Vacuolization Of Tubular Cells Research Articles

CFAP47 is implicated in X-linked polycystic kidney disease

IntroductionAutosomal dominant polycystic kidney disease (ADPKD) is a well-described condition in which ∼80% of all cases have a genetic explanation, and among sporadic cases without a family history, the genetic bases remains unclear in ∼30% of cases. This study aimed to identify genes associated with polycystic kidney disease (PKD) in patients with sporadic cystic kidney disease in which a clear genetic change was not identified in established genes. MethodsA next-generation sequencing panel analyzed known genes related to kidney cysts in 118 sporadic cases, followed by whole-genome sequencing on 47 unrelated individuals without identified candidate variants. Immunohistological examination was then conducted on both human kidney tissue and kidneys from Cfap47-/Y mice. ResultsThree male patients were found to have rare missense variants in the X-linked gene Cilia And Flagella Associated Protein 47 (CFAP47), none of whom had a family history of the condition. CFAP47 was expressed in primary cilia of human kidney tubules, and knockout mice exhibited vacuolation of tubular cells and tubular dilation, providing evidence that CFAP47 is a causative gene involved in cyst formation. ConclusionThis discovery of CFAP47 as a newly identified gene associated with PKD, displaying X-linked inheritance, emphasizes the need for further cases to understand the role of CFAP47 in PKD.

Agomelatine on cisplatin-induced nephrotoxicity via oxidative stress and apoptosis.

Drug-induced nephrotoxicity is the greatest deterrent to the use of cisplatin, which is a frequently used chemotherapeutic with proven effectiveness in cancer therapy. Agomelatine, which is used in the treatment of sleep disorders and depression, has gained attention in recent years with its antioxidative and anti-inflammatory effects. In this study, the effects of the synthetic melatonin agonist agomelatine on nephrotoxicity were investigated in a rat model of cisplatin-induced nephrotoxicity using biochemical, histological, and immunohistochemical methods. Thirty-two male rats were divided into 4 groups: 1. control group, 2. agomelatine group, 3. cisplatin group, 4. cisplatin + agomelatine group. In the cisplatin group, there were widespread atypical glomerular structures and vacuolization in tubular epithelial cells, necrotic tubules, deterioration of brush border structure in proximal tubules, and fibrotic areas characterized by diffuse polymorphonuclear leukocyte (PNL) and extensive collagen deposition in the interstitial spaces. However, in the cisplatin + agomelatine group, we observed a reduction in glomeruli of atypical structure and necrotic tubules, in PNL infiltration in interstitial spaces, and fibrotic areas compared to the cisplatin group. The cisplatin + agomelatine group showed lower malondialdehyde (MDA) serum creatinine, serum urea levels, and higher glutathione (GSH) levels compared to the cisplatin group. Immunohistochemical analyses revealed that the elevated NF-kβ/p65, 8-OHdG, and cleaved caspase-3 positivity in the cisplatin group had significantly decreased in the cisplatin + agomelatine group. In conclusion, agomelatine showed a nephroprotective effect against cisplatin-induced nephrotoxicity.

