The effect of isovitexin on lipopolysaccharide-induced renal injury and inflammation by induction of protective autophagy

Chronic kidney disease (CKD) is a systemic inflammatory syndrome that includes tubulointerstitial inflammation. Lipopolysaccharide (LPS), the outer membrane of Gram-negative bacteria, can increase reactive oxygen species production (ROS) that triggers cell inflammation. Isovitexin (IV) is a flavone that has the potential for anticancer, antioxidant, and anti-inflammatory. This study aimed to hypothesize that IV inhibited LPS-induced renal injury in vitro and in vivo. In vitro study, IV prevented LPS-induced ROS production and increased cell viability on SV40-MES-13 cells. Additionally, IV ameliorated mitochondrial membrane potential, downregulated inflammation and pyroptosis factors on LPS treatment. We found that LPS treatment reduced the expression of autophagy, however, this effect was reversed by IV. In vivo study, the renal injury model in C57BL/6 mice cotreatment with IV was examined. In addition, IV decreased LPS-induced glomerular atrophy and reduced inflammation-related cytokines releases. Further showed that IV could significantly reduce LPS-induced inflammation and pyroptosis factors in mice. Under the immunostaining, increased fluorescence of LC3 autophagy-related protein was recovered by IV. In summary, IV ameliorated renal injury, inflammation and increased protected autophagy by anti-ROS production, anti-inflammation, and anti-pyroptosis. In the future, the safety of isovitexin as a novel perspective for CKD patients should be evaluated in further clinical studies.

Hydrogen sulfide in the experimental models of arterial hypertension

Hydrogen sulfide (H₂S) is the third member of gasotransmitter family together with nitric oxide and carbon monoxide. H₂S is involved in the regulation of blood pressure by controlling vascular tone, sympathetic nervous system activity and renal sodium excretion. Moderate age-dependent hypertension and endothelial dysfunction develop in mice with knockout of cystathionine γ-lyase (CSE), the enzyme involved in H₂S production in the cardiovascular system. Decreased H₂S concentration as well as the expression and activities of H₂S-producing enzymes have been observed in most commonly used animal models of hypertension such as spontaneously hypertensive rats, Dahl salt-sensitive rats, chronic administration of NO synthase inhibitors, angiotensin II infusion and two-kidney-one-clip hypertension, the model of renovascular hypertension. Administration of H₂S donors decreases blood pressure in these models but has no major effects on blood pressure in normotensive animals. H₂S donors not only reduce blood pressure but also end-organ injury such as vascular and myocardial hypertrophy and remodeling, hypertension-associated kidney injury or erectile dysfunction. H₂S level and signaling are modulated by some antihypertensive medications as well as natural products with antihypertensive activity such as garlic polysulfides or plant-derived isothiocyanates as well as non-pharmacological interventions. Modifying H₂S signaling is the potential novel therapeutic approach for the management of hypertension, however, more experimental clinical studies about the role of H₂S in hypertension are required.

The protective mechanism of a novel polysaccharide from Lactobacillus-fermented Nostoc commune Vauch. on attenuating cadmium-induced kidney injury in mice

A novel polysaccharide (NCVP-F) from Lactobacillus-fermented Nostoc commune Vauch. was obtained to investigate its underlying mechanism in cadmium-induced kidney injury. Results indicated that in comparison with NCVP, NCVP-F with lower molecular weight of 365.369 kDa, exhibited higher mole percentage of Man and Glc-UA, whereas slightly lower mole percentage of other monosaccharides. NCVP-F is a α-pyran polysaccharide similar to NCVP. Meanwhile, NCVP-F can more effectively alleviate hepatorenal injury (ALT, AST, TG, BUN and SCr) and kidney tissue lesions in Cd-injured mice model by increasing antioxidant enzyme activity (SOD, GSH and GSH-Px), inhibiting cytokines levels (IL-6, IL-1β, TNF-α and IL-18). In addition, NCVP-F effectively inhibited apoptosis proteins (Bax, cytochrome c, a-caspase-9 and a-caspase-3) and enhanced anti-apoptotic protein (Bcl-2) probably via activating PI3K/AKT/mTOR pathway in the Cd-injury kidney. Furthermore, 16S rRNA sequencing results indicated that NCVP-F better enriched Lachnospiraceae, reduced Muribaculaceae, Alloprevotella and Blautia to regulate Cd-induced gut microbiota disorders, which was probably down-regulated 7 pathways including apoptosis and lipopolysaccharide biosynthesis, and up-regulated 63 pathways, such as carbohydrate metabolism and lipid metabolism. This study suggested that applying functional NCVP-F prepared by biotransformation with low molecular weight might be more beneficial.

