Pathophysiology of acute kidney injury

Arsenic Exposure-Induced Acute Kidney Injury by Regulating SIRT1/PINK1/Mitophagy Axis in Mice and in HK-2 Cells

Groundwater resources are often contaminated by arsenic, which poses a serious threat to human and animal's health. Some studies have demonstrated that acute arsenic exposure could induce kidney injury because the kidney is a key target organ for toxicity, but the exact mechanism remains unclear. Hence, we investigated the effect of SIRT1-/PINK1-mediated mitophagy on NaAsO2-induced kidney injury in vivo and in vitro. In our study, NaAsO2 exposure obviously induced renal tubule injury and mitochondrial dysfunction. Meanwhile, NaAsO2 exposure could inhibit the mRNA/protein level of SIRT1 and activate the mitophagy-related mRNA/protein levels in the kidney of mice. In HK-2 cells, we also confirmed that NaAsO2-induced nephrotoxicity depended on the activation of mitophagy. Moreover, the activation of SIRT1 by resveratrol alleviated NaAsO2-induced acute kidney injury via the activation of mitophagy in vivo and in vitro. Interestingly, the inhibition of mitophagy by cyclosporin A (CsA) further exacerbated NaAsO2-induced nephrotoxicity and inflammation in HK-2 cells. Taken together, our study found that SIRT1-regulated PINK1-/Parkin-dependent mitophagy was implicated in NaAsO2-induced acute kidney injury. In addition, we confirmed that PINK1-/Parkin-dependent mitophagy played a protective role against NaAsO2-induced acute kidney injury. Therefore, activation of SIRT1 and mitophagy may represent a novel therapeutic target for the prevention and treatment of NaAsO2-induced acute renal injury.

The Protective Pathways Activated in Kidneys of αMUPA Transgenic Mice Following Ischemia\Reperfusion-Induced Acute Kidney Injury

Despite the high prevalence of acute kidney injury (AKI), the therapeutic approaches for AKI are disappointing. This deficiency stems from the poor understanding of the pathogenesis of AKI. Recent studies demonstrate that αMUPA, alpha murine urokinase-type plasminogen activator (uPA) transgenic mice, display a cardioprotective pathway following myocardial ischemia. We hypothesize that these mice also possess protective renal pathways. Male and female αMUPA mice and their wild type were subjected to 30 min of bilateral ischemic AKI. Blood samples and kidneys were harvested 48 h following AKI for biomarkers of kidney function, renal injury, inflammatory response, and intracellular pathways sensing or responding to AKI. αMUPA mice, especially females, exhibited attenuated renal damage in response to AKI, as was evident from lower SCr and BUN, normal renal histology, and attenuated expression of NGAL and KIM-1. Notably, αMUPA females did not show a significant change in renal inflammatory and fibrotic markers following AKI as compared with wild-type (WT) mice and αMUPA males. Moreover, αMUPA female mice exhibited the lowest levels of renal apoptotic and autophagy markers during normal conditions and following AKI. αMUPA mice, especially the females, showed remarkable expression of PGC1α and eNOS following AKI. Furthermore, MUPA mice showed a significant elevation in renal leptin expression before and following AKI. Pretreatment of αMUPA with leptin-neutralizing antibodies prior to AKI abolished their resistance to AKI. Collectively, the kidneys of αMUPA mice, especially those of females, are less susceptible to ischemic I/R injury compared to WT mice, and this is due to nephroprotective actions mediated by the upregulation of leptin, eNOS, ACE2, and PGC1α along with impaired inflammatory, fibrotic, and autophagy processes.

Pharmacokinetic evaluation of oxaliplatin combined with S-1 (SOX) chemotherapy in a rat model of colorectal cancer with acute kidney injury: predictive renal biomarkers for dose optimisation

Dose adjustment based on renal function is essential in S-1, which contains the 5‑fluorouracil prodrug tegafur, and platinum-based agent oxaliplatin (SOX) combination chemotherapy for colorectal cancer in patients with chronic kidney disease. However, limited evidence on dose adjustment in acute kidney injury (AKI) and challenges in determining dosing strategies. This study investigated the pharmacokinetics of SOX chemotherapy and renal biomarkers in rats.AKI was prepared by renal ischaemia-reperfusion injury in 1,2-dimethylhydrazine-induced colorectal cancer model rats. Serum creatinine (sCr) levels were determined as a renal biomarker. After administration of S-1 (2 mg/kg tegafur) and oxaliplatin (5 mg/kg), drug concentrations of tegafur, 5-FU, and platinum were measured in the plasma and tumours.No alterations in the area under the plasma concentration-time curve (AUC0-24h) values of 5-fluorouracil were observed between control and AKI model rats. The tumour concentrations of 5-fluorouracil in the mild and severe AKI groups were significantly lower than control group. The AUC0-24h for platinum increased with AKI severity. Notably, population pharmacokinetic analysis identified sCr as a covariate in platinum distribution after SOX chemotherapy.To optimise dose adjustment of SOX chemotherapy in patients with AKI, sCr may be a key factor in determining the appropriate dose.

Adult-onset Still's Disease with Acute Kidney Injury Requiring Hemodialysis: A Case Report and Literature Review

Adult-onset Still's disease (AOSD) is characterized by high spiking fever, evanescent rash, and arthritis. However, AOSD rarely presents with severe acute kidney injury (AKI). We herein present the case of a 56-year-old woman with new-onset AOSD who rapidly developed AKI. A physical examination and laboratory data revealed spiking fever, evanescent rash, thrombocytopenia, hyperferritinemia, and azotemia. The patient was diagnosed with AOSD complicated by AKI and macrophage activation syndrome. Treatment with high-dose steroids, hemodialysis, and plasma exchange successfully resolved her AKI. In this report, we review previously published reports on AOSD accompanied by AKI and discuss this rare complication in AOSD.

Compound-42 alleviates acute kidney injury by targeting RIPK3-mediated necroptosis

BACKGROUND AND PURPOSE

Necroptosis plays an essential role in acute kidney injury and is mediated by receptor-interacting protein kinase 1 (RIPK1), receptor-interacting protein kinase 3 (RIPK3), and mixed lineage kinase domain-like pseudokinase (MLKL). A novel RIPK3 inhibitor, compound 42 (Cpd-42) alleviates the systemic inflammatory response. The current study was designed to investigate whether Cpd-42 exhibits protective effects on acute kidney injury and reveal the underlying mechanisms.

EXPERIMENTAL APPROACH

The effects of Cpd-42 were determined in vivo through cisplatin- and ischaemia/reperfusion (I/R)-induced acute kidney injury and in vitro through cisplatin- and hypoxia/re-oxygenation (H/R)-induced cell damage. Transmission electron microscopy and periodic acid-Schiff staining were used to identify renal pathology. Cellular thermal shift assay and RIPK3-knockout mouse renal tubule epithelial cells were used to explore the relationship between Cpd-42 and RIPK3. Molecular docking and site-directed mutagenesis were used to determine the binding site of RIPK3 with Cpd-42.

KEY RESULTS

Cpd-42 reduced human proximal tubule epithelial cell line (HK-2) cell damage, necroptosis and inflammatory responses in vitro. Furthermore, in vivo, cisplatin- and I/R-induced acute kidney injury was alleviated by Cpd-42 treatment. Cpd-42 inhibited necroptosis by interacting with two key hydrogen bonds of RIPK3 at Thr94 and Ser146, which further blocked the phosphorylation of RIPK3 and mitigated acute kidney injury.

CONCLUSION AND IMPLICATIONS

Acting as a novel RIPK3 inhibitor, Cpd-42 reduced kidney damage, inflammatory response and necroptosis in acute kidney injury by binding to sites Thr94 and Ser146 on RIPK3. Cpd-42 could be a promising treatment for acute kidney injury.

Emerging significance and therapeutic targets of ferroptosis: a potential avenue for human kidney diseases

Kidney diseases remain one of the leading causes of human death and have placed a heavy burden on the medical system. Regulated cell death contributes to the pathology of a plethora of renal diseases. Recently, with in-depth studies into kidney diseases and cell death, a new iron-dependent cell death modality, known as ferroptosis, has been identified and has attracted considerable attention among researchers in the pathogenesis of kidney diseases and therapeutics to treat them. The majority of studies suggest that ferroptosis plays an important role in the pathologies of multiple kidney diseases, such as acute kidney injury (AKI), chronic kidney disease, and renal cell carcinoma. In this review, we summarize recently identified regulatory molecular mechanisms of ferroptosis, discuss ferroptosis pathways and mechanisms of action in various kidney diseases, and describe the protective effect of ferroptosis inhibitors against kidney diseases, especially AKI. By summarizing the prominent roles of ferroptosis in different kidney diseases and the progress made in studying ferroptosis, we provide new directions and strategies for future research on kidney diseases. In summary, ferroptotic factors are potential targets for therapeutic intervention to alleviate different kidney diseases, and targeting them may lead to new treatments for patients with kidney diseases.

Redox Regulation of Nrf2 in Cisplatin-Induced Kidney Injury

Cisplatin, a potent chemotherapeutic agent, is marred by severe nephrotoxicity that is governed by mechanisms involving oxidative stress, inflammation, and apoptosis pathways. The transcription factor Nrf2, pivotal in cellular defense against oxidative stress and inflammation, is the master regulator of the antioxidant response, upregulating antioxidants and cytoprotective genes under oxidative stress. This review discusses the mechanisms underlying chemotherapy-induced kidney injury, focusing on the role of Nrf2 in cancer therapy and its redox regulation in cisplatin-induced kidney injury. We also explore Nrf2's signaling pathways, post-translational modifications, and its involvement in autophagy, as well as examine redox-based strategies for modulating Nrf2 in cisplatin-induced kidney injury while considering the limitations and potential off-target effects of Nrf2 modulation. Understanding the redox regulation of Nrf2 in cisplatin-induced kidney injury holds significant promise for developing novel therapeutic interventions. This knowledge could provide valuable insights into potential strategies for mitigating the nephrotoxicity associated with cisplatin, ultimately enhancing the safety and efficacy of cancer treatment.