#4043 FABRY DISEASE: A RARE ENTITY IN THE NEPHROLOGY SETTING

Abstract Background and Aims Fabry disease is a rare genetic disorder that affects multiple organs, including the kidneys. It is characterized by the accumulation of globotriaosylceramide (Gb3) in various tissues and organs, leading to progressive interstitial fibrosis and renal dysfunction. We aim to determine the renal manifestations of Fabry disease in particular the histological aspects. Method This study analyzed 9 patients with Fabry disease and renal involvement in a retrospective, single-center analysis. Clinical and biological data, as well as histologic findings, were collected based on patient's observations. Results Data was collected from 9 patients, including 7 males and 2 females, with an average age at diagnosis of 25.2 years (ranging from 17 to 32 years). All patients showed depleted activity of alpha 1 glycosidase, confirming the diagnosis. Acrosyndrome and vascular cutaneous lesions (angiokeratomas) were the dominant signs at admission with respectively (n=7; n=4), with only 3 patients being identified through familial screening without symptoms. Uncontrolled Hypertension was noted in 2 patients. Renal manifestations included renal hyperfiltration in 2 cases, isolated proteinuria in 4 patients, and renal failure in 3 others with a mean serum creatinine levels of 240 ± 36 µmol/l. Four patients underwent renal biopsy, which showed characteristic lesions of Fabry disease with sphingolipid accumulation and tubular cell vacuolization. Thickening of the glomerular capillary walls was observed in one patient. Interstitial fibrosis and tubular atrophy were noted in 3 patients. All patients received enzyme replacement therapy. Angiotensin-converting enzyme inhibitors (ACEi) and/or angiotensin II receptors blockers (ARB) were uses in 6 patients. Five patients progressed to terminal stage of renal failure requiring dialysis after an average follow-up period of 13±2.7 years. Four patients died from cardiovascular complications. Conclusion Early recognition and diagnosis of Fabry disease from the onset of glomerular hyperfiltration and albuminuria are crucial for the initiation of appropriate treatment and management, which can help to delay the progression of renal and other organ damage.

Dexmedetomidine alleviates vacuolization and necrosis in tubular epithelial cells induced by aortic cross-clamping.

Acute kidney injury (AKI) is one of the main causes of mortality in patients undergoing emergency surgery due to an abdominal aortic aneurysm. This study aimed to determine the potential nephroprotective characteristics of dexmedetomidine (DMD) for the establishment of a standard therapeutic method for AKI. Thirty Spraque Dawley rats were allocated to 4 groups: control, sham, ischemia-reperfusion, and ischemia/reperfusion (I/R)+dexmedatomidine. Necrotic tubules, degenerative Bowman's capsule and vascular congestion were observed in the I/R group. In addition, there was an increase in tissue malondialdehyde (MDA), interleukin (IL)-1 and IL-6 levels in tubular epithelial cells. In contrast, we observed decreased tubular necrosis, IL-1, IL-6 and MDA levels in the DMD treatment group. DMD has a nephroprotective effect against acute kidney injury resulting from I/R, which is related to aortic occlusion used in the treatment of ruptured abdominal aortic aneurysms.

Histopathological changes caused by noise exposure in lung, heart, kidney, and liver tissues in New Zealand white rabbits

Introduction: Noise exposure is a common phenomenon in all personal life activities. Due to the prevalence of exposure to noise, many people are exposed to noise. Some of the harmful effects of noise on human health have been proven so far. The purpose of this study was to experiment histopathological effects caused by exposure to white noise. Materials and methods: Four New Zealand white rabbits were exposed to 85±2 dB white noise for five consequent days. Heart, kidney, liver, and lung tissues were studied by the Hematoxylin and Eosin staining (H&E) method. The independent t-test was used for comparing the mean weight of tissues. Results: This study showed that exposure to 85±2 dB white noise did not significantly change heart and lungs tissues. Nevertheless, this study indicated that exposure to noise induced different pathological changes in kidney and liver tissues. Exposure to noise made congestion, unclear brush border, and tubular cell vacuolization in kidney tissue. Moreover, eosinophilic cytoplasm was made by noise exposure in liver tissue. Furthermore, no statistically significant difference was detected in the mean tissue weight/mean body weight in rabbits. Conclusion: This study showed that exposure to noise might be a risk factor for different renal and hepatic diseases. Nevertheless, more studies need to complete these results.

The effect of Anatolian syrup on experimentally induced acetaminophen and lipopolysaccharide associated acute kidney injury

