Changes in urinary renal injury markers in children with Mycoplasma pneumoniae pneumonia and a prediction model for related early renal injury

BACKGROUND

This study aims to analyse changes in urinary kidney injury markers in children with Mycoplasma pneumoniae pneumonia (MPP), investigate the risk factors for MPP-related acute kidney injury (AKI) and establish a model to predict MPP-related AKI.

METHODS

Ninety-five children were enrolled based on the study's inclusion and exclusion criteria. They were divided into a severe MPP (SMPP) group and a non-SMPP group and then into an AKI group and a non-AKI group according to the presence of AKI. A univariate logistic regression analysis was performed to explore the early risk factors for AKI. Based on a multivariate logistic regression analysis and a least absolute shrinkage and selection operator regression analysis, appropriate variables were selected to establish a prediction model, and R 4.2.2 software was used to draw nomograms and generate a dynamic nomogram website.

RESULTS

Seven urinary kidney injury markers were abnormally elevated in the SMPP group and the non-SMPP group: urinary N-acetyl-β-D-glucosaminidase (NAG), β2-microglobulin, α1-microglobulin, retinol-binding protein, urinary immunoglobulin G, urinary transferrin and urinary microalbumin. Sixteen children were identified with AKI during hospitalisation. The AKI group had higher levels of urinary NAG, α1-microglobulin, β2-microglobulin, urinary microalbumin, urinary transferrin and retinol-binding protein than the non-AKI group (P < 0.05). The MPP-related AKI prediction model consists of four indicators (serum immunoglobulin M [IgM], C-reactive protein [CRP], urine NAG and sputum plug presence) and a dynamic nomogram.

CONCLUSION

Urinary kidney injury markers are often elevated in children with MPP; urinary NAG is the marker most likely to be elevated, and it is especially evident in severe cases. The nomogram of the prediction model, comprising serum IgM, CRP, urinary NAG and sputum plug presence, can predict the probability of AKI in children with MPP.

Robust Rat and Mouse Models of Bilateral Renal Ischemia Reperfusion Injury

BACKGROUND/AIM

Acute and chronic kidney diseases are a major contributor to morbidity and mortality worldwide, with no specific treatments currently available for these. To enable understanding the pathophysiology of and testing novel treatments for acute and chronic kidney disease, a suitable in vivo model of kidney disease is essential. In this article, we describe two reliable rodent models (rats and mice) of efficacious kidney injury displaying acute to chronic kidney injury progression, which is also reversible through novel therapeutic strategies such as ischemic preconditioning (IPC).

MATERIALS AND METHODS

We utilized adult male Lewis rats and adult male wildtype (C57BL/6) mice, performed a midline laparotomy, and induced warm ischemia to both kidneys by bilateral clamping of both renal vascular pedicles for a set time, to mimic the hypoxic etiology of disease commonly found in kidney injury.

RESULTS

Bilateral ischemia reperfusion injury caused marked structural and functional kidney injury as exemplified by histology damage scores, serum creatinine levels, and kidney injury biomarker levels in both rodents. Furthermore, this effect displayed a dose-dependent response in the mouse model.

CONCLUSION

These rodent models of bilateral kidney IRI are reliable, reproducible, and enable detailed mechanistic study of the underlying pathophysiology of both acute and chronic kidney disease. They have been carefully optimised for single operator use with a strong track record of training both surgically trained and surgically naïve operators.

[Mechanism of renal injury and apoptosis in rats with nephrotic syndrome induced by mercury]

