase I. Meanwhile, NET formation is associated with KC activation and the formation of inflammatory factors.

CONCLUSIONS

NETs promote intrahepatic activation of coagulation and inflammation, leading to liver tissue injury. Strategies targeting NET formation may offer a potential therapeutic approach for treating cholestatic liver disease.

Pathophysiological consequences and treatment strategy of obstructive jaundice

Obstructive jaundice (OJ) is a common problem in daily clinical practice. However, completely understanding the pathophysiological changes in OJ remains a challenge for planning current and future management. The effects of OJ are widespread, affecting the biliary tree, hepatic cells, liver function, and causing systemic complications. The lack of bile in the intestine, destruction of the intestinal mucosal barrier, and increased absorption of endotoxins can lead to endotoxemia, production of proinflammatory cytokines, and induce systemic inflammatory response syndrome, ultimately leading to multiple organ dysfunction syndrome. Proper management of OJ includes adequate water supply and electrolyte replacement, nutritional support, preventive antibiotics, pain relief, and itching relief. The surgical treatment of OJ depends on the cause, location, and severity of the obstruction. Biliary drainage, surgery, and endoscopic intervention are potential treatment options depending on the patient's condition. In addition to modern medical treatments, Traditional Chinese medicine may offer therapeutic benefits for OJ. A comprehensive search was conducted on PubMed for relevant articles published up to August 1970. This review discusses in detail the pathophysiological changes associated with OJ and presents effective strategies for managing the condition.

Cellular and mitochondrial taurine depletion in bile duct ligated rats: a justification for taurine supplementation in cholestasis/cirrhosis

Taurine (TAU) is a free amino acid abundant in the human body. Various physiological roles have been attributed to TAU. At the subcellular level, mitochondria are the primary targets for TAU function. Meanwhile, it has been found that TAU depletion is associated with severe pathologies. Cholestasis is a severe clinical complication that can progress to liver fibrosis, cirrhosis, and hepatic failure. Bile duct ligation (BDL) is a reliable model for assessing cholestasis/cirrhosis and related complications. The current study was designed to investigate the effects of cholestasis/cirrhosis on tissue and mitochondrial TAU reservoirs. Cholestatic rats were monitored (14 and 42 days after BDL surgery), and TAU levels were assessed in various tissues and isolated mitochondria. There was a significant decrease in TAU in the brain, heart, liver, kidney, skeletal muscle, intestine, lung, testis, and ovary of the BDL animals (14 and 42 days after surgery). Mitochondrial levels of TAU were also significantly depleted in BDL animals. Tissue and mitochondrial TAU levels in cirrhotic animals (42 days after the BDL operation) were substantially lower than those in the cholestatic rats (14 days after BDL surgery). These data indicate an essential role for tissue and mitochondrial TAU in preventing organ injury induced by cholestasis/cirrhosis and could justify TAU supplementation for therapeutic purposes.

Comparative Study of the Results of Operations in Patients with Tumor and Non-Tumor Obstructive Jaundice Who Received and Did Not Receive Antioxidant Therapy for the Correction of Endotoxemia, Glycolysis, and Oxidative Stress

Purpose: To compare the results of surgical treatment and changes in biomarkers of cholestasis, endotoxicosis, cytolysis, lipid peroxidation, glycolysis disorders, and inflammation in patients with benign and malignant obstructive jaundice (OJ) in patients receiving and not receiving antioxidant pharmacotherapy (AOT). Patients and methods: The study included 113 patients (aged 21–90 years; 47 males and 66 females) who received surgical intervention for OJ due to non-malignant (71%) or malignant tumor (29%) etiologies. Patients were divided into two groups: Group I (n = 61) who did not receive AOT and Group II (n = 51) who received AOT (succinate-containing drug Reamberin) as part of detoxification infusion therapy. The surgical approach and scope of interventions in both groups were identical. Dynamic indicators of endotoxicosis, cholestasis, and cytolysis (total, direct, and indirect bilirubin, alanine aminotransferase [ALT], aspartate aminotransferase [AST], alkaline phosphatase [AP] and gamma-glutamyltransferase [GGT]), kidney function (urea), lipid peroxidation (malonic dialdehyde, MDA), inflammation (leukocytosis), and glycolysis disorders (lactate dehydrogenase (LDH), glucose) were evaluated. Results: Tumor jaundice, unlike non-tumor jaundice, persisted and was characterized by a more severe course, a higher level of hyperbilirubinemia, and lipid peroxidation. The prognostic value of the direct (and total) bilirubin, MDA, glycemia, and leukocytosis levels on the day of hospitalization, which increased significantly in severe jaundice and, especially, in deceased patients, was established. Decompression interventions significantly reduced levels of markers of liver failure, cytolysis, cholestasis, and lipid peroxidation on day 3 after decompression by 1.5–3 times from initial levels; this is better achieved in non-tumor OJ. However, 8 days after decompression, most patients did not normalize the parameters studied in both groups. AOT favorably influenced the dynamics (on day 8 after decompression) of total and direct bilirubin, ALT, AST, MDA, and leukocytosis in non-tumor jaundice, as well as the dynamics of direct bilirubin, AST, MDA, glucose, and LDH in tumor jaundice. Clinically, in the AOT group, a two-fold reduction in the operative and non-operative complications was recorded (from 23% to 11.5%), a reduction in the duration of biliary drainage by 30%, the length of stay in intensive care units was reduced by 5 days, and even hospital mortality decreased, especially in malignancy-induced OJ. Conclusion: A mechanism for the development of liver failure in OJ is oxidative stress with the appearance of enhanced lipid peroxidation and accompanied by hepatocyte necrosis. Inclusion of AOT in perioperative treatment in these patients improves treatment outcomes.