Aim: Acute kidney injury develops as a result of various etiologies and pathological mechanisms, with a high mortality rate. This study aimed to investigate the efficacy of Anatolian syrup on histopathological variables in experimentally induced acetaminophen and lipopolysaccharide associated acute kidney injury.Methods: In this study, 5 groups were formed using 40 male Wistar albino rats (200-220g, 2-4 months old), as follows: Sham, acetaminophen (1 g/kg intraperitoneal (ip)), 3) lipopolysaccharide (5 mg/kg ip), acetaminophen (1 g/kg ip) + Anatolian syrup (15 days orally), and lipopolysaccharide (5 mg/kg ip) + Anatolian syrup (15 days orally).Tubular atrophy, tubular dilatation, cytoplasmic vacuolization in tubular epithelial cells, tubular epithelial cell necrosis, interstitial inflammation, congestion, hemorrhage, glomerular damage and loss of brushy border were evaluated histopathologically semiquantitatively using scoring from 0 to 5.Results: In histopathological variables, tubular atrophy, tubular dilatation, cytoplasmic vacuolization, necrosis, congestion, hemorrhage, glomerular damage, and loss of brushy border were significantly reduced in the acetaminophen + Anatolian syrup group compared to the acetaminophen group and in the lipopolysaccharide + Anatolian syrup group compared to the lipopolysaccharide group (p

Protective effect of dapagliflozin against cyclosporine A-induced nephrotoxicity

This study aimed to reveal the possible protective effect of dapagliflozin (DAPA) against acute kidney damage due to cyclosporine A (CsA). Thirty-two mice with an eight-week-old Balb\\c albino strain were divided into four groups: control group, CsA group, DAPA group, and CsA + DAPA group. On day 9 of treatment, the animals were decapitated, and bilateral nephrectomy was performed. Oxidative stress and apoptosis were evaluated with caspase-3 activity, total oxidant status (TOS), total antioxidant status (TAS), malondialdehyde (MDA), myeloperoxidase (MPO), B-cell lymphoma-2 (Bcl-2), and Bcl-2-associated X protein (Bax) in the right kidney resection material. The left kidney resection material was evaluated histopathologically. CsA increased caspase-3 activity, Bax, TOS, MDA, TAS, and MPO levels, and the administration of DAPA with CsA significantly reduced this increase in levels (p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, and p < 0.001, respectively). CsA decreased Bcl-2 levels, and administration of CsA + DAPA significantly increased Bcl-2 levels compared with only CsA administration (p < 0.001). Additionally, administration of DAPA significantly reduced the histopathological findings (parenchymal inflammation, hyaline cast formation, vacuolization, and lysis of renal tubular cells) caused by CsA. DAPA reduces oxidative stress, apoptosis, and histopathological damage caused by CsA in renal tissue.

Sotagliflozin, a Dual SGLT1/2 Inhibitor, Improves Cardiac Outcomes in a Normoglycemic Mouse Model of Cardiac Pressure Overload.

Selective SGLT2 inhibition reduces the risk of worsening heart failure and cardiovascular death in patients with existing heart failure, irrespective of diabetic status. We aimed to investigate the effects of dual SGLT1/2 inhibition, using sotagliflozin, on cardiac outcomes in normal diet (ND) and high fat diet (HFD) mice with cardiac pressure overload. Five-week-old male C57BL/6J mice were randomized to receive a HFD (60% of calories from fat) or remain on ND for 12 weeks. One week later, transverse aortic constriction (TAC) was employed to induce cardiac pressure-overload (50% increase in right:left carotid pressure versus sham surgery), resulting in left ventricular hypertrophic remodeling and cardiac fibrosis, albeit preserved ejection fraction. At 4 weeks post-TAC, mice were treated for 7 weeks by oral gavage once daily with sotagliflozin (10 mg/kg body weight) or vehicle (0.1% tween 80). In ND mice, treatment with sotagliflozin attenuated cardiac hypertrophy and histological markers of cardiac fibrosis induced by TAC. These benefits were associated with profound diuresis and glucosuria, without shifts toward whole-body fatty acid utilization, increased circulating ketones, nor increased cardiac ketolysis. In HFD mice, sotagliflozin reduced the mildly elevated glucose and insulin levels but did not attenuate cardiac injury induced by TAC. HFD mice had vacuolation of proximal tubular cells, associated with less profound sotagliflozin-induced diuresis and glucosuria, which suggests dampened drug action. We demonstrate the utility of dual SGLT1/2 inhibition in treating cardiac injury induced by pressure overload in normoglycemic mice. Its efficacy in high fat-fed mice with mild hyperglycemia and compromised renal morphology requires further study.

