Glomerular Tuft Research Articles

Hematological and Histopathological Study Effect of Molybdate and Sulfate Alone and in Combination Overloaded Intake on Copper Outcome in Mature Male Rats

The object of this study were to evaluate the effect of molybdate and sulfate overload alone or in combination overload intake on copper outcome with regard toxicopathological changes in mature male rats. Twenty eight adult male rats were housed and arbitrarily divided into four equal groups (seven rat/group) and treated as follows for 60 days: control received distilled water, groups T1 received sodium molybdate 50 mg/kg B.W and T2: given orally 500 mg/kg B.W of sodium sulfate and T3 group were given sodium molybdate and sodium sulfate in combination at half dose in comparison with T1 and T2 doses. The blood tests results, which included Red Blood Cell count, hemoglobin concentration and Packed Cell Volume % that conducted a after one month and at the end of the experiment showed a significant reductions in general but were more in T1 group followed by T2 group, while T3 group showed less decline than that recorded in each of T1 and T2 groups. These functional changes were accompanied by structural changes in the hepatic and renal tissues. Histopathological changes following molybdate (50 mg/kg B.W) exposure were manifested by extensive areas of necrosis, hemorrhage, and hyperplasia of bile ductules. Besides focal area of necrosis and suppurative granuloma observed in livers of rats received 500 mg/kg B.W of sodium sulfate, mild infiltrate of mononuclear cell within the hepatic parenchyma, suppurative granuloma and proliferation of kupffer’s cells with hyperplasia of bile ductules seen in liver of rats received combination of them at half dose. While section of kidney from T1 group showed marked fibrous thickening of the capsule, severe cortical hemosiderosis with infiltrate of plasma cell and neutrophils, While in T2 group showed atrophy of glomerular tuft, focal interstitial mononuclear cells infiltration with deposition of hyaline cast. The histological changes revealed that renal damage was also observed in T3 group but at a little degree, depending on the result of this study it can be concluded that molybdate and sulfate alone and in combination succeeded to induce copper deficiency with severe changes in hematological and histopathological parameters in rats.

Kidney and Ileum Histopathology of Rattus norvegicus Toxicity Model of Rhodamine B and Saccharin Supplemented with Purple Roselle Yoghurt

Background: Rhodamin B and saccharin are chemicals that are harmful to the health of the body. Consumption of rhodamine B and saccharin for a long time can cause problems for the body such as impaired organ function. Purpose: The aim was to find out the benefits of giving purple rosella yogurt in preventing damage to the kidneys and ileum of Rattus norvegicus caused by rhodamine B and saccharin. Methods: Using RAL with 28 male Rattus novergicus aged 8-12 weeks. Group K(-) was not given any treatment, K(+R) was given rhodamine B, K(+S) was given saccharin, K(+K) was given rhodamine B and saccharin, P1 was given rhodamine B and yoghurt, P2 was given saccharin and yoghurt, P3 was given rhodamine B, saccharin, and yogurt. The dose of rhodamine B was 22.5 mg/kg, the dose of saccharin was 157.7 mg/kg, the volume of yoghurt was 1 ml/head. Administered orally with gastric tube for 14 days. The concentration of purple rosella extract used was 15% (v/v). Results: Group K(+K) showed the heaviest damage. Groups P1, P2, and P3 still found damage to the kidneys, in P1 they experienced thickening of Bowman's capsule in the glomerulus, in P2 they experienced a loss of more than 25% of the brush border in the tubules, and in P3 they experienced glomerular tufts in the glomerulus. In the ileum, P1 experienced thickening of the muscles, P2 experienced clusters of inflammatory cells in the submucosa, and P3 experienced 10-50% loss of goblet cells. Conclusion: Provision of purple rosella yogurt can prevent damage to the kidneys and ileum of Rattus novergicus due to rhodamine B and saccharin, although it is not optimal.

Effects of Microplastic (MP) Exposure at Environmentally Relevant Doses on the Structure, Function, and Transcriptome of the Kidney in Mice.

As a common emerging environmental pollutant, microplastics (MPs) have been detected in a variety of environmental media and human bodies. The potential toxic effects and mechanisms of MPs need to be revealed urgently. MPs can be deposited in the kidney, and exposure to high doses of MPs can cause nephrotoxicity in experimental animals. In this study, we investigated the effects of exposure to polystyrene microplastics (PS-MPs) at environmentally relevant doses (0.1 and 1 mg/L) on kidney structure, function, and transcriptome in mice. We found that mice exposed to PS-MPs in drinking water for eight weeks had no change in body weight or kidney coefficient. PS-MPs administration decreased the levels of blood urea nitrogen (BUN) in mice, while serum creatinine (CRE) and uric acid (UA) concentrations were unaffected. Through using periodic acid-Schiff (PAS) and Masson staining, we discovered that the glomerular tuft area increased in the PS-MP-treated mice, while the degree of renal fibrosis remained unchanged. Furthermore, renal cortex transcriptomic analysis identified 388 and 303 differentially expressed genes (DEGs) in the 0.1 and 1 mg/L dose groups, respectively. The DEGs were highly enriched in mitochondrial-related terms and pathways of thermogenesis and oxidative phosphorylation. Moreover, protein-protein interaction (PPI) network analysis revealed that cytochrome b-c1 complex subunit 10 (UQCR11) and cytochrome c oxidase subunit 3 (MT-CO3) were important node proteins. These findings suggest that environmental exposure to MPs can cause abnormalities in renal structure and filtration function and that long-term exposure to MPs may be a risk factor for renal disease.