Objective: To investigate the relationship between renal injury and apoptosis in rats with nephrotic syndrome induced by mercury, in order to find out the pathogenesis. Methods: Forty-eight healthy male SPF-grade BN (Brown-Norway) rats were divided into the control group and the exposure group by random number table. The nephrotic syndrome was caused by subcutaneous injection of HgCl(2) (1 mg/ml) in the abdominal weight per kg of body weight. The control group was injected with the same volume of NaCl as the exposure group. Some rats were sacrificed on the 14th, 21st, 28th, and 35th days, and the serum kidney injury indicators creatinine (CRE) and urea nitrogen (BUN) were detected, and the renal tissue mercury content was detected; the in situ terminal transferase labeling technology (TUNEL) was detected Apoptosis, immunofluorescence detection of Cyt C content, Western blot detection of mitochondrial pathway apoptosis-related proteins [B-cell lymphoma 2 (Bcl-2) , Bcl-2 related X protein (BAX) , cysteine proteinase 3 (Caspase 3) ], mitogen-activated protein kinase (MAPK) signaling pathway-related proteins[p38 mitogen-activated protein kinase (P38MAPK) , extracellular regulatory protein kinase (ERK) ] expression. Results: Compared with the control group, the BUN content in the serum of rats in the exposure group was significantly increased on days 7, 21, and 28, the CRE content was significantly increased on 21 days, the CRE content was significantly decreased on 28 and 35 days, and the organ coefficient and renal mercury content were 14 to 35 days. Significantly increased, and the differences were statistically significant (P<0.05) . Compared with the control group, rats in the exposed group showed increased glomerular stroma, tubule dilatation and other renal cell apoptosis at 14 to 35 days, and Cyt C expression was obvious in the exposed groups at 14, 21 days. Compared with the control group, the BAX content of the rats in the exposed group was significantly increased on the 21st day, the content of Caspase 3 in the rats on the 14th and 21st days was significantly increased, and the content of the P38MAPK in the 35th day was significantly increased (P<0.05) . Conclusion: HgCl(2) may cause renal cell damage through the mitochondrial pathway of apoptosis and cause nephrotic syndrome, and the MAPK signaling pathway may regulate this process and exert an inhibitory effect on apoptosis.

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.

Synthesis of glycyrrhizin analogues as HMGB1 inhibitors and their activity against sepsis in acute kidney injury

Glycyrrhizin (GL) is one of the antagonists of highly conserved nuclear protein (HMGB1). The researches have shown that the glycosyl of GL is an important pharmacophore for GL binding to HMGB1, and it is the determinant factor for mechanism of action. To get the HMGB1 inhibitors with higher activity and good pharmacokinetic properties, two classes of GL analogues containing C-N glycoside bond were synthesized, and their anti-inflammatory, anti-oxidative stress and anti-septic kidney injury were evaluated. The results are as follows. First, in the anti-inflammatory assay, all the compounds inhibited NO release in some degree; among them, compound 6 displayed the strongest NO inhibitory effect with IC50 value of 15.9 μM, and compound 15 with IC50 of 20.2 μM. The two compounds not only decreased IL-1β and TNF-α levels in RAW264.7 cells and HK-2 cells, but also downregulated the levels of NLRP3, P-NF-κB p65 and HMGB1 in activated HK-2 cells in a dose-dependent manner. Second, in the renal protection assay with H2O2-stimulated HK-2 cell line, they reduced MDA level and increased SOD in HK-2 cells; additionally, they also inhibited the HK-2 cell apoptosis and downregulated the Caspase-1 p20 level. Third, in the in vivo activity tests of the septic mouse, they also showed good activities just like in vitro, decreasing the IL-1β, TNF-α, MDA, blood creatinine (Scr) and urea nitrogen (BUN) in serum, and increasing SOD levels in a dose-dependent manner. The immunoblotting results showed the two compounds downregulated the levels of HMGB1, P-NF-κB p65, NLRP3 and Caspase-1 p20 protein. All in all, the two compounds improved the renal injury of septic mice, and alleviated the tube wall structure damage and renal tubular dilation in kidney, which further proved by H&E staining. This suggests the two compounds have septic acute kidney injury activity, and they will be potential therapeutic drugs for septic acute kidney injury.

