Renal Tubular Lesions Research Articles

Densidade urinária como um indicador para determinação da GGT urinária em cães com leishmaniose visceral

The urinary Gama-Glutamyl Transpeptidase to urinary Creatinine ratio (uGGT/uCR) is a laboratory marker that may signal renal tubular lesion in dogs with visceral leishmaniasis (VL). In this study, our goal was to determine whether urine specific gravity (USG) can accurately indicate an elevated uGGT/uCR and, consequently, tubular injury. Twenty-eight animals with VL and five healthy animals (control group) were included in the study. The diseased animals were classified as azotemic (n = 6) and non-azotemic (n = 22). The difference between all groups was tested with the Kruskal-Wallis test for the USG, uGGT/uCR, and urine protein: creatinine ratio (UPC). Sensitivity, specificity, positive and negative predictive value and the accuracy of using USG as an indicator of tubular injury were calculated with the Receiver Operating Characteristic (ROC curve). The probability of an animal with suboptimal USG presenting tubular injury was obtained by calculating the prevalence ratio. The Kruskal-Wallis test revealed differences between groups for all analyzed parameters (p< 0.05). The chosen USG cut-off value, determined by the ROC curve was 1.030, with an accuracy of 78.09%. The probability of a dog with LV and USG below 1.030 having a high uGGT/uCR ratio was 4.95 (p <0.01, 95% CI - 1.32-18.48) when compared to individuals with ideal DU. In conclusion, dogs positive for Leishmania sp. with low USG (<1.030) should have their uGGT/uCR ratio measured to verify the presence of tubular injury even before the onset of azotemia.

Chronic dehydration induces injury pathways in rats, but does not mimic histopathology of chronic interstitial nephritis in agricultural communities

CINAC-patients present renal proximal tubular cell lysosomal lesions which are also observed in patients experiencing calcineurin inhibitor (CNI) nephrotoxicity, suggesting that CINAC is a toxin-induced nephropathy. An alternative hypothesis advocates chronic dehydration as a major etiological factor for CINAC. Here, we evaluated histological and molecular changes in dehydrated versus toxin exposed rats. Wistar rats were divided in 3 groups. Group 1 (n = 6) had free access to drinking water (control group). Group 2 (n = 8) was water deprived for 10 h per 24 h, 5 days/week and placed in an incubator (37 °C) for 30 min/h during water deprivation. Group 3 (n = 8) underwent daily oral gavage with cyclosporine (40 mg/kg body weight). After 28 days, renal function, histopathology and proteomic signatures were analysed. Cyclosporine-treated rats developed focal regions of atrophic proximal tubules with associated tubulo-interstitial fibrosis. PASM staining revealed enlarged argyrophilic granules in affected proximal tubules, identified as lysosomes by immunofluorescent staining. Electron microscopy confirmed the enlarged and dysmorphic phenotype of the lysosomes. Overall, these kidney lesions resemble those that have been previously documented in farmers with CINAC. Dehydration resulted in none of the above histopathological features. Proteomic analysis revealed that dehydration and cyclosporine both induce injury pathways, yet of a clear distinct nature with a signature of toxicity only for the cyclosporine group. In conclusion, both cyclosporine and dehydration are injurious to the kidney. However, dehydration alone does not result in kidney histopathology as observed in CINAC patients, whereas cyclosporine administration does. The histopathological analogy between CINAC and calcineurin inhibitor nephrotoxicity in rats and humans supports the involvement of an as-yet-unidentified environmental toxin in CINAC etiology.

Cinnamon essential oil based on NLRP3 inflammasome and renal uric acid transporters for hyperuricemia

Cinnamon is widely used as a medicinal herb and a culinary spice. The major bioactive component of cinnamon is cinnamon essential oil (CEO). CEO has been reported to have anti-inflammatory and antioxidant effects, but its mechanism of action is not known. In this study, metabolomics was combined with “weighting coefficients” from network pharmacology to identify key pathways and targets, differential metabolites and key metabolic pathways for the therapeutic effects of CEO on Hyperuricemia (HUA), and to precisely investigate the molecular mechanisms of the therapeutic effects of CEO on HUA. Metabolomic analysis revealed that abnormal l-glutamate metabolism and dysregulation of Arachidonic acid (AA) metabolic pathways exacerbated inflammatory responses and oxidative stress, subsequently mediating pathological changes in HUA and exacerbating renal tissue damage. Pharmacodynamic validation showed that CEO alleviated the renal inflammatory response by inhibiting hepatic xanthine oxidase activity, upregulating superoxide dismutase and glutathione peroxidase levels, and downregulating malondialdehyde levels, synergistically inhibiting NLRP3 inflammasome activation, suppressing downstream inflammatory Interleukin-1 beta (IL-1β) and Interleukin-18 (IL-18) secretion, and enhancing antioxidant levels. Additionally, CEO exerted renal protective effects by upregulating the renal transporters OAT1 and ABCG2 and downregulating the GLUT9 and URAT1 levels, resulting in the downregulation of uric acid production and the alleviation of renal tubular lesions. This suggests that CEO could be considered as a potential functional food for kidney damage caused by hyperuricemia.