Glomerular microcirculation: Implications for diabetes, preeclampsia, and kidney injury.

This review outlines the features of tandem regulation of glomerular microcirculation by autoregulatory mechanisms and intraglomerular redistribution of blood flow. Multiple points of cooperation exist between autoregulatory and distributional mechanisms. Mutual interactions between myogenic and tubuloglomerular feedback (TGF) mechanisms regulating the inflow are briefly discussed. In addition to this, TGF operation involving purinergic, autocoid, and NO signaling affects, however, not only afferent arteriolar tone, but mesangial cell tone as well. The latter reversibly reconfigures the distribution of blood flow between the shorter and longer pathways in the glomerular tuft. I advance a hypothesis that blood flow in these pathways spontaneously alternates, and mesangial cell tonicity serves as a rheostatic shift between them. Furthermore, humoral messengers from macula densa cells, themselves dependent on myogenic mechanisms, fine-tune the secretion of renin and, subsequently, the local, intrarenal generation of angiotensin II, which, in turn, provides additional vasomotor signaling to glomerular capillaries through changing the tone of mesangial cells. This complex regulatory network may partially explain the phenomenon of renal functional reserve, as well as suggest implications for changes in renal function during pregnancy, early diabetes mellitus, and acute kidney injury.

HISTOPATHOLOGICAL CHANGES OF USING RAW LENTIL SEEDS AS A PARTIAL SUBSTITUTE FOR THE FISH MEAL IN DIETS OF THE COMMON CARP CYPRINUS CARPIO L.

This experiment was carried out at College of Veterinary Medicine, University of Sulaimani. Microscopically, no adverse histopathological changes were seen in the kidneys, liver, gills and intestines of Cyprinus carpio for T2(replacing fishmeal with 5% lentil) and T3 (replacing fishmeal with 10% lentil) in comparison with the control (T1). However, various levels of adverse histopathological changes were seen in the T4(replacing fish meal with 15% lentil) and T5 (replacing fishmeal with 20% lentil). In the kidneys, dilation of the Bowman’s spaces was evidently associated with a decrease in the mesangial cellularity of glomerular tuft. In the liver, congestion of the central vein was apparent together with centrilobular infiltration of inflammatory cells. In the gills, hyperplasia of primary and secondary lamellae was evident. In the intestine, vacuolar degeneration of the lining epithelial cells was apparent together with extravasation of RBCs associated with marked infiltration of inflammatory cells in the lamina propria. In conclusion, the partial replacement of the fishmeal in diets of C. carpio by crude lentil seeds was safe at the 5% and 10% levels as indicated by various levels of adverse histopathological effects on the kidneys, liver, gills, and intestine.

The Effect of Different Concentrations of Bee Venom on Kidney Tissue of Albino Male Rats Rattus

In this study, 60 males of albino rats (Rattus rattus) were tested to study the effect of BV on kidney tissue at two doses of 10 and 40 µg/kg and two times after 10 and 15 days. The sample included 40 rats divided into two groups; 20 rats for each group. These groups were injected intraperitoneally according to the mentioned periods and were considered as a control group. The results exhibited renal tubule dilation and slight atrophy of glomerular tuft in the kidneys of rats treated with 10 µg/kg for 10 days compared to kidneys in the control treatment. Furthermore, 10 µg/kg treatment for 15 days has caused renal tubule dilation and degeneration with cytoplasmic vacuolation. Our findings also showed a slight atrophy of the glomerular tuft as well as a reduction in the number of glomeruli in this subcapsular area. The results also indicate regeneration of kidney tubules in rats given 40 µg/kg for 10 days. Meanwhile, sections of the kidney for rats that were given 40 µg/kg for 15 days exhibited a slight atrophy of glomerular tuft hypertrophied tubular epithelial cells.