The renoprotective effects of Heme Oxygenase-1 during contrast-induced acute kidney injury in preclinical diabetic models

OBJECTIVES:Contrast-induced acute kidney injury (CI-AKI) is an important clinical problem that can be aggravated by diabetes mellitus, a major risk factor. However, heme oxygenase-1 (HO-1), a promising therapeutic target, can exert antioxidant effects against CI-AKI. Thus, we investigated the role of HO-1 in CI-AKI in the presence of diabetes mellitus.METHODS:Twenty-eight male Wistar rats weighing 250-300g were subjected to left uninephrectomy, and concomitantly, diabetes induced by streptozotocin (65 mg/kg). After 12 weeks, iodinated contrast (meglumine ioxithalamate, 6 mL/kg) and hemin (HO-1 inducer-10 mg/k) were administered 60 min before iodinated contrast treatment. The rats were randomly divided into four groups: control, diabetes mellitus (DM), DM iodinated contrast (DMIC), and DMIC hemin (DMICH). Kidney function, albuminuria, oxidative profile, and histology were assessed. All experimental data were subjected to statistical analyses.RESULTS:CI-AKI in preclinical diabetic models decreased creatinine clearance and increased urinary neutrophil gelatinase-associated lipocalin (NGAL) levels and the degree of albuminuria. Additionally, the levels of oxidative and nitrosative stress metabolites (urinary peroxides, thiobarbituric acid-reactive substances, and NO) were elevated, while thiol levels in kidney tissue were reduced. Kidney histology showed tubular cell vacuolization and edema. HO-1 inducer treatment improved kidney function and reduced urinary the NGAL levels. The oxidative profile showed an increase in the endogenous thiol-based antioxidant levels. Additionally, the tubular injury score was reduced following HO-1 treatment.CONCLUSIONS:Our findings highlight the renoprotective effects of HO-1 in CI-AKI and preclinical diabetic models. Therefore, HO-1 ameliorates kidney dysfunction, reduces oxidative stress, and prevents cell necrosis.

Outbreak and management of &lt;i&gt;Salmonella&lt;/i&gt; Enteritidis infection in 2-week-old Lohmann brown pullets

Avian salmonellosis has huge economic and public health impact. In this manuscript, a case of S. Enteritidis and its management within Jos Metropolis was reported. Fiftythree carcasses of 2-weeks old pullets were presented at the poultry and fish clinic of the Veterinary Teaching Hospital, University of Jos, Nigeria for investigation. There was persistent mortality despite 5 days medication with 20% Enrofloxacin (Floxinor®, Shijiazhuang Guanghua Pharmaceutical co. Ltd, Hebei, China). Cumulative mortality within 14 days was 203 birds in a flock of 4,000. Necropsy was done and harvested were subjected to microbial analysis for bacterial isolation, identification and antibiotic susceptibility test while portions of these organs were preserved in 10% formalin for histopathology. Necropsy findings were empty crops, hepatitis with petechial hemorrhages, nephritis, congested and consolidated lungs, peritonitis, congested spleens and mild enteritis. Histologically, there were vacuolation and necrosis of renal tubular epithelia cells and interstitial infiltration with heterophils. Severe disorganization of hepatic cords, infiltration with inflammatory cells and mild necrosis of hepatocytes were observed, while there was severe congestion and diffuse hemorrhages in the lungs. Cellular infiltration within the lamina propria of small intestine with stunting and blunting of the villi were observed. Organism isolated on MacConkey agar was identified as Salmonella Enteritidis. Antibiotic susceptibility test showed the organism to be most susceptible to Streptomycin, which was administered via drinking water at dosage of 40mg/kg with good recovery of the flock. It was concluded that the occurrence of Salmonella Enteritidis infection in this flock might be from the hatchery or via ingestion of contaminated feed and water. Day old chicks should be screened for Salmonella infection and strict biosecurity should be instituted on poultry farms.&#x0D; Keywords: Mortality, Necrosis, Pullets, Salmonella Enteritidis, streptomycin

Protection of procyanidin B2 on mitochondrial dynamics in sepsis associated acute kidney injury via promoting Nrf2 nuclear translocation.