Lipid peroxidation functional state changes in patients with obstructive jaundice depending on the level of bilirubin in the blood

Obstructive jaundice (OJ) is the most common syndrome among diseases of the hepatopancreatoduodenal region and is found in 12-45% of cases. OJ may be benign and malignant etiology. Despite the evidence of the participation of bilirubin in reducing the bactericidal properties of neutrophils, there are no data currently on changes in the functioning of the antioxidant defense system depending on the level of bilirubin in the blood of patients with OJ of various origins. Research in this direction reveals the possibility for the development of pathogenetic recommendations for influencing these links of the pathogenesis of the disease. The study included men with OJ of non-malignant (OJNMG) (n = 47; mean age - 52.02 ± 5.18 years) and OJ of malignant genesis (OJMG) (I-II stages of the malignant process) (n = 45; mean age - 53.02 ± 4.8 years), divided into three subgroups, depending on the level of bilirubin in the blood. The indicators of practically healthy men as a control (n = 50, average age - 48.7 ± 3.9 years) were used. Spectrophotometric and statistical research methods were used. A statistically significant decrease of superoxide dismutase, glutathione-S-transferase, glutathione-peroxidase, ceruloplasmin, an increase in the values of diene conjugates, malondialdehyde in the group of patients with OJNMG relative to the control was revealed, regardless of the level of bilirubin in the blood. The presence of malignant genesis of the disease with more intense changes in the studied parameters relative to control is accompanied. Comparison of indicators between groups of patients with OJ of different genesis showed a decrease in the values of glutathione-S-transferase and an increase in the level of diene conjugates in patients with OJMG and the level of bilirubin less than 60 μmol / L, as well as an increase in the content of diene conjugates in patients with OJNMG and a level of bilirubin 60- 200 μmol / L in comparison with the corresponding groups of patients with OJNMG. Thus, both in the groups with OJNMG and in the groups with OJMG, there is a significant decrease in the activity of the main antioxidant enzymes and an increase in lipid peroxidation products, regardless of the level of bilirubin in the blood. The presence of malignant genesis is characterized by more intense differences. The revealed changes can serve as additional criteria for optimizing the diagnosis and treatment of this cohort of patients.

Pentoxifylline mitigates cholestasis-related cholemic nephropathy

AIM OF THE STUDY

Cholestasis is the stoppage of bile flow that primarily affects liver function. On the other hand, kidneys are also severely influenced during cholestasis. Cholestasis-induced kidney injury is known as cholemic nephropathy (CN). There is no precise pharmacological option in CN. Previous studies revealed that oxidative stress plays a crucial role in the pathogenesis of CN. On the other hand, the positive effects of pentoxifylline (PTX) against renal injury with different etiologies have been frequently reported. In the current study, the potential nephroprotective role of PTX in cholestasis-induced renal injury is investigated.

MATERIAL AND METHODS

Bile duct ligated (BDL) rats were treated with PTX (10, 50, and 100 mg/kg), and renal markers of oxidative stress, urine level of inflammatory cytokines, as well as renal histopathological alterations were monitored.

RESULTS

Significant changes in oxidative stress markers were detected in the BDL group. On the other hand, it was found that PTX (10, 50, and 100 mg/kg) significantly ameliorated cholestasis-induced oxidative stress in renal tissue. Renal histopathological changes, including interstitial inflammation, tubular atrophy, fibrosis, and cast formation, were detected in the BDL rats. Moreover, urine pro-inflammatory cytokines [interleukin (IL)-1, IL-9, IL-18, tumor necrosis factor α (TNF-α), and interferon γ (INF-γ)] were significantly increased in the cholestatic animals. PTX (10, 50, and 100 mg/kg, 14 days) significantly ameliorated renal histopathological alterations and urine levels of inflammatory cytokines.

CONCLUSIONS

These data indicate a potential nephroprotective role for PTX in cholestasis. The effects of PTX on oxidative stress parameters and the inflammatory response could play a primary role in its renoprotective mechanisms.