HucMSC exosomes attenuate partial bladder outlet obstruction-induced renal injury and cell proliferation via the Wnt/β-catenin pathway

Bladder outlet obstruction (BOO) can cause serious complications including kidney damage; nevertheless, there are currently no animal models for studying BOO-induced kidney damage. Mesenchymal stem cells (MSCs) are widely used in therapeutic studies of renal fibrosis. However, MSC-derived exosomes show improved safety profile and more controllable characteristics compared with those of MSCs. Herein, we established a kidney injury mouse model of partial bladder outlet obstruction (PBOO) and evaluated the effects of human umbilical cord MSC-derived exosomes (hucMSC-Exos) on PBOO-induced reflux kidney injury in this model. Exosomes were isolated from a hucMSC-conditioned medium, purified by ultracentrifugation, and examined. Living image was performed to indicate the distribution of hucMSC-Exos. The PBOO-treated mice interacted with PBS (phosphate-buffered saline) or hucMSC-Exos. Morphologic changes and expression of interstitial-fibrosis-related, cell proliferation and Wnt/β-catenin signaling-pathway indices were evaluated. At 7 days after induction of PBOO, structural destruction of renal tubules was observed. Expression of the interstitial markers and the cellular-proliferation index increased significantly in the PBOO group compared with the control group (p < 0.05). The isolated exosomes were 30-150 nm in diameter, showing a round shape and bilayer membrane structure with CD63, TSG101, Alix expressed, enriched in the kidney of the PBOO group. Administering hucMSC-Exos to post-PBOO mice reversed renal injury and suppressed expression of Wnt/β-catenin signaling pathway-related proteins. hucMSC-Exos inhibited PBOO-induced kidney injury and cellular proliferation and suppressed the Wnt/β-catenin signaling pathway. Our findings will spur the development of novel hucMSC-Exo-mediated therapies for treating patients with renal fibrosis.

Exploring the nephrotoxicity of sulfur-containing derivatives in sulfur-fumigated Panacis Quinquefolii Radix based on chemical profiling and untargeted metabolomics

ETHNOPHARMACOLOGICAL RELEVANCE

Panacis Quinquefolii Radix (PQR) is often illegally sulfur fumigated to extend shelf life and improve appearance, but existing regulations of detecting SO₂ residues do not accurately identify desulfurized sulfur-fumigated PQR (SF-PQR). Although sulfur-containing derivatives (SCDs) have been reported in some sulfur-fumigated herbs, there is a lack of research on the generation mechanisms and toxicity of SCDs. Our previous study reported the nephrotoxicity of SF-PQR, and there is an urgent necessity to illuminate the mechanism of toxicity as well as its association with SCDs.

AIM OF THE STUDY

To investigate the transformation pattern of chemical components and SCDs in SF-PQR, and to disclose the linkage between SCDs and SF-PQR nephrotoxicity.

MATERIALS AND METHODS

The extracts of PQR (before and after SF) were detected by the UPLC-LTQ-Orbitrap-MS method, and SCDs were screened as quality markers (Q-markers). The composition of sulfur combustion products was examined by ion chromatography to exploit the conversion mechanism of SCDs. After administration of PQR extracts to mice for two weeks, serum was collected for GC-MS-based untargeted metabolomics study to mine for differential metabolites. The upstream genes were traced by network analysis to probe toxicity targets. Molecular docking was used to uncover the interactions between SCDs and the targets.

RESULTS

Thirty-three compounds were identified and 11 SCDs of saponins were screened, including four SO₃ sulfonation products and five H₂SO₃ sulfonation products. Metabolomics study showed significant alterations in serum biochemistry of SF-PQR group, with substantial increases in fumarate and 2-heptanone content, and induced disturbances in glycerolipid metabolism and phenylalanine, tyrosine, and tryptophan biosynthesis in mice. Network analysis revealed that the key toxicity targets were DECR1, PLA2G1B, and CAT. Molecular docking indicated that SCDs had stable interaction forces with the above three toxicity targets.

CONCLUSION

SF-PQR caused kidney damage by affecting glycerolipid metabolism and phenylalanine, tyrosine, and tryptophan biosynthesis. Eleven SCDs were potential nephrotoxic substances and Q-markers for identifying SF-PQR. This study is the first to systematically elucidate the mechanism of SF-PQR-related nephrotoxicity, providing a robust basis for the construction of new quality control standards and a global prohibition of sulfur fumigation.

Using Serum Cystatin C to Predict Acute Kidney Injury Following Infant Cardiac Surgery

Acute kidney injury (AKI) following cardiopulmonary bypass (CPB) is associated with increased morbidity and mortality. Serum Cystatin C (CysC) is a novel biomarker synthesized by all nucleated cells that may act as an early indicator of AKI following infant CPB. Prospective observational study of infants (< 1 year) requiring CPB during cardiac surgery. CysC was measured at baseline and 12, 24, 48, and 72 h following CPB initiation. Each post-op percent difference in CysC (e.g. %CysC_12h) from baseline was calculated. Clinical variables along with urine output (UOP) and serum creatinine (SCr) were followed. Subjects were divided into two groups: AKI and non-AKI based upon the Kidney Disease Improving Global Outcomes (KDIGO) classification. AKI occurred in 41.9% (18) of the 43 infants enrolled. Patient demographics and baseline CysC levels were similar between groups. CysC levels were 0.97 ± 0.28 mg/L over the study period, and directly correlated with SCr (R = 0.71, p < 0.0001). Although absolute CysC levels were not significant between groups, the %CysC_12h was significantly greater in the AKI group (AKI: - 16% ± 22% vs. Non-AKI - 28% ± 9% mg/L; p = 0.003). However, multivariate analysis demonstrated that a lower UOP (Odds Ratio:0.298; 95% CI 0.073, 0.850; p = 0.02) but not %CysC_12h was independently associated with AKI. Despite a significant difference in the %CysC_12h, only UOP was independently associated with AKI. Larger studies of a more homogenous population are needed to understand these results and to explore the variability in this biomarker seen across institutions.