In septic acute kidney injury (SAKI), the positive feedback between damaged mitochondria and accumulation of reactive oxygen species results in cell and tissue damage through multiple mechanisms. Removing the damaged mitochondria or neutralizing the reactive oxygen species has been considered beneficial to alleviating cell damage. The antioxidant Procyanidin B2 has been reported to inhibits reactive oxygen species and thereby reduces cell injury. However, it is unclear whether this effect is associated with clearance of damaged mitochondria. Here, we evaluated the efficacy of procyanidin B2 on SAKI, and focused on its effects on mitochondrial dynamics and removing damaged mitochondria via mitophagy. The results showed that the renal function, renal tubular cell vacuolization and oxidative stress were decreased in SAKI mice treated with procyanidin B2, moreover, skewed mitochondrial fusion/fission, mitochondrial mediated apoptosis and impaired mitophagy were improved in SAKI mice treated with procyanidin B2. In mechanism, the improvement of procyanidin B2 on mitochondrial dynamics were associated with increased nuclear translocation of the transcription factor, Nrf2. In summary, our findings highlighted that the protective efficacy of procyanidin B2 in reducing cellular damage in SAKI, and mechanisms improving mitochondrial dynamics and quality control at least in part by promoting Nrf2 translocation into the nucleus.

Kidney-based in vivo model for drug-induced nephrotoxicity testing

The need is critical and urgent for a real-time, highly specific, and sensitive acute kidney injury biomarker. This study sought to establish a sensitive and specific Miox-NanoLuc transgenic mouse for early detection of drug-induced nephrotoxicity. We generated Miox-NanoLuc transgenic mice with kidney-specific NanoLuc overexpression. Our data showed that Miox-NanoLuc-produced luminescence was kidney-specific and had good stability at room temperature, 4 °C, − 20 °C, and repeated freeze–thaw cycles. Serum levels of BUN and creatinine were significantly increased at day 2 or 3 in cisplatin-treated mice and at day 5 in aristolochic acid (AAI)-treated mice. Particularly, the serum and urine Miox-NanoLuc luminescence levels were significantly increased at day 1 in cisplatin-treated mice and at day 3 in AAI-treated mice. Renal pathological analysis showed that the kidney sections of cisplatin-treated mice at day 5 and AAI-treated mice at day 13 showed cytolysis and marked vacuolization of tubular cells. In conclusion, we developed a new platform to early quantify drug-induced nephrotoxicity before serum BUN and creatinine levels increased and pathological tubular cell injury occurred. This model may serve as an early detection for drug- and food-induced nephrotoxicity and as an animal model to investigate tubular cell injury.

Nephrotoxic effects caused by co-exposure to noise and toluene in New Zealand white rabbits: A biochemical and histopathological study

The biological and renal effects made by simultaneous and non-simultaneous exposure to toluene and noise were investigated. Twenty-four New Zealand white rabbits were exposed to 100 dB of white noise and 1000 ppm of toluene vapor for two weeks. The examined biochemical factors were urea, uric acid, creatinine, glucose, triglyceride, cholesterol, and albumin serum levels, measured on different days after the end of the exposure. Moreover, glutathione peroxidase activity (GPX), malondialdehyde dismutase activity (MDA), and superoxide dismutase (SOD) parameters were measured in the kidney tissue. The hematoxylin and eosin staining method was used for histopathological experiments. Overall, the noise increased albumin, uric acid, creatinine, and glucose levels, but it decreased urea, cholesterol, and triglyceride levels. Toluene decreased albumin, uric acid, and urea levels, while it increased creatinine, triglyceride, cholesterol, and glucose levels. Simultaneous exposure to noise and toluene decreased albumin, uric acid, cholesterol, and urea levels, whereas it increased creatinine, glucose, and triglyceride levels. GPX, MDA, and SOD levels increased by simultaneous and non-simultaneous exposure to noise and toluene. Furthermore, massive tubular degeneration, tubular cell vacuolization, glomerular disorganization, congestion, glomerular cell shrinkage, and unclear brush border were detected in the kidney tissue.