Huangkui capsule attenuates diabetic kidney disease through the induction of mitophagy mediated by STING1/PINK1 signaling in tubular cells

BackgroundMitochondria is critic to tubulopathy, especially in diabetic kidney disease (DKD). Huangkui capsule (HKC; a new ethanol extract from the dried corolla of Abelmoschus manihot) has significant clinical effect on DKD. Previous studies have shown that HKC protects kidney by regulating mitochondrial function, but its mechanism is still unclear. The latest research found that the stimulator of interferon genes (STING1) signal pathway is closely related to mitophagy. However, whether HKC induces mitophagy through targeting STING1/PTEN-Induced putative kinase (PINK1) in renal tubular remains elusive. ObjectiveThis study aims to clarify the therapeutic effect of HKC on renal tubular mitophagy in DKD and its potential mechanism in vivo and in vitro. MethodsForty male C57BL/6 mice were randomly divided into 5 groups: CON group, DKD group, HKC-L (1.0 g/kg/day, by gavage), HKC-H (2.0 g/kg/day), and LST group. Diabetes model was induced by high-fat diet (HFD) combined with intraperitoneal injection of Streptozotocin (STZ). LST (losartan) is used as a positive control drug. Then, the glomeruli, renal tubular lesions, mitochondrial morphology and function of renal tubular cells and mitophagy levels were detected in mice. In addition, a high glucose injury model was established using HK2 human renal tubular cells. Pretreate HK2 cells with HKC or LST and detect mitochondrial function, mitophagy level, and autophagic flux. In addition, small interfering RNAs (siRNAs) of STING1 and PINK1 and overexpressing pcDNA3.1 plasmids were transfected into HK-2 cells to validate the mitophagy mechanism regulated by STING1/PINK1 signaling. ResultsThe ratio of urinary albumin to creatinine (ACR), fasting blood glucose, body weight in the early DKD mice model was increased, with damage to the glomerulus and renal tubules, mitochondrial structure and dysfunction in the renal tubules, and inhibition of STING1/PINK1 mediated mitophagy. Although the fasting blood glucose, body weight and serum creatinine levels were hardly ameliated, high dose HKC (2.0 g/kg/day) treatment significantly reduced ACR in the DKD mice to some extent, improved renal tubular injury, accurately upregulated STING1/PINK1 signaling mediated mitophagy levels, improved autophagic flux, and restored healthy mitochondrial pools. In vitro, an increase in mitochondrial fragments, fusion to fission, ROS and apoptosis, and a decrease in respiratory function, mtDNA, and membrane potential were observed in HK2 cells exposed to high glucose. HKC treatment significantly protected mitochondrial dynamics and function, which is consistent with in vivo results. Further research has shown that HKC can increase the level of mitophagy mediated by STING1/PINK1 in HK2 cells. ConclusionsOur results suggest that HKC ameliorates renal tubulopathy in DKD and induces mitophagy partly through the up-regulation of the STING1/PINK1 pathway. These findings may provide an innovative therapeutic basis for DKD treatment.

Secreted phosphoprotein 1 exacerbates renal ischemia-reperfusion injury by inhibiting PI3K/AKT signaling pathway

BackgroundRenal ischemia-reperfusion injury (IRI) is a prevalent reason for acute kidney injury and a key clinical issue for patients under anesthesia and about to have surgery. We aim to investigate the Secreted phosphoprotein 1 (SPP1) role in renal IRI and the underlying mechanisms. MethodsUsing Gene Expression Omnibus (GEO) database helped in analyzing the SPP1 expression in renal IRI. We established two models, a mouse renal ischemia-reperfusion (I/R) besides a hypoxia-reoxygenation (H/R) HK-2 cell. Renal tubular lesions were measured using H&E staining. Depending on the TUNEL assay, immunohistochemistry, qRT-PCR, as well as western blot, we applied the assessment of apoptosis and apoptosis-associated protein levels. At the same time, a western blot was performed for assessing PI3K/AKT pathway-associated proteins. ResultsGEO data and experimental validation revealed elevated SPP1 content in the kidney tissues of renal I/R mice more than in sham mice. In vitro and in vivo studies revealed an increase in cell apoptosis due to SPP1 overexpression, but the opposite is true when SPP1 is silenced. SPP1 downregulation led to high p-PI3K and p-AKT protein levels, and the LY294002 application inhibited SPP1 inhibition-mediated anti-apoptotic effect ConclusionTaken together, SPP1 exacerbates renal IRI in vivo and in vitro via promoting programmed cell death by inhibiting PI3K/AKT signaling pathway.

