Predictivity of acute kidney injury risk scores for late kidney injury in patients with chronic coronary syndrome

Late rather than acute kidney injury after percutaneous coronary intervention (PCI) has been recently recognized as a predictor of future adverse events in patient with coronary artery disease. The risk-predicting models for acute kidney injury reported by Mehran et al., Bartholomew et al., and Tsai et al. were derived from a large cohort and externally validated, although the applicability of these models for predicting late kidney injury is unknown. A total of 327 patients undergoing elective PCI procedures were included. We calculated the three scores and tested their diagnostic ability for predicting late kidney injury (> 6 months after PCI), defined as an increase in creatinine levels ≥ 0.3 mg/dl or ≥ 50% from baseline. During the median follow-up period of 28 months, 27 (8.3%) patients had late kidney injury. All three scores significantly predicted late kidney injury, among which the score by Tsai et al. had a better diagnostic ability (area under the curve 0.83, best cut-off value 14, p < 0.001). With the best cut-off value, patients with Tsai score ≥ 14 had a significantly higher rate of late kidney injury than their counterpart (27.4% vs. 2.8%, p < 0.001). In conclusion, established risk scores for acute kidney injury may be useful for predicting late kidney injury after PCI in patients with chronic coronary syndrome.

Early life PCB138 exposure induces kidney injury secondary to hyperuricemia in male mice

Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants (POPs) that have adverse effects on human health. However, the long-term health effects and potential mechanism of neonatal exposure to PCBs are still unclear. In this study, nursing male mice exposed to PCB138 at 0.5, 5, and 50 μg/kg body weight (bw) from postnatal day (PND) 3 to PND 21 exhibited increased serum uric acid levels and liver uric acid synthase activity at 210 days of age. We also found an increased kidney somatic index in the 50 μg/kg group and kidney fibrosis in the 5 and 50 μg/kg groups. Mechanistically, PCB138 induced mitochondrial dysfunction and endoplasmic reticulum (ER) stress, which might have led to inflammatory responses, such as activation of the NF-κB (nuclear factor kappa-B) and NLRP3 (NOD-like receptor protein 3) pathways. The inflammatory response might regulate renal fibrosis and hypertrophy. In summary, this study reports a long-term effect of neonatal PCB exposure on uric acid metabolism and secondary nephrotoxicity and clarifies the underlying mechanism. Our work also indicates that early life pollutant exposure may be an important cause of diseases later in life.

Extracellular Vesicles That Herald the Scarcity of Oxygen

The natural, membrane-bound nanoscale particles, called extracellular vesicles (EVs) have emerged as an effective, versatile vehicle to transport desired drugs specifically to injury sites. Heralding the presence of the scarcity of oxygen, EVs produced from the cells upregulating the expression of the critical transcriptional regulator of hypoxia, HIF-1, can induce a response in ischemia-reperfusion-damaged cells to ameliorate renal tubular injury and inflammation.

The effects of exercise on kidney injury: the role of SIRT1

In patients with kidney injury, muscle mass and strength decrease with altered muscle protein synthesis and degradation along with complications such as inflammation and low physical activity. A treatment strategy to maintain muscle metabolism in kidney injury is important. One of the proposed strategies in this regard is exercise, which in addition to inducing muscle hypertrophy, reducing plasma creatinine and urea and decreasing the severity of tubal injuries, can boost immune function and has anti-inflammatory effects. One of the molecules that have been considered as a target in the treatment of many diseases is silent information regulator 1 (SIRT1). Exercise increases the expression of SIRT1 and improves its activity. Therefore, studies that examined the effect of exercise on kidney injury considering the role of SIRT1 in this effect were reviewed to determine the direction of kidney injury research in future regarding to its prevalence, especially following diabetes, and lack of definitive treatment. In this review, we found that SIRT1 can be one of renoprotective target pathways of exercise. However, further studies are needed to determine the role of SIRT1 in different kidney injuries following exercise according to the type and severity of exercise, and the type of kidney injury.

Effect of Eucommia ulmoides leaves on hyperuricemia and kidney injury induced by a high-fat/high-fructose diet in rats

OBJECTIVES

To investigate the protective and preventive treatment effects of Eucommia ulmoides leaves on a rat model of high-fat and high-fructose diet (HFFD) induced hyperuricemia and renal injury.

MATERIALS AND METHODS

Network pharmacology and molecular-docking methods were used to predict the effects and action mechanisms of the major components of E. ulmoides leaves on hyperuricemia. Combining literature collection, we used SciFinder and the Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) and Analysis Platform to collect E. ulmoides leaf flavonoid and iridoid components. Swiss Target Prediction, Similarity ensemble approach (SEA), GeneCards, and the Online Mendelian Inheritance in Man (OMIM) database were used to obtain core targets, and the Search Tool for Recurring Instances of Neighbouring Genes (STRING) protein database was used as core target for gene ontology enrichment Set and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Molecular docking was applied to predict the pathways regulating the metabolism of uric acid. The selected targets and targeting efficacy were validated using a rat model of hyperuricemia and renal injury induced by a high-fat and high-fructose diet.

