Symmetric Dimethylarginine Is a Sensitive Biomarker of Glomerular Injury in Rats

Glomerular filtration rate is the gold-standard method for assessment of renal function but is rarely performed in routine toxicity studies. Standard serum biomarkers of renal function are insensitive and become elevated only with significant loss of organ function. Symmetric dimethylarginine (SDMA) is a ubiquitous analyte that is freely filtered by the glomerulus and can be detected in serum. It has shown utility for the detection of renal injury in dogs and cats in clinical veterinary practice, but the potential utility of SDMA to detect renal injury in preclinical species or toxicity studies has not been thoroughly investigated. We utilized a well-characterized glomerular toxicant, puromycin aminonucleoside, to induce podocyte injury and subsequent proteinuria in young male Sprague-Dawley rats. At the end of 1 or 2 weeks, blood, urine, and kidney tissue were collected for analysis. One week following a single 50 mg/kg dose, urea nitrogen, creatinine, and albumin mean values were within historical control ranges, while SDMA was increased. Glomerular changes in these animals included periodic acid–Schiff positive globules within podocytes, podocyte hypertrophy by light microscopy, and podocyte degeneration with effacement of foot processes by electron microscopy (EM). Taken together, our data indicate that SDMA may be a useful biomarker for early detection of glomerular toxicities in rats.

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Mitochondria-Targeted Antioxidant Mito-Tempo Protects Against Aldosterone-Induced Renal Injury In Vivo

Cellular Physiology and Biochemistry ◽

10.1159/000485287 ◽

2017 ◽

Vol 44 (2) ◽

pp. 741-750 ◽

Cited By ~ 14

Author(s):

Wei Ding ◽

Tingyan Liu ◽

Xiao Bi ◽

Zhiling Zhang

Keyword(s):

Electron Microscopy ◽

Renal Function ◽

Nlrp3 Inflammasome ◽

Renal Injury ◽

Periodic Acid ◽

Inflammasome Activation ◽

Periodic Acid Schiff ◽

Nlrp3 Inflammasome Activation

Background/Aims: Growing evidence suggests mitochondrial dysfunction (MtD) and the Nlrp3 inflammasome play critical roles in chronic kidney disease (CKD) progression. We previously reported that Aldosterone (Aldo)-induced renal injury in vitro is directly caused by mitochondrial reactive oxygen species (mtROS)-mediated activation of the Nlrp3 inflammasome. Here we aimed to determine whether a mitochondria-targeted antioxidant (Mito-Tempo) could prevent Aldo-induced kidney damage in vivo. Methods: C57BL/6J mice were treated with Aldo and/or Mito-Tempo (or ethanol as a control) for 4 weeks. Renal injury was evaluated by Periodic Acid-Schiff reagent or Masson’s trichrome staining and electron microscopy. ROS were measured by DCFDA fluorescence and ELISA. MtD was determined by real-time PCR and electron microscopy. Activation of the Nlrp3 inflammasome and endoplasmic reticulum stress (ERS) was detected via western blot. Results: Compared with control mice, Aldo-infused mice showed impaired renal function, increased mtROS production and MtD, Nlrp3 inflammasome activation, and elevated ERS. We showed administration of Mito-Tempo significantly improved renal function and MtD, and reduced Nlrp3 inflammasome activation and ERS in vivo. Conclusion: Mitochondria-targeted antioxidants may attenuate Aldo-infused renal injury by inhibiting MtD, the Nlrp3 inflammasome, and ERS in vivo. Therefore, targeting mtROS might be an effective strategy for preventing CKD.

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Autofluorescence microscopy as a label-free tool for renal histology and glomerular segmentation

10.1101/2021.07.16.452703 ◽

2021 ◽

Author(s):

Nathan Heath Patterson ◽

Elizabeth K Neumann ◽

Kavya Sharman ◽

Jamie L Allen ◽

Raymond C Harris ◽

...