Sodium acetate ameliorates cisplatin-induced kidney injury in vitro and in vivo

Cisplatin is an effective chemotherapeutic drug against tumors. Studies often report on the improvement of kidney injury by probiotics or short-chain fatty acids (SCFAs); however, the effects of SCFAs on cisplatin-induced kidney injury are rarely studied. The aim of this study is to evaluate the function of sodium acetate on preventing cisplatin-induced kidney injury. Cell viability was detected by MTT assay. SA-β-gal staining was performed to investigate premature senescence. Reactive oxygen species (ROS) production was analyzed by H₂DCFDA staining. Propidium iodide (PI) staining was analyzed by cell cycle. Protein expression was determined by Western blot assay. Annexin Ⅴ/PI staining was used to investigate cisplatin-induced apoptosis. Tumor growth and kidney injury were evaluated in C57BL/6 mice. Sodium acetate ameliorated cisplatin-induced premature senescence and ROS production in SV40 MES-13 glomerular cells, NRK-52E renal tubular cells, and NRK-49F renal fibroblast cells. Cisplatin-induced cell cycle arrest was inhibited by sodium acetate in SV40 MES-13 and NRK-49F cells. Sodium acetate alleviated cisplatin-induced apoptosis in vivo and in vitro but not cisplatin-induced fibrosis. Our study demonstrated that sodium acetate inhibited cisplatin-induced premature senescence, cell cycle arrest, and apoptosis by attenuating ROS production. This strategy may be useful in the treatment of cisplatin-induced kidney injury.

Avasopasem manganese (GC4419) protects against cisplatin-induced chronic kidney disease: An exploratory analysis of renal metrics from a randomized phase 2b clinical trial in head and neck cancer patients

Head and neck squamous cell carcinoma (HNSCC) patients treated with high-dose cisplatin concurrently with radiotherapy (hdCis-RT) commonly suffer kidney injury leading to acute and chronic kidney disease (AKD and CKD, respectively). We conducted a retrospective analysis of renal function and kidney injury-related plasma biomarkers in a subset of HNSCC subjects receiving hdCis-RT in a double-blinded, placebo-controlled clinical trial (NCT02508389) evaluating the superoxide dismutase mimetic, avasopasem manganese (AVA), an investigational new drug. We found that 90 mg AVA treatment prevented a significant reduction in estimated glomerular filtration rate (eGFR) three months as well as six and twelve months after treatment compared to 30 mg AVA and placebo. Moreover, AVA treatment may have allowed renal repair in the first 22 days following cisplatin treatment as evidenced by an increase in epithelial growth factor (EGF), known to aid in renal recovery. An upward trend was also observed in plasma iron homeostasis proteins including total iron (Fe-blood) and iron saturation (Fe-saturation) in the 90 mg AVA group versus placebo. These data support the hypothesis that treatment with 90 mg AVA mitigates cisplatin-induced CKD by inhibiting hdCis-induced renal changes and promoting renal recovery.

Liraglutide ameliorates gentamicin-induced acute kidney injury in rats via PGC-1α- mediated mitochondrial biogenesis: Involvement of PKA/CREB and Notch/Hes-1 signaling pathways

Acute kidney injury (AKI) is a challenging side effect which may clinically impede the use of gentamicin (GM). The present study explored the impact of liraglutide (Lir) on GM-induced kidney injury in rats. Lir (0.2 and 0.4 mg/kg, s.c) was given for 10 days (a dose/day) starting 3 days before giving GM (100 mg/kg, i.p) once daily for 7 days. Interestingly, Lir notably ameliorated GM-induced elevated levels of renal injury markers; urea and creatinine. Moreover, Lir remarkably mitigated malondialdehyde (MDA) level and elevated glutathione (GSH) level as well as superoxide dismutase (SOD) activity. Also, Lir pre-treatment notably diminished inflammatory markers levels; interleukin-1β (IL-1β), tumor necrosis factor alpha (TNF-α), vascular cell adhesion molecule (VCAM), monocyte chemoattractant protein 1 (MCP-1) and interferon gamma (INF-γ). In addition, Lir significantly replenished expression of Peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1α), Protein kinase A (PKA), cAMP response element-binding protein (CREB), nuclear Nuclear factor erythroid 2-related factor 2 (Nrf2), heme Oxygenase-1 (HO-1), B-cell lymphoma 2 (Bcl-2), and remarkably attenuated expression of Notch homolog 1 (Notch1), Hairy and enhancer of split-1 (Hes-1), Bcl-2-associated X (Bax), cleaved caspase 3 and nuclear Nuclear factor Kappa B (NF-κB (p65)). The nephroprotective activity of Lir was further confirmed by histopathological examination as well as transmission electron microscopy (TEM). In conclusion Lir achieved its nephroprotective effects through the amelioration of oxidative stress, inflammatory and apoptotic manifestations. It is worth-mentioning that the current study is the first to focus on the involvement of mitochondrial biogenesis and its upstream regulators, PKA/CREB and Notch/Hes-1 signaling pathways in the nephroprotective potentials of Lir. The attenuation of the aforementioned injurious aspects is partially attributed to the improvement of the mitochondrial status as demonstrated by elevated PGC-1α expression via acceleration of PKA/CREB and abatement of Notch/Hes-1 signaling pathways.