The role and mechanism of action of miR-483-3p in mediating the effects of IGF-1 on human renal tubular epithelial cells induced by high glucose

This study aimed to elucidate the influence of miR-483-3p on human renal tubular epithelial cells (HK-2) under high glucose conditions and to understand its mechanism. Human proximal tubular epithelial cells (HK-2) were exposed to 50 mmol/L glucose for 48 h to establish a renal tubular epithelial cell injury model, denoted as the high glucose group (HG group). Cells were also cultured for 48 h in a medium containing 5.5 mmol/L glucose, serving as the low glucose group. Transfection was performed in various groups: HK-2 + low glucose (control group), high glucose (50 mM) (HG group), high glucose + miR-483-3p mimics (HG + mimics group), high glucose +miR-483-3p inhibitor (HG + inhibitor group), and corresponding negative controls. Real-time quantitative polymerase chain reaction (qPCR) assessed the mRNA expression of miR-483-3p, bax, bcl-2, and caspase-3. Western blot determined the corresponding protein levels. Proliferation was assessed using the CCK-8 assay, and cell apoptosis was analyzed using the fluorescence TUNEL method. Western blot and Masson's staining were conducted to observe alterations in cell fibrosis post miR-483-3p transfection. Furthermore, a dual-luciferase assay investigated the targeting relationship between miR-483-3p and IGF-1. The CCK8 assay demonstrated that the HG + mimics group inhibited HK-2 cell proliferation, while the fluorescent TUNEL method revealed induced cell apoptosis in this group. Conversely, the HG + inhibitor group promoted cell proliferation and suppressed cell apoptosis. The HG + mimics group upregulated mRNA and protein expression of pro-apoptotic markers (bax and caspase-3), while downregulating anti-apoptotic marker (bcl-2) expression. In contrast, the HG + inhibitor group showed opposite effects. Collagen I and FN protein levels were significantly elevated in the HG + mimics group compared to controls (P < 0.05). Conversely, in the HG + inhibitor group, the protein expression of Collagen I and FN was notably reduced compared to the HG group (P < 0.05). The dual luciferase reporter assay confirmed that miR-483-3p could inhibit the luciferase activity of IGF-1's 3'-UTR region (P < 0.05). miR-483-3p exerts targeted regulation on IGF-1, promoting apoptosis and fibrosis in renal tubular epithelial cells induced by high glucose conditions.

Transcriptome analysis provides insights into high fat diet-induced kidney injury and moderate intensity continuous training-mediated protective effects

Although physics exercise has been utilized to prevent and treat a variety of metabolic diseases, its role in obesity-related kidney diseases remains poorly understood. In this study, we assessed the protective potential of moderate intensity continuous training (MICT) against high fat diet (HFD)-induced kidney injury and found that MICT could significantly reduce obesity indexes (body weight, serum glucose, total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol) and kidney injury indexes (serum creatinine and the expression of Kim-1 mRNA) in HFD-fed mice. PAS staining and Masson staining displayed that MICT maintained the morphological structure of kidney subunits and reduced kidney fibrosis in HFD-fed mice. By kidney RNA-seq, we identified several genes and pathways (Cd9, Foxq1, Mier3, TGF-β signaling pathway etc.) that might underlie HFD-induced kidney injury and MICT-mediated protective effects. In conclusion, this study revealed the protective role of MICT in HFD-induced kidney injury and suggested potential targets for the prevention and treatment of obesity-related kidney diseases.

The polarization of M2 macrophages can be adjusted to alleviate renal injury by methylprednisolone in sepsis-AKI

Acute kidney injury in sepsis patients has an extreme mortality rate in clinical. It obviously seems that immune cells, for example, macrophages are involved with this process. Macrophages, as highly important immune cells, play a significant role in the development of human kidney diseases. But the specific role of macrophages in this process is still unclear. Under different timeline points, we surprisingly found that macrophages had the most dynamic changes in acute kidney injury immune cells. Based on macrophages' functions, they are primarily classified into M1 macrophages (pro-inflammatory) and M2 macrophages (anti-inflammatory). The polarization of M2 macrophages is closely associated with the seriousness of sepsis-induced kidney injury, but how to modulate their polarization to alleviate sepsis-associated renal damage remains unknown. We discovered that the polarization of M2 macrophages after methylprednisolone injection can significantly alleviate acute kidney injury by reducing secreted cytokine. This study suggests that the proportion of macrophage subtypes can be regulated by methylprednisolone to alleviate acute kidney injury in sepsis to provide a new sight for a clinical to provide a promising strategy for renal injury caused.