Keyword(s):

Recognition Performance ◽

Periodic Acid ◽

Kidney Tissue ◽

Human Kidney ◽

True Positive Rate ◽

Label Free ◽

Periodic Acid Schiff ◽

Renal Histology ◽

Fresh Frozen ◽

Histological Staining

Functional tissue units (FTUs) composed of multiple cells like the glomerulus in the kidney nephron play important roles in health and disease. Histological staining is often used for annotation or segmentation of FTUs, but chemical stains can introduce artefacts through experimental factors that influence analysis. Secondly, many molecular -omics techniques are incompatible with common histological stains. To enable FTU segmentation and annotation in human kidney without the need for histological staining, we detail here the use of widefield autofluorescence (AF) microscopy as a simple, label-free modality that provides detailed renal morphology comparable to periodic acid-Schiff (PAS) stained tissue in both formalin-fixed paraffin-embedded (FFPE) and fresh frozen samples and with no tissue processing beyond sectioning. We demonstrate automated deep learning-based glomerular unit recognition and segmentation on PAS and AF images of the same tissue section from 9 fresh frozen samples and 9 FFPE samples. All training comparisons were carried out using registered AF microscopy and PAS stained whole slide images originating from the same section, and the recognition models were built with the exact same training and test examples. Measures of recognition performance, such as the Dice-Sorensen coefficient, the true positive rate, and the positive predictive value differed less than 2% between standard PAS and AF microscopy for both preservation methods. These results demonstrate that AF is a potentially powerful tool to study human kidney tissue, that it can serve as a label-free source for automated and manual annotation of tissue structures.

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Psoriasis-Like Inflammation Induced Renal Dysfunction through the TLR/NF-κB Signal Pathway

BioMed Research International ◽

10.1155/2020/3535264 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

Fang Ren ◽

Min Zhang ◽

Caiyun Zhang ◽

Hong Sang

Keyword(s):

Renal Injury ◽

Periodic Acid ◽

Severity Index ◽

Skin Lesions ◽

Signal Pathway ◽

Inflammatory Factors ◽

Urine Protein ◽

Periodic Acid Schiff ◽

Associated Proteins ◽

Pas Staining

Pathological studies have shown an association between psoriasis and renal injury (RI), but the mechanism between RI and psoriasis was still unclear. This paper was designed to investigate the relationship and mechanism between psoriasis-like inflammation and renal injury in BALB/C mice. Mice were topically smeared imiquimod followed by various analyses in skin lesions, urine protein, kidney/serum inflammatory cytokines, kidney function, podocyte membrane proteins, and toll-like receptors/nuclear factor kappa-b (TLR/NF-κB) pathway-associated proteins. Meanwhile, lipopolysaccharide (LPS) and dexamethasone (DEX) were intraperitoneally injected to promote and inhibit inflammation accompanied by imiquimod to elaborate the relevance between inflammatory levels and RI. In the model group, the Psoriasis Area and Severity Index (PASI) scores of scaly and erythema obviously increased (p<0.01), creatinine and blood urea nitrogen significantly increased (p<0.01), the positive area of hematoxylin-eosin (HE) and periodic acid-Schiff (PAS) staining in kidney increased (p<0.01), malondialdehyde significantly increased with superoxide dismutase (SOD) decreased (p<0.01), 24-hour urine protein increased and the expressions of podocin and CD2 associate protein (CD2AP) decreased (p<0.01), and kidney/serum inflammatory factors (IL-17, IL-1β, IL-6, TNF-α, and IL-22) and TLR/NF-κB-related expression (TLR2, TLR4, MyD88, and NF-κBp65) all increased (p<0.01). The RI was aggravated with the TLR/NF-κB related expression being upregulated by LPS (p<0.05). On the contrary, the RI was alleviated by DEX (p<0.05). Our data showed that psoriasis-like inflammation damaged the renal function via the TLR/NF-κB signal pathway. Inhibiting TLR/NF-κB-related protein expression may be effective for the treatment of RI caused by psoriasis.