Ulinastatin ameliorated streptozotocin-induced diabetic nephropathy: Potential effects via modulating the components of gut-kidney axis and restoring mitochondrial homeostasis

Growing evidence supports the role of the gut-kidney axis and persistent mitochondrial dysfunction in the pathogenesis of diabetic nephropathy (DN). Ulinastatin (UTI) has a potent anti-inflammatory effect, protecting the kidney and the gut barrier in sepsis, but its effect on DN has yet to be investigated. This study aimed to assess the potential mitigating effect of UTI on DN and investigate the possible involvement of gut-kidney axis and mitochondrial homeostasis in this effect. Forty male Wistar rats were divided equally into four groups: normal; UTI-treated control; untreated DN; and UTI-treated DN. At the end of the experiment, UTI ameliorated DN by modulating the gut-kidney axis as it improved serum and urinary creatinine, urine volume, creatinine clearance, blood urea nitrogen, urinary albumin, intestinal morphology including villus height, crypt depth, and number of goblet cells, with upregulating the expression of intestinal tight-junction protein claudin-1, and counteracting kidney changes as indicated by significantly decreasing glomerular tuft area and periglomerular and peritubular collagen deposition. In addition, it significantly reduced intestinal and renal nuclear factor kappa B (NF-κB), serum Complement 5a (C5a), renal monocyte chemoattractant protein-1 (MCP-1), renal intercellular adhesion molecule 1 (ICAM1), and renal signal transducer and activator of transcription 3 (STAT3), mitochondrial dynamin related protein 1 (Drp1), mitochondrial fission 1 protein (FIS1), mitochondrial reactive oxygen species (ROS), renal hydrogen peroxide (H2O2), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels. Furthermore, it significantly increased serum short chain fatty acids (SCFAs), and mitochondrial ATP levels and mitochondrial transmembrane potential. Moreover, there were significant correlations between measured markers of gut components of the gut-kidney axis and renal function tests in UTI-treated DN group. In conclusion, UTI has a promising therapeutic effect on DN by modulating the gut-kidney axis and improving renal mitochondrial dynamics and redox equilibrium.

Vitamin D deficiency contributes to the diabetic kidney disease progression via increase ZEB1/ZEB2 expressions

BackgroundDiabetic kidney disease (DKD) remains one of the main causes of end-stage renal disease (ESRD) and mortality in diabetic patients worldwide. Vitamin D deficiency (VitDD) is one of the main consequences of different chronic kidney disease (CKD) types and is associated with rapid progression to ESRD. Nevertheless, the mechanisms that lead to this process are poorly understood. This study aimed to characterize a model of diabetic nephropathy progression in VitDD and the epithelial-mesenchymal-transition (EMT) role in these processes.MethodsWistar Hannover rats received a diet with or without VitD before type 1 diabetes (T1D) induction. After this procedure, the rats were accompanied for 12 and 24 weeks after T1D induction and the renal function, structure, cell transdifferentiating markers and zinc finger e-box binding homeobox 1/2 (ZEB1/ZEB2) contribution to kidney damage were evaluated during the DKD progression.ResultsThe results showed an increase in glomerular tuft, mesangial and interstitial relative areas and renal function impairment in VitD-deficient diabetic rats compared to diabetic rats that received a VitD-containing diet. These alterations can be associated with increased expression of EMT markers, ZEB1 gene expression, ZEB2 protein expression and TGF-β1 urinary excretion. Decreased miR-200b expression, an important post-transcriptional regulator of ZEB1 and ZEB2 was also observed.ConclusionOur data demonstrated that VitD deficiency contributes to the rapid development and progression of DKD in diabetic rats induced by increase ZEB1/ZEB2 expressions and miR-200b downregulation.

316-OR: ADA Presidents' Select Abstract: Structural Lesions on Kidney Biopsy in Youth-Onset Type 1 Diabetes (T1D) and Type 2 Diabetes (T2D)