RESULTS

A total of 32 chemical components with effective targets, which regulated the PI3K-AKT pathway and endocrine resistance, were collected. Molecular docking results showed that iridoids and flavonoids are bound to proteins related to inflammation and uric acid metabolism. In addition, it was verified via animal experiments that an E. ulmoides leaf extract ameliorated hyperuricemia, renal injury, and inflammation, which are closely related to the targets Interleukin- 6 (IL-6), Tumor necrosis factor-α (TNF-α), Toll-Like Receptor 4 (TLR4), and Glucose transporter 9 (GLUT9).

CONCLUSION

E. ulmoides leaf flavonoids and iridoids ameliorate hyperuricemia and uric-acid-induced inflammation through a multi-component, multi-target, and multi-pathway mechanism, which provides a theoretical basis for the development of therapeutics from E. ulmoides leaf components.

LncRNA NEAT1 knockdown ameliorates LPS-induced human kidney injury by mediating the miR-330-5p/FOXO3 axis

BACKGROUND

Sepsis is a systemic process with multiple inflammatory responses and organ injuries, particularly in the damage of the kidney. Recently, numerous studies suggest that long non-coding RNAs (lncRNAs) are involved in sepsis-related kidney injury. This study aimed to investigate the functional role and mechanism of lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) in sepsis-related kidney injury.

METHODS

Cell model of kidney injury was constructed in human kidney 2 (HK-2) cells with the treatment of lipopolysaccharide (LPS). The expression of NEAT1 was measured by quantitative real-time PCR (qRT-PCR). Cell viability was examined using CCK-8 assay. Flow cytometry was performed to detect cell apoptosis, and apoptosis-related proteins were quantified by western blot. The release of proinflammatory cytokines was assessed by ELISA. Oxidative stress was assessed by the levels of SOD and MDA using kits. The putative relationship between miR-330-5p and NEAT1 or FOXO3 was confirmed using dual-luciferase reporter assay, RIP assay and pull-down assay.

RESULT

The expression of NEAT1 was increased in LPS-treated HK-2 cells. LPS exposure promoted apoptotic rate, inflammatory responses and oxidative stress in HK-2 cells, which were largely ameliorated by NEAT1 knockdown. MiR-330-5p was verified as a target of NEAT1, and miR-330-5p inhibition reversed the effects of NEAT1 knockdown in LPS-treated HK-2 cells. Moreover, FOXO3 was a target of miR-330-5p, and miR-330-5p restoration-blocked cell apoptosis, inflammation and oxidative stress in LPS-treated HK-2 cells were recovered by FOXO3 overexpression.

CONCLUSION

NEAT1 downregulation meliorated LPS-induced HK-2 cell injuries partly by regulating the miR-330-5p/FOXO3 pathway.

Hyperthyroidism exacerbates ischemic reperfusion injury in the kidney

Thyroid hormones are critical regulators of vertebrate development and metabolism. Under hyperthyroid conditions, excess thyroid hormones induce expression of several enzymes and activities via activation of ligand-bound thyroid hormone receptors (TRs). Arginase (ARG) is downstream of a ligand-bound TR and overexpression of ARG2 induces the production of reactive oxygen species and subsequent exacerbation of kidney ischemia/reperfusion (I/R) injury. To clarify the association between I/R-induced kidney injury and hyperthyroidism, mice were pretreated with L-thyroxine (LT4) or vehicle alone, then subjected to I/R. Proximal tubular cell-specific conditional knockout of thyroid hormone receptor β (TRβcKO) mice was generated and the effects of I/R were analyzed. Hyperthyroidism enhanced tubular damage and fibrosis in the kidneys of mice after I/R. Hyperthyroidism induced tubular cell necroptosis following inflammatory cell accumulation in the kidney after I/R. ARG2 expressions and reactive oxygen species accumulated in the kidneys of hyperthyroid mice after I/R, but these changes were ameliorated in the kidneys of TRβcKO mice. Hyperthyroidism-enhanced kidney injury was ameliorated in the kidney of TRβcKO mice after I/R. These results suggest that excess thyroid hormones are disadvantageous for the kidney under ischemic stress. Overt hypothyroidism represents a severe thyroid hormone deficiency disease that requires LT4 treatment, while overreplacement or iatrogenic thyrotoxicosis might cause kidney injury.