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Endoplasmic Reticulum Chaperon Tauroursodeoxycholic Acid Attenuates Aldosterone-Infused Renal Injury

Mediators of Inflammation ◽

10.1155/2016/4387031 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 2

Author(s):

Honglei Guo ◽

Hongmei Li ◽

Lilu Ling ◽

Yong Gu ◽

Wei Ding

Keyword(s):

Endoplasmic Reticulum ◽

Inflammatory Response ◽

Er Stress ◽

Renal Injury ◽

Periodic Acid ◽

Periodic Acid Schiff ◽

Tauroursodeoxycholic Acid ◽

Receive Treatment ◽

Inflammatory Molecules

Aldosterone (Aldo) is critically involved in the development of renal injury via the production of reactive oxygen species and inflammation. Endoplasmic reticulum (ER) stress is also evoked in Aldo-induced renal injury. In the present study, we investigated the role of ER stress in inflammation-mediated renal injury in Aldo-infused mice. C57BL/6J mice were randomized to receive treatment for 4 weeks as follows: vehicle infusion, Aldo infusion, vehicle infusion plus tauroursodeoxycholic acid (TUDCA), and Aldo infusion plus TUDCA. The effect of TUDCA on the Aldo-infused inflammatory response and renal injury was investigated using periodic acid-Schiff staining, real-time PCR, Western blot, and ELISA. We demonstrate that Aldo leads to impaired renal function and inhibition of ER stress via TUDCA attenuates renal fibrosis. This was indicated by decreased collagen I, collagen IV, fibronectin, and TGF-β expression, as well as the downregulation of the expression of Nlrp3 inflammasome markers, Nlrp3, ASC, IL-1β, and IL-18. This paper presents an important role for ER stress on the renal inflammatory response to Aldo. Additionally, the inhibition of ER stress by TUDCA negatively regulates the levels of these inflammatory molecules in the context of Aldo.

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Histoprotective effect of vitamin D against carbon tetrachloride nephrotoxicity in rats

Human & Experimental Toxicology ◽

10.1177/0960327115598387 ◽

2015 ◽

Vol 35 (7) ◽

pp. 713-723 ◽

Cited By ~ 2

Author(s):

SMEO Elmubarak ◽

N Özsoy

Keyword(s):

Vitamin D ◽

Carbon Tetrachloride ◽

Periodic Acid ◽

Kidney Tissue ◽

Albino Rats ◽

Periodic Acid Schiff ◽

Glucose Levels ◽

Tissue Sections ◽

Wistar Albino Rats ◽

Hematoxylin Eosin

This study investigated the protective effect of vitamin D against carbon tetrachloride (CCl4)-induced nephrotoxicity in rats. Adult male Wistar albino rats were divided into four groups ((A) control; (B) 10-week exposure to CCl4; (C) 10-week exposure to CCl4 + vitamin D treatment; and (D) 10-week exposure to CCl4 + 12 weeks of vitamin D treatment). The CCl4 dose (1.5 ml kg−1) was injected subcutaneously twice a week, while the 0.5 mg kg−1 dose of vitamin D was administered intraperitoneally every day, as appropriate for each group. Whole animal and kidney weights as well as serum urea, creatinine, and glucose levels were measured. Kidney tissue sections were stained with hematoxylin–eosin, Masson’s trichrome, and periodic acid–Schiff. Tubular and glomerular degeneration were detected in the kidney tissues of CCl4-treated rats, together with dilatation and vacuolization within the tubules and hemorrhage in the intertubular region. In the kidney glomeruli; congestion, atrophy, and adhesion to parietal layer were observed. Tissue disorganization and aggregation of Bowman’s capsules were noted. Mononuclear cell infiltration was observed between the glomeruli and the tubules. In contrast, the kidney sections and functional parameters of vitamin D-treated rats were similar to the controls, suggesting that vitamin D treatment is able to reduce renal damage.

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Platelet Inhibition Prevents NLRP3 Inflammasome Activation and Sepsis-Induced Kidney Injury

International Journal of Molecular Sciences ◽

10.3390/ijms221910330 ◽

2021 ◽

Vol 22 (19) ◽

pp. 10330

Author(s):

Marivee Borges-Rodriguez ◽

Corbin A. Shields ◽

Olivia K. Travis ◽

Robert W. Tramel ◽

Cedar H. Baik ◽

...