Kidney injury: An overlooked manifestation in autoimmune encephalitis

AIM

To investigate the prevalence and clinical features of kidney injury in patients with autoimmune encephalitis (AE).

METHODS

Kidney injury was suspected in kidney-involving group due to persistent abnormal in urinary protein and serum albumin. Data on demographics and clinical features were compared between kidney-involving group and kidney-sparing group (patients without kidney injury) using Wilcoxon rank-sum test or chi-square test. Renal biopsy was conducted to identify the type of kidney injury.

RESULTS

Approximate 30 % (32 of 108) patients with AE were suspicious of kidney injury. Nine patients further tested 24 h urine total protein, and seven of them had an elevated urine protein higher than 150 mg. The predominantly patterns of kidney injury were elevated urine protein, decreased serum albumin and normal kidney function. Compared to kidney-sparing group, the spectrum of AE antibodies in kidney-involving group was different, manifested as less anti-N-methyl-d-aspartate receptor antibodies (50 % vs. 72.4 %, p = 0.025) and more anti-contactin-associated protein like 2 antibodies (18.8 % vs. 1.3 %, p = 0.003). Definite pathological changes indicative of IgA nephropathy and membranous nephropathy in renal biopsy of two cases provided evidence of autoimmune attacks.

DISCUSSION

Kidney injury occurred in considerable proportion of patients with AE. An in-depth screening for nephropathy could be essential for AE.

Platelet-derived extracellular vesicles are associated with kidney injury in patients with urosepsis

BACKGROUND

There is increasing evidence that platelet-derived extracellular vesicles (PEVs) may be involved in the mechanisms of inflammatory storm and organ damage in sepsis. However, there are no available studies on PEVs and renal injury in patients with urosepsis.

METHODS

We analyzed the concentration and ratio of PEVs in plasma by flow cytometry and measured plasma IL-1β/IL-6/TNF-α/NGAL levels by ELISA. Correlation analysis was also used to examine the concentration of PEVs in relation to levels of inflammatory factors and indicators of kidney damage, as well as the severity of the disease. Finally, the receiver operating characteristic curves were produced for PEVs concentrations as a diagnosis of S-AKI/AKI.

RESULTS

We found significantly higher levels of IL-1β/IL-6/TNF-α/NGAL in patients with urogenital sepsis. Furthermore, the concentrations of PEVs in plasma were significantly elevated in patients with urosepsis, especially in patients with Gram-negative bacterial infections, which were significantly and positively correlated with IL-1β/IL-6/TNF-α/NGAL levels. The area under the curve for PEVs diagnosing S-AKI and AKI was 0.746 [0.484, 1.000] and 0.943 [0.874, 1.000] respectively.

CONCLUSION

Overall, the present study suggested that PEVs may mediate the release of inflammatory mediators in patients with urosepsis and participate in the mechanism of acute kidney injury, as well as having potential as diagnostic indicators of S-AKI and AKI and as early warning indicators of the severity of patients with urosepsis.

Cysteine conjugates of acetaminophen and p-aminophenol are potent inducers of cellular impairment in human proximal tubular kidney HK-2 cells

Acetaminophen (APAP) belong among the most used analgesics and antipyretics. It is structurally derived from p-aminophenol (PAP), a potent inducer of kidney toxicity. Both compounds can be metabolized to oxidation products and conjugated with glutathione. The glutathione-conjugates can be cleaved to provide cysteine conjugates considered as generally nontoxic. The aim of the present report was to synthesize and to purify both APAP- and PAP-cysteine conjugates and, as the first study at all, to evaluate their biological effects in human kidney HK-2 cells in comparison to parent compounds. HK-2 cells were treated with tested compounds (0-1000 µM) for up to 24 h. Cell viability, glutathione levels, ROS production and mitochondrial function were determined. After 24 h, we found that both APAP- and PAP-cysteine conjugates (1 mM) were capable to induce harmful cellular damage observed as a decrease of glutathione levels to 10% and 0%, respectively, compared to control cells. In addition, we detected the disappearance of mitochondrial membrane potential in these cells. In the case of PAP-cysteine, the extent of cellular impairment was comparable to that induced by PAP at similar doses. On the other hand, 1 mM APAP-cysteine induced even larger damage of HK-2 cells compared to 1 mM APAP after 6 or 24 h. We conclude that cysteine conjugates with aminophenol are potent inducers of oxidative stress causing significant injury in kidney cells. Thus, the harmful effects cysteine-aminophenolic conjugates ought to be considered in the description of APAP or PAP toxicity.