BCS1Neonatal growth retardation and lactic acidosis initiated by novel mutation sites in L gene

This study aims to analyze the clinical characteristics and genetic variations of two cases with developmental delay and lactic acidosis in a family, and to explore the relationship between genetic variations and clinical features. A retrospective analysis was conducted on the clinical characteristics of two siblings with developmental delay and lactic acidosis who were treated at the Neonatal Department of Children's Hospital of Chongqing Medical University in May 2019 and December 2021, respectively. Whole-exome sequencing was used to detect genetic variations in the affected children. Homology modeling of the BCS1L protein was performed to analyze the structural and functional changes of the protein. The correlation between genetic variations and clinical phenotypes was analyzed. The results showed that the main clinical features of the two affected children in this family were manifestations of mitochondrial respiratory chain complex Ⅲ deficiency, including prematurity, developmental delay, respiratory failure, lactic acidosis, cholestasis, liver dysfunction, renal tubular lesions, coagulation dysfunction, anemia, hypoglycemia, hypotonia, and early death. Whole-exome sequencing revealed a novel deletion mutation c.486_488delGGA (p.E163del) and a novel missense mutation c.992C>T (p.T331I) in the BCS1L gene. Structural analysis of the homology modeling showed that the compound heterozygous mutation had a significant impact on protein function. In conclusion, the novel mutation site c.992C>T (p.T331I) in the BCS1L gene is a "likely pathogenic" mutation, and the compound heterozygous mutation is closely related to the phenotype of mitochondrial respiratory chain complex Ⅲ deficiency.

Inhibition of ferroptosis of renal tubular cells with total flavones of Abelmoschus manihot alleviates diabetic tubulopathy.

Ferroptosis-related renal tubular lesions play important roles in diabetic kidney disease (DKD) progression, and these pathophysiological responses are collectively described as diabetic tubulopathy (DT), which lacks an effective treatment. Total flavones from Abelmoschus manihot (TFA), a natural extract that extensively used in patients with chronic kidney disease, has been used for treatment of renal tubular injury in DKD; however, whether TFA alleviates DT and its potential mechanisms remain unclear. Hence, we investigated the effects of TFA, compared to dapagliflozin, in DT management both in vivo and in vitro, using a DKD rat model and the NRK-52 E cells. Following modeling, the DKD rats received TFA, dapagliflozin, or vehicle for 6 weeks. For the in vitro research, the NRK-52 E cells were exposed to advanced glycation end products (AGEs) plus ferrostatin-1 (Fer-1), dapagliflozin, or TFA. Changes in biochemical parameters and renal tubular injury were analyzed in vivo, while changes in ferroptosis of renal tubular cells and the ferroptosis-related proteins expression were analyzed both in vivo and in vitro. We found that TFA and dapagliflozin improved biochemical parameters, renal tubular injury, and ferroptosis in the DKD rats. Moreover, TFA and dapagliflozin inhibited ferroptosis by ameliorating iron deposition, lipid peroxidation capacity, and ferroptosis-related proteins expression in vitro, which was similar to the effects of Fer-1. Collectively, this study demonstrated that TFA treated DT in a manner similar to dapagliflozin by inhibiting ferroptosis of renal tubular cells via improving iron deposition and antioxidant capacity. Our findings provide new pharmacological evidence for TFA application in DT treatment.

Total Marrow Irradiation Reduces Organ Damage in a Bone Marrow Transplant Model of Sickle Cell Disease