Onconephrology: Update in Anticancer Drug-Related Nephrotoxicity

The relation that connects cancer and renal damage is bidirectional and this renal damage worsens quality of life and increases morbidity in high-complexity patients such as patients with cancer and kidney injury. Strikingly, in the last decade, the treatment of advanced cancer has clearly advanced in terms of new therapeutic strategies with the ability to transform the advanced metastatic cancer in a chronic condition. In this new era of cancer therapies, cancer treatment including conventional chemotherapy, targeted cancer agents and immunotherapies among others are significantly associated with kidney injury. Renal toxicity that is currently seen in onconephrology departments is in part related to the new therapies such as immunotherapy, and to the prolonged survival achieved at the expense of increasing therapy lines, and a combination of different drugs. In this review, we will discuss in a practical way, nephrotoxicity caused by the main oncospecific treatments such as classical chemotherapy agents, targeted therapies, and immunotherapy. In addition, strategies for prevention and management recommendations in patients with malignancies and kidney disease will also be addressed.

Renoprotective anti-CD45RB antibody induces B cell production in systemic lupus erythematosus based on single-cell RNA-seq analysis

OBJECTIVE

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease that commonly affects the kidney. Single-cell RNA sequencing (scRNA-seq) technology is a powerful tool for characterizing individual cells and elucidating biological mechanisms at the cellular level. The purpose of this study was to identify the mechanism underlying kidney injury in SLE using scRNA-seq technology.

METHODS

scRNA-seq data of peripheral blood mononuclear cells (PBMCs) in SLE were retrieved from the GEO database, followed by batch effect elimination, dimensionality reduction, cluster analysis, cell annotation and enrichment analysis. A model of SLE was developed in NZB/WF1 mice. Effects of anti-CD45RB antibody on the SLE-induced kidney injury were evaluated, and we measured the distribution of regulatory T cells and B cells in mouse spleen and kidney tissues, levels of kidney function-related indexes, deposition of IgG and C3 in the glomeruli, and the levels of inflammatory cytokines.

RESULTS

CD45RB was a specific marker gene of B cell clusters and had influence on the B cells. anti-CD45RB antibody treatment induced regulatory B cells and consequently arrested the kidney injury caused by SLE. In addition, depletion of regulatory T cells was found to partially undermine the alleviatory effect of anti-CD45RB antibody on SLE-induced kidney injury.

CONCLUSION

Collectively, our data suggest that anti-CD45RB antibody can prevent the SLE-induced kidney injury, pointing to anti-CD45RB antibody as a potential therapeutic strategy in kidney injury-related disease.

microRNA-338-3p suppresses lipopolysaccharide-induced inflammatory response in HK-2 cells

BACKGROUND

Inflammation is the most common cause of kidney damage, and inflammatory responses in a number of diseases are mediated by microRNA-338-3p (miR-338-3p). However, there are only a few reports which described the regulation of miR-338-3p in human proximal tubular cells. The goal of this study was to see how miR-338-3p affected lipopolysaccharide (LPS)-caused inflammatory response in HK-2 cells.

METHODS

LPS was used to construct an inflammatory model in HK-2 cells. miR-338-3p mimic was used to increase the levels of miR-338-3p in HK-2 cells. MTT, JC-1 staining, and apoptosis assays were used to detect cell viability, mitochondrial membrane potential (MMP), and apoptosis, respectively. The production of inflammatory factors and the levels of p38, p65, phospho-p65, phospho-p38, Bax, Bcl-2, cleaved caspase-9, and cleaved caspase-3 were investigated using real-time polymerase chain reaction, western blotting, or enzyme-linked immunosorbent assay.

RESULTS

The levels of miR-338-3p were significantly lower in serum from patients with sepsis-induced kidney injury compared to the serum from healthy volunteers (P < 0.05). LPS reduced the level of miR-338-3p in HK-2 cells (P < 0.05). HK-2 cell viability, mitochondrial membrane potential, and Bcl-2 mRNA and protein levels were decreased by LPS (all P < 0.05). Apoptosis, the mRNA and protein levels of inflammatory cytokines (IL-1β, IL-6, IL-8, and TNF-α) and Bax, and the levels of cleaved caspase-9 and caspase-3 were increased by LPS (all P < 0.05). Raising the level of miR-338-3p mitigated these effects of LPS (all P < 0.05).

CONCLUSION

LPS-induced inflammation in HK-2 cells is reduced by miR-338-3p.