Unveiling the bidirectional role of MMP9: A key player in kidney injury

Matrix metalloproteinases (MMPs) are a group of zinc-dependent proteolytic metalloenzymes that are involved in numerous pathological conditions, including nephropathy. MMP9, a member of the MMPs family, is categorized as a constituent of the gelatinase B subgroup, and its involvement in extracellular matrix (ECM) remodeling and renal fibrosis highlights its importance in the development and progression of renal diseases. The exact role of MMP9 in the development of kidney diseases is still controversial. This study investigated the dual role of MMP9 in kidney injury, discussing its implications in the pathogenesis of kidney diseases and investigating the design and mechanism of MMP9 inhibitors based on previous studies. This study provides an effective basis for the development of novel and selective MMP9 inhibitors for treating renal diseases.

An innocent bystander or a predisposing culprit? Kidney injury following pediatric liver transplantation

BACKGROUND

Survival after pediatric liver transplantation has increased dramatically over the years, revealing extra-hepatic complications including impaired kidney function. We conducted a large single-center retrospective study to evaluate kidney outcomes after pediatric liver transplantation.

METHODS

From electronic charts of 121 children who underwent liver transplantation during 2007-2020, we collected pre- and post-transplant data. We investigated the presence of post-transplant permanent kidney injury, including proteinuria, hypertension, and decreased estimated glomerular filtration rate (eGFR). We excluded children who died, underwent liver-kidney transplantation, or had less than 1 year of follow-up.

RESULTS

During a median follow-up of 5.1 (interquartile range 2.9-7.3) years, eGFR decreased, mostly in the first year post-transplant. In addition, 41% of the children presented with acute kidney injury. At their last follow-up, 35% showed permanent kidney injury (hypertension 13%, proteinuria 36%, and eGFR < 90 mL/min per 1.73 m2 7%). Kidney ultrasounds were abnormal for 44% of the children at the last visit, compared to 11% before transplant (p < 0.001). In multivariate analysis, abnormal kidney ultrasound before transplant (odds ratio = 4.53, 95% CI 1.1-18.7) and liver disease with potential risk of primary kidney involvement (odds ratio = 4.77, 95% CI 1.58-14.4) were predictors for hypertension or decreased eGFR at the last follow-up.

CONCLUSIONS

The high prevalence of kidney injury after pediatric liver transplantation and the pretransplant predictors for kidney injury highlight the importance of a thorough kidney pretransplant evaluation and follow-up.

[Blunt abdominal trauma in children and adolescents: treatment concepts in the acute phase]

Fatal accidents due to blunt force trauma are the leading cause of death in children and adolescents [1]. Abdominal trauma is the third most common cause of death after traumatic brain injury and thoracic injuries [2]. Abdominal injury is seen in approximately 2-5% of children involved in accidents [3]. Blunt abdominal injuries are common sequelae of traffic accidents (for example as seat belt injury), falls, and sports accidents. Penetrating abdominal injuries are rare in central Europe. Spleen, liver, and kidney lacerations are the most common injuries after blunt abdominal trauma [4]. In most situations, nonoperative management (NOM) has become the gold standard with the surgeon leading the multidisciplinary treatment [5].

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.

Occurrence and influencing factors of cyclosporine A on the kidney injury following allogeneic hematopoietic stem cell transplantation: A systematic review and meta-analysis

OBJECTIVE

Whether cyclosporine A (CsA) is a risk factor of kidney injury after allogeneic hematopoietic stem cell transplantation (allo-HSCT) has not been determined. We aim to comprehensively review the correlation and influencing factors between CsA and kidney injury in patients following allo-HSCT.

METHODS

We searched PubMed, Embase (Ovid), Cochrane Central Register of Controlled Trials (CENTRAL), CNKI, VIP, Wanfang and CBM Database from inception to March 2022. Two researchers independently conducted literature screening, data extraction and quality assessment. Qualitative and quantitative methods were combined to analyze the data.