Recent epidemiological studies suggest a more aggressive clinical course of diabetic kidney disease in youth-onset T2D compared with youth-onset T1D. We compared kidney structural lesions in participants with youth-onset T2D and T1D to determine if youth-onset T2D was associated with greater early tissue injury. Quantitative microscopy was performed on kidney tissue obtained from research kidney biopsies in 27 youth with diabetes (13 T2D, 14 T1D). Group differences in clinical and morphometric parameters were tested using t-tests, Wilcoxon signed-rank test and linear models. At biopsy, the 13 participants with T2D were younger than the 14 with T1D (17±2 vs. 23±2 years; p<0.0001), had shorter diabetes duration (2.4±1.9 vs. 12.3±5.2 years; p<0.0001), but similar HbA1c (6.6±1.0 vs. 7.3±1.0 %; p=0.10) and median urine albumin-to-creatinine ratio (6 [min-max: 1-163] vs. 7 [2-58] mg/g; p=0.96). Youth with T2D exhibited greater glomerular tuft area (17588±4806 vs. 13821±2748 um2, p=0.018), glomerular volume (3.4±1.4 vs. 2.31±0.68 106um3, p=0.018), glomerular nuclear count (101±23 vs. 63±11, p<0.0001) mesangial volume (0.44±0.15 vs. 0.28±0.09 106um3, p=0.002) and mesangial matrix (2291±531 vs. 2001±566 um2, p=0.008). Glomerular sclerosis was only present in one individual with T2D. Despite similar clinical characteristics and considerably shorter diabetes duration, youth with T2D exhibited more severe kidney structural lesions than young persons with youth-onset T1D. Studies are underway to elucidate the metabolic and molecular pathways underlying these structural differences, as well as to delineate potential ultrastructural differences in T2D vs. T1D by electron microscopy. Disclosure V.Nair: None. V.Shah: Advisory Panel; LifeScan Diabetes Institute, Medscape, Consultant; DKSH, Research Support; Novo Nordisk, Tandem Diabetes Care, Inc., Dexcom, Inc., Insulet Corporation, JDRF, National Institutes of Health, Speaker's Bureau; Dexcom, Inc., Insulet Corporation. K.L.Tommerdahl: None. K.Sharma: Advisory Panel; Reata Pharmaceuticals, Inc., Otsuka America Pharmaceutical, Inc. I.De boer: Advisory Panel; AstraZeneca, Boehringer Ingelheim and Eli Lilly Alliance, Boehringer Ingelheim International GmbH, Otsuka America Pharmaceutical, Inc., Bayer Inc., Consultant; George Clinical, Gilead Sciences, Inc., Medscape, Research Support; Dexcom, Inc. P.Saulnier: Board Member; Novo Nordisk, Consultant; Grünenthal Group. H.C.Looker: None. R.G.Nelson: None. J.B.Hodgin: None. P.Bjornstad: Advisory Panel; AstraZeneca, Novo Nordisk, Lilly, Horizon Therapeutics plc, Boehringer Ingelheim (Canada) Ltd., LG Chem, Consultant; Bayer Inc., Bristol-Myers Squibb Company. A.Naik: Advisory Panel; CareDx. F.Alakwaa: None. J.A.Schaub: None. T.B.Vigers: None. M.Bitzer: None. L.Pyle: None. F.C.Brosius: Advisory Panel; Gilead Sciences, Inc. P.E.Ladd: None. Funding National Institute of Diabetes and Digestive and Kidney Diseases; JDRF

Effect of Proprotein Convertase Subtilisin/Kexin Type 9 Inhibition on Podocytes in Mouse Nephrotic Syndrome

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is known to play a crucial role in dyslipidemia, and an increase in serum PCSK9 levels has also been reported in patients with nephrotic syndrome (NS). However, the specific effects of PCSK9 in kidney disease and the therapeutic potential of targeting PCSK9 in NS remain elusive. We thus investigated the effects of evolocumab (EVO) in mice with adriamycin (ADR)-induced NS. Male BALB/c mice were divided into the following 4 groups: Control, N = 11; EVO (monoclonal antibody for PCSK9), N = 11; ADR, N = 11; and ADR+EVO, N = 11. We also performed in vitro experiments using immortalized murine podocyte cells to validate the direct effects of PCSK9 on podocytes. EVO decreased urinary albumin levels and ameliorated podocytopathy in mice with ADR nephropathy. Further, EVO suppressed the Nod-like receptor protein 3 (NLRP3) inflammasome pathway in podocytes. PCSK9 expression upregulated CD36, a scavenger receptor of oxidized low-density lipoprotein (Ox-LDL), which in turn stimulated the absorption of Ox-LDL in vitro. EVO downregulated CD36 expression in podocytes both in vitro and in vivo. Immunofluorescence staining analysis reveals that CD36 and PCSK9 colocalized in the glomerular tufts of mice with ADR nephropathy. In the patients with focal segmental glomerulosclerosis, the CD36+ area in glomerular tufts increased compared with those diagnosed with minor glomerular abnormalities. This study revealed that EVO ameliorated mouse ADR nephropathy through the regulation of CD36 and NLRP3 inflammasome signaling. EVO treatment represents a potential therapeutic strategy for human NS.