Sickle cell disease (SCD) is associated with significant organ pathology. Currently, the only curative option is bone marrow transplantation (BMT) after myeloablative conditioning. However, significant organ damage from myeloablative total body irradiation (TBI) remains one of the major side effects of BMT. To reduce exposure to vital organs, but efficient enough to maintain engraftment, we developed 3D image guided-total marrow irradiation (TMI) for targeted delivery to the bone marrow (BM) and spleen of humanized BERK sickle mice while sparing the vital organs. We hypothesized that TMI will prevent organ damage compared to that induced by TBI during BMT. Sickle mice were treated with: [i] TBI (4:4), 4 Gy to the BM & 4 Gy to the whole body; [ii] TMI (4:0), 4 Gy to BM, 0 Gy to the body, and [iii] TMI (8:2), 8 Gy to BM & 2 Gy to the whole body. After 24h of irradiation, SS mice were transplanted with 5 million donor BM cells from HbAA BERK mice expressing normal human hemoglobin A (n=3/group). Thirty days after BMT mice were euthanized, and organs were necropsied for histopathology. Formalin-fixed paraffin-embedded sections of the lung, liver, kidney, spleen, and bone marrow (femur & tibia) were stained with H&E and Prussian blue (iron deposits). Morphologic findings of vascular congestion, inflammatory infiltrate, and iron deposits were scored from '0' for no lesion up to '6' for severe lesions occupying 90-100% of the field (Manci et al., Blood 2006). Tubular brush border thickness was assessed on periodic acid Schiff's (PAS)-hematoxylin-stained kidney sections using a 0-4 grading scale: no changes ='0'; lesion area <25%=1; 25%-50% = 2; >50% = 3 and 100% = 4 (Kasztan et al. J Am Soc Nephrol. 2017). We observed significantly increased vascular congestion in the liver (p=0.003), and spleen (p=0.013), and inflammatory infiltrates in the lungs (p=0.031) of TBI-treated mice compared to TMI (8:2). Total body irradiation has been shown to induce inflammation with granulocyte infiltration into tissues in association with endothelial damage, vascular dilatation, and congestion. Moreover, increase iron content in BM and serum and disrupted iron metabolism is another known sequala of total body irradiation, which contributes to hemosiderin formation in tissues. We found significant increase in iron deposits in TBI (4:4) vs TMI (8:2) in liver (p=0.001), spleen (p=0.014), and kidney (p=0.043). TBI (4:4) led to more renal tubular lesions (p=0.003) marked by a significant loss in the tubular brush border on PAS-stained kidney sections compared to TMI (8:2). Thus, TMI shows lesser damaging effect on vital organs compared to TBI, while TMI (8:2) showed donor chimerism similar to TBI on days 7 and 14 but higher than TMI (4:0) treated mice. However, the engraftment failed (less than 10% chimerism) in all groups by day 30. To improve engraftment, we transplanted 10- and 25-million donor HbAA BERK BM cells into TMI (4:0) and TMI (8:2) treated sickle mice. TMI (8:2) showed sustained donor chimerism but TMI (4:0) did not. Histopathological analysis 90 days post-BMT showed that TMI (8:2) treatment (n=3) results in significantly lesser organ pathology Vs untreated sickle mice (n=2), as evinced by reduction in: vascular congestion (lung, p=0.014; liver, p=0.014; spleen p= 0.014), inflammatory infiltrate (lung, p= 0.031; liver p= 0.005), liver infarctions (p=0.003) and liver and kidney iron deposits (p=0.041 & 0.021, respectively). Untreated mice showed a significant loss in the tubular brush border compared to TMI (8:2) treatment (p=0.008). BM in TMI (8:2) (cellularity~70%) showed improvement in cellular differentiation and topography in comparison to the untreated (cellularity ~90% ) that were packed with minimal fat spaces, thin trabeculae, and marked erythroid hyperplasia. These data suggest recovery from sickle cell phenotype with TMI-8:2 without significant organ pathology. Additionally, toluidine blue stained skin sections showed that the number (~45 Vs ~15) and % degranulating mast cells (~85 % Vs 50 %) were significantly lower in TMI (8:2) Vs untreated sickle mice (p<0.05), suggesting that TMI (8:2) treatment and successful engraftment of healthy donor cells may reduce inflammation and pain phenotype. We show that dose escalated TMI (8:2) is well tolerated with reduced organ pathology. Therefore, TMI has the potential to improve BMT-related outcomes without an adverse effect on organ damage.

Важливість визначення ренального тубулярного біомаркера KIM-1 у дітей з ювенільним ідіопатичним артритом

Renal tubular lesions play an important role in the development and progression of chronic kidney disease (CKD). There has been only one cohort retrospective study of the prevalence of CКD in children with juvenile idiopathic arthritis (JIA). Therefore, early diagnosis of kidney damage using renal biomarkers is important. Purpose - to determine the frequency and risk factors for the development of structural tubular lesions by studying the level of kidney injury molecule-1 (KIM-1) in the urine of children with JIA, depending on the characteristics of the clinical course of the disease, use of nonsteroidal anti-inflammatory drugs (NSAIDs). Materials and methods. 80 children from JIA were examined. To measure the marker KIM-1 in urine samples, an enzyme-linked immunosorbent assay was used. Results. The indicator of the urinary marker KIM-1 in the examined children was 0.997±0.1662 (0.98; 0.90-1.12) ng/ml. High activity of JIA affects the level of urinary KIM-1 - among children with high activity of the disease, 20% had a high level of KIM-1. Involvement of ≥6 joints almost 3-fold increased the in CIdence of elevated urinary KIM-1 levels (OR=5.00; 95% CI: 1.65-15.15; p&lt;0.006). Risk factors for structural tubular kidney lesions in children with JIA were identified: high JIA activity (OR=7.25; 95% CI: 1.22-43.22; p&lt;0.04), arthritis ≥6 joints (OR=5.00; 95% CI: 1.65-15.15; p&lt;0.006), arthritis of the small joints of the hands (OR=4.85; 95% CI: 1.39-16.87; p&lt;0.02), arthritis of the wrist joints (OR=3.78; 95% CI: 1.21-11.83; p&lt;0.03), arthritis of the hip joints (OR=10.41; 95% CI: 1.02-106.7; p&lt;0.05). The level of urinary biomarker KIM-1 was negatively affected by long-term use of NSAIDs (ρ=0.60, p&lt;0.004). An increased level of KIM-1 in urine is associated with hypertension (OR=12.43; 95% CI: 2.26-68.27; p&lt;0.003) and reduced Estimated Glomerular Filtration Rate (eGFR) according to the Hoek formula (OR=15.58; 95% CI: 4.02-60.36; p&lt;0.001), which suggests the presence of CKD in children with JIA as a result of tubular lesions. Conclusions. Structural damage of the renal tubules, which was established by studying the biomarker KIM-1 in the urine and the relationship with reduced eGFR according to the Hoek formula, suggests the presence of CKD in children with JIA as a result of tubular lesions. Urine KIM-1 testing should be included in the JIA screening plan for early diagnosis of renal disease. The study was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the institution specified in the work. Informed consent was obtained from the parents of the children for the research. The authors declare no conflicts of interest. Key words: juvenile idiopathic arthritis, tubular biomarker KIM-1, children.