RESULTS

We included a total of 30 studies. Meta-analyses of total incidence of kidney injury related to CsA was 37.0% [95% CI (25.4%, 48.6%); n = 15]. The proportion of CsA-related acute kidney injury to total acute kidney injury following allo-HSCT was 59.7% [95% CI (49.1%, 70.3%); n = 9]. One study found that AKI had a significant association with CsA in multivariate analysis [RR = 6.173; 95% CI (4.032, 9.434)]. With respect to cyclosporine combination and nephrotoxicity, 6/9 studies demonstrated that the concomitant medications for CsA (especially aminoglycoside antibiotics and amphotericin B) had negative effect on kidney functions related to CsA in allo-HSCT patients. No consensus was reached for "dose of CsA", "duration of CsA use", "comorbidities" and "CsA levels" across studies.

CONCLUSIONS

CsA may be a risk factor for kidney injury in patients following allo-HSCT, especially the concomitant use of CsA and nephrotoxic medications.

A case of acute kidney injury due to native kidney BK polyomavirus-associated nephropathy in a human T-lymphotropic virus type 1 carrier

BACKGROUND

BK polyomavirus-associated nephropathy (BKPyVAN) has become a major cause of kidney dysfunction and graft loss in kidney transplant recipients. On rare occasion, polyomavirus has also been known to affect native kidneys of immunocompromised individuals. Only a small number of opportunistic infections have been reported in the carrier phase of human T-lymphotropic virus type 1 (HTLV-1). This is the first reported case of BKPyVAN in native kidneys of an HTLV-1 carrier.

CASE PRESENTATION

A 61-year-old man was referred to our hospital from a primary care physician for work-up and treatment of pneumonia. He was diagnosed with Pneumocystis pneumonia and identified as a HTLV-1 carrier who had not yet developed adult T-cell leukemia (ATL). The pneumonia was successfully treated with sulfamethoxazole-trimethoprim. He had never been diagnosed with any kind of kidney dysfunction. Laboratory investigations showed a serum creatinine of 5.3 mg/dL, and urinary sediment showed cells with nuclear enlargement and inclusion bodies suggesting viral infection. The urinary Papanicolaou stain showed inclusions in swollen, ground-glass nuclei, typical of "decoy cells". Renal biopsy showed degeneration of tubules with epithelial enlargement, vacuolar degeneration, nuclear inclusion bodies, and detachment from the tubular basement membrane. Tubular nuclei showed positive staining positive for simian virus 40 large-T antigen. Polymerase chain reaction tests for BK polyomavirus DNA of both urine and plasma were positive. These findings confirmed a diagnosis of BKPyVAN. Intravenous immunoglobulin therapy did not improve renal function, necessitating maintenance hemodialysis therapy.

CONCLUSIONS

BKPyVAN should be considered when acute kidney injury occurs with opportunistic infection. HTLV-1 carriers can develop opportunistic infections even before the onset of ATL.

Gut bacteria exacerbates TNBS-induced colitis and kidney injury through oxidative stress

Gut microbiota has been implicated in the initiation and progression of various diseases; however, the underlying mechanisms remain elusive and effective therapeutic strategies are scarce. In this study, we investigated the role and mechanisms of gut microbiota in TNBS-induced colitis and its associated kidney injury while evaluating the potential of dietary protein as a therapeutic intervention. The intrarectal administration of TNBS induced colitis in mice, concurrently with kidney damage. Interestingly, this effect was absent when TNBS was administered intraperitoneally, indicating a potential role of gut microbiota. Depletion of gut bacteria with antibiotics significantly attenuated the severity of TNBS-induced inflammation, oxidative damage, and tissue injury in the colon and kidneys. Mechanistic investigations using cultured colon epithelial cells and bone-marrow macrophages unveiled that TNBS induced cell oxidation, inflammation and injury, which was amplified by the bacterial component LPS and mitigated by thiol antioxidants. Importantly, in vivo administration of thiol-rich whey protein entirely prevented TNBS-induced colonic and kidney injury. Our findings suggest that gut bacteria significantly contribute to the initiation and progression of colitis and associated kidney injury, potentially through mechanisms involving LPS-induced exaggeration of oxidative cellular damage. Furthermore, our research highlights the potential of dietary thiol antioxidants as preventive and therapeutic interventions.