Therapeutic effect of trace elements on multiple myeloma and mechanisms of cancer process

In the human body, trace elements and other micronutrients play a vital role in growth, health and immune system function. The trace elements are Iron, Manganese, Copper, Iodine, Zinc, Cobalt, Fluoride, and Selenium. Estimating the serum levels of trace elements in hematologic malignancy patients can determine the severity of the tumor. Multiple myeloma (MM) is a hematopoietic malignancy and is characterized by plasma cell clonal expansion in bone marrow. Despite the advances in treatment methods, myeloma remains largely incurable. In addition to conventional medicine, treatment is moving toward less expensive noninvasive alternatives. One of the alternative treatments is the use of dietary supplements. In this review, we focused on the effect of three trace elements including iron, zinc and selenium on important mechanisms such as the immune system, oxidative and antioxidant factors and cell cycle. Using some trace minerals in combination with approved drugs can increase patients' recovery speed. Trace elements can be used as not only a preventive but also a therapeutic tool, especially in reducing inflammation in hematological cancers such as multiple myeloma. We hope that the prospect of the correct use of trace element supplements in the future could be promising for the treatment of diseases.

Induction of Metabolic Reprogramming in Kidney by Singlet Diradical Nanoparticles

Polycyclic aromatic compounds with an open-shell singlet diradical ground state, namely singlet diradicals, have recently gained attention in the fields of organic electronics, photovoltaics, and spintronics owing to their unique electronic structures and properties. Notably, singlet diradicals exhibit tunable redox amphoterism, which makes them excellent redox-active materials for biomedical applications. However, the safety and therapeutic efficacy of singlet diradicals in biological systems have not yet been explored. Herein, the study presents a newly designed singlet diradical nanomaterial, diphenyl-substituted biolympicenylidene (BO-Ph), exhibiting low cytotoxicity in vitro, non-significant acute nephrotoxicity in vivo, and the ability to induce metabolic reprogramming in kidney organoids. Integrated transcriptome and metabolome analyses reveal that the metabolism of BO-Ph stimulates glutathione (GSH) synthesis and fatty acid degradation, increases the levels of intermediates in the tricarboxylic acid (TCA) and carnitine cycles, and eventually boosts oxidative phosphorylation (OXPHOS) under redox homeostasis. Benefits of BO-Ph-induce metabolic reprogramming in kidney organoids include enhancing cellular antioxidant capacity and promoting mitochondrial function. The results of this study can facilitate the application of singlet diradical materials in the treatment of clinical conditions induced by mitochondrial abnormalities in kidney.

Pannexin 1 targets mitophagy to mediate renal ischemia/reperfusion injury

Renal ischemia/reperfusion (I/R) injury contributes to the development of acute kidney injury (AKI). Kidney is the second organ rich in mitochondrial content next to the heart. Mitochondrial damage substantially contributes for AKI development. Mitophagy eliminates damaged mitochondria from the cells to maintain a healthy mitochondrial population, which plays an important role in AKI. Pannexin 1 (PANX1) channel transmembrane proteins are known to drive inflammation and release of adenosine triphosphate (ATP) during I/R injury. However, the specific role of PANX1 on mitophagy regulation in renal I/R injury remains elusive. In this study, we find that serum level of PANX1 is elevated in patients who developed AKI after cardiac surgery, and the level of PANX1 is positively correlated with serum creatinine and urea nitrogen levels. Using the mouse model of renal I/R injury in vivo and cell-based hypoxia/reoxygenation (H/R) model in vitro, we prove that genetic deletion of PANX1 mitigate the kidney tubular cell death, oxidative stress and mitochondrial damage after I/R injury through enhanced mitophagy. Mechanistically, PANX1 disrupts mitophagy by influencing ATP-P2Y-mTOR signal pathway. These observations provide evidence that PANX1 could be a potential biomarker for AKI and a therapeutic target to alleviate AKI caused by I/R injury.

Concentrated urine, low urine flow, and postoperative elevation of plasma creatinine: A retrospective analysis of pooled data

Elevations of plasma creatinine are common after major surgery, but their pathophysiology is poorly understood. To identify possible contributing mechanisms, we pooled data from eight prospective studies performed in four different countries to study circumstances during which elevation of plasma creatinine occurs. We included 642 patients undergoing mixed major surgeries, mostly open gastrointestinal. Plasma and urinary creatinine and a composite index for renal fluid conservation (Fluid Retention Index, FRI) were measured just before surgery and on the first postoperative morning. Urine flow was measured during the surgery. The results show that patients with a postoperative increase in plasma creatinine by >25% had a high urinary creatinine concentration (11.0±5.9 vs. 8.3±5.6 mmol/L; P< 0001) and higher FRI value (3.2±1.0 vs. 2.9±1.1; P< 0.04) already before surgery was initiated. Progressive increase of plasma creatinine was associated with a gradually lower urine flow and larger blood loss during the surgery (Kruskal-Wallis test, P< 0.001). The patients with an elevation > 25% also showed higher creatinine and a higher FRI value on the first postoperative morning (P< 0.001). Elevations to > 50% of baseline were associated with slightly lower mean arterial pressure (73 ± 10 vs. 80 ± 12 mmHg; P< 0.005). We conclude that elevation of plasma creatinine in the perioperative period was associated with low urine flow and greater blood loss during surgery and with concentrated urine both before and after the surgery. Renal water conservation-related mechanisms seem to contribute to the development of increased plasma creatinine after surgery.

Breast Milk Mesenchymal Stem Cells and/or Derived Exosomes Mitigated Adenine-Induced Nephropathy via Modulating Renal Autophagy and Fibrotic Signaling Pathways and Their Epigenetic Regulations

Chronic kidney disease (CKD), a global health concern, is highly prevalent among adults. Presently, there are limited therapeutic options to restore kidney function. This study aimed to investigate the therapeutic potential of breast milk mesenchymal stem cells (Br-MSCs) and their derived exosomes in CKD. Eighty adult male Sprague Dawley rats were randomly assigned to one of six groups, including control, nephropathy, nephropathy + conditioned media (CM), nephropathy + Br-MSCs, nephropathy + Br-MSCs derived exosomes (Br-MSCs-EXOs), and nephropathy + Br-MSCs + Br-MSCs-EXOs. Before administration, Br-MSCs and Br-MSCs-EXOs were isolated, identified, and labeled with PKH-26. SOX2, Nanog, and OCT3/4 expression levels in Br-MSCs and miR-29b, miR-181, and Let-7b in both Br-MSCs and Br-MSCs-EXOs were assayed. Twelve weeks after transplantation, renal function tests, oxidative stress, expression of the long non-coding RNA SNHG-7, autophagy, fibrosis, and expression of profibrotic miR-34a and antifibrotic miR-29b, miR-181, and Let-7b were measured in renal tissues. Immunohistochemical analysis for renal Beclin-1, LC3-II, and P62, Masson trichome staining, and histopathological examination of kidney tissues were also performed. The results showed that Br-MSCs expressed SOX2, Nanog, and OCT3/4, while both Br-MSCs and Br-MSCs-EXOs expressed antifibrotic miR-181, miR-29b, and Let-7b, with higher expression levels in exosomes than in Br-MSCs. Interestingly, the administration of Br-MSCs + EXOs, EXOs, and Br-MSCs improved renal function tests, reduced renal oxidative stress, upregulated the renal expression of SNHG-7, AMPK, ULK-1, Beclin-1, LC3, miR-29b, miR-181, Let-7b, and Smad-7, downregulated the renal expression of miR-34a, AKT, mTOR, P62, TGF-β, Smad-3, and Coli-1, and ameliorated renal pathology. Thus, Br-MSCs and/or their derived exosomes appear to reduce adenine-induced renal damage by secreting antifibrotic microRNAs and potentiate renal autophagy by modulating SNHG-7 expression.

Unveiling the potential of mitochondrial dynamics as a therapeutic strategy for acute kidney injury

Acute Kidney Injury (AKI), a critical clinical syndrome, has been strongly linked to mitochondrial malfunction. Mitochondria, vital cellular organelles, play a key role in regulating cellular energy metabolism and ensuring cell survival. Impaired mitochondrial function in AKI leads to decreased energy generation, elevated oxidative stress, and the initiation of inflammatory cascades, resulting in renal tissue damage and functional impairment. Therefore, mitochondria have gained significant research attention as a potential therapeutic target for AKI. Mitochondrial dynamics, which encompass the adaptive shifts of mitochondria within cellular environments, exert significant influence on mitochondrial function. Modulating these dynamics, such as promoting mitochondrial fusion and inhibiting mitochondrial division, offers opportunities to mitigate renal injury in AKI. Consequently, elucidating the mechanisms underlying mitochondrial dynamics has gained considerable importance, providing valuable insights into mitochondrial regulation and facilitating the development of innovative therapeutic approaches for AKI. This comprehensive review aims to highlight the latest advancements in mitochondrial dynamics research, provide an exhaustive analysis of existing studies investigating the relationship between mitochondrial dynamics and acute injury, and shed light on their implications for AKI. The ultimate goal is to advance the development of more effective therapeutic interventions for managing AKI.