Keyword(s):

Renal Function ◽

Platelet Activation ◽

Nlrp3 Inflammasome ◽

Renal Injury ◽

Cecal Ligation ◽

Receptor Protein ◽

Inflammasome Activation ◽

Glomerular Injury ◽

Activated Platelets ◽

Nlrp3 Inflammasome Activation

Platelets, cellular mediators of thrombosis, are activated during sepsis and are increasingly recognized as mediators of the immune response. Platelet activation is significantly increased in sepsis patients compared to ICU control patients. Despite this correlation, the role of activated platelets in contributing to sepsis pathophysiology remains unclear. We previously demonstrated NOD-like receptor protein 3 inflammasome (NLRP3) inflammasome activation in sepsis-induced platelets from cecal-ligation puncture (CLP) rats. Activated platelets were associated with increased pulmonary edema and glomerular injury in CLP vs. SHAM controls. In this study, we investigated whether inhibition of platelet activation would attenuate NLRP3 activation and renal and pulmonary injury in response to CLP. CLP was performed in male and female Sprague Dawley (SD) rats (n = 10/group) to induce abdominal sepsis and SHAM rats served as controls. A subset of CLP animals was treated with Clopidogrel (10 mg/kg/day, CLP + CLOP) to inhibit platelet activation. At 72 h post-CLP, platelet activation and NLRP3 inflammasome assembly were evaluated, IL-1β and IL-18 were measured in plasma, and tissues, renal and pulmonary pathology, and renal function were assessed. Activated platelets were 7.8 ± 3.6% in Sham, 22 ± 6% in CLP and significantly decreased to 14.5 ± 0.6% in CLP + CLOP (n = 8–10/group, p < 0.05). NLRP3 inflammasome assembly was inhibited in platelets of CLP + CLOP animals vs. CLP. Significant increases in plasma and kidney IL-1β and IL-18 in response to CLP were decreased with Clopidogrel treatment. Renal injury, but not lung histology or renal function was improved in CLP + CLOP vs. CLP. These data provide evidence that activated platelets may contribute to sepsis-induced renal injury, possibly via NLRP3 activation in platelets. Platelets may be a therapeutic target to decrease renal injury in septic patients.

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Jian-Pi-Yi-Shen formula enhances perindopril inhibition of chronic kidney disease progression by activation SIRT3, modulation mitochondrial dynamics and antioxidant effects

Bioscience Reports ◽

10.1042/bsr20211598 ◽

2021 ◽

Author(s):

Xinhui Liu ◽

Ruyu Deng ◽

Xian Wei ◽

Yuzhi Wang ◽

Jiali Weng ◽

...

Keyword(s):

Chronic Kidney Disease ◽

Renal Function ◽

Kidney Disease ◽

Mitochondrial Dynamics ◽

Periodic Acid ◽

Public Health Problem ◽

Global Public Health ◽

Periodic Acid Schiff ◽

Pathological Lesions ◽

Antioxidant Effects

Chronic kidney disease (CKD) is a global public health problem. Renin–angiotensin system (RAS) blockade is the mainstay of CKD therapy with limitations. Jian-Pi-Yi-Shen formula (JPYSF) is a traditional herbal decoction and has been used for treating CKD for decades. The purpose of this study was to investigate the intervention effects of combined used of perindopril erbumine (PE) and JPYSF on CKD progression and explore their underlying mechanisms. CKD rat model was induced by feeding a diet containing 0.75% w/w adenine for 3 weeks. CKD rats were treated with PE or JPYSF or PE+JPYSF from the induction of CKD and lasted 4 weeks. Renal function was evaluated by serum creatinine and blood urea nitrogen. Pathological lesions were observed by periodic acid-Schiff and Masson’s trichrome staining. The protein expression was tested by Western blot and immunohistochemistry analysis. The morphology of mitochondria was observed by transmission electron microscope. The results showed that combined used of PE and JPYSF could better improve renal function and pathological lesions and ameliorate renal fibrosis in CKD rats. Administration of PE and JPYSF enhanced sirtuin 3 (SIRT3) expression, inhibited mitochondrial fission, promoted mitochondrial fusion, and suppressed oxidative stress in the kidney of CKD rats. In conclusion, combined use of PE and JPYSF protected against CKD more effectively than either alone. The underlying mechanism may be associated with activation of SIRT3, modulation of mitochondrial dynamics and antioxidant effects.