The inhibition of NFкB signaling and inflammatory response as a strategy for blunting bile acid-induced hepatic and renal toxicity

The cholestatic liver injury could occur in response to a variety of diseases or xenobiotics. Although cholestasis primarily affects liver function, it has been well-known that other organs such as the kidney could be influenced in cholestatic patients. Severe cholestasis could lead to tissue fibrosis and organ failure. Unfortunately, there is no specific therapeutic option against cholestasis-induced organ injury. Hence, finding the mechanism of organ injury during cholestasis could lead to therapeutic options against this complication. The accumulation of potentially cytotoxic compounds such as hydrophobic bile acids is the most suspected mechanism involved in the pathogenesis of cholestasis-induced organ injury. A plethora of evidence indicates a role for the inflammatory response in the pathogenesis of several human diseases. Here, the role of nuclear factor-kB (NFkB)-mediated inflammatory response is investigated in an animal model of cholestasis. Bile duct ligated (BDL) animals were treated with sulfasalazine (SSLZ, 10 and 100 mg/kg, i.p) as a potent inhibitor of NFkB signaling. The NFkB proteins family activity in the liver and kidney, serum and tissue levels of pro-inflammatory cytokines, tissue biomarkers of oxidative stress, serum markers of organ injury, and the liver and kidney histopathological alterations and fibrotic changes. The oxidative stress-mediated inflammatory-related indices were monitored in the kidney and liver at scheduled time intervals (3, 7, and 14 days after BDL operation). Significant increase in serum and urine markers of organ injury, besides changes in biomarkers of oxidative stress and tissue histopathology, were evident in the liver and kidney of BDL animals. The activity of NFkB proteins (p65, p50, p52, c-Rel, and RelB) was significantly increased in the liver and kidney of cholestatic animals. Serum and tissue levels of pro-inflammatory cytokines (IL-1β, IL-2, IL-6, IL-7, IL-12, IL-17, IL-18, IL-23, TNF-α, and INF-γ) were also higher than sham-operated animals. Moreover, TGF- β, α-SMA, and tissue fibrosis (Trichrome stain) were evident in cholestatic animals' liver and kidneys. It was found that SSLZ (10 and 100 mg/kg/day, i.p) alleviated cholestasis-induced hepatic and renal injury. The effect of SSLZ on NFkB signaling and suppression of pro-inflammatory cytokines could play a significant role in its protective role in cholestasis. Based on these data, NFkB signaling could receive special attention to develop therapeutic options to blunt cholestasis-induced organ injury.

Mitigation of cholestasis-associated hepatic and renal injury by edaravone treatment: Evaluation of its effects on oxidative stress and mitochondrial function

Background and aim

The liver is the primary organ affected by cholestasis, and complications such as renal injury, renal failure, and the need for renal transplantation are associated with cholestatic liver disease. There is substantial evidence indicating that reactive oxygen species (ROS) and mitochondrial impairment are fundamental mechanisms underlying cholestasis-induced hepatic and renal injury. Edaravone (EDV) is a potent radical scavenger and antioxidant that may prevent oxidative stress and improve impaired mitochondrial function in various diseases. This study was performed to evaluate the effects and mechanisms of action of EDV on hepatic and renal injury in an animal model of cholestasis.

Methods

Rats subjected to bile duct ligation (BDL) were treated with EDV 1 or 10 mg/kg/day intraperitoneally for 14 consecutive days. Biomarkers of oxidative stress and mitochondrial impairment in the liver and kidney were assessed in EDV-treated and untreated rats with cholestasis.

Results

Significant increases in tissue ROS level, lipid peroxidation, protein carbonylation, and oxidized glutathione level were detected in rats subjected to BDL. Additionally, significant decreases in tissue glutathione level and antioxidant capacity were observed in the hepatic and renal tissues of rats with cholestasis. Markers of mitochondrial impairment, including mitochondrial depolarization, lipid peroxidation, mitochondrial permeabilization, depleted adenosine triphosphate content, and decreased dehydrogenase activity, were also detected in rats subjected to BDL. Furthermore, portal inflammation, necrosis, and tissue fibrosis were detected in the liver and significant tubular atrophy and interstitial inflammation, as well as fibrotic lesions, were detected in the kidneys of rats with cholestasis. EDV treatment significantly mitigated cholestasis-associated hepatic and renal injury.

Conclusions

The antioxidative properties of EDV and its positive effects on the indices of mitochondrial function may be critical factors contributing to protection against cholestasis-associated hepatic and renal injury.

Metformin alleviates cholestasis-associated nephropathy through regulating oxidative stress and mitochondrial function

Background and aim

Cholestasis-associated renal injury or cholemic nephropathy (CN) is a serious clinical problem. Previous studies mentioned that oxidative stress and mitochondrial impairment play a role in CN. There is no specific pharmacological intervention for CN. Metformin is an anti-diabetic drug administered for decades. On the other hand, novel pharmacological properties have emerged for this drug. The effect of metformin on oxidative stress parameters has been well-recognized in different experimental models. It has also been found that metformin positively affected mitochondrial function. The current study aimed to evaluate the effects of metformin in an animal model of CN.