#5348 THE EFFECTS OF RITUXIMAB IN NON-HCV-RELATED MIXED CRYOGLOBULINEMIC VASCULITIS

Abstract Background and Aims Remarkable results in severe HCV-related cryoglobulinemic vasculitis have been obtained with Rituximab. Details of the clinical characteristics and effective treatment of non HCV-related cryogloulinemic syndromes are presently lacking. Method This paper reports on a prospective single-Center open study aimed at evaluating the clinical presentation and effects of Rituximab administered alone in patients with severe non HCV-related cryoglobulinemic syndrome Results The study group included 11 patients followed for at least 6 months. Three patients had type I cryoglobulinemia, 6 had type II and the remaining 2 patients had type III. Mean cryocrit was 2.5%. Four out of 11 patients had symptomatic sicca complex with anti-SSA (Ro)/anti SSB (La) antibodies. All 11 patients presented with biopsy-proven renal involvement, 4 out of 11 with leukocytoclastic vasculitis, and 8 with involvement of the peripheral nervous system. Renal biopsy revealed diffuse membranoproliferative glomerulonephritis (MPGN) in 9 out of 11 patients. Extracapillary proliferation and necrosis of the glomerular tuft was observed in 1 of these 9 cases. Interstitial nephritis together with mesangial expansion and capillary immune deposits were observed in 1 patient. Prevalent interstitial fibrosis and glomerular sclerosis were detected in the remaining case. Patients underwent treatment with rituximab alone. After 6 months we observed a remarkable improvement in the necrotizing skin ulcers and a substantial amelioration of the electrophysiological parameters of motor and sensory peripheral neuropathy. Improvement in both renal function (from 2.8 to 1.4 mg/dl, p < 0.001) and proteinuria (from 4.2 g/24 to 0.4 g/24 h, p < 0.001) was found in 10 out of 11 patients, while 1 could not be fully treated because of a severe infusion reaction and sudden development of anti-Rituximab antibodies. Good renal response was confirmed at the end of follow-up (38.4 months). Three patients had a relapse at 6, 12, and 48 months, respectively. Conclusion In our cohort the administration of 4 once-weekly infusions of Rituximab followed by 2 more infusions after 1 and 2 months proved to be effective in the management of these rare patients.

Protective effects of long-term nitrate administration against ovariectomy-induced kidney dysfunction in rats.

Menopause is associated with higher risks of chronic kidney disease. We determined the effect of nitrate on ovariectomy-induced kidney dysfunction METHODS: Control, ovariectomized (OVX), control + nitrate, and OVX + nitrate female Wistar rats (n = 10/group); sodium nitrate (100mg/L) administered in drinking water for 9months. Glomerular filtration rate (GFR) and albumin excretion rate (AER) were calculated from serum and urine parameters. At month 9, serum and kidney levels of nitric oxide (NO) metabolites (NOx), oxidative stress indices, and mRNA expression of endothelial NO synthase (eNOS) were measured; with histological analyses of the kidney. Compared to controls, OVX rats had lower GFR (31%, p = 0.0079), higher glomerular tuft volume (30%, p = 0.0402), and Bowman's capsule space (39%, p = 0.0224). OVX rats had lower serum NOx (33%, p = 0.0061) and kidney eNOS mRNA expression (34%, p = 0.0368). Nitrate administration to: (i) control rats increased serum NOx (59%, p < 0.0001), with no effect on other parameters; (ii) OVX rats increased serum (85%, p < 0.0001) and kidney (106%, p = 0.0008) NOx values, and restored kidney eNOS expression to normal value. Nitrate administration to OVX rats increased GFR (36%, p = 0.0361) and restored glomerular tuft volume and Bowman's capsule space to normal values. In OVX rats, it also increased serum catalase (CAT) activity, serum and kidney total antioxidant capacity (TAC), and decreased serum malondialdehyde (MDA). Low-dose long-term nitrate administration protects against ovariectomy-induced kidney dysfunction in rats. This effect is associated with reducing ovariectomy-induced oxidative stress and restoring eNOS-derived NO deficiency in systemic circulation and the kidney.

Oxidative Stress and Immunopathological Alterations of Clarias gariepinus Exposed to Monocyclic Aromatic Hydrocarbons (BTX)

This study’s goal was to assess the catfish’s response to exposure to monoaromatic petroleum hydrocarbons (benzene, toluene, and xylene) and its recovery after exposure using oxidative stress, histopathological, and immunological changes as biomarkers. Four groups: one as control and other three exposed to benzene (0.762 ng/L), toluene (26.614 ng/L), and xylene (89.403 ng/L), respectively, for 30 days and then recovery period for 30 days. The levels of the cortisol, lipid peroxidation, and cytokines (IL-1β, IL-6) increased significantly (p < 0.05) after exposure to benzene and xylene compared to control. Superoxide dismutase (SOD), total antioxidant capacity (TAC), and acetylcholinstease (Ach) decreased significantly (p < 0.05) in fishes exposed to benzene only compared to control group. While glutathione-S-transferase (GST) did not show any change in different treatment groups compared to control group. The histopathological signs of liver exposed to benzene, toluene, and xylene displayed aggregation of melanomacrophages, congestion of sinusoids, vacuolar degeneration of hepatocytes, necrotic area with inflammatory cell infiltration, and thrombus of central vein. Kidney exposed to benzene, toluene, and xylene showed dilatation of Bowman’s space with atrophy of glomerular tuft, lyses of RBCs with mononuclear cell infiltration, multifocal area of hemopoietic tissue necrosis, organized thrombus with perivascular hemorrhage, focal inflammatory cellular reaction, renal tubular necrosis, and thrombus of blood vessels. Spleen exposed to benzene, toluene, and xylene showed hyperplasia of lymphoid follicles in white pulp in a mild degree. These lesions appeared to a mild degree or disappeared completely after recovery period to BTX except spleen. In conclusion, monocyclic aromatic hydrocarbons (BTX) are hazardous to fish and the toxicity level was as benzene > xylene > toluene even though after recovery period.