SIRM-SIN-AIOM: appropriateness criteria for evaluation and prevention of renal damage in the patient undergoing contrast medium examinations-consensus statements from Italian College of Radiology (SIRM), Italian College of Nephrology (SIN) and Italian Association of Medical Oncology (AIOM)

The increasing number of examinations and interventional radiological procedures that require the administration of contrast medium (CM) in patients at risk for advanced age and/or comorbidities highlights the problem of CM-induced renal toxicity. A multidisciplinary group consisting of specialists of different disciplines—radiologists, nephrologists and oncologists, members of the respective Italian Scientific Societies—agreed to draw up this position paper, to assist clinicians increasingly facing the challenges posed by CM-related renal dysfunction in their daily clinical practice.

The major risk factor for acute renal failure following CM administration (post-CM AKI) is the preexistence of renal failure, particularly when associated with diabetes, heart failure or cancer.

In accordance with the recent guidelines ESUR, the present document reaffirms the importance of renal risk assessment through the evaluation of the renal function (eGFR) measured on serum creatinine and defines the renal risk cutoff when the eGFR is < 30 ml/min/1.73 m2 for procedures with intravenous (i.v.) or intra-arterial (i.a.) administration of CM with renal contact at the second passage (i.e., after CM dilution with the passage into the pulmonary circulation).

The cutoff of renal risk is considered an eGFR < 45 ml/min/1.73 m2 in patients undergoing i.a. administration with first-pass renal contact (CM injected directly into the renal arteries or in the arterial district upstream of the renal circulation) or in particularly unstable patients such as those admitted to the ICU.

Intravenous hydration using either saline or Na bicarbonate solution before and after CM administration represents the most effective preventive measure in patients at risk of post-CM AKI. In the case of urgency, the infusion of 1.4% sodium bicarbonate pre- and post-CM may be more appropriate than the administration of saline.

In cancer patients undergoing computed tomography, pre- and post-CM hydration should be performed when the eGFR is < 30 ml/min/1.73 m2 and it is also advisable to maintain a 5 to 7 days interval with respect to the administration of cisplatin and to wait 14 days before administering zoledronic acid.

In patients with more severe renal risk (i.e., with eGFR < 20 ml/min/1.73 m2), particularly if undergoing cardiological interventional procedures, the prevention of post-CM AKI should be implemented through an internal protocol shared between the specialists who treat the patient.

In magnetic resonance imaging (MRI) using gadolinium CM, there is a lower risk of AKI than with iodinated CM, particularly if doses < 0.1 mmol/kg body weight are used and in patients with eGFR > 30 ml/min/1.73 m2. Dialysis after MRI is indicated only in patients already undergoing chronic dialysis treatment to reduce the potential risk of systemic nephrogenic fibrosis.

Relevant Equine Renal Anatomy, Physiology, and Mechanisms of Acute Kidney Injury: A Review

Regulation of renal blood flow is by both extrinsic and intrinsic systems. Intrinsic regulation occurs via the afferent and efferent arterioles and tubuloglomerular feedback mechanisms with activation of the juxtaglomerular apparatus. Mechanisms of acute kidney injury are frequently associated with changes in renal blood flow. Acute tubular necrosis and apoptosis are common in horses following ischemic or toxic insults and in sepsis-associated acute kidney injury. Sepsis-associated renal injury often has a complex mechanism of disease involving both functional and obstructive changes in intrarenal circulation. Acute interstitial nephritis may occur following Leptospira sp infection or can be secondary to tubular necrosis.

Chikungunya virus as a trigger for different renal disorders: an exploratory study

INTRODUCTION

Chikungunya virus was detected in cases of acute chikungunya fever in renal tissue. However, chikungunya virus-related kidney injury still lacks characterization, and it is unknown whether the kidneys are reservoirs for the virus. We sought to detect histopathological changes and viral antigens in renal tissue, and to evaluate kidney injury markers in different phases of chikungunya fever.

METHODS

Two groups were evaluated in this exploratory study: patients with biopsy-proven kidney injury established after chikungunya fever, and patients with post-chikungunya fever chronic joint manifestations without known kidney injury, in whom we actively searched for kidney injury markers.

RESULTS

In the first group, 15 patients had kidney injury 0.5-24 months after chikungunya fever. The most frequent histopathological diagnoses were glomerular lesions. No viral antigens were detected in renal tissue. High-risk genotypes were detected in patients with atypical hemolytic uremic syndrome and focal and segmental glomerulosclerosis. In the second group, 114 patients had post-chikungunya fever joint manifestations on average for 35.6 months. Mean creatinine and proteinuria were 0.9 mg/dl and 71.5 mg/day, respectively. One patient had isolated hematuria. There was no indication for renal biopsy in this group.

CONCLUSIONS

Several histopathological features were found after chikungunya fever, without virus detection in renal tissue. These findings suggest that chikungunya virus may trigger kidney lesions with varying degrees of severity at different stages of infection. However, the probability that this virus replicates in the renal tissue seems unlikely.