Vitamin A and retinoid signaling in the kidneys

Vitamin A (VA, retinol) and its metabolites (commonly called retinoids) are required for the proper development of the kidney during embryogenesis, but retinoids also play key roles in the function and repair of the kidney in adults. Kidneys filter 180-200 liters of blood per day and each kidney contains approximately 1 million nephrons, which are often referred to as the 'functional units' of the kidney. Each nephron consists of a glomerulus and a series of tubules (proximal tubule, loop of Henle, distal tubule, and collecting duct) surrounded by a network of capillaries. VA is stored in the liver and converted to active metabolites, most notably retinoic acid (RA), which acts as an agonist for the retinoic acid receptors ((RARs α, β, and γ) to regulate gene transcription. In this review we discuss some of the actions of retinoids in the kidney after injury. For example, in an ischemia-reperfusion model in mice, injury-associated loss of proximal tubule (PT) differentiation markers occurs, followed by re-expression of these differentiation markers during PT repair. Notably, healthy proximal tubules express ALDH1a2, the enzyme that metabolizes retinaldehyde to RA, but transiently lose ALDH1a2 expression after injury, while nearby myofibroblasts transiently acquire RA-producing capabilities after injury. These results indicate that RA is important for renal tubular injury repair and that compensatory mechanisms exist for the generation of endogenous RA by other cell types upon proximal tubule injury. ALDH1a2 levels also increase in podocytes, epithelial cells of the glomeruli, after injury, and RA promotes podocyte differentiation. We also review the ability of exogenous, pharmacological doses of RA and receptor selective retinoids to treat numerous kidney diseases, including kidney cancer and diabetic kidney disease, and the emerging genetic evidence for the importance of retinoids and their receptors in maintaining or restoring kidney function after injury. In general, RA has a protective effect on the kidney after various types of injuries (eg. ischemia, cytotoxic actions of chemicals, hyperglycemia related to diabetes). As more research into the actions of each of the three RARs in the kidney is carried out, a greater understanding of the actions of vitamin A is likely to lead to new insights into the pathology of kidney disorders and the development of new therapies for kidney diseases.

Incidence of Post-laparotomy Acute Kidney Injury Among Abdominal Trauma Patients and Its Associated Risk Factors at King Abdulaziz Medical City, Riyadh

Background This research study investigates the prevalence of acute kidney injury (AKI) in trauma patients undergoing emergency laparotomies. AKI is a common complication in major surgeries and is associated with various adverse effects. The study aims to explore the relationship between AKI and other comorbidities in this specific context. Methodology This is a retrospective cohort study. All patients who had laparotomy after abdominal trauma at King Abdulaziz Medical City (KAMC) and met the inclusion criteria were included in the study. Nonprobability consecutive sampling was used. Data were collected by chart review using the Best-Care system at KAMC. Descriptive statistics were used to summarize and describe the characteristics of the study participants. Frequencies and percentages were calculated for categorical variables, such as comorbidities. For continuous variables, mean and standard deviations were calculated and tabulated. All statistical calculations were performed using IBM SPSS Statistics for Windows, Version 27.0 (IBM Corp., Armonk, NY, USA). Results This research study included 152 patients who underwent laparotomy, and the majority of patients (146, 96%) did not experience AKI. Several comorbidities were observed, with hypertension and diabetes being the most prevalent at 37 (24.3%) and 35 (23%), respectively. Intraoperative hypotension was experienced by 23 (15.1%) patients, while 129 (84.9%) did not have this issue. Norepinephrine was the most common vasopressor used (25.7%), followed by ephedrine and a combination of norepinephrine and epinephrine. Gender and age groups did not show significant associations with AKI, comorbidities like diabetes, heart failure, and chronic kidney disease (CKD) demonstrated significant relationships with AKI. There was no significant difference in eGFR and serum creatinine baseline levels between patients meeting AKI criteria and those who did not. Conclusions The low overall incidence of AKI in this patient population is encouraging. However, healthcare professionals must be aware of the significant impact of comorbidities such as diabetes, heart failure, and CKD on AKI development. Vigilant monitoring of postoperative kidney function, particularly serum creatinine levels within the first 48 hours, is essential for early detection and timely intervention. By understanding and addressing these risk factors, healthcare providers can take proactive steps to prevent and manage AKI in patients undergoing laparotomy, ultimately leading to improved patient outcomes and reduced healthcare costs.

Follow-up of perfusion index and inferior vena cava collapsibility index in fluid therapy in prerenal acute renal failure

Introduction

Acute renal failure (ARF), which may occur as a result of hypovolemia, is frequently diagnosed in emergency departments. It is essential to determine these patients' volume status and fluid requirement. The aim of this study was to examine the change in the inferior vena cava (IVC) collapsibility index and perfusion index (PI) in order to evaluate fluid deficit, volume status, and response to fluid therapy in patients with prerenal ARF who presented with signs of hypovolemia.

Materials and methods

The study sample included 104 patients diagnosed with prerenal ARF due to hypovolemia in our emergency department. After obtaining informed consent from the patients, intravenous (IV) fluid therapy (20 cc/kg IV infusion of 0.9% sodium chloride solution for 30 min) was initiated. The PI and IVC collapsibility index were measured before and after the treatment.

Results

Of the patients included in this study, 56.7% were women. The mean age was 76.06 years. Of the patients, 46.2% had a history of multiple diseases. Avoidant/restrictive food intake disorder was the most common complaint (28.8%). The mean PI of the patients was 2.20 at admission, which increased to 3.27 after treatment. The mean IVC collapsibility index was 38.39 at admission, which decreased to 29.36 after treatment. There was a significant and negative correlation between the PI and IVC collapsibility index of the patients.

Conclusions

Early diagnosis and treatment of ARF in emergency departments are critical. Serial measurements of the IVC collapsibility index and PI are helpful in monitoring patients' response to fluid therapy.

Emerging Insights Into Necroptosis: Implications for Renal Health and Diseases

Necroptosis is a regulated form of cell death that has gained increasing attention in recent years. It plays a significant role in various physiological and pathological processes, including renal health and disease. This review article provides an overview of necroptosis as a regulated cell death pathway and explores its implications in renal physiology and renal diseases. The molecular signaling pathways involved in necroptosis, including the key players such as receptor-interacting protein kinases (RIPKs) and mixed lineage kinase domain-like protein (MLKL), are discussed in detail. The crosstalk between necroptosis and other cell death pathways, particularly apoptosis, is explored to understand the interplay between these processes in renal cells. In normal physiological conditions, necroptosis has been found to play a crucial role in renal development and tissue homeostasis. However, dysregulated necroptosis can contribute to tissue damage, inflammation, and fibrosis in renal diseases. The review highlights the involvement of necroptosis in acute kidney injury, chronic kidney disease, and renal transplant rejection, elucidating the underlying pathophysiological mechanisms and consequences. The therapeutic targeting of necroptosis in renal diseases is an emerging area of interest. Current and emerging strategies to modulate necroptosis, including the inhibition of key mediators and regulators, are discussed here. Additionally, the potential therapeutic targets and inhibitors of necroptosis, along with preclinical and clinical studies exploring their efficacy, are reviewed.

Exploiting Machine Learning Technologies to Study the Compound Effects of Serum Creatinine and Electrolytes on the Risk of Acute Kidney Injury in Intensive Care Units

Assessing the risk of acute kidney injury (AKI) has been a challenging issue for clinicians in intensive care units (ICUs). In recent years, a number of studies have been conducted to investigate the associations between several serum electrolytes and AKI. Nevertheless, the compound effects of serum creatinine, blood urea nitrogen (BUN), and clinically relevant serum electrolytes have yet to be comprehensively investigated. Accordingly, we initiated this study aiming to develop machine learning models that illustrate how these factors interact with each other. In particular, we focused on ICU patients without a prior history of AKI or AKI-related comorbidities. With this practice, we were able to examine the associations between the levels of serum electrolytes and renal function in a more controlled manner. Our analyses revealed that the levels of serum creatinine, chloride, and magnesium were the three major factors to be monitored for this group of patients. In summary, our results can provide valuable insights for developing early intervention and effective management strategies as well as crucial clues for future investigations of the pathophysiological mechanisms that are involved. In future studies, subgroup analyses based on different causes of AKI should be conducted to further enhance our understanding of AKI.

GOLPH3 promotes endotoxemia-induced liver and kidney injury through Golgi stress-mediated apoptosis and inflammatory response

Sepsis is a serious clinical condition characterized by a systemic inflammatory response, a leading cause of acute liver and kidney injury, and is associated with a high morbidity and mortality. Understanding the molecular mechanisms underlying the acute liver and kidney injury is crucial for developing an effective therapy. Golgi apparatus plays important roles and has various substrates mediating cellular stress responses. Golgi phosphoprotein 3 (GOLPH3), linking Golgi membranes to the cytoskeleton, has been identified as an important oncogenic regulator; however, its role in endotoxemia-induced acute liver and kidney injury remains elusive. Here, we found that upregulation of GOLPH3 was associated with endotoxemia-induced acute liver and kidney injury. Lipopolysaccharide (LPS) treatment increased Golgi stress and fragmentation, and associated pro-inflammatory mediator (Tnfα, IL-6, and IL-1β) production in vivo and in vitro. Interestingly, the downregulation of GOLPH3 significantly decreased LPS-induced Golgi stress and pro-inflammatory mediators (Tnfα, IL-6, Mcp1, and Nos2), and reversed apoptotic cell deaths in LPS-treated hepatocytes and renal tubular cells. GOLPH3 knockdown also reduced inflammatory response in LPS-treated macrophages. The AKT/NF-kB signaling pathway was suppressed in GOLPH3 knockdown, which may be associated with a reduction of inflammatory response and apoptosis and the recovery of Golgi morphology and function. Taken together, GOLPH3 plays a crucial role in the development and progression of acute liver and kidney injury by promoting Golgi stress and increasing inflammatory response and apoptosis, suggesting GOLPH3 as a potential therapeutic target for endotoxemia-induced tissue injury.