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Yiqi Jiedu Huayu Decoction Alleviates Renal Injury in Rats With Diabetic Nephropathy by Promoting Autophagy

Frontiers in Pharmacology ◽

10.3389/fphar.2021.624404 ◽

2021 ◽

Vol 12 ◽

Author(s):

Chen Xuan ◽

Yu-Meng Xi ◽

Yu-Di Zhang ◽

Chun-He Tao ◽

Lan-Yue Zhang ◽

...

Keyword(s):

Renal Function ◽

Diabetic Nephropathy ◽

Renal Fibrosis ◽

Periodic Acid ◽

Kidney Injury ◽

Mtor Pathway ◽

Control Group ◽

Therapeutic Effects ◽

Sprague Dawley ◽

Periodic Acid Schiff

Diabetic nephropathy (DN), a common microvascular complication of diabetes, is one of the main causes of end-stage renal failure (ESRD) and imposes a heavy medical burden on the world. Yiqi Jiedu Huayu decoction (YJHD) is a traditional Chinese medicine formula, which has been widely used in the treatment of DN and has achieved stable and reliable therapeutic effects. However, the mechanism of YJHD in the treatment of DN remains unclear. This study aimed to investigate the mechanism of YJHD in the treatment of DN. Sprague-Dawley rats were randomly divided into a normal control group, a diabetic group, an irbesartan group, and three groups receiving different doses of YJHD. Animal models were constructed using streptozotocin and then treated with YJHD for 12 consecutive weeks. Blood and urine samples were collected during this period, and metabolic and renal function was assessed. Pathological kidney injury was evaluated according to the kidney appearance, hematoxylin-eosin staining, Masson staining, periodic-acid Schiff staining, periodic-acid Schiff methenamine staining, and transmission electron microscopy. The expression levels of proteins and genes were detected by immunohistochemistry, western blotting, and real-time qPCR. Our results indicate that YJHD can effectively improve renal function and alleviate renal pathological injury, including mesangial matrix hyperplasia, basement membrane thickening, and fibrosis. In addition, YJHD exhibited podocyte protection by alleviating podocyte depletion and morphological damage, which may be key in improving renal function and reducing renal fibrosis. Further study revealed that YJHD upregulated the expression of the autophagy-related proteins LC3II and Beclin-1 while downregulating p62 expression, suggesting that YJHD can promote autophagy. In addition, we evaluated the activity of the mTOR pathway, the major signaling pathway regulating the level of autophagy, and the upstream PI3K/Akt and AMPK pathways. YJHD activated the AMPK pathway while inhibiting the PI3K/Akt and mTOR pathways, which may be crucial to its promotion of autophagy. In conclusion, our study shows that YJHD further inhibits the mTOR pathway and promotes autophagy by regulating the activity of the PI3K/Akt and AMPK pathways, thereby improving podocyte injury, protecting renal function, and reducing renal fibrosis. This study provides support for the application of and further research into YJHD.

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Hyperhomocysteinemia-Induced Oxidative Stress Aggravates Renal Damage in Hypertensive Rats

American Journal of Hypertension ◽

10.1093/ajh/hpaa086 ◽

2020 ◽

Author(s):

Ning Gao ◽

Yuzhen Zhang ◽

Li Li ◽

Lei Lei ◽

Ping Cao ◽

...