Protease-activated receptor-1 mediated calcium oscillations in renal mesangial cells

INTRODUCTION. Mesangial cells provide structural support to the glomerular tuft and modulate the glomerular capillary flow via their contractile properties. Mesangial cells undergo phenotypic changes into myofibroblast-like cells, such as proliferation, mesangial expansion, abnormal glomerular tuft formation, and reduced numbers of capillary loops, are present in several glomerular diseases, including diabetic nephropathy and glomerulonephritis. In addition, thrombin-induced mesangial remodeling was found in diabetic patients, and expression of the corresponding protease-activated receptors (PARs) in the renal mesangium was reported. However, the functional PAR-mediated signaling and mechanisms in mesangial cells were not examined. This study aims to investigate protease-activated mechanisms regulating mesangial cell contraction and glomerular capillary flow. METHODS. We used primary human renal mesangial cells (HRMC) to determine the signaling mechanisms mediated by PAR1 thrombin-activated receptors. Confocal fluorescent microscopy was utilized to detect changes in intracellular Ca 2+ response to specific PAR1 modulators. Pharmacology and patch clamp electrophysiology was further applied to reveal downstream signaling mechanisms responsible for intracellular Ca 2+ oscillations. RESULTS. PAR1-mediated Ca 2+ response displayed high sensitivity to specific agonist (TFLLR-NH 2 ) with EC 50 values of 3 and 6.3 nM for male and female-derived cultured cells, respectively (the competition of a ligand for receptor binding fit converged; adj. R 2 =0.98). The response to PAR1 activation promoted initial cytosolic Ca 2+ increase followed by synchronized, damped Ca 2+ oscillations with a lag of 6.74±0.84 min between peaks. The pre-application of a specific inhibitor (RWJ56110) eliminated PAR1-mediated response, and oscillations were blocked by the changes of an extracellular solution to zero Ca 2+ . The specific inhibitors for store-operated calcium (SOCs) (Pyr6) and TRPC3 (GSK 2833503A) channels strongly attenuated oscillation behavior (up to 40% when added separately and up to 65% when both were applied; two-way ANOVA, * p&lt;0.0001). In addition, the effect of a specific inhibitor of TRPC6 channels (BI-749327) had a minimal impact on Ca 2+ flux. Further single-channel electrophysiology experiments in HRMC cells confirmed the involvement of SOC and TRPC3 channels in PAR1-mediated GPCR activation. CONCLUSION. Our results indicate that coagulation proteases like thrombin may strongly regulate mesangial cell contraction and corresponding glomerular capillary flow by PAR1 GPCRs-related activation. The contraction mechanism is mediated presumably through SOCs entry and TRPC3 channels. Since high thrombin levels are linked to poor diabetic control, the described signaling may play a crucial role in the development of diabetic glomerular disease. DK126720 (to OP), DK129227 (to AS and OP), Veterans Affairs Support Veterans Affairs (Merit Award I01 BX000820 to JL), research grant from Dialysis Clinic, Inc (to JL). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

A glomerulus chip with spherically twisted cell-laden hollow fibers as glomerular capillary tufts

Glomerulus-on-a-chip, as a promising alternative for drug nephrotoxicity evaluation, is attracting increasing attention. For glomerulus-on-a-chip, the more biomimetic the chip is, the more convincing the application of the chip is. In this study, we proposed a hollow fiber-based biomimetic glomerulus chip that can regulate filtration in response to blood pressure and hormone levels. On the chip developed here, bundles of hollow fibers were spherically twisted and embedded in designed Bowman’s capsules to form spherical glomerular capillary tufts, with podocytes and endotheliocytes cultured on the outer and inner surfaces of the hollow fibers, respectively. We evaluated the morphology of cells, the viability of cells, and the metabolic function of cells in terms of glucose consumption and urea synthesis by comparing the results obtained under fluidic and static conditions, confirmed the barrier function of the endotheliocyte-fiber membrane-podocyte structure by monitoring the diffusion of fluorescein isothiocyanate (FITC)-labeled inulin, albumin and IgG, and, for the first time, achieved on-chip filtration regulation in response to the hormone atrial natriuretic peptide. In addition, the application of the chip in the evaluation of drug nephrotoxicity was also preliminarily demonstrated. This work offers insights into the design of a more physiologically similar glomerulus on a microfluidic chip.