Cell Profiling of Acute Kidney Injury to Chronic Kidney Disease Reveals Novel Oxidative Stress Characteristics in the Failed Repair of Proximal Tubule Cells

Chronic kidney disease (CKD) is a major public health issue around the world. A significant number of CKD patients originates from acute kidney injury (AKI) patients, namely "AKI-CKD". CKD is significantly related to the consequences of AKI. Damaged renal proximal tubular (PT) cell repair has been widely confirmed to indicate the renal prognosis of AKI. Oxidative stress is a key damage-associated factor and plays a significant role throughout the development of AKI and CKD. However, the relationships between AKI-CKD progression and oxidative stress are not totally clear and the underlying mechanisms in "AKI-CKD" remain indistinct. In this research, we constructed unilateral ischemia-reperfusion injury (UIRI)-model mice and performed single-nucleus RNA sequencing (snRNA-seq) of the kidney samples from UIRI and sham mice. We obtained our snRNA-seq data and validated the findings based on the joint analysis of public databases, as well as a series of fundamental experiments. Proximal tubular cells associated with failed repair express more complete senescence and oxidative stress characteristics compared to other subgroups. Furthermore, oxidative stress-related transcription factors, including Stat3 and Dnmt3a, are significantly more active under the circumstance of failed repair. What is more, we identified abnormally active intercellular communication between PT cells associated with failed repair and macrophages through the APP-CD74 pathway. More notably, we observed that the significantly increased expression of CD74 in hypoxia-treated TECs (tubular epithelial cells) was dependent on adjacently infiltrated macrophages, which was essential for the further deterioration of failed repair in PT cells. This research provides a novel understanding of the process of AKI to CKD progression, and the oxidative stress-related characteristics that we identified might represent a potentially novel therapeutic strategy against AKI.

Renal mitochondrial restoration by gymnemic acid in gentamicin-mediated experimental nephrotoxicity: evidence from serum, kidney and histopathological alterations

Background: Nephrotoxicity refers to the toxigenic impact of compounds and medications on kidney function. There are a variety of drug formulations, and some medicines that may affect renal function in multiple ways via nephrotoxins production. Nephrotoxins are substances that are harmful to the kidneys. Purpose: This investigation examines the renoprotective effect of gymnemic acid (GA) on Wistar rats in gentamicin-induced nephrotoxicity by analyzing serum, kidney, and histopathological markers. Study-design/methods: The current study investigated the protective effect of GA at doses of 20, 40, and 60 mg/kg against gentamicin-induced nephrotoxicity in rats. Vitamin E was administered to compare the antioxidant capacity and efficacy of GA. In addition to the treatment groups, 100 mg/kg of gentamicin was administered intraperitoneal for 14 days. At the end of the study protocol, kidney homogenate, blood, and serum were evaluated biochemically. Serum creatinine, blood urea, glomerular filtration rate (GFR), mitochondrial dysfunctions, inflammatory cytokines, and renal oxidative stress were examined to assess gentamicin-induced nephrotoxicity. In addition, the impact of GA on the above-mentioned nephrotoxic markers were evaluated and further confirmed by histological analysis. Results: This study establishes a correlation between antibiotic use, especifically aminoglycosides and acute renal failure. The research demonstrates the nephrotoxic effects of aminoglycosides, inducing mitochondrial ETC-complex dysfunction, and renal tissue inflammation in experimental rats. GA's antioxidant properties restored renal oxidative stress markers, reducing kidney inflammation and injury. Histopathological analysis revealed a significant reduction in renal injury with GA treatment. Additionally, GA demonstrated greater efficacy than Vitamin E in restoring antioxidant potential and mitochondrial enzymes. Conclusion: Consequently, our findings imply that long-term use of GA may be a suitable therapeutic strategy for reducing aminoglycoside toxicity. The current study suggests GA's potential in treating gentamicin-induced nephrotoxicity and acute renal failure, meriting further investigation using advanced techniques.

The Road from AKI to CKD: Molecular Mechanisms and Therapeutic Targets of Ferroptosis

Acute kidney injury (AKI) is a prevalent pathological condition that is characterized by a precipitous decline in renal function. In recent years, a growing body of studies have demonstrated that renal maladaptation following AKI results in chronic kidney disease (CKD). Therefore, targeting the transition of AKI to CKD displays excellent therapeutic potential. However, the mechanism of AKI to CKD is mediated by multifactor, and there is still a lack of effective treatments. Ferroptosis, a novel nonapoptotic form of cell death, is believed to have a role in the AKI to CKD progression. In this study, we retrospectively examined the history and characteristics of ferroptosis, summarized ferroptosis's research progress in AKI and CKD, and discussed how ferroptosis participates in regulating the pathological mechanism in the progression of AKI to CKD. Furthermore, we highlighted the limitations of present research and projected the future evolution of ferroptosis. We hope this work will provide clues for further studies of ferroptosis in AKI to CKD and contribute to the study of effective therapeutic targets to prevent the progression of kidney diseases.

Dynamic predictive scores for cardiac surgery-associated agitated delirium: a single-center retrospective observational study

BACKGROUND

Prevention, screening, and early treatment are the aims of postoperative delirium management. The scoring system is an objective and effective tool to stratify potential delirium risk for patients undergoing cardiac surgery.

METHODS

Patients who underwent cardiac surgery between January 1, 2012, and January 1, 2019, were enrolled in our retrospective study. The patients were divided into a derivation cohort (n = 45,744) and a validation cohort (n = 11,436). The AD predictive systems were formulated using multivariate logistic regression analysis at three time points: preoperation, ICU admittance, and 24 h after ICU admittance.

RESULTS

The prevalence of AD after cardiac surgery in the whole cohort was 3.6% (2,085/57,180). The dynamic scoring system included preoperative LVEF ≤ 45%, serum creatinine > 100 µmol/L, emergency surgery, coronary artery disease, hemorrhage volume > 600 mL, intraoperative platelet or plasma use, and postoperative LVEF ≤ 45%. The area under the receiver operating characteristic curve (AUC) values for AD prediction were 0.68 (preoperative), 0.74 (on the day of ICU admission), and 0.75 (postoperative). The Hosmer‒Lemeshow test indicated that the calibration of the preoperative prediction model was poor (P = 0.01), whereas that of the pre- and intraoperative prediction model (P = 0.49) and the pre, intra- and postoperative prediction model (P = 0.35) was good.

CONCLUSIONS

Using perioperative data, we developed a dynamic scoring system for predicting the risk of AD following cardiac surgery. The dynamic scoring system may improve the early recognition of and the interventions for AD.

DNA binding protein YB-1 is a part of the neutrophil extracellular trap mediation of kidney damage and cross-organ effects

Open-heart surgery is associated with high morbidity, with acute kidney injury (AKI) being one of the most commonly observed postoperative complications. Following open-heart surgery, in an observational study we found significantly higher numbers of blood neutrophils in a group of 13 patients with AKI compared to 25 patients without AKI (AKI: 12.9±5.4 ×109 cells/L; non-AKI: 10.1±2. 9 ×109 cells/L). Elevated serum levels of neutrophil extracellular trap (NETs) components, such as dsDNA, histone 3, and DNA binding protein Y-box protein (YB)-1, were found within the first 24 hours in patients who later developed AKI. We could demonstrate that NET formation and hypoxia triggered the release of YB-1, which was subsequently shown to act as a mediator of kidney tubular damage. Experimentally, in two models of AKI mimicking kidney hypoperfusion during cardiac surgery (bilateral ischemia/reperfusion (I/R) and systemic lipopolysaccharide (LPS) administration), a neutralizing YB-1 antibody was administered to mice. In both models, prophylactic YB-1 antibody administration significantly reduced the tubular damage (damage score range 1-4, the LPS model: non-specific IgG control, 0.92±0.23; anti-YB-1 0.65±0.18; and in the I/R model: non-specific IgG control 2.42±0.23; anti-YB-1 1.86±0.44). Even in a therapeutic, delayed treatment model, antagonism of YB-1 ameliorated AKI (damage score, non-specific IgG control 3.03±0.31; anti-YB-1 2.58±0.18). Thus, blocking extracellular YB-1 reduced the effects induced by hypoxia and NET formation in the kidney and significantly limited AKI, suggesting that YB-1 is part of the NET formation process and an integral mediator of cross-organ effects.

Trajectories of systolic blood pressure decline in kidney transplant donors prior to circulatory death and delayed graft function

BACKGROUND

Kidneys donated after circulatory death suffer a period of functional warm ischaemia before death, which may lead to early ischaemic injury. Effects of haemodynamic trajectories during the agonal phase on delayed graft function (DGF) is unknown. We aimed to predict the risk of DGF using patterns of trajectories of systolic blood pressure (SBP) declines in Maastricht category 3 kidney donors.

METHODS

We conducted a cohort study of all kidney transplant recipients in Australia who received kidneys from donation after circulatory death donors, divided into a derivation cohort (transplants between 9 April 2014 and 2 January 2018 [462 donors]) and a validation cohort (transplants between 6 January 2018 and 24 December 2019 [324 donors]). Patterns of SBP decline using latent class models were evaluated against the odds of DGF using a two-stage linear mixed effects model.

RESULTS

In the derivation cohort, 462 donors were included in the latent class analyses and 379 donors in the mixed effects model. Of the 696 eligible transplant recipients, 380 (54.6%) experienced DGF. Ten different trajectories, with distinct patterns of SBP decline were identified. Compared with recipients from donors with the slowest decline in SBP after withdrawal of cardiorespiratory support, the adjusted odds ratio (aOR) for DGF was 5.5 [95% confidence interval (CI) 1.38-28.0] for recipients from donors with a steeper decline and lowest SBP [mean 49.5 mmHg (standard deviation 12.5)] at the time of withdrawal. For every 1 mmHg/min reduction in the rate of decline of SBP, the respective aORs for DGF were 0.95 (95% CI 0.91-0.99) and 0.98 (95% CI 0.93-1.0) in the random forest and least absolute shrinkage and selection operator models. In the validation cohort, the respective aORs were 0.95 (95% CI 0.91-1.0) and 0.99 (95% CI 0.94-1.0).

CONCLUSION

Trajectories of SBP decline and their determinants are predictive of DGF. These results support a trajectory-based assessment of haemodynamic changes in donors after circulatory death during the agonal phase for donor suitability and post-transplant outcomes.

LTBP4 Protects Against Renal Fibrosis via Mitochondrial and Vascular Impacts

BACKGROUND

As a part of natural disease progression, acute kidney injury (AKI) can develop into chronic kidney disease via renal fibrosis and inflammation. LTBP4 (latent transforming growth factor beta binding protein 4) regulates transforming growth factor beta, which plays a role in renal fibrosis pathogenesis. We previously investigated the role of LTBP4 in chronic kidney disease. Here, we examined the role of LTBP4 in AKI.