Methods

Rats underwent bile duct ligation (BDL) and were treated with metformin (250 and 500 mg/kg) for 14 consecutive days. Two weeks after the BDL operations, urine, serum, and kidney samples were collected and analyzed.

Results

Markers of oxidative stress, including reactive oxygen species (ROS) formation, lipid peroxidation, protein carbonylation, depleted antioxidant capacity, and decreased glutathione (GSH) levels were detected in BDL animals. Moreover, mitochondrial indices, including adenosine triphosphate (ATP) level, dehydrogenase activity, mitochondrial membrane potential, and mitochondrial permeability, were impaired in the kidney of cholestatic rats. Renal histopathological alterations in cholestatic animals included tubular degeneration and interstitial inflammation, cast formation, and fibrosis. It was found that metformin significantly alleviated oxidative stress and improved mitochondrial indices in the kidney of cholestatic rats. Tissue histopathological alterations were also mitigated in metformin-treated groups.

Conclusions

Metformin could be a candidate for managing CN. The nephroprotective role of metformin is primarily associated with its effects on oxidative stress parameters and mitochondrial function.

The activation of nuclear factor-E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling blunts cholestasis-induced liver and kidney injury

Cholestasis is a severe clinical complication that severely damages the liver. Kidneys are also the most affected extrahepatic organs in cholestasis. The pivotal role of oxidative stress has been mentioned in the pathogenesis of cholestasis-induced organ injury. The activation of the nuclear factor-E2-related factor 2 (Nrf2) pathway is involved in response to oxidative stress. The current study was designed to evaluate the potential role of Nrf2 signaling activation in preventing bile acids-induced toxicity in the liver and kidney. Dimethyl fumarate was used as a robust activator of Nrf2 signaling. Rats underwent bile duct ligation surgery and were treated with dimethyl fumarate (10 and 40 mg/kg). Severe oxidative stress was evident in the liver and kidney of cholestatic animals (P < 0.05). On the other hand, the expression and activity of Nrf2 and downstream genes were time-dependently decreased (P < 0.05). Moreover, significant mitochondrial depolarization, decreased ATP levels, and mitochondrial permeabilization were detected in bile duct-ligated rats (P < 0.05). Histopathological alterations included liver necrosis, fibrosis, inflammation and kidney interstitial inflammation, and cast formation. It was found that dimethyl fumarate significantly decreased hepatic and renal injury in cholestatic animals (P < 0.05). Based on these data, the activation of the cellular antioxidant response could serve as an efficient therapeutic option for managing cholestasis-induced organ injury.

Silymarin mitigates bile duct obstruction-induced cholemic nephropathy

Bile duct obstruction or cholestasis can occur by several diseases or xenobiotics. Cholestasis and the accumulation of the bile constituents in the liver primarily damage this organ. On the other hand, extrahepatic organs are also affected by cholestasis. The kidney is the most affected tissue during cholestatic liver injury. Cholestasis-associated renal injury is known as cholemic nephropathy (CN). Several lines of evidence specify the involvement of oxidative stress and mitochondrial impairment in the pathogenesis of CN. The current study aimed to assess the role of silymarin as a potent antioxidant on CN-induced oxidative stress and mitochondrial dysfunction in the kidney. Bile duct ligated (BDL) rats were treated with silymarin (10 and 100 mg/kg, oral) for seven consecutive days. A significant increase in reactive oxygen species (ROS), lipid peroxidation, protein carbonylation, and oxidized glutathione (GSSG) levels were evident in the kidney of BDL animals. Moreover, reduced glutathione (GSH) content and total antioxidant capacity were significantly decreased in the kidney of cholestatic rats. Mitochondrial depolarization, decreased mitochondrial dehydrogenases activity, mitochondrial permeabilization, and depleted ATP stores were detected in the kidney mitochondria isolated from BDL animals. Kidney histopathological alterations, as well as serum and urine levels of renal injury biomarkers, were also significantly different in the BDL group. It was found that silymarin treatment significantly ameliorated CN-induced renal injury. The antioxidant effects of silymarin and its positive impact on mitochondrial indices seem to play a significant role in its renoprotective effects during cholestasis.

N-acetyl cysteine treatment mitigates biomarkers of oxidative stress in different tissues of bile duct ligated rats