Sepsis due to kidney injury caused by a toothpick: a case report and literature review

BACKGROUND

Toothpicks are common foreign bodies which may injure surrounding organs leading to a series of atypical symptoms. We present a rare clinical case that septicemia caused by a toothpick penetrated into the right kidney.

CASE PRESENTATION

We describe a 51-year-old patient who presented with right-sided backache and hematuresis for 2 days. Blood culture persistently grew Streptococcus gordonii. Ultrasound of the patient's urinary tract revealed a strong striated echo in the middle of the right kidney. Complete abdominal computed tomography revealed a duodenal foreign body penetrating into the right kidney. The toothpick was removed under endoscopy and hemostasis was given. Antibiotic treatment was upgraded. The patient was recovered and discharged from his stay on the fifteenth day.

CONCLUSIONS

Early identification of the etiology of sepsis can effectively alleviate patient's distress and reduce hospital stay. Clinicians should identify the source of sepsis through a medical history and examination.

Kidney disease and COVID-19 disease severity-systematic review and meta-analysis

We aimed to identify prevalence and association of comorbid chronic kidney disease (CKD), acute kidney injury (AKI) and utilization prevalence of continuous renal replacement therapy (CRRT) in COVID-19-hospitalized patients as a function of severity status. With the ongoing struggle across the globe to combat COVID-19 disease, published literature has described the role of kidney disease in COVID-19 patients based on single/multicenter experiences across the globe. We extracted data from observational studies describing comorbid CKD, AKI and CRRT and outcomes and severity of COVID-19-hospitalized patients from December 1, 2019-August 20, 2020 following PRISMA guidelines. Severity of COVID-19 includes intensive care unit admission, oxygen saturation < 90%, invasive mechanical ventilation utilization, in-hospital admission and mortality. Meta-analysis was performed using a random-effects model to calculate pooled estimates, and forest plots were created. In total, 29 studies with 15,017 confirmed COVID-19 patients were included. The overall prevalence of AKI was 11.6% [(430/3693)], comorbid CKD 9.7% [(1342/13,728)] and CRRT 2.58% [(102/3946)] in our meta-analysis. We also found higher odds of comorbid CKD (pooled OR: 1.70; 95%CI: 1.21-2.40; p = 0.002), AKI (8.28; 4.42-15.52; p < 0.00001) and utilization of CRRT (16.90; 9.00-31.74; p < 0.00001) in patients with severe COVID-19 disease. Conclusion Our meta-analysis suggests that comorbid CKD, AKI and utilization of CRRT were significantly associated with COVID-19 disease severity. Clinicians should focus on early triaging of COVID-19 patients with comorbid CKD and at risk for AKI to prevent complication and mortality.

High grade renal trauma: Does the mechanism of penetrating injury influence renal salvage rate?

BACKGROUND

Most of the data on high grade Traumatic renal injuries (TRI) has come from centres which predominantly encounter blunt trauma. Blunt and penetrating mechanisms are not analogous, and it is imprudent to blindly extrapolate management strategies between the two groups. In addition, within the broad group of penetrating mechanisms of injury there are also major differences between gunshot wounds (GSW) and stab wounds (SW). The aim of this comparative study of GSW and SW to the kidney is to quantify the impact of the mechanism of injury on nephrectomy rate in high grade TRI.

METHODS

A prospective trauma registry was interrogated retrospectively. All patients sustaining a high grade (Grade III to V) penetrating TRI were included. The diagnosis was made either with cross-sectional imaging or intra-operative findings. The nephrectomy rate of the different mechanisms of penetrating (GSW vs SW) TRI was compared in each grade.

RESULTS

A total of 28 GSW and 27 SW causing high grade TRIs (Grade III-V) were included over the 85 months of the study. GSW lead to a higher nephrectomy rate than SWs 50.0 vs 19%, (p = 0.023). When comparing grade for grade, Grade III: 20.0 (GSW) vs 21% (SW), (p = 1). Grade IV: 71 (GSW) vs 17%, (SW) (p = 0.058) and Grade V: 100 (GSW) vs 0%, (SW) (p = 0.28). When comparing Grade IV - V together, the difference is 85 (GSW) vs 15%, (SW) (p = 0.001).

CONCLUSION

On a grade to grade comparison GSWs have a much higher risk for nephrectomy than SW's in grade IV and V TRI. TRI secondary to GSWs appears to be an independent risk factor for nephrectomy in high grade injuries. The mechanism of penetrating TRI should be considered in future management algorithms and clinical approaches.