Urinary profile of PAHs and related compounds in women working in beauty salons

Polycyclic aromatic hydrocarbons (PAHs) are a group of chemical compounds which interest to human biological monitoring researches because of their potential carcinogenic, mutagenic, and teratogenic properties. However, the exposure of female beauticians to these contaminants is not well-reported. For biomonitoring of potential exposure of female cosmeticians to PAHs in beauty salons, urine samples were taken from cosmetologist women (n = 50.00) and housewives (n = 35.00) as the exposure group (EG) and control group (CG), respectively. Next, unmetabolized PAHs levels as well as the concentration of - 1-hydroxypyrene (1-OHP) were analyzed in these specimens. In addition, since benzene has some common source with PAHs, in this study t, t'-Muconic acid (TTMA) level was also determined as the metabolite and indicator of exposure to benzene. The results indicated a high detection frequency of the target compounds (PAHs, 1-OHP and TTMA) in the urine specimens of beauticians. The results also showed that there is a significant difference between the concentration of these pollutants in the urine specimens of the exposure and control groups. The median concentration of ΣPAHs, 1-OHP, and TTMA in the before exposure (BE) specimens collected from the exposure group were 337.42 ng/L, 593.92 ng/L, and 247.90 μg/L, respectively. However, a higher concentration of these contaminants was observed in the after exposure specimens with a median concentration of 423.29 ng/L, 745.03 ng/L, and 310.97 μg/L, respectively. In terms of contribution of PAHs compounds in total toxic equivalents, DahA, BaP, and IndP with 59.03, 28.73, and 2.86 % had the largest share. In this study, it was also observed that some kidney damage biomarkers as well as some oxidative stress injury biomarkers are positively and significantly correlated with the urinary values of ∑PAHs. Thus, it can be concluded that high health risks threaten the female beauticians regarding kidney injury and DNA oxidative stress.

Highly pathogenic coronaviruses and the kidney

Since the end of 2019, the outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has triggered a pneumonia epidemic, posing a significant public health challenge in 236 countries, territories, and regions worldwide. Clinically, in addition to the symptoms of pulmonary infection, many patients with SARS-CoV-2 infections, especially those with a critical illness, eventually develop multiple organ failure in which damage to the kidney function is common, ultimately leading to severe consequences such as increased mortality and morbidity. To date, three coronaviruses have set off major global public health security incidents: Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), Middle East Respiratory Syndrome Coronavirus (MERS-CoV), and SARS-CoV-2. Among the diseases caused by the coronaviruses, the coronavirus disease 2019 (COVID-19) has been the most impactful and harmful. Similar to with SARS-CoV-2 infections, previous studies have shown that kidney injury is also common and prominent in patients with the two other highly pathogenic coronaviruses. Therefore, in this review, we aimed to comprehensively summarize the epidemiological and clinical characteristics of these three pandemic-level infections, provide a deep analysis of the potential mechanism of COVID-19 in various types of kidney diseases, and explore the causes of secondary kidney diseases of SARS-CoV-2, so as to provide a reference for further research and the clinical prevention of kidney damage caused by coronaviruses.

Parapelvic Cysts: An Imaging Marker of Kidney Disease Potentially Leading to the Diagnosis of Treatable Rare Genetic Disorders? A Narrative Review of the Literature

Simple renal cysts are a common finding during abdominal imaging assessment. The incidence increases with age and it is higher in male gender. Parapelvic cysts are a subset of simple cysts that arise within the renal parenchyma, adjacent to the renal sinus, characterized by being generally single, larger, and incompletely surrounded by renal parenchyma. Noteworthy, parapelvic cysts are a rare and understudied condition which, although considered clinically insignificant due to the absence of influence on renal function, still have a controversial aetiopathogenesis. On the other hand, urological management and differential diagnosis have been thoroughly investigated. The aim of our review is to provide an overall vision on this rare condition, usually misdiagnosed and underestimated, on the basis of more recent data. An accurate differential diagnosis of parapelvic cysts can lead to the identification of treatable conditions such as Fabry disease, autosomal dominant polycystic kidney disease, polycystic liver disease and tuberous sclerosis complex disease.

Protective activities of ellagic acid and urolithins against kidney toxicity of environmental pollutants: A review

Oxidative stress and inflammation are two possible mechanisms related to nephrotoxicity caused by environmental pollutants. Ellagic acid, a powerful antioxidant phytochemical, may have great relevance in mitigating pollutant-induced nephrotoxicity and preventing the progression of kidney disease. This review discusses the latest findings on the protective effects of ellagic acid, its metabolic derivatives, the urolithins, against kidney toxicity caused by heavy metals, pesticides, mycotoxins, and organic air pollutants. We describe the chelating, antioxidant, anti-inflammatory, antifibrotic, antiautophagic, and antiapoptotic properties of ellagic acid to attenuate nephrotoxicity. Furthermore, we present the molecular targets and signaling pathways that are regulated by these antioxidants, and suggest some others that should be explored. Nevertheless, the number of reports is still limited to establish the efficacy of ellagic acid against kidney damage induced by environmental pollutants. Therefore, additional preclinical studies on this topic are required, as well as the development of well-designed clinical trials.