Cholestasis is a multifaceted clinical complication. Obstructive jaundice induced by bile duct ligation (BDL) is known as an animal model to investigate cholestasis and its associated complications. N-acetyl cysteine (NAC) is an antioxidant, radical scavenger, and thiol reductant widely investigated for its cytoprotective properties. The current investigation was designed to evaluate the role of NAC treatment on biomarkers of oxidative stress and organ histopathological alterations in a rat model of cholestasis/cirrhosis. BDL animals were supplemented with NAC (100 and 300 mg/kg, i.p, 42 consecutive days). Biomarkers of oxidative stress in the liver, brain, heart, skeletal muscle, lung, serum, and kidney tissue, as well as organ histopathological changes, were monitored. A significant increase in reactive oxygen species, lipid peroxidation, and protein carbonylation were detected in different tissues of BDL rats. Moreover, tissue antioxidant capacity was hampered, glutathione (GSH) reservoirs were depleted, and oxidized glutathione (GSSG) levels were significantly increased in the BDL group. Significant tissue histopathological alterations were evident in cirrhotic animals. It was found that NAC treatment (100 and 300 mg/kg, i.p) significantly mitigated biomarkers of oxidative stress and alleviated tissue histopathological changes in cirrhotic rats. These data represent NAC as a potential protective agent with therapeutic capability in cirrhosis and its associated complications.HIGHLIGHTSCholestasis is a multifaceted clinical complication that affects different organsOxidative stress plays a pivotal role in cholestasis-associated complicationsTissue antioxidant capacity is hampered in different tissues of cholestatic animalsAntioxidant therapy might play a role in the management of cholestasis-induced organ injuryNAC alleviated biomarkers of oxidative stress in cholestatic animalsNAC significantly improved tissues histopathological alterations in cholestatic rats.

Neutrophil extracellular traps enhance procoagulant activity and thrombotic tendency in patients with obstructive jaundice

BACKGROUND & AIMS

Patients with obstructive jaundice (OJ) are considered to be prothrombotic with increased risk of thromboembolism complications. The role of neutrophil extracellular traps (NETs) in procoagulant activity (PCA) and thrombosis risk in patients with OJ is unclear. In this study, we investigated NETs formation in OJ patients and the role of elevated unconjugated bilirubin (UCB) in inducing NETs, resulting in enhanced PCA and endothelial injury.

METHODS

NETs of OJ patients and healthy controls were measured. NETs PCA was assessed via coagulation time (CT), fibrin formation and purified coagulation complex production assays. Visualization of NETs and mitochondrial reactive oxygen species (MitoROS) were performed with a fluorescence microscope. We further used confocal microscopy to quantify the exposure of phosphatidylserine (PS), fibrin strands and FVa/Xa on Human umbilical vein endothelial cells (HUVECs).

RESULTS

Assessment of NETs components levels revealed greater NETs production in OJ patients than in healthy controls. Importantly, OJ-NETs were responsible for enhanced PCA. UCB induced NETs formation via MitoROS accumulation and mitochondrial mobilization. HUVECs cocultured with OJ NETs lost their cell-cell junctions and consequently converted to a procoagulant phenotype. The PCA was attenuated by using DNase I alone or in combination with lactadherin.

CONCLUSIONS

Our results suggest that UCB-induced NETs play a prominent role in promoting the hypercoagulable and prothrombotic state in OJ patients. The increased MitoROS accumulation in neutrophils initiated NETosis. NETs are promising targets for indicating or improving coagulation disorders in OJ patients.

The pathogenesis of renal injury in obstructive jaundice: A review of underlying mechanisms, inducible agents and therapeutic strategies

Kidney injury is one of the main complications of obstructive jaundice (OJ) and its pathogenesis has not been clarified. As an independent risk factor for OJ associated with significant morbidity and mortality, it can be mainly divided into two types of morphological injury and functional injury. We called these dysfunctions caused by OJ-induced kidney injury as OJKI. However, the etiology of OJKI is still not fully clear, and research studies on how OJKI becomes a facilitated factor of OJ are limited. This article reviews the underlying pathological mechanism from five aspects, including metabolisms of bile acids, hemodynamic disturbances, oxidative stress, inflammation and the organic transporter system. Some nephrotoxic drugs and measures that can enhance or reduce the renal function with potential intervention in perioperative periods to alleviate the incidence of OJKI were also described. Furthermore, a more in-depth study on the pathogenesis of OJKI from multiple aspects for exploring more targeted treatment measures were further put forward, which may provide new methods for the prevention and treatment of clinical OJKI and improve the prognosis.

Poly (ADP-Ribose) polymerase-1 (PARP-1) overactivity plays a pathogenic role in bile acids-induced nephrotoxicity in cholestatic rats