Antibiotic Exposure Aggravates Bacteroides-Linked Uremic Toxicity in the Gut-Kidney Axis.

Epidemiological and experimental evidence has implicated a potent link between antibiotic exposure and susceptibility to various diseases. Clinically, antibiotic treatment during platinum chemotherapy is associated with poor prognosis in patients with malignancy. In the present study, mucosal antibiotic exposure was assessed for its impact on renal distress as a sequela of platinum-based chemotherapy. Clinical transcriptome dataset-based evaluations demonstrated that levels of dysbiosis-responsive genes were elevated during renal distress, indicating pathological communications between gut and kidney. Experimentally, mucosal exposure to streptomycin aggravated platinum-induced renal tubular lesions in a mouse model. Moreover, antibiotic-induced dysbiosis increased susceptibility to gut mucosal inflammation, epithelial disruption, and bacterial exposure in response to cisplatin treatment. Further investigation of the luminal microbes indicated that antibiotic-induced dysbiosis promoted the dominance of Bacteroides species. Moreover, the functional assessment of dysbiotic microbiota predicted tryptophan metabolic pathways. In particular, dysbiosis-responsive Bacteroides acidifaciens was associated with the production of the uremic toxin indoxyl sulfate and renal injuries. The results of this study including bacterial community-based evaluations provide new predictive insights into the interorgan communications and interventions against dysbiosis-associated disorders.

Abstract P168: Pretargeted radioimmunotherapy using 225Ac for intraperitoneal Her2-expressing epithelial ovarian carcinoma xenografts

Abstract Objectives Epithelial ovarian carcinoma (EOC) is a common and lethal gynecologic malignancy that frequently presents as advanced staged disease, such as peritoneal carcinomatosis (PC). We previously reported cures in BT-474 murine xenografts with Pretargeted Radioimmunotherapy (PRIT) using 177Lu radiohaptens targeting Her2 via a bispecific antibody (BsAb). Here-in we report the use of PRIT with alpha emitter 225Ac labelled PrDOTA to treat a PC model of SKOV3, a Her2+ cell line of EOC. Methods 6 wk old female athymic nude mice inoculated IP with 1E5 luciferase/GFP-transfected SKOV3 cells were separated into 5 groups (n=10). Treatment mice received 1 or 2 cycles of Anti-Her2-C825 BsAb + [225Ac]PrDOTA (Her2-Targeted), at 14 and 21 days after inoculation, respectively. Control groups received Anti-Her2 BsAb only, Anti-GPA33 BsAb + [225Ac]PrDOTA (Off-Targeted) or no treatment. On cycle day 1, the mice were injected IP with 0.25mg (1.19nmol) BsAb. On cycle day 2, 25µg (2.76nmol) CCA16-DOTAY clearing agent (CA) was given IV 22h from BsAb. Mice in therapy groups were injected IP with 1µCi (0.74-0.79nmol) [225Ac]PrDOTA-Bn 4h after CA. Weekly weights and BLIs with IP cavity ROIs were obtained and normalized to the respective values for each mouse at week 0 pre-treatment. End points: weight loss &amp;gt;20% baseline, moribund, or severe abdominal distension. At 154 days, 15 surviving treatment and 1 untreated control mice were submitted for hematology and histopathology. Results Histologic cures and prolonged survival were demonstrated in treatment mice (17/20 at 133 days) as compared to control mice (12/27 at 133 d, Logrank p&amp;lt;0.04). 3 mice from control groups were excluded due to BLI values &amp;lt;50% background in the first 3 weeks, suggesting no tumor burden. Tumors, as measured by normalized BLI values (nBLI), regressed in treatment mice when compared to control mice (2-way ANOVA p&amp;lt;0.01). nBLI values between treatment mice (1 and 2 cycles) and control mice (BsAb only, Off-target, no treatment) diverged at week 10 (Tukey’s test p&amp;lt;0.01). There was no difference in nBLI values between mice treated with 1 or 2 cycles of targeted PRIT (Tukey’s test p&amp;gt;0.05; all weeks). BLI of mice treated with 1 and 2 cycle of Her2 PRIT decreased 47% when compared to baseline within 1 week (T test p=0.04), suggesting treatment effects as early as 1 week. There were no differences in weights when compared to baseline (2-way ANOVA p&amp;gt;0.05). While the untreated mouse had high peritoneal adenocarcinoma tumor burden, there was no histologic evidence of viable neoplasia in 15/15 submitted treatment mice. Treatment mice had moderate renal tubular degenerative lesions on histology, but this did not affect renal function based on serum BUN or Cr. All hematologic parameters were within normal limits for treated mice. Conclusions 1 and 2 cycles of [225Ac]PrDOTA-PRIT against Her2 resulted in histologic cures and prolonged survival in IP SKOV3 xenografts with minimal toxicity. The anti-Her2 PrDOTA-PRIT system is a promising theranostic approach for otherwise incurable PC. Citation Format: Sebastian K. Chung, Christopher S. Chandler, Daniela Burnes Vargas, Shin H. Seo, Michael R. McDevitt, Darren Veach, Blesida Punzalan, Xu Hong, Hong-fen Guo, Garrett M. Nash, Andrea Cercek, Nai-Kong V. Cheung, Steven M. Larson, Sarah M. Cheal. Pretargeted radioimmunotherapy using 225Ac for intraperitoneal Her2-expressing epithelial ovarian carcinoma xenografts [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P168.