Nephrotoxicity evaluation of 3-monochloropropane-1,2-diol exposure in Sprague-Dawley rats using data-independent acquisition-based quantitative proteomics analysis

3-Monochloropropane-1,2-diol (3-MCPD), as a heat-induced food process contaminant, possesses strongly toxic effect on kidney. The present study focuses on characterizing the proteome and clarifying the underlying molecular regulatory mechanisms in a model of kidney injury in rats treated with 3-MCPD. Data-independent acquisition (DIA)-mass spectrometry (MS) based proteomics was used to identify dysregulated proteins in kidney tissues of Sprague-Dawley (SD) rats treated with 30 mg/kg/day 3-MCPD by gavage for 28 days. It was found that a total of 975 proteins were deregulated after 3-MCPD treatment. Bioinformatic analyses revealed that several enzymes related to the metabolisms of amino acid, lipid and carbohydrate in endogenous metabolism were altered in response to 3-MCPD treatment. Moreover, some proteins involved in these pathways were also changed, mainly including oxidative stress, oxidative phosphorylation, apoptosis and autophagy. Our study unravels the vital roles of loss of mitochondrial homeostasis and function and cell death pathways in the development of renal damage induced by 3-MCPD, which provides further valuable insights into the initiation and resolution of 3-MCPD nephrotoxicity. The proposed DIA-MS workflow not only provides a choice for proteomic analysis in toxicological research, but also provides a more comprehensive understanding of the molecular mechanisms of nephrotoxicity induced by toxins.

Regulation of FGF23: Beyond Bone

PURPOSE OF REVIEW

Fibroblast growth factor 23 (FGF23) is a bone- and bone marrow-derived hormone that is critical to maintain phosphate homeostasis. The principal actions of FGF23 are to reduce serum phosphate levels by decreasing kidney phosphate reabsorption and 1,25-dihydroxyvitamin D synthesis. FGF23 deficiency causes hyperphosphatemia and ectopic calcifications, while FGF23 excess causes hypophosphatemia and skeletal defects. Excess FGF23 also correlates with kidney disease, where it is associated with increased morbidity and mortality. Accordingly, FGF23 levels are tightly regulated, but the mechanisms remain incompletely understood.

RECENT FINDINGS

In addition to bone mineral factors, additional factors including iron, erythropoietin, inflammation, energy, and metabolism regulate FGF23. All these factors affect Fgf23 expression, while some also regulate FGF23 protein cleavage. Conversely, FGF23 may have a functional role in regulating these biologic processes. Understanding the bi-directional relationship between FGF23 and non-bone mineral factors is providing new insights into FGF23 regulation and function.

RNA sequencing reveals induction of specific renal inflammatory pathways in a rat model of malignant hypertension

In malignant hypertension, far more severe kidney injury occurs than in the "benign" form of the disease. The role of high blood pressure and the renin-angiotensin-aldosterone system is well recognized, but the pathogenesis of the renal injury of malignant hypertension (MH) remains incompletely understood. Using the rat model of two-kidney, one-clip renovascular hypertension in which some but not all animals develop MH, we performed a transcriptomic analysis of gene expression by RNA sequencing to identify transcriptional changes in the kidney cortex specific for MH. Differential gene expression was assessed in three groups: MH, non-malignant hypertension (NMH), and normotensive, sham-operated controls. To distinguish MH from NMH, we considered two factors: weight loss and typical renovascular lesions. Mean blood pressure measured intraarterially was elevated in MH (220 ± 6.5 mmHg) as well as in NMH (192 ± 6.4 mmHg), compared to controls (119 ± 1.7 mmHg, p < 0.05). Eight hundred eighty-six genes were exclusively regulated in MH only. Principal component analysis revealed a separated clustering of the three groups. The data pointed to an upregulation of many inflammatory mechanisms in MH including pathways which previously attracted relatively little attention in the setting of hypertensive kidney injury: Transcripts from all three complement activation pathways were upregulated in MH compared to NMH but not in NMH compared with controls; immunohistochemistry confirmed complement deposition in MH exclusively. The expression of chemokines attracting neutrophil granulocytes (CXCL6) and infiltration of myeloperoxidase-positive cells were increased only in MH rats. The data suggest that these pathways, especially complement deposition, may contribute to kidney injury under MH. KEY MESSAGES: The most severe hypertension-induced kidney injury occurs in malignant hypertension. In a rat model of malignant hypertension, we assessed transcriptional responses in the kidney exposed to high blood pressure. A broad stimulation of inflammatory mechanisms was observed, but a few specific pathways were activated only in the malignant form of the disease, notably activation of the complement cascades. Complement inhibitors may alleviate the thrombotic microangiopathy of malignant hypertension even in the absence of primary complement abnormalities.

Assessment of the renal angina index for the prediction of acute kidney injury in patients admitted to a European pediatric intensive care unit

BACKGROUND

Acute kidney injury (AKI) is associated with worse outcomes and increased morbidity and mortality in pediatric intensive care unit (PICU) patients. The renal angina index (RAI) has been proposed as an early prediction tool for AKI development.