Procollagen C-proteinase enhancer-1 and renal failure in multiple myeloma

BACKGROUND

Renal involvement is present in approximately 50% of multiple myeloma (MM) cases and is associated with a poor prognosis. Procollagen C-Proteinase Enhancer 1 (PCPE-1) is an extracellular matrix glycoprotein that has been shown to increase collagen production by enhancing the activity of Procollagen C-Proteinase (PCP) involved in collagen fibrillogenesis and contribute to the fibrotic process. This study investigates the relationship between PCPE-1 and renal function in myeloma patients.

METHODS

Eighty-one adults, consisting of 61 patients diagnosed with MM and 20 healthy controls, were included in this cross-sectional study. The MM patients with renal injury (RI) were classified as "MM-RI( +)" and those with no RI as "MM-RI(-)".

RESULTS

The median serum PCPE-1 level was 10.7 (5.0-39.4) ng/mL for the entire study population, 9.9 (5.0-13.6) ng/mL for the control group, 10.0 (6.4-22.5) ng/mL for the MM-RI(-) group, and 11.4 (8.1-39.4) ng/mL for the MM-RI( +) group. The difference between the control group and MM-RI( +) group was statistically significant (p < 0.013). PCPE-1 levels negatively correlated with estimated glomerular filtration rate (eGFR), serum albumin, and hemoglobin levels but positively correlated with serum creatinine and CRP levels in the entire study population. Among MM patients, only serum phosphorus and beta-2-microglobulin (β2M) were positively correlated with PCPE-1. PCPE-1 levels was not affected by other parameters in the entire study population and in the MM group.

CONCLUSIONS

Although serum PCPE-1 was higher in the MM-RI( +) group, it was thought to be associated with low GFR reflecting non-specific kidney injury rather than myeloma-related kidney injury.

Effects of cilostazol, a Phosphodiesterase-3 inhibitor, on kidney function and redox imbalance in acute kidney injury caused by Bothrops alternatus venom

The mechanisms of pathogenesis of acute kidney injury (AKI) in snakebites is multifactorial and involves hemodynamic disturbances, with release of free radical causing cytotoxic effects. The phosphodiesterase-3 (PDE3) inhibitor, Cilostazol, has been reported to provide protection against renal oxidative stress.

OBJECTIVE

We evaluated the protective effects of cilostazol against Bothrops alternatus snake venom (BaV)-induced nephrotoxicity.

METHODS

Wistar rat kidneys (n = 6, 260-300 g) were isolated and perfused with Krebs-Henseleit solution containing 6 g/100 mL of bovine serum albumin. After 30 min, the kidneys were perfused with BaV to a final concentration of 1 and 3 μg/mL, and subsequently evaluated for perfusion pressure (PP), renal vascular resistance (RVR), urinary flow (UF), glomerular filtration rate (GFR), and percentage of electrolyte tubular sodium and chloride transport (%TNa⁺, %TCl^-). Oxidative stress and renal histological analyses were performed.

RESULTS

BaV caused a reduction in all the evaluated renal parameters (PP, RVR, GFR, UF, %TNa⁺, and %TCl^-). Although only the effects on PP and UF were reversed with cilostazol treatment, the decrease in the malondialdehyde levels, without changes in glutathione levels, further reduced the venom-induced renal tissue changes.

CONCLUSION

Our data suggest that PDE3 is involved in BaV-induced nephrotoxicity, as cilostazol administration significantly ameliorated these effects.

Prediction of mortality and morbidity following paraquat poisoning based on trend of liver and kidney injury

Background

Paraquat is a non-selective herbicide that causes severe tissue damage in various organs including the liver and kidney. The aim of this study was to determine the trend of the liver and kidney injury in patients with paraquat poisoning.

Methods

This retrospective cross-sectional study was performed at the Khorshid Hospital referral poisoning emergency center. The medical records of all patients with acute paraquat poisoning admitted from March 2017 to October 2020 were reviewed. Demographic factors, liver and kidney function tests and outcomes were recorded. Patients were divided into two groups based on the outcome of mortality (death or survived). The two groups were compared in terms of changes in creatinine and liver enzymes during hospitalization.

Results

A significant difference in mean creatinine levels between the two groups was observed from the third day after admission. The peak median Cr was 3.5 mg/dl for deceased patients in day 6 and 1.47 mg/dl for survived patients on 4th day. Minor elevations of ALT and AST were present in those who died. Logistic regression analysis shows patients who had level of creatinine higher than normal from the 2nd to 6th day post overdose, the risk of mortality was 4.83 to 7.44 times more than patients with normal creatinine level. The mean (SD) area under the curve for outcome prediction was reported to be excellent for creatinine on the 8th day post overdose (85.7 ± 13.2). Creatinine was higher than 2 on the 8th day post ingestion and had a sensitivity 100% and specificity 85.7% for mortality prediction (P value, 0.05).

Conclusions

The risk of mortality secondary to paraquat ingestion was highly associated with a rise in creatinine. Minor elevations of ALT and AST were also present in those who died. The creatinine concentration on different days post overdose can be helpful in predicting the severity of poisoning especially when the serum paraquat levels are not available.