METHODS

LTBP4 expression was evaluated in human renal tissues, obtained from healthy individuals and patients with AKI, using immunohistochemistry. LTBP4 was knocked down in both C57BL/6 mice and human renal proximal tubular cell line HK-2. AKI was induced in mice and HK-2 cells using ischemia-reperfusion injury and hypoxia, respectively. Mitochondrial division inhibitor 1, an inhibitor of DRP1 (dynamin-related protein 1), was used to reduce mitochondrial fragmentation. Gene and protein expression were then examined to assess inflammation and fibrosis. The results of bioenergetic studies for mitochondrial function, oxidative stress, and angiogenesis were assessed.

RESULTS

LTBP4 expression was upregulated in the renal tissues of patients with AKI. Ltbp4-knockdown mice showed increased renal tissue injury and mitochondrial fragmentation after ischemia-reperfusion injury, as well as increased inflammation, oxidative stress, and fibrosis, and decreased angiogenesis. in vitro studies using HK-2 cells revealed similar results. The energy profiles of Ltbp4-deficient mice and LTBP4-deficient HK-2 cells indicated decreased ATP production. LTBP4-deficient HK-2 cells exhibited decreased mitochondrial respiration and glycolysis. Human aortic endothelial cells and human umbilical vein endothelial cells exhibited decreased angiogenesis when treated with LTBP4-knockdown conditioned media. Mitochondrial division inhibitor 1 treatment ameliorated inflammation, oxidative stress, and fibrosis in mice and decreased inflammation and oxidative stress in HK-2 cells.

CONCLUSIONS

Our study is the first to demonstrate that LTBP4 deficiency increases AKI severity, consequently leading to chronic kidney disease. Potential therapies focusing on LTBP4-associated angiogenesis and LTBP4-regulated DRP1-dependent mitochondrial division are relevant to renal injury.

Amazonia Phytotherapy Reduces Ischemia and Reperfusion Injury in the Kidneys

Acute kidney injury (AKI) is defined as a sudden decrease in kidney function. Phytomedicines have shown positive effects in the treatment of AKI worldwide. The aim of this study was to evaluate the effect of Abuta grandifolia on the renal function of rats submitted to AKI. A phytochemical study of the plant was performed through liquid chromatography coupled with mass spectrometry (CL-EM) and DPPH and ABTS antioxidant tests. Renal function tests were performed in 20 male adult Wistar rats weighing from 250 to 300 g distributed in the following groups: SHAM (submitted to laparotomy with simulation of renal ischemia); ABUTA (animals that received 400 mg/kg of AG, orally-VO, once a day, for 5 days, with simulation of renal ischemia); I/N (animals submitted to laparotomy for clamping of bilateral renal pedicles for 30 min, followed by reperfusion); ABUTA + I/R (animals that received AG-400 mg/kg, 1× per day, VO, for 5 days, submitted to renal ischemia after treatment with herbal medicine). The results suggest that the consumption of Abuta grandifolia promoted renoprotection, preventing the reduction of renal function induced by ischemia, oxidizing activity, and deleterious effects on the renal tissue, confirmed by the decrease of oxidative metabolites and increase of antioxidants in the animals' organisms.

Inflammatory mediators act at renal pericytes to elicit contraction of vasa recta and reduce pericyte density along the kidney medullary vascular network

Introduction: Regardless of initiating cause, renal injury promotes a potent pro-inflammatory environment in the outer medulla and a concomitant sustained decrease in medullary blood flow (MBF). This decline in MBF is believed to be one of the critical events in the pathogenesis of acute kidney injury (AKI), yet the precise cellular mechanism underlying this are still to be fully elucidated. MBF is regulated by contractile pericyte cells that reside on the descending vasa recta (DVR) capillaries, which are the primary source of blood flow to the medulla. Methods: Using the rat and murine live kidney slice models, we investigated the acute effects of key medullary inflammatory mediators TNF-α, IL-1β, IL-33, IL-18, C3a and C5a on vasa recta pericytes, the effect of AT1-R blocker Losartan on pro-inflammatory mediator activity at vasa recta pericytes, and the effect of 4-hour sustained exposure on immunolabelled NG2+ pericytes. Results and discussion: Exposure of rat and mouse kidney slices to TNF-α, IL-18, IL-33, and C5a demonstrated a real-time pericyte-mediated constriction of DVR. When pro-inflammatory mediators were applied in the presence of Losartan the inflammatory mediator-mediated constriction that had previously been observed was significantly attenuated. When live kidney slices were exposed to inflammatory mediators for 4-h, we noted a significant reduction in the number of NG2+ positive pericytes along vasa recta capillaries in both rat and murine kidney slices. Data collected in this study demonstrate that inflammatory mediators can dysregulate pericytes to constrict DVR diameter and reduce the density of pericytes along vasa recta vessels, further diminishing the regulatory capacity of the capillary network. We postulate that preliminary findings here suggest pericytes play a role in AKI.

Loss of renal tubular G9a benefits acute kidney injury by lowering focal lipid accumulation via CES1

Surgery-induced renal ischemia and reperfusion (I/R) injury and nephrotoxic drugs like cisplatin can cause acute kidney injury (AKI), for which there is no effective therapy. Lipid accumulation is evident following AKI in renal tubules although the mechanisms and pathological effects are unclear. Here, we report that Ehmt2-encoded histone methyltransferase G9a is upregulated in patients and mouse kidneys after AKI. Renal tubular specific knockout of G9a (Ehmt2Ksp ) or pharmacological inhibition of G9a alleviates lipid accumulation associated with AKI. Mechanistically, G9a suppresses transcription of the lipolytic enzyme Ces1; moreover, G9a and farnesoid X receptor (FXR) competitively bind to the same promoter regions of Ces1. Ces1 is consistently observed to be downregulated in the kidney of AKI patients. Pharmacological inhibition of Ces1 increases lipid accumulation, exacerbates renal I/R-injury and eliminates the beneficial effects on AKI observed in Ehmt2Ksp mice. Furthermore, lipid-lowering atorvastatin and an FXR agonist alleviate AKI by activating Ces1 and reducing renal lipid accumulation. Together, our results reveal a G9a/FXR-Ces1 axis that affects the AKI outcome via regulating renal lipid accumulation.

Efficacy of Cooling Centers for Mitigating Physiological Strain in Older Adults during Daylong Heat Exposure: A Laboratory-Based Heat Wave Simulation

BACKGROUND

Health agencies, including the U.S. Centers for Disease Control and Prevention and the World Health Organization, recommend that heat-vulnerable older adults without home air-conditioning should visit cooling centers or other air-conditioned locations (e.g., a shopping mall) during heat waves. However, experimental evidence supporting the effectiveness of brief air-conditioning is lacking.

OBJECTIVE

We evaluated whether brief exposure to an air-conditioned environment, as experienced in a cooling center, was effective for limiting physiological strain in older adults during a daylong laboratory-based heat wave simulation.

METHODS

Forty adults 64-79 years of age underwent a 9-h simulated heat wave (heat index: 37°C) with (cooling group, n=20) or without (control group, n=20) a cooling intervention consisting of 2-h rest in an air-conditioned room (∼23°C, hours 5-6). Core and skin temperatures, whole-body heat exchange and storage, cardiovascular function, and circulating markers of acute inflammation were assessed.

RESULTS

Core temperature was 0.8°C (95% CI: 0.6, 0.9) lower in the cooling group compared with the control group at the end of the cooling intervention (p<0.001; hour 6), and it remained 0.3°C (95% CI: 0.2, 0.4) lower an hour after returning to the heat (p<0.001; hour 7). Despite this, core temperatures in each group were statistically equivalent at hours 8 and 9, within ±0.3°C (p≤0.005). Cooling also acutely reduced demand on the heart and improved indices of cardiovascular autonomic function (p≤0.021); however, these outcomes were not different between groups at the end of exposure (p≥0.58).

DISCUSSION

Brief air-conditioning exposure during a simulated heat wave caused a robust but transient reduction in core temperature and cardiovascular strain. These findings provide important experimental support for national and international guidance that cooling centers are effective for limiting physiological strain during heat waves. However, they also show that the physiological impacts of brief cooling are temporary, a factor that has not been considered in guidance issued by health agencies. https://doi.org/10.1289/EHP11651.

Metabolomics in Acute Kidney Injury: The Experimental Perspective

Acute kidney injury (AKI) affects increasing numbers of in-hospital patients in Central Europe and the USA, the prognosis remains poor. Although substantial progress has been achieved in the identification of molecular/cellular processes that induce and perpetuate AKI, more integrated pathophysiological perspectives are missing. Metabolomics enables the identification of low-molecular-weight (< 1.5 kD) substances from biological specimens such as certain types of fluid or tissue. The aim of the article was to review the literature on metabolic profiling in experimental AKI and to answer the question if metabolomics allows the integration of distinct pathophysiological events such as tubulopathy and microvasculopathy in ischemic and toxic AKI. The following databases were searched for references: PubMed, Web of Science, Cochrane Library, Scopus. The period lasted from 1940 until 2022. The following terms were utilized: "acute kidney injury" OR "acute renal failure" OR "AKI" AND "metabolomics" OR "metabolic profiling" OR "omics" AND "ischemic" OR "toxic" OR "drug-induced" OR "sepsis" OR "LPS" OR "cisplatin" OR "cardiorenal" OR "CRS" AND "mouse" OR "mice" OR "murine" OR "rats" OR "rat". Additional search terms were "cardiac surgery", "cardiopulmonary bypass", "pig", "dog", and "swine". In total, 13 studies were identified. Five studies were related to ischemic, seven studies to toxic (lipopolysaccharide (LPS), cisplatin), and one study to heat shock-associated AKI. Only one study, related to cisplatin-induced AKI, was performed as a targeted analysis. The majority of the studies identified multiple metabolic deteriorations upon ischemia/the administration of LPS or cisplatin (e.g., amino acid, glucose, lipid metabolism). Particularly, abnormalities in the lipid homeostasis were shown under almost all experimental conditions. LPS-induced AKI most likely depends on the alterations in the tryptophan metabolism. Metabolomics studies provide a deeper understanding of pathophysiological links between distinct processes that are responsible for functional impairment/structural damage in ischemic or toxic or other types of AKI.