OBJECTIVES

The objective was to evaluate outcomes of RAI-positive patients and to compare RAI performance with traditional AKI markers across different patient groups (medical/post-surgical). This was an observational retrospective study. All children admitted to a tertiary hospital PICU over a 3-year period were included. Electronic medical records were reviewed. Day 1 RAI was calculated, as was the presence and staging of day 3 AKI.

RESULTS

A total of 593 patients were included; 56% were male, the mean age was 55 months, and 17% had a positive RAI. This was associated with day 3 AKI development and worse outcomes, such as greater need for kidney replacement therapy, longer duration of mechanical ventilation, vasoactive support and PICU stay, and higher mortality. For all-stage kidney injury, RAI presented a sensitivity of 87.5% and a specificity of 88.1%. Prediction of day 3 all-stage AKI by RAI had an AUC=0.878; its performance increased for severe AKI (AUC = 0.93). RAI was superior to serum creatinine increase and KDIGO AKI staging on day 1 in predicting severe AKI development. The performance remained high irrespective of the type of admission.

CONCLUSIONS

The RAI is a simple and inexpensive tool that can be used with medical and post-surgical PICU patients to predict AKI development and anticipate complications, allowing for the adoption of preventive measures.

Calcitriol Treatment Attenuates Uric Acid-Induced Kidney Injury via Super Oxide Dismutase-1 (SOD-1) Upregulation and Fibrosis Reduction

Background

Hyperuricemia induces nephropathy through the mediation of oxidative stress, tubular injury, inflammation, and fibrosis. The high uric acid level is associated with the reduction of vitamin D levels. However, the reno-protective effects of this vitamin in hyperuricemia condition remain unknown. This study aimed to elucidate calcitriol treatment in a uric acid-induced hyperuricemia mice model.

Methods

: Uric acid (125 mg/kg body weight [BW]) was administered intraperitoneally for 7 (UA7) and 14 (UA14) days. Calcitriol (0.5 g/kg BW) was intraperitoneally injected for the following seven days, after 14 days of uric acid induction (UA14VD7 group). The control group received NaCl 0.9%, by the same route. Serum creatinine was measured using calorimetric method, and uric acid levels were assessed using enzymatic calorimetric assay. Tubular injury and fibrosis were assessed using PAS and Sirius red staining. RT-PCR and real-time reverse transcription PCR were carried out for the analyses of SOD-1, Collagen-1, and TGF-1 mRNA expression in the kidney. Immunostaining of super oxide dismutase type 1 (SOD-1) was performed to detect its expression in the kidney.

Results

Uric acid and creatinine levels markedly increased in UA14 groups, followed by an exacerbation of tubular injury. RT-PCR revealed the upregulation of Collagen-1 and TGF-1, along with the downregulation of SOD-1. Calcitriol treatment attenuated the injury with reducing uric acid and creatinine levels, as well as tubular injury. This was associated with lower Collagen-1 and TGF-1 mRNA expression compared to the UA7 and UA14 groups. SOD-1 was upregulated in epithelial cells in the UA14VD7 group.

Conclusion

Calcitriol treatment after uric acid induction may attenuate kidney injury through upregulation of SOD-1 and downregulation of Collagen-1 and TGF-1 gene expression.

Role of air pollution in chronic kidney disease: an update on evidence, mechanisms and mitigation strategies

Air pollution results from a variable and complex mixture of harmful gases and suspended particles and is the most worrisome of all environmental hazards. It is implicated in several non -communicable diseases and is recognized to be a public health problem. Though the initial exposure to air pollution is through the respiratory system, kidneys are thought to be exposed to higher concentrations owing to their filtration function. Chronic kidney disease is the insidious end result of several disease processes which cumulatively form a large healthcare burden, particularly in low- and middle-income countries. There is a growing body of evidence that air pollution may be a contributing factor that leads to CKD by not only its direct effects, but can also compound the effect of other factors/diseases causing kidney injury. PM_2.5 exposure particularly has been implicated, although there is some evidence regarding other air pollutants as well. These pollutants are thought to act on kidneys through several interlinked systemic pathways and mechanisms which individually and collectively damage the nephrons. Long-term exposures seem to gradually diminish renal function and lead to end-stage renal disease. A thorough understanding of the mechanism of kidney injury is the key for formulating and implementing effective strategies for reducing this burden. Maintaining the air quality, promoting education, improving health quality and promotion of targeted nephroprotective measures through effective policy and research support are required in addressing this global public health problem.