Cholestatic liver disease is a clinical complication with a wide range of etiologies. The liver is the primary organ influenced by cholestasis. Other organs, rather than the liver (e.g., kidneys), could also be affected by cholestatic liver disease. Cholestasis-induced renal injury is known as cholemic nephropathy (CN). Although the structural and functional alterations of the kidney in cholestasis have been well described, the cellular and molecular mechanisms of CN are not well understood. Some studies mentioned the role of oxidative stress and mitochondrial impairment in CN. Several cellular targets, including proteins, lipids, and DNA, could be affected by oxidative stress. Poly (ADP-Ribose) polymerase-1 (PARP-1) is an enzyme that its physiological activity plays a fundamental role in DNA repair. However, PARP-1 overexpression is associated with enhanced oxidative stress and cell death. The current study was designed to evaluate the role of PARP-1 activity in the pathogenesis of CN. Bile duct ligated (BDL) rats were treated with nicotinamide (NA) as a PARP-1 inhibitor. Kidney, urine, and plasma samples were collected at scheduled time intervals (3, 7, 14, and 28 days after BDL surgery). Serum and urine biomarkers of kidney injury, markers of oxidative stress and DNA damage, PARP-1 expression and activity in the kidney tissue, inflammatory response, renal fibrosis markers, and kidney histopathological alterations were assessed. Significant changes in the serum and urine biomarkers of kidney injury were evident in the BDL rats. Markers of oxidative stress were increased, and tissue ATP levels and antioxidant capacity were decreased in the kidney of cholestatic animals. A significant increase in PARP-1 expression and activity was evident in BDL rats (3, 7, 14, and 28 days after BDL). Moreover, inflammatory response (IL-1β and TNF-α expression; and myeloperoxidase activity), renal tissue histopathological alterations, and kidney fibrosis (α-SMA and TGF-β expression, as well as collagen deposition) were detected in cholestatic animals. It was found that the PARP-1 inhibitor, NA (50 and 100 mg/kg, i.p), significantly mitigated cholestasis-induced renal injury. The positive effects of NA were more significant at a lower dose and the early stage of CN. These data indicate a pathogenic role for PARP-1 overexpression in CN.

Suppression of cirrhosis-related renal injury by N-acetyl cysteine

Cirrhosis-induced renal injury or cholemic nephropathy (CN) is a serious clinical complication with poor prognosis. CN could finally lead to renal failure and the need for organ transplantation. Unfortunately, there is no specific pharmacological intervention against CN to date. On the other hand, various studies mentioned the role of oxidative stress and mitochondrial impairment in the pathogenesis of CN. The current study aimed to evaluate the potential protective effects of NAC as a thiol-reducing agent and antioxidant in CN. Bile duct ligation (BDL) was used as a reliable animal model of cholestasis. BDL animals received NAC (0.25% and 1% w: v) in drinking water for 28 consecutive days. Finally, urine, blood, and kidney samples were collected and analyzed. Significant elevation in serum biomarkers of renal injury, along with urine markers of kidney damage, was evident in the BDL group. Moreover, markers of oxidative stress, including reactive oxygen species (ROS) formation, lipid peroxidation, protein carbonylation, and increased oxidized glutathione (GSSG) were evident detected in the kidney of cholestatic rats. Renal tissue antioxidant capacity and reduced glutathione (GSH) were also significantly depleted in the BDL group. Significant mitochondrial depolarization, depleted ATP content, and mitochondrial permeabilization was also detected in mitochondria isolated from the kidney of cholestatic animals. Renal histopathological alterations consisted of significant tissue fibrosis, interstitial inflammation, and tubular atrophy. It was found that NAC (0.25 and 1% in drinking water for 28 consecutive days) blunted histopathological changes, decreased markers of oxidative stress, and improved mitochondrial indices in the kidney of cirrhotic rats. Moreover, serum and urine biomarkers of renal injury were also mitigated in upon NAC treatment. These data indicate a potential renoprotective role for NAC in cholestasis. The effects of NAC on cellular redox state and mitochondrial function seem to play a fundamental role in its renoprotective effects during CN.

Oral administration of thiol-reducing agents mitigates gut barrier disintegrity and bacterial lipopolysaccharide translocation in a rat model of biliary obstruction

It has been well documented that cirrhosis is associated with the intestinal injury. Intestinal injury in cirrhosis could lead to bacterial lipopolysaccharide (LPS) translocation to the systemic circulation. It has been found that high plasma LPS is connected with higher morbidity and mortality in cirrhotic patients. Therefore, finding therapeutic approaches to mitigate this complication has great clinical value. Several investigations mentioned the pivotal role of oxidative stress in cirrhosis-associated intestinal injury. It has been well-known that the redox balance of enterocytes is disturbed in cirrhotic patients. In the current study, the effects of thiol-reducing agents N-acetylcysteine (NAC) (0.5 and 1% w: v) and dithiothreitol (DTT) (0.5 and 1% w: v) on biomarkers of oxidative stress, tissue histopathological alterations, and LPS translocation is investigated in a rat model of cirrhosis. Bile duct ligation (BDL) surgery was used to induce cirrhosis in male Sprague-Dawley rats. Animals (n ​= ​48; 8 animals/group) were supplemented with NAC and DTT for 28 consecutive days. Significant changes in ileum and colon markers of oxidative stress were evident in BDL rats as judged by increased reactive oxygen species (ROS), lipid peroxidation, oxidized glutathione (GSSG), and protein carbonylation along with decreased antioxidant capacity and glutathione (GSH) content. Blunted villus, decreased villus number, and inflammation was also detected in the intestine of BDL animals. Moreover, serum LPS level was also significantly higher in BDL rats. NAC and DTT administration (0.5 and 1% w: v, gavage) significantly decreased biomarkers of oxidative stress, mitigated intestinal histopathological alterations, and restored tissue antioxidant capacity. Moreover, NAC and/or DTT significantly suppressed LPS translocation to the systemic circulation. The protective effects of thiol reducing agents in the intestine of cirrhotic rats could be attributed to the effect of these chemicals on the cellular redox environment and biomarkers of oxidative stress.