Effect of Fc-Elabela-21 on renal ischemia/reperfusion injury in mice: Mediation of anti-apoptotic effect via Akt phosphorylation

IntroductionRenal ischemia/reperfusion injury (IRI) is the most common cause of acute kidney injury (AKI), and patients with AKI have a high rate of mortality. Apelin is a therapeutic candidate for treatment of IRI and Elabela (ELA) is a recently discovered hormone that also activates the apelin receptor (APJ). We examined the use of ELA as a preventive treatment for IRI using in vitro and in vivo models. MethodsMale mice were subjected to renal IRI, with or without administration of a stabilized form of ELA (Fc-ELA-21) for 4 days. Renal tubular lesions were measured using H&E staining, reactive oxygen species (ROS) were measured using a dihydroethidium stain assay, and renal cell apoptosis was measured using the TUNEL assay and flow cytometry. Immortalized human proximal tubular epithelial (HK-2) cells were pretreated with or without LY294002 and/or ELA-32, maintained at normoxic or hypoxic conditions, and then returned to normal culture conditions to mimic IRI. Cell apoptosis was determined using the TUNEL assay and cell proliferation was determined using the MTT assay. The levels of Akt, p-Akt, ERK1/2, p- ERK1/2, Bcl-2, Bax, caspase-3 and cleaved caspase-3 were measured using western blotting. ResultsFc-ELA-21 administration reduced renal tissue damage, ROS production, and apoptosis in mice that had renal IRI. ELA-32 reduced HK-2 cell apoptosis and restored the proliferation of cells subjected to IRI. Akt phosphorylation had a role in the anti-apoptotic effect of ELA. ConclusionThis study of in vitro and in vivo models of IRI indicated that the preventive and anti-apoptotic effects of ELA were mediated via the PI3K/Akt signaling pathway.

GATA3 Is a Useful Immunohistochemical Marker to Differentiate Variants of Renal Tubular Lesions from Different Segments of Renal Tubules

Abstract Introduction/Objective GATA3 is found in glomerular mesangial cells, and the distal tubules &amp; collecting ducts in metanephros and eventual kidneys, but not associated with the proximal tubules and loops of Henle. We hypothesize that GATA3 can be used as a marker to identify the origin of tubular differentiation in most renal tumors. Methods/Case Report Ten negative controls and 43 renal mass lesions (RCC, papillary, clear cell papillary, and chromophobe carcinomas, oncocytoma, and polycystic kidney disease). GATA3 nuclear stain was graded as negative (absent stain), equivocal and positive (&amp;lt; 5 and &amp;gt; 5% cells, respectively). Details of their GATA3 nuclear expression was analyzed for identifying their tubular segmental origins. Results (if a Case Study enter NA) In 10 normal renal parenchyma, GATA3 was positive in mesangial cells, distal tubules, and collecting ducts, but was negative in the proximal tubules and loop of Henle. The cystic lining of glomerulocystic renal disease was stained negatively for GATA3 (proximal tubular origin), whereas pediatric and adult variants of polycystic kidney diseases was positive for GATA3 staining (distal tubular origin). 1/10 ten clear cell RCC and papillary RCC showed focal positive GATA3 stain. GATA3 showed weakly positive staining in some oncocytomas (4/11) and some chromophobe RCC (4/11), indicating that they might be derived from the junctional segment between the loop of Henle and the distal tubules. By contrast, all clear cell papillary RCC (distal tubule origin) were diffusely positive. Conclusion Our results indicate that GATA3 is a useful immunohistochemical marker to determine the developmental origin in the specific renal tubular segment for the majority of renal mass lesions. Thus, it may be useful for routine differential diagnosis of these lesions.

The role of CDX2 in renal tubular lesions during diabetic kidney disease.