Ectodomain shedding by ADAM proteases as a central regulator in kidney physiology and disease

Besides its involvement in blood and bone physiology, the kidney's main function is to filter substances and thereby regulate the electrolyte composition of body fluids, acid-base balance and toxin removal. Depending on underlying conditions, the nephron must undergo remodeling and cellular adaptations. The proteolytic removal of cell surface proteins via ectodomain shedding by A Disintegrin and Metalloproteases (ADAMs) is of importance for the regulation of cell-cell and cell-matrix adhesion of renal cells. ADAM10 controls glomerular and tubule development in a Notch1 signaling-dependent manner and regulates brush border composition. ADAM17 regulates the renin angiotensin system and is together with ADAM10 involved in calcium phosphate homeostasis. In kidney disease ADAMs, especially ADAM17 contribute to inflammation through their involvement in IL-6 trans-signaling, Notch-, epithelial growth factor receptor-, and tumor necrosis factor α signaling. ADAMs are interesting drug targets to reduce the inflammatory burden, defective cell adhesion and impaired signaling pathways in kidney diseases.

Early kidney injury predicts disease progression in patients with COVID-19: a cohort study

BACKGROUND

The receptor of severe respiratory syndrome coronavirus 2 (SARS-CoV-2), angiotensin-converting enzyme 2, is more abundant in kidney than in lung tissue, suggesting that kidney might be another important target organ for SARS-CoV-2. However, our understanding of kidney injury caused by Coronavirus Disease 2019 (COVID-19) is limited. This study aimed to explore the association between kidney injury and disease progression in patients with COVID-19.

METHODS

A retrospective cohort study was designed by including 2630 patients with confirmed COVID-19 from Huoshenshan Hospital (Wuhan, China) from 1 February to 13 April 2020. Kidney function indexes and other clinical information were extracted from the electronic medical record system. Associations between kidney function indexes and disease progression were analyzed using Cox proportional-hazards regression and generalized linear mixed model.

RESULTS

We found that estimated glomerular filtration rate (eGFR) and creatinine clearance (Ccr) decreased in 22.0% and 24.0% of patients with COVID-19, respectively. Proteinuria was detected in 15.0% patients and hematuria was detected in 8.1% of patients. Hematuria (HR 2.38, 95% CI 1.50-3.78), proteinuria (HR 2.16, 95% CI 1.33-3.51), elevated baseline serum creatinine (HR 2.84, 95% CI 1.92-4.21) and blood urea nitrogen (HR 3.54, 95% CI 2.36-5.31), and decrease baseline eGFR (HR 1.58, 95% CI 1.07-2.34) were found to be independent risk factors for disease progression after adjusted confounders. Generalized linear mixed model analysis showed that the dynamic trajectories of uric acid was significantly related to disease progression.

CONCLUSION

There was a high proportion of early kidney function injury in COVID-19 patients on admission. Early kidney injury could help clinicians to identify patients with poor prognosis at an early stage.

Baicalin protects against zearalenone-induced chicks liver and kidney injury by inhibiting expression of oxidative stress, inflammatory cytokines and caspase signaling pathway

Zearalenone (ZEA) is a secondary metabolite produced by fungi such as Fusarium and Fusarium flavum, which is classified as a mycotoxin. Crops and feed in a humid surrounding are widely polluted by ZEA, which further endangering the healthful aquaculture of poultry and even human health. Up to now, prevention and cure of mycotoxicosis is still a crucial subject of poultry husbandry. Baicalin (BAI) is a flavonoid refined from dried roots of Scutellaria baicalensis possessing the function of hepatoprotective, anti-inflammatory, anti-oxidant, and anti-atherosclerotic efficacies.etc. But whether Baicalin also has a protective effect against ZEA intoxication is unclear. Therefore, the aim of this study was to establish a model of ZEA-induced toxic injury in chicks, and then to investigate the way in which Baicalin plays a protective role in the mechanism of ZEA-induced liver and kidney injury in chicks. The results exhibit that Baicalin could not only significantly decrease aspartate aminotransferase (AST) , alanine aminotransferase (ALT) and creatinine (Cre) levels in serum, but also ameliorate ZEA-induced pathologic changes of liver and kidney. Baicalin could also significantly regulate ZEA-induced the changes of catalase (CAT) , malondialdehyde (MDA) , total sulfhydryl group , except for glutathione peroxidase (GSH-px) , and inhibit the mRNA levels of inflammatory cytokines tumor necrosis factor-α (TNF-α) , interleukin-1β (IL-1β) and cyclooxygenase-2 (COX-2) with caspase-3 and caspase-11 in the caspase signaling pathway , meanwhile inhibit the cell apoptosis in immunohistochemistry. In summary, we successfully established a model of ZEA-induced liver injury in chicks, and confirm that Baicalin can reduce ZEA-induced liver and kidney injury in chicks. The mechanism of these effects is via inhibiting inflammation, oxidative stress and apoptosis, which also indicates the potential applicability of Baicalin for the prevention and treatment of ZEA-induced toxicity in chicks.