Keyword(s):

Oxidative Stress ◽

Renal Injury ◽

Renal Damage ◽

Periodic Acid ◽

Hypertensive Rats ◽

Periodic Acid Schiff ◽

Spontaneously Hypertensive ◽

Expression Levels ◽

Wistar Kyoto ◽

The Relationship

Abstract BACKGROUND Hyperhomocysteinemia (HHcy) plays a synergistic role with hypertension in vascular injury; however, the relationship between HHcy and hypertension in renal injury remains unclear. Here, we sought to evaluate the relationship between HHcy and hypertension in the context of renal injury and to elucidate the mechanism of action underlying this relationship. METHODS Wistar Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) were randomized into WKY, WKY + HHcy, SHR, and SHR + HHcy groups. Blood pressure, plasma homocysteine, serum malondialdehyde (MDA), serum superoxide dismutase (SOD), urinary albumin creatinine ratio (UACR), and glomerular filtration rate (GFR) were measured. Renal histopathology and expression levels of NOX2, NOX4, and nephrin in the kidneys were examined. RESULTS The WKY + HHcy and SHR groups exhibited lower serum SOD and GFR levels, relative to the WKY group, along with higher levels of both serum MDA and UACR. Higher mRNA and protein expression levels of NOX2 and NOX4, along with lower expression levels of nephrin, were observed in the kidneys of WKY + HHcy and SHR rats, relative to WKY controls, respectively. Similar effects were observed in the SHR + HHcy group, relative to the SHR group and WKY + HHcy group, respectively. Periodic acid-Schiff staining showed an increase in the glomerular extracellular matrix in the WKY + HHcy and SHR + HHcy groups compared with their respective controls. CONCLUSIONS HHcy appears to synergistically increase hypertensive renal damage by enhancing oxidative stress.

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Renal functional decline and glomerulotubular injury are arrested but not restored by release of unilateral ureteral obstruction (UUO)

AJP Renal Physiology ◽

10.1152/ajprenal.00425.2012 ◽

2013 ◽

Vol 304 (4) ◽

pp. F432-F439 ◽

Cited By ~ 23

Author(s):

Wassim Chaabane ◽

Françoise Praddaude ◽

Marie Buleon ◽

Acil Jaafar ◽

Marion Vallet ◽

...

Keyword(s):

Kidney Disease ◽

Ureteral Obstruction ◽

Periodic Acid ◽

Unilateral Ureteral Obstruction ◽

Sham Operation ◽

Glomerular Injury ◽

Periodic Acid Schiff ◽

Glomerular Volume ◽

Atubular Glomeruli ◽

Proximal Tubular

Murine unilateral ureteral obstruction (UUO), a major model of progressive kidney disease, causes loss of proximal tubular mass and formation of atubular glomeruli. Adult C57BL/6 mice underwent a sham operation or reversible UUO under anesthesia. In group 1, kidneys were harvested after 7 days. In group 2, the obstruction was released after 7 days, and a physiological study of both kidneys was performed 30 days later. Renal blood flow (RBF), glomerular filtration rate (GFR), urine protein, and albumin excretion were measured after ligation of either the left or right ureter. Glomerular volume (periodic acid-Schiff), glomerulotubular integrity and proximal tubular mass ( Lotus tetragonolobus lectin), and interstitial collagen (Sirius red) were measured by histomorphometry. Obstructed kidney weight was reduced by 15% at 7 days but was not different from sham after a 30-day recovery. Glomerular volume and proximal tubular area of the obstructed kidney were reduced by 55% at 7 days, but normalized after 30 days. Interstitial collagen deposition increased 2.4-fold after 7 days of UUO and normalized after release. However, GFR and RBF were reduced by 40% and urine albumin/protein ratio was increased 2.8-fold 30 days after release of UUO. This was associated with a 50% reduction in glomerulotubular integrity despite a 30-day recovery ( P < 0.05 for all data). We conclude that release of 7-day UUO can arrest progression but does not restore normal function of the postobstructed kidney. Although the remaining intact nephrons have hypertrophied, glomerular injury is revealed by albuminuria. These results suggest that glomerulotubular injury should become the primary target of slowing progressive kidney disease.

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