Aqueous extract of Daucus carota exerts a protective effect on the Renal, Hepatic and Duodenal mucosal histology in Diclofenac Induced Tissue Injury

Objective: The use of ethnobiology in treatment of many diseases especially in rural residents with limited access to medical technology, treatment and equipment is beneficial and necessary. Daucus carota (DC) root extract was used as pre-treatment in adult Wistar rats exposed to diclofenac sodium (DF) to investigate a protective effect on the histology of liver, kidney and duodenum. Materials and Method: Twenty-five adult Wistar rats were used for this study and were randomly divided into 5 groups of 5 rats each, which included: Group A - Normal control; Group B – 50mg/kg DF control; Group C – 50mg/kg DC + 50mg/kg DF, Group D – 100mg/kg DC + 50mg/kg DF; and, Group E – 140mg/kg DC + 50mg/kg DC. Results and Discussion: The results showed a reduction in damage to the hepatocytes, maintenance of sinusoidal integrity and reduction in the number of inflammatory cells in the hepatic parenchyma, In the kidney tissue, the extract preserved the glomerular capillary tuft, renal tubular epithelial cells, conserved Bowman’s space and lining epithelium of the capsule in a dose dependent manner. The intestinal mucosa in groups treated with higher doses of the extract were completely preserved and intact with minimal erosion of epithelial lining along with preservation of lamina propria and intestinal glands. Conclusion: Pre-administration of DC, preferably at concentrations of 100mg/kg and 140mg/kg reduced hepatotoxicity, renal tissue and mucosal layer damage in the duodenum following administration of DF. This preservation of tissues improved as concentration of the extract increased verifying that its efficiency was dose dependent.

An Improved Method for Estimating Nephron Number and the Association of Resulting Nephron Number Estimates with Chronic Kidney Disease Outcomes.

Nephron number currently can be estimated only from glomerular density on a kidney biopsy combined with cortical volume from kidney imaging. Because of measurement biases, refinement of this approach and validation across different patient populations have been needed. The prognostic importance of nephron number also has been unclear. The authors present an improved method of estimating nephron number that corrects for several biases, resulting in a 27% higher nephron number estimate for donor kidneys compared with a prior method. After accounting for comorbidities, the new nephron number estimate does not differ between kidney donors and kidney patients with tumor and shows consistent associations with clinical characteristics across these two populations. The findings also indicate that low nephron number predicts CKD independent of biopsy and clinical characteristics in both populations. Nephron number can be estimated from glomerular density and cortical volume. However, because of measurement biases, this approach needs refinement, comparison between disparate populations, and evaluation as a predictor of CKD outcomes. We studied 3020 living kidney donors and 1354 patients who underwent radical nephrectomy for tumor. We determined cortex volume of the retained kidney from presurgical imaging and glomerular density by morphometric analysis of needle core biopsy of the donated kidney and wedge sections of the removed kidney. Glomerular density was corrected for missing glomerular tufts, absence of the kidney capsule, and then tissue shrinkage on the basis of analysis of 30 autopsy kidneys. We used logistic regression (in donors) and Cox proportional hazard models (in patients with tumor) to assess the risk of CKD outcomes associated with nephron number. Donors had 1.17 million nephrons per kidney; patients with tumor had 0.99 million nephrons per kidney. A lower nephron number was associated with older age, female sex, shorter height, hypertension, family history of ESKD, lower GFR, and proteinuria. After adjusting for these characteristics, nephron number did not differ between donors and patients with tumor. Low nephron number (defined by <5th or <10th percentile by age and sex in a healthy subset) in both populations predicted future risk of CKD outcomes independent of biopsy and clinical characteristics. Compared with an older method for estimating nephron number, a new method that addresses several sources of bias results in nephron number estimates that are 27% higher in donors and 1% higher in patients with tumor and shows consistency between two populations. Low nephron number independently predicts CKD in both populations.

Patterns of Renal Dysfunction and Profile of Kidney Biopsies in Hematopoietic Stem Cell Transplant Recipients