Urinary level of un-metabolized parabens in women working in beauty salons

Parabens are a group of chemical additive extensively utilized in various health care products and ubiquitously observed in the different environmental matrixes. Nevertheless, the exposure of women working in beauty salons to these pollutants is not well-documented. For this purpose, 50.00 women working in beauty salons were chosen as the exposed group (EG) and 35.00 housewives were chosen as the control group (GC). The concentration of methyl paraben (MeP), ethyl paraben (EtP), butyl paraben (BuP), propyl paraben (PrP), benzyl paraben (BzP), heptyl paraben (HepP), and para-hydroxybenzoic acid (4-HB) metabolite were quantified in the collected urine samples. It was seen that paraben sexist with a high detection frequency (DF) in the urine of women working in beauty salons. The results also revealed that the significant difference between the urinary parabens level in the EG and CG (P value < 0.05). The median concentration of Σparaben and HB-4 metabolite in the before exposure (BE) samples was 124.00 and 219.00 μg/L, while in the after exposure (AE) samples, it was 156.00 and 249.00 μg/L, respectively. Moreover, the parabens levels in the AE samples were considerably higher than in BE samples in women working in beauty salons (P value < 0.05). This research also documented that "personal care products (PCPs) usage" can be known as a leading factor for the urinary paraben level in the studied individuals. The median total estimated daily intakes (TEsDI) for MeP, EtP, and PrP for the studied women were obtained as 8.02, 4.57, and 7.88 μg/L respectively. Also, a significant and positive association was observed between EtP, PrP as well as BuP and 8-OhdG (as a DNA oxidative stress biomarker) (P value < 0.01). Further, a significant and positive association was found between EtP as well as BuP and some biomarkers of kidney damage (like uTIMP-1 and uKim-1). Accordingly, it can be stated that women working in beauty salons are at a high risk in terms of DNA oxidative stress and kidney damage.

Is the prognosis of congenital single functioning kidney benign? A population-based study

BACKGROUND

We investigated the risk of kidney injury among adolescents with and without a congenital single functioning kidney (SFK).

METHODS

This retrospective study is based on a medical evaluation database of 17-year-old Israeli conscripts, born during 1989-1999. Those with congenital SFK diagnosis, verified by a pediatric nephrologist's review of the original military medical committee classifications, were compared to the rest of the cohort. Kidney injury (KI) was defined as proteinuria, high blood pressure (BP), or estimated glomerular filtration rate (eGFR) < 90 ml/min/1.73 m² prior to army recruitment. Risk factors for KI were examined using logistic regression.

RESULTS

Of 979,630 screened candidates, 353 were diagnosed with SFK. The yearly incidence of SFK gradually increased in the first years of the study, reaching a plateau in 1995 (5.5 ± 1.2/10,000 births/year). The male to female ratio was 2.7:1. Concomitant genital malformations were documented in 5.5% of those with SFK. KI was more prevalent in the SFK than the control group (42.2% vs. 23.5%, p < 0.001). All three components of KI were more common in the SFK than the control group: high BP (31.7% vs. 23.1%, p < 0.001), proteinuria (18.2% vs. 0.4%, p < 0.001), and eGFR <90 ml/min/1.73m² (12.0% vs 0.1%, p < 0.001). Multivariate analysis of the SFK group revealed associations of higher mean BMI, male sex, and smaller ultrasonographic kidney length with KI.

CONCLUSIONS

This large population-based study documents a significant risk for KI among adolescents with SFK. Obesity represents a major modifiable risk factor for KI, implicating the need for closer follow-up in this group during childhood.

Retrospective evaluation of children with unilateral renal agenesis

BACKGROUND

Children born with unilateral renal agenesis (URA) are thought to have a risk of developing hypertension, proteinuria, and progressive chronic kidney disease (CKD). The present study aimed to evaluate the long-term prognosis and clinical characteristics of children with URA.

METHODS

The study included 171 patients aged < 18 years diagnosed as URA who were followed-up for ≥ 1 year and 121 healthy controls matched for age, gender, and BMI.

RESULTS

Median age at diagnosis was 2 years (IQR: 1 month-16 years) and the incidence of URA in males (65.4%) was higher than in females. Among the patients, 21 (12.2%) had other urinary system anomalies. It was noted that 2.3% of the patients had proteinuria, 15.2% had hyperfiltration, and 2.9% had CKD. Hypertension based on ambulatory blood pressure monitoring (ABPM) was diagnosed in 18 (10.5%) of the patients, of whom 10 had masked hypertension. Diastolic blood pressure in the URA patients was significantly higher than in the healthy controls. The incidence of hypertension and CKD was significantly higher in the patients with other urinary system anomalies.

CONCLUSIONS

Patients with a single functional kidney should be periodically evaluated throughout their lifetime for urine protein, blood pressure, and kidney functions. The most remarkable finding of this study is the importance of the use of ABPM for evaluating blood pressure in pediatric URA patients, especially for the detection of masked hypertension and the non-dipper phenomenon, which cannot be achieved with office blood pressure measurement.