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Gut permeability is a clinical complication in cholestasis/cirrhosis

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Intestinal injury leads to lipopolysaccharide (LPS) translocation to the bloodstream

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LPS translocation to the systemic circulation could cause systemic inflammation

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Oxidative stress is involved in the mechanisms of cirrhosis-induced gut permeability

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Oral administration of thiol-reducing agents mitigated intestinal tissue oxidative stress

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Serum LPS levels were lower in thiol reducing agents-treated animals

Defining the Safety Profile for Performing Pancreatoduodenectomy in the Setting of Hyperbilirubinemia

BACKGROUND

Hyperbilirubinemia is commonly observed in patients requiring pancreatoduodenectomy (PD). Thus far, literature regarding the danger of operating in the setting of hyperbilirubinemia is equivocal. What remains undefined is at what specific level of bilirubin there is an adverse safety profile for undergoing PD. The aim of this study is to identify the optimal safety profile of patients with hyperbilirubinemia undergoing PD.

PATIENTS AND METHODS

The present work analyzed 803 PDs from 2004 to 2018. A generalized additive model was used to determine cutoff values of total serum bilirubin (TB) that were associated with increases in adverse outcomes, including 90-day mortality. Subgroup comparisons and biliary stent-specific analyses were performed for patients with TB below and above the cutoff.

RESULTS

TB of 13 mg/dL was associated with an increase in 90-day mortality (P = 0.043) and was the dominant risk factor on multivariate logistic regression [odds ratio (OR) 8.193, P = 0.001]. Increased TB levels were also associated with reoperations, number of complications per patient, and length of stay. Patients with TB greater than or equal to 13 mg/dL (TB ≥ 13) who received successful biliary decompression through stenting had less combined death and serious morbidity (P = 0.048).

CONCLUSIONS

Preoperative TB ≥ 13 mg/dL was associated with increased 90-day mortality after PD. Reducing a TB ≥ 13 is generally recommended before proceeding to surgery.

The footprints of mitochondrial impairment and cellular energy crisis in the pathogenesis of xenobiotics-induced nephrotoxicity, serum electrolytes imbalance, and Fanconi's syndrome: A comprehensive review

Fanconi's Syndrome (FS) is a disorder characterized by impaired renal proximal tubule function. FS is associated with a vast defect in the renal reabsorption of several chemicals. Inherited and/or acquired conditions seem to be connected with FS. Several xenobiotics including many pharmaceuticals are capable of inducing FS and nephrotoxicity. Although the pathological state of FS is well described, the exact underlying etiology and cellular mechanism(s) of xenobiotics-induced nephrotoxicity, serum electrolytes imbalance, and FS are not elucidated. Constant and high dependence of the renal reabsorption process to energy (ATP) makes mitochondrial dysfunction as a pivotal mechanism which could be involved in the pathogenesis of FS. The current review focuses on the footprints of mitochondrial impairment in the etiology of xenobiotics-induced FS. Moreover, the importance of mitochondria protecting agents and their preventive/therapeutic capability against FS is highlighted. The information collected in this review may provide significant clues to new therapeutic interventions aimed at minimizing xenobiotics-induced renal injury, serum electrolytes imbalance, and FS.

Bilirubin encephalopathy (kernicterus) in an adult cat

Case summary

An adult cat presented with neurological signs and marked icterus. Clinical pathology tests detected increased serum alkaline phosphatase levels, as well as alanine aminotransferase, total bilirubin, unconjugated bilirubin and conjugated bilirubin above the normal reference intervals. Ultrasonography showed hepatomegaly and a dilated gall bladder. Following these results, the cat was referred for a cholecystectomy owing to a clinical suspicion of obstructive cholecystitis. The animal died in the postoperative period and was referred for necropsy. Grossly, the animal had marked icterus. On the cortical surface and in the brain parenchyma there were marked yellowish areas. The liver was diffusely reddish-orange, enlarged and the capsular surface was slightly irregular. The gall bladder was absent. At its anatomical site and surrounding the common hepatic duct, a whitish nodular neoplasia of 2.0 cm was found. Microscopically, a cholangioma was diagnosed in the region of the common hepatic duct. In the white matter of the cerebellar vermis, there was axonal degeneration associated with gliosis. In the Purkinje neuron layer there was slight multifocal necrosis. Some neurons contained amorphous and brownish pigment (bilirubin) in the cytoplasm. Clinical and pathological findings indicated hepatic and post-hepatic icterus from obstructive cholangioma, resulting in kernicterus.

Relevance and novel information

Kernicterus is a neurological disorder that is rarely diagnosed in animals, especially in adults. This report provides evidence that kernicterus can occur in adult cats, secondary to increased unconjugated and conjugated bilirubin concentrations.