Renal tubules are vulnerable targets of various factors causing kidney injury in diabetic kidney disease (DKD), and the degree of tubular lesions is closely related to renal function. Abnormal renal tubular epithelial cells (RTECs) differentiation and depletion of cell junction proteins are important in DKD pathogenesis. Caudal-type homeobox transcription factor 2 (CDX2), represents a key nuclear transcription factor that maintains normal proliferation and differentiation of the intestinal epithelium. The present study aimed to evaluate the effects of CDX2 on RTECs differentiation and cell junction proteins in DKD. The results demonstrated that CDX2 was mainly localized in renal tubules, and downregulated in various DKD models. CDX2 upregulated E-cadherin and suppressed partial epithelial-mesenchymal transition (EMT), which can alleviate hyperglycemia-associated RTECs injury. Cystic fibrosis transmembrane conductance regulator (CFTR) was regulated by CDX2 in NRK-52E cells, and CFTR interfered with β-catenin activation by binding to Dvl2, which is an essential component of Wnt/β-catenin signaling. CFTR knockdown abolished the suppressive effects of CDX2 on Wnt/β-catenin signaling, thereby upregulating cell junction proteins and inhibiting partial EMT in RTECs. In summary, CDX2 can improve renal tubular lesions during DKD by increasing CFTR amounts to suppress the Wnt/β-catenin signaling pathway.

New Potential Biomarkers for Chronic Kidney Disease Management—A Review of the Literature

The prevalence of chronic kidney disease (CKD) is increasing worldwide, and the mortality rate continues to be unacceptably high. The biomarkers currently used in clinical practice are considered relevant when there is already significant renal impairment compromising the early use of potentially successful therapeutic interventions. More sensitive and specific biomarkers to detect CKD earlier on and improve patients’ prognoses are an important unmet medical need. The aim of this review is to summarize the recent literature on new promising early CKD biomarkers of renal function, tubular lesions, endothelial dysfunction and inflammation, and on the auspicious findings from metabolomic studies in this field. Most of the studied biomarkers require further validation in large studies and in a broad range of populations in order to be implemented into routine CKD management. A panel of biomarkers, including earlier biomarkers of renal damage, seems to be a reasonable approach to be applied in clinical practice to allow earlier diagnosis and better disease characterization based on the underlying etiologic process.

Identification of compound mutations of SLC12A3 gene in a Chinese pedigree with Gitelman syndrome exhibiting Bartter syndrome-liked phenotypes

BackgroundGitelman syndrome is a rare salt-losing renal tubular disorder associated with mutation of SLC12A3 gene, which encodes the Na-Cl co-transporter (NCCT). Gitelman syndrome is characterized by hypokalemia, metabolic alkalosis, hypomagnesemia, hypocalciuria, and renin-angiotensin-aldosterone system (RAAS) activation. Different SLC12A3 variants may lead to phenotypic variability and severity.MethodsIn this study, we reported the clinical features and genetic analysis of a Chinese pedigree diagnosed with Gitelman syndrome.ResultsThe proband exhibited hypokalaemia, hypomagnesemia, metabolic alkalosis, but hypercalciuria and kidney stone formation. The increased urinary calcium excretion made it confused to Bartter syndrome. The persistent renal potassium wasting resulted in renal tubular lesions, and might affect urinary calcium reabsorption and excretion. Genetic analysis revealed mutations of SLC12A3 gene with c.433C > T (p.Arg145Cys), c.1077C > G (p.Asn359Lys), and c.1666C > T (p.Pro556Ser). Potential alterations of structure and function of NCCT protein due to those genetic variations of SLC12A3 are predicted. Interestingly, one sibling of the proband carried the same mutant sites and exhibited similar clinical features with milder phenotypes of hypokalemia and hypomagnesemia, but hypocalciuria rather than hypercalciuria. Family members with at least one wild type copy of SLC12A3 had normal biochemistry. With administration of spironolactone, potassium chloride and magnesium supplement, the serum potassium and magnesium were maintained within normal ranges.ConclusionsIn this study, we identified compound mutations of SLC12A3 associated with varieties of clinical features. Further efforts are needed to investigate the diversity in clinical manifestations of Gitelman syndrome and its correlation with specific SLC12A3 mutations.

Establishment of Rat Model of Insulin Resistance Exposed to Chronic Renal Allograft Dysfunction

BackgroundThe main cause of chronic renal allograft dysfunction (CRAD) still remains unclear. Insulin resistance (IR) may be a potential inducement, but there is insufficient evidence about this association. We aimed to establish a rat model of CRAD complicated with IR and to explore the function and pathologic changes of the renal allograft induced by IR. MethodsF344-to-Lewis rats of CRAD were fed a high-fat diet to induce IR. They were divided into 3 groups: IR (CRAD+IR), CRAD, and control (CTL). Serum levels of blood urea nitrogen (BUN) and serum creatinine (Scr) were measured to evaluate the renal function. The Homeostasis Model Assessment (HOMA)-IR index was detected by comparing the values of fasting serum insulin levels (FINS) with fasting blood glucose levels (FBG). The pathologic analysis was conducted by the degree of renal lesions including glomerular lesions, renal tubular lesions, hemorrhage, inflammatory cell infiltration, fibrillation, and hyperplasia of the renal interstitium. ResultsIn the second, third, and fourth month after surgery, serum levels of Scr and BUN in the IR group were reduced more than those in the CRAD group, while they were both higher compared to the CTL group, suggesting that renal function in the CRAD group was declined. The HOMA-IR in the IR group was greater than that in the CRAD and CTL groups, showing that simple high-fat diet feeding significantly and steadily increased FINS and FBG in CRAD complicated with IR rats. Pathologic changes indicated that the CRAD rat model was successfully constructed and was still in the early-middle stages of renal lesions 4 months after surgery, yet IR presented a significant effect on CRAD. ConclusionThese results indicate that the stable CRAD complicated with IR rat model can be established through a high-fat diet in CRAD rats in 4 months, and IR could be an influencing factor.