Introduction: Post hematopoietic stem cell transplant (HSCT), kidney can be subjected to injury by various causes. Of these, graft versus host disease (GvHD) affecting the kidney is an under-recognized entity with no clear guidelines on its diagnosis, clinicopathological manifestations, and outcomes. Material and Methods: Out of 2,930 patients who underwent HSCT at our center between 2005 and 2020, kidney biopsy was performed in 19 allogenic and 5 autologous recipients. Results: The mean age of the cohort at transplant was 33.2 ± 7 years, and 15 (62%) were males. Median time to kidney biopsy from HSCT was 14 (IQR, 9–30) months. Aplastic anemia was the most common underlying hematological disease (54.2%). All 19 allogenic recipients were classified based on clinicopathological manifestations into either thrombotic microangiopathy (TMA, 12/19 [63%]) or nephrotic syndrome (NS, 7/19 [37%]) pattern. Glomerular tuft “mesangiolysis” was the dominant pattern of injury noted in 9/12 cases of TMA pattern. There was a predominance of acute microangiopathic changes restricted primarily to the glomerular compartment. Of the 7 patients with NS pattern, membranous nephropathy was seen in 4 (57%) and minimal change disease in 3 (43%) patients. Thirty-nine percent (7/18) stained positive for C4d which was predominantly glomerular. Allogenic recipients who did not receive immunosuppression (IS) for renal disease had a lower eGFR at biopsy, a longer latency between withdrawal of GvHD prophylaxis and biopsy, and were significantly at a higher risk of kidney failure (IS: 2/11, 18.1% vs. no IS: 2/6, 33.3%, p = 0.04). “Associated extra-renal GvHD” occurred in 11/19 (57.9%) allogenic recipients. Patients with “associated extra-renal GvHD” had significantly more deaths (6/11, 60% vs. 0, p = 0.02) but comparable renal outcomes. Conclusion: Renal GvHD can present with or without “associated extra-renal GvHD” after a prolonged period of withdrawal of GvHD prophylaxis, requiring careful diagnostic vigilance and consideration of IS.

Dysregulation of Angiopoietin-like-4 Associated with Hyperlipidemia-induced Renal Injury by AMPK/ACC Pathway.

Angiopoietin-like protein 4 (Angptl4) is a glycoprotein that is involved in regulating lipid metabolism, which has been indicated as a link between hypertriglyceridemia and albuminuria in glomerulonephropathy. Deregulated lipid metabolism is increasingly recognized as an important risk factor of glomerulonephropathy. This study aimed to investigate the Angptl4 expression in renal tissue and podocyte under hyperlipidemia conditions and explore the potential molecular mechanisms. The role of Angptl4 in hyperlipidemia-induced glomerular disease and the detailed underlying mechanisms are unclear. This study sought new insights into this issue. We measured Angptl4 levels in the plasma and urine from patients with hyperlipidemia and healthy people. Rats were fed a high fat diet (HFD) to induce dyslipidemia model and the human podocytes were stimulated by palmitic acid as in vivo and in vitro experiments. The podocytes injury and the Angptl4 level in renal tissues were evaluated. Furthermore, the mechanism of Angptl4 on podocytes injury was investigated. The urinary Angptl4 level was gradually upregulated in both patients with hyperlipidaemia and high fat-diet-induced rats. HFD rats showed increased 24 h urinary protein and glomerular tuft area at week 12. The levels of nephrin and WT-1 were down-regulated, but the Angptl4 levels were markedly upregulated on the glomerular of rats on HFD. In the human podocytes, lipid accumulation accompanied by increases of Angptl4, but the expression of nephrin, WT-1, p-AMPKα and p-ACC was decreased after palmitic acid treatment. However, this injury effect was mediated by the aminoimidazole-4-carboxamide-1β-D-ribofuranoside (AICAR), activator of the low energy sensor AMPK/ACC signaling. This study was the first of its kind to show that podocyte damage induced by dyslipidemia could be associated with upregulated Angptl4 and that patients with hyperlipidemia might have relatively high urinary Angptl4 expression. The dysregulation of Angptl4 in the podocytes under hyperlipidemia is possibly carried out through AMPK/ACC signaling pathway.

Antioxidants Role Against Acrylamide Toxicity on Urogenital System: An Overview

Acrylamide (AA) is a chemical substance which is used as a soil stabilizing agent and in the production of copolymers and polymers since 1970. The presence of an AA adduct in food was observed in rats fed with fried food which led to a substantial increase in levels of hemoglobin adduct. Foods that are rich in carbohydrate when prepared at high temperature (above 120 ºC) by baking, toasting, frying, roasting or cooking results in the production of AA by the reaction of the amino acid with glucose present in it. Several studies observed AA toxicity on nervous system, reproductive system, and immune system. To justify this toxicity there is not a clear mechanism described. In this review article the mechanisms of AA toxicity on urogenital system and role of antioxidants against its toxicity has been reviewed. According to previous studies the main factor that induces AA toxicity is oxidative stress. AA treated groups revealed degeneration of the kidney’s epithelial lining and the glomerular tuft. Adverse effect on reproductive system by AA has been evidenced by sperm-head abnormalities, dominant lethal effects, and testicular epithelial tissue degeneration. Therefore, it is advised that modifying of food processing methods and consuming lot of vegetables and fruits containing antioxidants. These antioxidants give us some supports to the cells of our body organs against the AA sources which cause cell defects.