Incidence of acute kidney injury after noncardiac surgery in patients receiving intraoperative dexmedetomidine: a retrospective study

Background

Postoperative acute kidney injury (AKI) is a common complication and is associated with increased hospital length of stay and 30 day all-cause mortality. Unfortunately, we have neither a defined strategy to prevent AKI nor an effective treatment. In vitro, animal, and human studies have suggested that dexmedetomidine may have a renoprotective effect. We conducted a retrospective cohort study to evaluate if intraoperative dexmedetomidine was associated with a reduced incidence of AKI.

Methods

We collected data from 6625 patients who underwent major non-cardiothoracic cancer surgery. Before and after propensity score matching, we compared the incidence of postoperative AKI in patients who received intraoperative dexmedetomidine and those who did not. AKI was defined according to the Kidney Disease Improving Global Outcomes (creatinine alone values) criteria and calculated for postoperative Days 1, 2, and 3.

Results

Twenty per cent (n=1301) of the patients received dexmedetomidine. The mean [standard deviation] administered dose was 78 [49.4] mcg. Patients treated with dexmedetomidine were matched to those who did not receive the drug. Patients receiving dexmedetomidine had a longer anaesthesia duration than the non-dexmedetomidine group. The incidence of AKI was not significantly different between the groups (dexmedetomidine 8% vs no dexmedetomidine 7%; P=0.333). The 30 day rates of infection, cardiovascular complications, or reoperation attributable to bleeding were higher in patients treated with dexmedetomidine. The 30 day mortality rate was not statistically different between the groups.

Conclusions

The administration of dexmedetomidine during major non-cardiothoracic cancer surgery is not associated with a reduction in AKI within 72 h after surgery.

Comparison of acute kidney injury following brain death between male and female rats

BACKGROUND

Clinical reports associate kidneys from female donors with worse prognostic in male recipients. Brain Death (BD) produces immunological and hemodynamic disorders that affect organ viability. Following BD, female rats are associated with increased renal inflammation interrelated with female sex hormone reduction. Here, the aim was to investigate the effects of sex on BD-induced Acute Kidney Injury (AKI) using an Isolated Perfused rat Kidney (IPK) model.

METHODS

Wistar rats, females, and males (8 weeks old), were maintained for 4h after BD. A left nephrectomy was performed and the kidney was preserved in a cold saline solution (30 min). IPK was performed under normothermic temperature (37°C) for 90 min using WME as perfusion solution. AKI was assessed by morphological analyses, staining of complement system components and inflammatory cell markers, perfusion flow, and creatinine clearance.

RESULTS

BD-male kidneys had decreased perfusion flow on IPK, a phenomenon that was not observed in the kidneys of BD-females (p < 0.0001). BD-male kidneys presented greater proximal (p = 0.0311) and distal tubule (p = 0.0029) necrosis. However, BD-female kidneys presented higher expression of eNOS (p = 0.0060) and greater upregulation of inflammatory mediators, iNOS (p = 0.0051), and Caspase-3 (p = 0.0099). In addition, both sexes had increased complement system formation (C5b-9) (p=0.0005), glomerular edema (p = 0.0003), and nNOS (p = 0.0051).

CONCLUSION

The present data revealed an important sex difference in renal perfusion in the IPK model, evidenced by a pronounced reduction in perfusate flow and low eNOS expression in the BD-male group. Nonetheless, the upregulation of genes related to the proinflammatory cascade suggests a progressive inflammatory process in BD-female kidneys.

Acute kidney injury in diabetic patients: A narrative review

Diabetes mellitus (DM) is the most common cause of chronic kidney disease, which leads to end-stage renal failure worldwide. Glomerular damage, renal arteriosclerosis, and atherosclerosis are the contributing factors in diabetic patients, leading to the progression of kidney damage. Diabetes is a distinct risk factor for acute kidney injury (AKI) and AKI is associated with faster advancement of renal disease in patients with diabetes. The long-term consequences of AKI include the development of end-stage renal disease, higher cardiovascular and cerebral events, poor quality of life, and high morbidity and mortality. In general, not many studies discussed extensively "AKI in DM." Moreover, articles addressing this topic are scarce. It is also important to know the cause of AKI in diabetic patients so that timely intervention and preventive strategies can be implemented to decrease kidney injury. Aim of this review article is to address the epidemiology of AKI, its risk factors, different pathophysiological mechanisms, how AKI differs between diabetic and nondiabetic patients and its preventive and therapeutic implications in diabetics. The increasing occurrence and prevalence of AKI and DM, as well as other pertinent issues, motivated us to address this topic.

Renal fibrosis in type 2 cardiorenal syndrome: An update on mechanisms and therapeutic opportunities

Cardiorenal syndrome (CRS) is a state of coexisting heart failure and renal insufficiency in which acute or chronic dysfunction of the heart or kidney lead to acute or chronic dysfunction of the other organ.It was found that renal fibrosis is an important pathological process in the progression of type 2 CRS to end-stage renal disease, and progressive renal impairment accelerates the deterioration of cardiac function and significantly increases the hospitalization and mortality rates of patients. Previous studies have found that Hemodynamic Aiteration, RAAS Overactivation, SNS Dysfunction, Endothelial Dysfunction and Imbalance of natriuretic peptide system contribute to the development of renal disease in the decompensated phase of heart failure, but the exact mechanisms is not clear. Therefore, in this review, we focus on the molecular pathways involved in the development of renal fibrosis due to heart failure and identify the canonical and non-canonical TGF-β signaling pathways and hypoxia-sensing pathways, oxidative stress, endoplasmic reticulum stress, pro-inflammatory cytokines and chemokines as important triggers and regulators of fibrosis development, and summarize the therapeutic approaches for the above signaling pathways, including SB-525334 Sfrp1, DKK1, IMC, rosarostat, 4-PBA, etc. In addition, some potential natural drugs for this disease are also summarized, including SQD4S2, Wogonin, Astragaloside, etc.

Dynamic cellular changes in acute kidney injury caused by different ischemia time

Ischemia reperfusion injury (IRI), often related to surgical procedures, is one of the important causes of acute kidney injury (AKI). To decipher the dynamic process of AKI caused by IRI (with prolonged ischemia phase), we performed single-cell RNA sequencing (scRNA-seq) of clinically relevant IRI murine model with different ischemic intervals. We discovered that Slc5a2^hi proximal tubular cells were susceptible to AKI and highly expressed neutral amino acid transporter gene Slc6a19, which was dramatically decreased over the time course. With the usage of mass spectrometry-based metabolomic analysis, we detected that the level of neutral amino acid isoleucine dropped off in AKI mouse plasma metabolites. And the reduction of plasma isoleucine was also verified in patients with cardiac surgery-associated acute kidney injury (CSA-AKI). The findings advanced the understanding of dynamic process of AKI and introduced reduction of isoleucine as a potential biomarker for CSA-AKI.

Cx3cr1 controls kidney resident macrophage heterogeneity

Kidney macrophages are comprised of both monocyte-derived and tissue resident populations; however, the heterogeneity of kidney macrophages and factors that regulate their heterogeneity are poorly understood. Herein, we performed single cell RNA sequencing (scRNAseq), fate mapping, and parabiosis to define the cellular heterogeneity of kidney macrophages in healthy mice. Our data indicate that healthy mouse kidneys contain four major subsets of monocytes and two major subsets of kidney resident macrophages (KRM) including a population with enriched Ccr2 expression, suggesting monocyte origin. Surprisingly, fate mapping data using the newly developed Ms4a3Cre Rosa Stopf/f TdT model indicate that less than 50% of Ccr2+ KRM are derived from Ly6chi monocytes. Instead, we find that Ccr2 expression in KRM reflects their spatial distribution as this cell population is almost exclusively found in the kidney cortex. We also identified Cx3cr1 as a gene that governs cortex specific accumulation of Ccr2+ KRM and show that loss of Ccr2+ KRM reduces the severity of cystic kidney disease in a mouse model where cysts are mainly localized to the kidney cortex. Collectively, our data indicate that Cx3cr1 regulates KRM heterogeneity and niche-specific disease progression.

Post-injury Inhibition of Endothelin-1 Dependent Renal Vasoregulation Mitigates Rhabdomyolysis-Induced Acute Kidney Injury

In patients with rhabdomyolysis, the overwhelming release of myoglobin into the circulation is the primary cause of kidney injury. Myoglobin causes direct kidney injury as well as severe renal vasoconstriction. An increase in renal vascular resistance (RVR) results in renal blood flow (RBF) and glomerular filtration rate (GFR) reduction, tubular injury, and acute kidney injury (AKI). The mechanisms that underlie rhabdomyolysis-induced AKI are not fully understood but may involve the local production of vasoactive mediators in the kidney. Studies have shown that myoglobin stimulates endothelin-1 (ET-1) production in glomerular mesangial cells. Circulating ET-1 is also increased in rats subjected to glycerol-induced rhabdomyolysis. However, the upstream mechanisms of ET-1 production and downstream effectors of ET-1 actions in rhabdomyolysis-induced AKI remain unclear. Vasoactive ET-1 is generated by ET converting enzyme 1 (ECE-1)-induced proteolytic processing of inactive big ET to biologically active peptides. The downstream ion channel effectors of ET-1-induced vasoregulation include the transient receptor potential cation channel, subfamily C member 3 (TRPC3). This study demonstrates that glycerol-induced rhabdomyolysis in Wistar rats promotes ECE-1-dependent ET-1 production, RVR increase, GFR decrease, and AKI. Rhabdomyolysis-induced increases in RVR and AKI in the rats were attenuated by post-injury pharmacological inhibition of ECE-1, ET receptors, and TRPC3 channels. CRISPR/Cas9-mediated knockout of TRPC3 channels attenuated ET-1-induced renal vascular reactivity and rhabdomyolysis-induced AKI. These findings suggest that ECE-1-driven ET-1 production and downstream activation of TRPC3-dependent renal vasoconstriction contribute to rhabdomyolysis-induced AKI. Hence, post-injury inhibition of ET-1-mediated renal vasoregulation may provide therapeutic targets for rhabdomyolysis-induced AKI.