Oxymatrine Inhibits Twist-Mediated Renal Tubulointerstitial Fibrosis by Upregulating Id2 Expression.

The final pathway for the development of diabetic nephropathy (DN) into chronic renal failure in DN is glomerulosclerosis and tubulointerstitial fibrosis. Renal tubular lesions can occur in the early stage of DN renal injury. Cumulative evidence shows that oxymatrine (OMT) has a variety of biological and pharmacological properties. In recent years, more attention has been paid on the preventive and therapeutic influence of OMT on organ fibrosis. In this experiment, db/db mice were intraperitoneally injected with OMT 120 mg/kg for 8 weeks, and NRK-52E cultured with 30 mmol/L glucose and 0.1 mg/mL OMT for 48-hour. We investigated the relationship between Id2 and Twist in NRK-52E cells and the effect of OMT on the expression of E-cadherin, α-SMA, Fibronectin, and Collagen-IV by Western blot, Real-time PCR, Immunofluorescence, cell transfection, Co-Immunoprecipitation, and Luciferase assays. OMT increased the expression of Id2 but decreased that of Twist under high glucose condition in vitro and in vivo. The promoted recovery of Id2 facilitated its binding to Twist and affected E-cadherin activity inhibiting EMT and the excessive proliferation and abnormal deposition of ECM. In brief, OMT promotes Id2 to reverse EMT and exert anti-fibrotic effect in diabetic renal tubular epithelial cells by binding Id2 to Twist and affecting its transcriptional activation of downstream target genes. Or findings provide a new experimental basis for delaying the progress and for treatment of diabetic renal fibrosis.

New Insights into the Pathogenesis of Diabetic Nephropathy: Proximal Renal Tubules Are Primary Target of Oxidative Stress in Diabetic Kidney.

Diabetic nephropathy is a major source of end-stage renal failure, affecting about one-third cases of diabetes mellitus. It has long been accepted that diabetic nephropathy is mainly characterized by glomerular defects, while clinical observations have implied that renal tubular damage is closely linked to kidney dysfunction at the early stages of diabetic nephropathy. In this study, we conducted pathohistological analyses focusing on renal tubular lesions in the early-stage diabetic kidney with the use of a streptozotocin (STZ)-induced diabetes mellitus mouse model. The results revealed that histological alterations in renal tubules, shown by a vacuolar nucleic structure, accumulations of PAS-positive substance, and accelerated restoration stress, occur initially without the presence of glomerular lesions in the early-stage diabetic kidney, and that these tubular defects are localized mainly in proximal renal tubules. Moreover, enhanced expression of RAGE, suggesting an aberrant activation of AGEs-RAGE signaling pathway, and accumulation of oxidative modified mitochondria through the impaired autophagy/lysosome system, were also seen in the damaged diabetic proximal renal tubules. Our findings indicate that proximal tubular defects are the initial pathological events increasingly linked to the progression of diabetic nephropathy, and that controlling renal tubular damage could be an effective therapeutic strategy for the clinical treatment of diabetic nephropathy.

Evaluation of urine N-acetyl-β-D-glucosaminidase in renal tubular interstitial lesions of IgA nephropathy

Objective To explore the clinical significance of urine NAG in judging the condition of renal tubular interstitial lesions in patients with IgA nephropathy (IgAN). Methods The data of 82 IgAN patients who had been clinical and pathological diagnosed in our hospital from February 2014 to June 2018 were collected. According to NAG normal level, all patients were divided into NAG normal group and high NAG group. The difference of clinic index and pathological scores between two groups were compared, and the clinical and pathological risk factor which have correlation with urine NAG were assessed. Results There had significant differences in Cr, micro-albumin(mALB), Cys-C, and NAG between two groups(P<0.05). The pathological lesion scores of mesangial cell proliferation, interstitial inflammatory cell infiltration, renal interstitial fibrosis, and tubular atrophy comparison between groups were compared. There were statistically significant differences(P<0.05). The correlation analysis showed that there were positive correlations of NAG with mALB, eGFR , renal interstitial inflammatory cell infiltration, renal tubular atrophy, renal fibrosis and the mesangial cell proliferation. Conclusions Urinary NAG levels are closely related to renal function, proteinuria and tubule-interstitial lesions, which can be used as clinical indicators to evaluate and monitor the degree of tubule-interstitial lesions in IgAN. Key words: Glomerulonephritis, IGA; Uridine Diphosphate N-Acetylglucosamine; Nephritis, Interstitial