Cardiac magnetic resonance imaging versus computed tomography to guide transcatheter aortic valve replacement: study protocol for a randomized trial (TAVR-CMR)

Background

The standard procedure for the planning of transcatheter aortic valve replacement (TAVR) is the combination of echocardiography, coronary angiography, and cardiovascular computed tomography (TAVR-CT) for the exact determination of the aortic valve dimensions, valve size, and implantation route. However, up to 80% of the patients undergoing TAVR suffer from chronic renal insufficiency. Alternatives to reduce the need for iodinated contrast agents are desirable. Cardiac magnetic resonance (CMR) imaging recently has emerged as such an alternative. Therefore, we aim to investigate, for the first time, the non-inferiority of TAVR-CMR to TAVR-CT regarding efficacy and safety end-points.

Methods

This is a prospective, randomized, open-label trial. It is planned to include 250 patients with symptomatic severe aortic stenosis scheduled for TAVR based on a local heart-team decision. Patients will be randomized in a 1:1 fashion to receive a predefined TAVR-CMR protocol or to receive a standard TAVR-CT protocol within 2 weeks after inclusion. Follow-up will be performed at hospital discharge after TAVR and after 1 and 2 years. The primary efficacy outcome is device implantation success at discharge. The secondary endpoints are a combined safety endpoint and a combined clinical efficacy endpoint at baseline and at 1 and 2 years, as well as a comparison of imaging procedure related variables. Endpoint definitions are based on the updated 2012 VARC-2 consensus document.

Discussion

TAVR-CMR might be an alternative to TAVR-CT for planning a TAVR procedure. If proven to be effective and safe, a broader application of TAVR-CMR might reduce the incidence of acute kidney injury after TAVR and thus improve outcomes.

Trial registration

The trial is registered at ClinicalTrials.gov (NCT03831087). The results will be disseminated at scientific meetings and publication in peer-reviewed journals.

Interval training and Crataegus persica ameliorate diabetic nephropathy via miR-126/Nrf-2 mediated inhibition of stress oxidative in rats with diabetes after myocardial ischemia-reperfusion injury

Myocardial disorders are the most common cause of renal failure and mortality in diabetic patients, but the molecular mechanism of this process is not yet clear. The reduction of nuclear Erythroid2-related factor-2 (Nrf-2) and positive regulators of Nrf-2 proteins, such as DJ-1 and microRNA-126 (miR-126), after hypoxia and the promotion of reactive oxygen species, might be an intervention indicator in renal failure after myocardial ischemia-reperfusion. Therefore, this study evaluates the renoprotective effect of exercise training and Crataegus persica extract (CE) on myocardial ischemia-reperfusion-induced kidney injury in diabetic rats. Fifty rats were divided into five groups: healthy sedentary control (Con), sedentary diabetic (D), interval trained diabetic (TD), diabetic plus Crataegus persica extract treatment (CD), and interval trained diabetic plus Crataegus persica extract treatment (TCD) groups. The rats in the exercise groups were subjected to moderate-intensity interval training five days per week for ten weeks. The rats in CD and TCD groups received 300 mg/kg of Crataegus persica through gavage for ten weeks. Then, the subjects underwent 30 min of myocardial ischemia and subsequently reperfusion for 24 h. At the end of the experiment, insulin sensitivity, oxidative stress, renal function, histopathology of the kidney, Nrf-2, miR-126, and DJ-1 gene expression levels were evaluated. The results show that the treatments decreased elevated levels of renal oxidative stress, glomerular filtration rate, insulin sensitivity, and pathological score in diabetic rats. Also, the expression of Nrf-2 and miR-126, unlike DJ-1, decreased in diabetic rats due to interval training. Due to the results, diabetes aggravates acute myocardial ischemia-reperfusion-induced kidney injury, while moderate-intensity interval training and Crataegus persica treatment simultaneously ameliorate myocardial ischemia-reperfusion-induced renal injury via miR-126/Nrf-2 pathway and improve insulin sensitivity and renal function in type 1 diabetic rats.

Megalin, a multi-ligand endocytic receptor, and its participation in renal function and diseases: A review

The endocytosis mechanism is a complicated system that is essential for cell signaling and survival. Megalin, a membrane-associated endocytic receptor, and its related proteins such as cubilin, the neonatal Fc receptor for IgG, and NaPi-IIa are important in receptors-mediated endocytosis. Physiologically, megalin uptakes plasma vitamins and proteins from primary urine, preventing their loss. It also facilitates tubular retrieval of solutes and endogenous components that may be involved in modulation and recovery from kidney injuries. Moreover, megalin is responsible for endocytosis of xenobiotics and drugs in renal tubules, increasing their half-life and/or their toxicity. Fluctuations in megalin expression and/or functionality due to changes in its regulatory mechanisms are associated with some sort of kidney injury. Also, it's an important component of several pathological conditions, including diabetic nephropathy and Dent disease. Thus, exploring the fundamental role of megalin in the kidney might help in the protection and/or treatment of multiple kidney-related diseases. Hence, this review aimed to explore the physiological roles of megalin in the kidney and their implications for kidney-related injuries.

The effect of interval and continuous work on markers of acute kidney injury in a hot environment

PURPOSE

To examine the effect of high-intensity interval work (HIIW) and moderate-intensity continuous work (MICW) on markers of acute kidney injury (AKI) and kidney function in a hot environment.