Comparative analysis of effects of conditioned mediums obtained from 2D or 3D cultured mesenchymal stem cells on kidney functions of diabetic rats: Early intervention could potentiate transdifferentiation of parietal epithelial cell into podocyte precursors

AIM

The secretome of mesenchymal stem cells (MSCs) could be a potential therapeutic intervention for diabetes and associated complications like nephropathy. This study aims to evaluate the effects of conditioned mediums (CMs) collected from umbilical cord-derived MSCs incubated under 2-dimensional (2D) or 3D culture conditions on kidney functions of rats with type-I diabetes (T1D).

MAIN METHODS

Sprague-Dawley rats were treated with 20 mg/kg streptozocin for 5 consecutive days to induce T1D, and 12 doses of CMs were applied intraperitoneally for 4 weeks. The therapeutic effects of CMs were comparatively investigated by biochemical, physical, histopathological, and immunohistochemical analysis.

KEY FINDINGS

3D-CM had significantly higher total protein concentration than the 2D-CM Albumin/creatinine ratios of both treatment groups were significantly improved in comparison to diabetes. Light microscopic evaluations showed that glomerular and cortical tubular damages were significantly ameliorated in only the 3D-CM applied group compared to the diabetes group, which were correlated with transmission electron microscopic observations. The nephrin and synaptopodin expressions increased in both treatment groups compared to diabetes. The WT1, Ki-67, and active caspase-3 expressions in glomeruli and parietal layers of the treatment groups suggest that both types of CMs suppress apoptosis and promote possible parietal epithelial cells' (PECs') transdifferentiation towards podocyte precursor cells by switching on WT1 expression in parietal layer rather than inducing new cell proliferation.

SIGNIFICANCE

3D-CM was found to be more effective in improving kidney functions than 2D-CM by ameliorating glomerular damage through the possible mechanism of transdifferentiation of PECs into podocyte precursors and suppressing glomerular apoptosis.

Protective effects of astaxanthin solid lipid nanoparticle as a promising candidate against acute kidney injury in rats

Acute kidney injury (AKI) is a sudden onset of renal injury that occurs within a few hours or days. Ischemia-reperfusion (IR) is a major cause of AKI. There are multiple dysregulated mechanisms behind the pathogenesis of AKI and IR which urges the need for finding multi-targeting therapies. Natural products are multi-targeting agents with promising sources of anti-inflammation, antioxidant, and antiapoptosis. Among them, astaxanthin (AST) is a keto-carotenoid with a high antioxidant potential. Using solid lipid nanoparticles (SLNs) as a novel formulation of AST helps to increase its efficacy and reduce side effects against AKI. After SLN preparation and loading of AST, the physicochemical properties were evaluated, using scanning electron microscopy (SEM) and dynamic light scattering (DLS) tests. For the in vivo study, 28 rats were divided into four groups, including sham, ischemia/reperfusion (I/R), and groups receiving protective and daily doses of AST-SLN (5 and 10 mg/kg, i.p.) during all 5 days before ischemia. Exactly 24 h after ischemia, kidneys were isolated for histological studies, and also, serum levels of catalase (CAT), glutathione (GSH), nitrite, blood urea, and creatinine were measured. The results indicated that intraperitoneal administration of SLN-AST reduced oxidative stress by decreasing serum nitrite levels, while increasing CAT and GSH. SLN-AST also improved renal function by decreasing serum urea and creatinine and preventing tissue damage. Therefore, SLN-AST could be a hopeful adjuvant candidate to prevent AKI by modulating renal function, preventing tissue damage, and through antioxidant mechanisms.