EFFECTS OF SALVIA MILTIORRHIZAE ON THE KIDNEY OF RATS WITH SEVERE ACUTE PANCREATITIS AND OBSTRUTIVE JAUNDICE

Background:

Severe acute pancreatitis (SAP) and obstructive jaundice (OJ) are frequent recurring diseases that bring about huge threat to human health. Some reports have demonstrated that Salviae miltiorrhizae can protect multiple organs of SAP and OJ model animals or patients, but their related mechanisms were not clear. In this study, we observed the effects of Salvia miltiorrhizae injection on apoptosis and NF-κB expression in kidney and explored the protective effect and mechanism of Salvia miltiorrhizae on the kidney of SAP or OJ rats. The results obtained will provide a theoretical basis for clinical application of Salvia miltiorrhizae.

Material and Methods:

A total of 288 rats were used for SAP -and OJ-associated experiments. The mortality rates of rats, the contents of serum BUN and CREA, the expression levels of Bax, NF-κB proteins and the apoptosis index were observed, respectively.

Results:

The pathological changes in the kidney of SAP or OJ rats in treated group were mitigated to varying degrees. At 6 and 12 hours after operation in SAP rats or on 21 and 28 days after operation in OJ rats, the contents of serum CREA in treated group were significantly lower than those in model control group; At 3 and 6 hours after operation, the staining intensity of Bax protein of kidney in treated group was significantly lower than that in model control group; on 14 days after operation, the apoptosis index in the kidney of OJ rats in treated group was significantly lower than that in model control group.

Conclusion:

Salvia miltiorrhizae can exert protective effects on the kidney of SAP and OJ rats.

Effects of asymmetric dimethylarginine on renal arteries in portal hypertension and cirrhosis

AIM

To evaluate the effects of asymmetric dimethylarginine (ADMA) in renal arteries from portal hypertensive and cirrhotic rats.

METHODS

Rat renal arteries from Sham (n = 15), pre-hepatic portal hypertension (PPVL; n = 15) and bile duct ligation and excision-induced cirrhosis (BDL; n = 15) were precontracted with norepinephrine, and additional contractions were induced with ADMA (10^-6-10^-3 mol/L), an endogenous inhibitor of nitric oxide (NO) synthase. Concentration-response curves to acetylcholine (1 × 10^-9-3 × 10^-6 mol/L) were determined in precontracted renal artery segments with norepinephrine in the absence and in the presence of ADMA. Kidneys were collected to determine the protein expression and activity of dimethylarginine dimethylaminohydrolase (DDAH), an enzyme that catabolizes ADMA.

RESULTS

In renal arteries precontracted with norepinephrine, ADMA caused endothelium-dependent contractions. The pD₂ values to ADMA were similar in the Sham and PPVL groups (4.20 ± 0.08 and 4.11 ± 0.09, P > 0.05, respectively), but were lower than those of the BDL group (4.79 ± 0.16, P < 0.05). Acetylcholine-induced endothelium-dependent relaxation that did not differ, in terms of pD₂ and maximal relaxation, among the 3 groups studied. Treatment with ADMA (3 × 10^-4 mol/L) inhibited acetylcholine-induced relaxation in the 3 groups, but the inhibition was higher (P < 0.05) in the BDL group compared with that for the Sham and PPVL groups. The mRNA and protein expression of DDAH-1 were similar in kidneys from the three groups. Conversely, DDAH-2 expression was increased (P < 0.05) in PPVL and further enhanced (P < 0.05) in the BDL group. However, renal DDAH activity was significantly decreased in the BDL group.

CONCLUSION

Cirrhosis increased the inhibitory effect of ADMA on basal- and induced-release of NO in renal arteries, and decreased DDAH activity in the kidney.

Insight into the metabolic mechanism of scoparone on biomarkers for inhibiting Yanghuang syndrome

Scoparone (6,7-dimethoxycoumarin) is the representative ingredient of Yinchenhao (Artemisia capillaris Thunb.) which is a famous Chinese medicinal herb and shows favorable efficacy for all kinds of liver disease, specifically for the treatment of Yanghuang syndrome (YHS). The precise molecular mechanism concerning the action of scoparone on YHS is yet to be fully elucidated. The aim of the present study was to determine the mechanism of scoparone and evaluate its efficacy on metabolite levels. The differential expression of metabolites responsible for the pharmacological effects of scoparone was characterized and the protection effect of scoparone against this disease. Using multivariate statistical analysis, 33 biomarkers were identified using precise MS/MS and play an important role in the regulation of key metabolic pathways associated with liver disease. In addition, pathological results also showed consistent changes in the YHS model group and after treatment with scoparone, both the metabolic profile and histopathology resembled that of normal level, which suggesting favorable efficacy over the observed time period. The present work indicated that a metabolomics platform provided a new insight into understanding the mechanisms of action of natural medicines such as scoparone.