METHODS

Nine males completed 2 h of work (2 × 60 min with 10 min passive rest) in a hot environment (40 °C and 15% relative humidity) as either HIIW [2 min at 80% peak oxygen consumption (VO₂peak) and 3 min at 30% VO₂peak] or MICW (matched for total work of HIIW). Blood and urine samples were collected immediately before (Pre), after (Post), 1 h (1 h Post), and 24 h after (24 h Post) the trials. Urine flow rate (UFR), creatinine clearance, insulin-like growth factor binding protein 7 (IGFBP7), urinary neutrophil gelatinase-associated lipocalin (uNGAL), and urinary kidney injury marker 1 (uKIM-1) were measured to assess kidney function and injury.

RESULTS

Log IGFBP7 (p < 0.01), log uNGAL (p < 0.01), and log uKIM-1 (p = 0.01) all displayed a main effect for time after both HIIW and MICW. IGFBP7 (p = 0.01) and uKIM-1 (p < 0.01), corrected for Uosm, were higher after HIIW compared to MICW at Post, while IGFBP7 was also higher 1 h Post after HIIW compared to MICW (p = 0.02). UFR significantly decreasing from Pre to Post (p < 0.01) and 1 h Post (p < 0.01), but no main effect for condition (p = 0.53).

CONCLUSION

Both HIIW and MICW in a hot environment caused an increase in biomarkers of kidney injury (IGFBP7, KIM-1, and NGAL), but HIIW may have a greater impact on biomarkers related to AKI.

Urine Macrophages Polarization Predicts Renal Function Recovery after Nephron-Sparing Surgery in Patients with Renal Cell Carcinoma

INTRODUCTION

This study was conducted to investigate the underlying associations between urine macrophages polarization and renal function recovery after nephron-sparing surgery (NSS) in patients with renal cell carcinoma (RCC) and to explore the potential application values of urine macrophages polarization in predicting the severity of renal ischemia/reperfusion injury (RIRI).

METHODS

Sixty-two patients with unilateral RCC who underwent NSS in our departments were prospectively recorded and followed up for long-term renal function to assess the onset of acute kidney injury (AKI) and chronic kidney disease (CKD). Urine samples of patients were collected 72 h after surgery for analyzing pro-inflammatory (classically activated/M1) and pro-reparative (alternatively activated/M2) macrophages polarization by flow cytometry. The detailed correlations between urine macrophages polarization and renal function recovery after NSS were explored by statistical analyses.

RESULTS

The cumulative incidence of postoperative AKI was 27.4% (17/62), and 47.0% (8/17) of those eventually developed to CKD during the follow-up. The mean urine M1/M2 ratio was 10.54 ± 8.13 in the AKI group and 3.93 ± 3.10 in the non-AKI group, presenting a significant statistical difference (p < 0.0001). Meanwhile, the urine M1/M2 ratio presented amazing potential in predicting postoperative CKD as well, with a mean ratio of 12.54 ± 9.41 in the CKD group and 4.28 ± 3.21 in the non-CKD group (p < 0.0001). Though univariate analysis implied that urine M1/M2 ratio was a relevant factor of both postoperative AKI and CKD in NSS surgical patients, multivariate analysis did not show satisfying predicting potential in postoperative CKD, mainly due to the very limited candidates enrolled in this study.

CONCLUSION

Urine macrophages polarization could predict renal function recovery after NSS in patients with RCC. The urine M1/M2 ratio might a potential biomarker of RIRI but needs to be further verified in clinical settings.

Renal function after liver transplantation: Real-world experience with basiliximab induction and delayed reduced-dose tacrolimus

BACKGROUND

Routine use of delayed reduced-dose calcineurin-inhibitor treatment with induction immunosuppression in liver transplantation to minimize post-operative kidney injury is still scarce.

AIM

To evaluate real-world experience of basiliximab induction with delayed reduced-dose tacrolimus.

METHODS

In a retrospective cohort study, kidney function was evaluated pre- and postoperatively by measured glomerular filtration rate (mGFR). Adult patients undergoing liver transplantation between 2000 and 2017 were divided into a conventional treatment group (immediate-introduction of tacrolimus, target trough levels 10-15 ng/mL, and corticosteroids, n = 203) and a revised treatment group (basiliximab induction, reduced-dose tacrolimus, target through levels 5-8 ng/mL, delayed until day three, and mycophenolate mofetil 2000 mg/day, n = 343).

RESULTS

Mean mGFR was similar between groups at wait-listing (85.3 vs 84.1 ml/min/1.73m², p = 0.60), but higher in the revised treatment group at 3 (56.8 vs 63.4 ml/min/1.73m², p = 0.004) and 12 months post-transplant (60.9 vs 69.7 ml/min/1.73m², p<0.001); this difference remained after correcting for multiple confounders and was independent of pre-transplant mGFR. In the revised treatment group, biopsy proven acute rejection rate was lower (38% vs. 21%, p<0.001), and graft-survival better (p = 0.01).

CONCLUSION

Basiliximab induction with delayed reduced-dose tacrolimus is associated with less kidney injury when compared to standard-dose tacrolimus, without increased risk of rejection, graft loss or death.