The Potential Biotherapeutic Targets of Contrast-Induced Acute Kidney Injury

Contrast-induced acute kidney injury (CI-AKI) is manifested by an abrupt decline in kidney function as a consequence of intravascular exposure to contrast media. With the increased applicability of medical imaging and interventional procedures that utilize contrast media for clinical diagnosis, CI-AKI is becoming the leading cause of renal dysfunction. The pathophysiological mechanism associated with CI-AKI involves renal medullary hypoxia, the direct toxicity of contrast agents, oxidative stress, apoptosis, inflammation, and epigenetic regulation. To date, there is no effective therapy for CI-AKI, except for the development of strategies that could reduce the toxicity profiles of contrast media. While most of these strategies have failed, evidence has shown that the proper use of personalized hydration, contrast medium, and high-dose statins may reduce the occurrence of CI-AKI. However, adequate risk predication and attempts to develop preventive strategies can be considered as the key determinants that can help eliminate CI-AKI. Additionally, a deeper understanding of the pathophysiological mechanism of CI-AKI is crucial to uncover molecular targets for the prevention of CI-AKI. This review has taken a step further to solidify the current known molecular mechanisms of CI-AKI and elaborate the biomarkers that are used to detect early-stage CI-AKI. On this foundation, this review will analyze the molecular targets relating to apoptosis, inflammation, oxidative stress, and epigenetics, and, thus, provide a strong rationale for therapeutic intervention in the prevention of CI-AKI.

Acute kidney injury in patients with acute-on-chronic liver failure: clinical significance and management

Acute-on-chronic-liver failure (ACLF) refers to a phenomenon in which patients with chronic liver disease develop multiple organ failure due to acute exacerbation of underlying liver disease. More than 10 definitions of ACLF are extant around the world, and there is lack of consensus on whether extrahepatic organ failure is a main component or a consequence of ACLF. Asian and European consortiums have their own definitions of ACLF. The Asian Pacific Association for the Study of the Liver ACLF Research Consortium does not consider kidney failure as a diagnostic criterion for ACLF. Meanwhile, the European Association for the Study of the Liver Chronic Liver Failure and the North American Consortium for the Study of End-stage Liver Disease do consider kidney failure as an important factor in diagnosing and assessing the severity of ACLF. When kidney failure occurs in ACLF patients, treatment varies depending on the presence and stage of acute kidney injury (AKI). In general, the diagnosis of AKI in cirrhotic patients is based on the International Club of Ascites criteria: an increase of 0.3 mg/dL or more within 48 hours or a serum creatinine increase of 50% or more within one week. This study underscores the importance of kidney failure or AKI in patients with ACLF by reviewing its pathophysiology, prevention methods, and treatment approaches.

Immunohistochemical Pattern of Histone H2A Variant Expression in an Experimental Model of Ischemia-Reperfusion-Induced Acute Kidney Injury

Ischemia-reperfusion injury (IRI) is a frequent cause of AKI, resulting in vasoconstriction, cellular dysfunction, inflammation and the induction of oxidative stress. DNA damage, including physical DNA strand breaks, is also a potential consequence of renal IRI. The histone H2A variants, primary H2AX and H2AZ participate in DNA damage response pathways to promote genome stability. The aim of this study was to evaluate the immunohistochemical pattern of histone H2A variants' (H2AX, γH2AX(S139), H2AXY142ph and H2AZ) expression in an experimental model of ischemia-reperfusion-induced acute kidney injury in spontaneously hypertensive rats. Comparing the immunohistochemical nuclear expression of γH2AX(S139) and H2AXY142ph in AKI, we observed that there is an inverse ratio of these two histone H2AX variants. If we follow different regions from the subcapsular structures to the medulla, there is an increasing extent gradient in the nuclear expression of H2AXY142ph, accompanied by a decreasing nuclear expression of γH2AX. In addition, we observed that different structures dominated when γH2AX and H2AXY142ph expression levels were compared. γH2AX was expressed only in the proximal tubule, with the exception of when they were dilated. In the medulla, H2AXY142ph is predominantly expressed in the loop of Henle and the collecting ducts. Our results show moderate sporadic nuclear H2AZ expression mainly in the cells of the distal tubules and the collecting ducts that were surrounded by dilated tubules with PAS (periodic acid-Schiff stain)-positive casts. These findings may indicate the degree of DNA damage, followed by postischemic AKI, with potential clinical and prognostic implications regarding this condition.

Ensemble machine learning algorithm for predicting acute kidney injury in patients admitted to the neurointensive care unit following brain surgery

Acute kidney injury (AKI) is a common postoperative complication among patients in the neurological intensive care unit (NICU), often resulting in poor prognosis and high mortality. In this retrospective cohort study, we established a model for predicting AKI following brain surgery based on an ensemble machine learning algorithm using data from 582 postoperative patients admitted to the NICU at the Dongyang People's Hospital from March 1, 2017, to January 31, 2020. Demographic, clinical, and intraoperative data were collected. Four machine learning algorithms (C5.0, support vector machine, Bayes, and XGBoost) were used to develop the ensemble algorithm. The AKI incidence in critically ill patients after brain surgery was 20.8%. Intraoperative blood pressure; postoperative oxygenation index; oxygen saturation; and creatinine, albumin, urea, and calcium levels were associated with the postoperative AKI occurrence. The area under the curve value for the ensembled model was 0.85. The accuracy, precision, specificity, recall, and balanced accuracy values were 0.81, 0.86, 0.44, 0.91, and 0.68, respectively, indicating good predictive ability. Ultimately, the models using perioperative variables exhibited good discriminatory ability for early prediction of postoperative AKI risk in patients admitted to the NICU. Thus, the ensemble machine learning algorithm may be a valuable tool for forecasting AKI.

Assessing Kidney Injury Induced by Mercuric Chloride in Guinea Pigs with In Vivo and In Vitro Experiments

Acute kidney injury, which is associated with high levels of morbidity and mortality, affects a significant number of individuals, and can be triggered by multiple factors, such as medications, exposure to toxic chemicals or other substances, disease, and trauma. Because the kidney is a critical organ, understanding and identifying early cellular or gene-level changes can provide a foundation for designing medical interventions. In our earlier work, we identified gene modules anchored to histopathology phenotypes associated with toxicant-induced liver and kidney injuries. Here, using in vivo and in vitro experiments, we assessed and validated these kidney injury-associated modules by analyzing gene expression data from the kidneys of male Hartley guinea pigs exposed to mercuric chloride. Using plasma creatinine levels and cell-viability assays as measures of the extent of renal dysfunction under in vivo and in vitro conditions, we performed an initial range-finding study to identify the appropriate doses and exposure times associated with mild and severe kidney injuries. We then monitored changes in kidney gene expression at the selected doses and time points post-toxicant exposure to characterize the mechanisms of kidney injury. Our injury module-based analysis revealed a dose-dependent activation of several phenotypic cellular processes associated with dilatation, necrosis, and fibrogenesis that were common across the experimental platforms and indicative of processes that initiate kidney damage. Furthermore, a comparison of activated injury modules between guinea pigs and rats indicated a strong correlation between the modules, highlighting their potential for cross-species translational studies.

The combined effect of zinc oxide nanoparticles and milrinone on acute renal ischemia/reperfusion injury in rats: Potential underlying mechanisms

AIM

To investigate the efficacy of zinc oxide nanoparticles (ZnO-NPs) and/or milrinone (MIL) on renal ischemia/reperfusion injury (I/RI) in rats and their possible underlying mechanisms.

MATERIALS AND METHODS

Forty-eight adult male Sprague-Dawley albino rats were randomly assigned into six equal-sized groups (n = 8): normal control, sham-operated, I/R group (45 min/24 h), ZnO-NPs group (10 mg/Kg i.p.), MIL group (0.5 mg/Kg i.p.), and ZnO-NPs + MIL group in the same previous doses.

KEY FINDINGS

In comparison to the I/R-operated group, administration of either ZnO-NPs or MIL significantly decreased serum creatinine and urea concentrations, and renal vascular permeability (p < 0.05). The oxidative stress was significantly declined, as evidenced by increased GPx, CAT, and SOD activities and decreased MDA and NO concentrations. Renal expressions of TNF-α, NF-κB, KIM-1, NGAL, and caspase-3 decreased significantly, while Nrf2 increased significantly. Histopathology investigation revealed improvement with minimal renal lesions and fibrosis after ZnO-NPs or MIL treatments. The combined treatments synergistically improved the studied parameters more than either treatment alone. These findings were validated by molecular modeling, which revealed that MIL inhibited TNF-α, NF-kB, caspase-3, KIM-1 and NGAL.

SIGNIFICANCE

Both ZnO-NPs and MIL exerted cytoprotective effects against acute renal I/RI, and a combination of both was found to be even more effective. This renoprotective effect is suggested to be mediated through activation of Nrf2 and the prevention of the NF-κB activation-induced oxidative stress and inflammation, which may strengthen the potential role of ZnO-NPs or MIL in renal I/RI protection during surgical procedures.

The impact of intrauterine growth restriction and prematurity on nephron endowment

In humans born at term, maximal nephron number is reached by the time nephrogenesis is completed - at approximately 36 weeks' gestation. The number of nephrons does not increase further and subsequently remains stable until loss occurs through ageing or disease. Nephron endowment is key to the functional capacity of the kidney and its resilience to disease; hence, any processes that impair kidney development in the developing fetus can have lifelong adverse consequences for renal health and, consequently, for quality and length of life. The timing of nephrogenesis underlies the vulnerability of developing human kidneys to adverse early life exposures. Indeed, exposure of the developing fetus to a suboptimal intrauterine environment during gestation - resulting in intrauterine growth restriction (IUGR) - and/or preterm birth can impede kidney development and lead to reduced nephron endowment. Furthermore, emerging research suggests that IUGR and/or preterm birth is associated with an elevated risk of chronic kidney disease in later life. The available data highlight the important role of early life development in the aetiology of kidney disease and emphasize the need to develop strategies to optimize nephron endowment in IUGR and preterm infants.