Protective effects of the secondary metabolites from Quercus salicina Blume against gentamicin-induced nephrotoxicity in zebrafish (Danio rerio) model

To reveal the protective effect on the nephrotoxicity of Quercus salicina Blume(QS), a traditional medicine for the treatment of urolithiasis, the 50 % ethanol extract from the branches and leaves of QS was chemically studied by systematic solvent extraction and HPLC chromatography. Two phenolic acids and three flavonoids were identified by nuclear magnetic resonance spectroscopy, namely Ferulic acid (1), p-Hydroxycinnamic acid (2), Hesperidin (3), Formononetin (4), and Quercetin (5). At the same time, the gentamicin-induced nephrotoxicity of zebrafish was used as a model for the first time. The antioxidant activity of these derivatives with good antioxidant activity screened from free radical scavenging experiments in vitro (DPPH and ABTS) was evaluated in vivo, including protein levels (LPO, NO, GSH, and SOD), kidney injury factor (KIM-1), zebrafish kidney pathology and real-time PCR. The results showed that metabolites 1, 3, and 5 had strong antioxidant activity, and oxidative stress in renal tissue was significantly reduced; KIM-1, TNF-α, and IL-6 mRNA expression in a dose-dependent manner, which preliminarily revealed the protective effect of the secondary metabolites of QS on nephrotoxicity, and preliminarily discussed the structure-activity relationship. This study provides an experimental basis for further exploring the mechanism of QS in the kidney.

Impact of humanized vancomycin infusion on kidney function and kidney injury in a translational rat model

Allometric dose scaling aims to create isometric exposures between animals and humans and is often employed in preclinical pharmacokinetic/pharmacodynamic models. Bolus-administration with allometric scaling is the most simple and commonly used strategy in pre-clinical kidney injury studies; however, it is possible to humanize drug exposures. Currently, it is unknown if dose-matched, bolus-administration with allometric scaling results in similar outcomes compared to humanized infusions in the vancomycin induced kidney injury model. We utilized a preclinical Sprague-Dawley rat model to compare traditional allometrically-scaled, dose-matched, bolus-administration of vancomycin to an infusion-pump controlled, humanized infusion scheme to assess for differences in iohexol-measured kidney function and urinary kidney injury biomarkers. Following 24 h of vancomycin administration, rats in the humanized infusion group had equivalent area under the curve exposures to animals in the dose-matched bolus group (93.7 mg·h/L [IQR 90.2-97.2] vs. 99.5 mg·h/L [IQR 95.1-104.0], P = 0.07). No significant differences in iohexol-measured kidney function nor meaningful differences in urinary kidney injury biomarkers, kidney injury molecule-1, clusterin, and osteopontin, were detected. Administration of intravenous vancomycin as either a humanized infusion or dose-matched bolus resulted in similar vancomycin exposures. No differences in iohexol-measured GFR nor meaningful differences in urinary kidney injury biomarkers were observed among male Sprague-Dawley rats.

Homeostatic changes of trace elements in diazinon toxicity in rat model: The beneficial role of resveratrol

Background and objectives

Diazinon (DZN) is a cholinesterase inhibitor widely used to relieve agricultural pests and upgrade the productivity of crops. Resveratrol (Res), as a phenolic plant compound, has a protective role against free radicals. This study intended to evaluate the impacts of Res on homeostatic disturbances induced by DZN in rats.

Method

Twenty-four Wistar rats (4 weeks) were randomly distributed into four groups of six animals each. The first group (control group) received corn oil. The second group (Res group) received orally Res (20 mg/kg. The third group (DZN group) received the oral DZN (70 mg/kg); the fourth group (Res plus DZN group) was treated simultaneously with DZN (70 mg/kg) and Res (20 mg/kg); for a period of 5 weeks. The serum, liver, kidney, and heart levels of the Copper (Cu), zinc (Zn), iron (Fe), selenium (Se), and magnesium (Mg) as main trace elements are measured.

Results

DZN treatment decreased significantly serum, liver, kidney, and heart levels of Cu, Zn, Fe, Se, and Mg in comparison with the control group. Res administration enhanced serum, liver, kidney, and content of heart elements compared to the DZN group.

Conclusions

These results suggested that Res could ameliorate the homeostatic imbalance induced by DZN. Res had a protective effect against DZN-provoking heart, renal, and hepatic toxicity in animal models.

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.