Nanodrugs alleviate acute kidney injury: Manipulate RONS at kidney

Currently, there are no clinical drugs available to treat acute kidney injury (AKI). Given the high prevalence and high mortality rate of AKI, the development of drugs to effectively treat AKI is a huge unmet medical need and a research hotspot. Although existing evidence fully demonstrates that reactive oxygen and nitrogen species (RONS) burst at the AKI site is a major contributor to AKI progression, the heterogeneity, complexity, and unique physiological structure of the kidney make most antioxidant and anti-inflammatory small molecule drugs ineffective because of the lack of kidney targeting and side effects. Recently, nanodrugs with intrinsic kidney targeting through the control of size, shape, and surface properties have opened exciting prospects for the treatment of AKI. Many antioxidant nanodrugs have emerged to address the limitations of current AKI treatments. In this review, we systematically summarized for the first time about the emerging nanodrugs that exploit the pathological and physiological features of the kidney to overcome the limitations of traditional small-molecule drugs to achieve high AKI efficacy. First, we analyzed the pathological structural characteristics of AKI and the main pathological mechanism of AKI: hypoxia, harmful substance accumulation-induced RONS burst at the renal site despite the multifactorial initiation and heterogeneity of AKI. Subsequently, we introduced the strategies used to improve renal targeting and reviewed advances of nanodrugs for AKI: nano-RONS-sacrificial agents, antioxidant nanozymes, and nanocarriers for antioxidants and anti-inflammatory drugs. These nanodrugs have demonstrated excellent therapeutic effects, such as greatly reducing oxidative stress damage, restoring renal function, and low side effects. Finally, we discussed the challenges and future directions for translating nanodrugs into clinical AKI treatment.

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AKI is a common clinical acute syndrome with high morbidity and mortality but without effective clinical drug available.

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Hypoxia and accumulation of toxic substances are key pathological features of various heterogeneous AKI.

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Excessive RONS is the core of the pathological mechanism of AKI.

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The development of nanodrugs is expected to achieve successful treatment in AKI.

Salt-sensitive hypertension after reversal of unilateral ureteral obstruction

The incidence of ureter obstruction is increasing and patients recovering from this kidney injury often progress to chronic kidney injury. There is evidence that a long-term consequence of recovery from ureter obstruction is an increased risk for salt-sensitive hypertension. A reversal unilateral ureteral obstruction (RUUO) model was used to study long-term kidney injury and salt-sensitive hypertension. In this model, we removed the ureteral obstruction at day 10 in mice. Mice were divided into four groups: (1) normal salt diet, (2) high salt diet, (3) RUUO normal salt diet, and (4) RUUO high salt diet. At day 10, the mice were fed a normal or high salt diet for 4 weeks. Blood pressure was measured, and urine and kidney tissue collected. There was a progressive increase in blood pressure in the RUUO high salt diet group. RUUO high salt group had decreased sodium excretion and glomerular injury. Renal epithelial cell injury was evident in RUUO normal and high salt mice as assessed by neutrophil gelatinase-associated lipocalin (NGAL). Kidney inflammation in the RUUO high salt group involved an increase in F4/80 positive macrophages; however, CD3+ positive T cells were not changed. Importantly, RUUO normal and high salt mice had decreased vascular density. RUUO was also associated with renal fibrosis that was further elevated in RUUO mice fed a high salt diet. Overall, these findings demonstrate long-term renal tubular injury, inflammation, decreased vascular density, and renal fibrosis following reversal of unilateral ureter obstruction that could contribute to impaired sodium excretion and salt-sensitive hypertension.

CYP24A1 and CYP3A4 Levels, Renal, Hepatic Changes, and Incidence of Oxidative Stress in Tramadol-Alcohol Concomitant Misuse

Introduction Long-term population-based research has demonstrated a link between heavy drinking and the prevalence of kidney disorders; similarly, alcohol abuse has long been recognized as one of the main causes of liver diseases. A recent trend of concomitant use of the opioid analgesic Tramadol and alcohol among young males in sub-Saharan Africa has emerged. Aim and objectives This study's primary aim was to evaluate the incidence of concomitant use of alcohol and Tramadol among adult males, and observe the role of cytochrome p450 3A4 and CYP24A1 proteins and some oxidative stress indicators such as Malondialdehyde, lactate dehydrogenase, among study participants. The secondary aim was to evaluate the effect of alcohol and Tramadol concomitant use on Liver and kidney indices. Methods Our study population was male subjects with a history of Alcohol and Tramadol concomitant use. Liver enzymes, renal indices, oxidative stress markers, and CYP3A4 and CYP24A1 were determined from the serum of test and control participants. IBM Statistical Package for Social Sciences (SPSS) Statistics (version 21.0) was used to analyze the data obtained. Result One hundred and forty-two male subjects were included in this study. Eighty two (82) were males who admitted to abuse of Alcohol and Tramadol concomitantly for at least a year. The dose of Tramadol commonly used by Test subjects was 200 mg (43.9% of the test population), Tramadol users in the study population were largely Undergraduates (75.6% of Test participants). Gamma-glutamyl transferase and lactate dehydrogenase were significantly higher in Test subjects consuming Tramadol and alcohol combination (43.13±1.02 and 117.29±2.45, respectively) versus control (24.87±0.82; p=0.00 and 101.93±1.25; p=0.00). There was a significant decrease in serum bicarbonate levels of Test subjects (16.19±0.53) versus control (22.60±0.68; p=0.000). Cytochrome P450 24A1, was significantly lower in Test subjects (subjects consuming Tramadol and alcohol combination) (0.90±0.06; p=0.01), and significantly threefold higher in subjects with acute myeloid leukemia (AML) (5.16±0.5; p=0.00), when compared with values of non-drug/alcohol users that served as normal control (1.27±0.07). Conclusion The menace of Tramadol and alcohol concomitant abuse has taken a worrisome dimension in sub-Saharan Africa. In this study 77.4% of participants reported euphoria as reason for combining Alcohol and Tramadol, 6.5% claimed it was for faster pain relief and enhanced sexual performance or prolong penile erection was the response of 58.1% of the test participants. Findings of reduced CYP3A4 with Alcohol and Tramadol concomitant use could be associated with delayed drug inactivation and increased drug euphoric action.

The Combined Treatment of Glutathione Sodium Salt and Ascorbic Acid for Preventing Contrast-Associated Acute Kidney Injury in ST-Elevation Myocardial Infarction Patients Undergoing Primary PCI: A Hypothesis to Be Validated

The occurrence of Contrast-Associated Acute Kidney Injury (CA-AKI) in patients with ST-Elevation Myocardial Infarction (STEMI) has a negative impact on the length of hospital stay and mortality. Reactive Oxygen Species (ROS) release, along with vasoconstriction and hypoperfusion, play a key role in its development. To date, there is still no validated prophylactic therapy for this disease. The use of antioxidants, based on experimental and clinical studies, looks promising. Taking into consideration previous literature, we speculate that an early, combined and prolonged intravenous administration of both Glutathione (GSH) and ascorbic acid in STEMI patients undergoing primary Percutaneous Coronary Intervention (pPCI) may be of value in counteracting the occurrence of CA-AKI. We aimed at evaluating this hypothesis by applying a multicenter research protocol, using a double-blind randomized, placebo-controlled trial design. The primary endpoint will be to test the efficacy of this combined antioxidant therapy in reducing the occurrence of renal damage, in patients with acute myocardial infarction treated with pPCI. Furthermore, we will investigate the effect of the study compounds on changes in oxidative stress markers and platelet activation levels through bio-humoral analyses.

The protective effects of a novel AT2 receptor agonist, β-Pro7Ang III in ischemia-reperfusion kidney injury

BACKGROUND AND PURPOSE

This study investigated the reno-protective effects of a highly selective AT₂R agonist peptide, β-Pro⁷Ang III in a mouse model of acute kidney injury (AKI).

METHODS

C57BL/6 J mice underwent either sham surgery or unilateral kidney ischemia-reperfusion injury (IRI) for 40 min. IRI mice were treated with either β-Pro⁷Ang III or perindopril and at 7 days post-surgery the kidneys analysed for histopathology and the development of fibrosis and matrix metalloproteinase (MMP)-2 and -9 activity. The association of the therapeutic effects of β-Pro⁷Ang III with macrophage number and phenotype was determined in vivo and in vitro.

KEY RESULTS

Decreased kidney tubular injury, interstitial matrix expansion and reduced interstitial immune cell infiltration in IRI mice receiving β-Pro⁷Ang III treatment was observed at day 7, compared to IRI mice without treatment. This correlated to reduced collagen accumulation and MMP-2 activity in IRI mice following β-Pro⁷Ang III treatment. FACS analysis showed a reduced number and proportion of CD45⁺CD11b⁺F4/80⁺ macrophages in IRI kidneys in response to β-Pro⁷Ang III, correlating with a significant increase in M2 macrophage markers and decreased M1 markers at day 3 and 7 post-IR injury, respectively. In vitro analysis of cultured THP-1 cells showed that β-Pro⁷Ang III attenuated lipopolysaccharide (LPS)-induced tumour necrosis factor-α (TNF-α) and interleukin (IL)- 6 production but increased IL-10 secretion, compared to LPS alone.

CONCLUSION

Administration of β-Pro⁷Ang III via mini-pump improved kidney structure and reduced interstitial collagen accumulation, in parallel with an alteration of macrophage phenotype and anti-inflammatory cytokine release, therefore mitigating the downstream progression of ischemic AKI.