Metformin Preconditioning and Postconditioning to Reduce Ischemia Reperfusion Injury in an Isolated Ex Vivo Rat and Porcine Kidney Normothermic Machine Perfusion Model.

Metformin may act renoprotective prior to kidney transplantation by reducing ischemia‐reperfusion injury (IRI). This study examined whether metformin preconditioning and postconditioning during ex vivo normothermic machine perfusion (NMP) of rat and porcine kidneys affect IRI. In the rat study, saline or 300 mg/kg metformin was administered orally twice on the day before nephrectomy. After 15 minutes of warm ischemia, kidneys were preserved with static cold storage for 24 hours. Thereafter, 90 minutes of NMP was performed with the addition of saline or metformin (30 or 300 mg/L). In the porcine study, after 30 minutes of warm ischemia, kidneys were preserved for 3 hours with oxygenated hypothermic machine perfusion. Subsequently, increasing doses of metformin were added during 4 hours of NMP. Metformin preconditioning of rat kidneys led to decreased injury perfusate biomarkers and reduced proteinuria. Postconditioning of rat kidneys resulted, dose‐dependently, in less tubular cell necrosis and vacuolation. Heat shock protein 70 expression was increased in metformin‐treated porcine kidneys. In all studies, creatinine clearance was not affected. In conclusion, both metformin preconditioning and postconditioning can be done safely and improved rat and porcine kidney quality. Because the effects are minor, it is unknown which strategy might result in improved organ quality after transplantation.

Kidney Involvement in COVID-19: Need for Better Definitions

Since the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus outbreak in China at the end of 2019, increasing interest emerged regarding renal involvement during coronavirus disease 2019 (COVID-19). AKI with or without proteinuria is described in a variable percentage of patients with COVID-19, and several reports outlined an increased mortality risk in those with AKI. The mechanisms of renal injury during COVID-19 are difficult to study due to the interference of several coexisting factors, such as polypharmacy, hypoxia, and cytokine storm. Just like severe acute respiratory syndrome coronavirus, SARS-CoV-2 virus entry into target cells is facilitated by the presence of angiotensin-converting enzyme 2 (ACE2) expressed in respiratory cells as well as renal tubular cells and podocytes, making the hypothesis of a direct renal infection particularly intriguing. Farkash et al.1 observed renal tubular vacuolization and virus-like inclusions in tubular cells by electron microscopy (EM) in the autopsy of a patient with COVID-19. Similar EM findings together with suggestive immunohistochemical stain for SARS-CoV-2 proteins in tubules were shown in a few patients from two independent Chinese COVID-19 autopsy cohorts (Diao B, Wang C, Wang R, Feng Z, Tan Y, Wang H, et al. [2020] Human kidney is a target for novel severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] infection. 10.1101/2020.03.04.20031120).2 However, the same immunohistochemical was not considered specific when used by others.3 Of note, when specific and highly sensitive molecular methods for tissue viral identification were used (i.e., RNAscope3 or real-time PCR,4 the presence of SARS-CoV-2 RNA could not be demonstrated within renal tissue, and none of the aforementioned autopsy studies included viral RNA isolation in the kidney. Interestingly, viral nephropathies with direct tubular infection and viral replication within epithelial cells (i.e., BK virus nephropathy) are usually associated with substantial viruria due to the direct release of viral particles in the tubular lumen following cytopathic cell injury. So far, there is no solid evidence of a correlation between urinary levels of SARS-CoV-2 viral copies and the degree of kidney injury in patients with COVID-19.5 Moreover, the presence of viral particles by pure morphologic evaluation (EM) does not demonstrate by itself a direct cytopathic effect nor a replicative potential because it only supports viral entry. More specific morphologic correlates of viral cytopathy (nuclear atypia/dysmorphology and syncytia) have not been shown yet. Three cases of collapsing glomerulopathy during SARS-CoV-2 infection have been reported,6 presenting with severe kidney injury and variable proteinuria: in genetically predisposed subjects, increased levels of cytokines (i.e., IFNs) in patients with COVID-19 are thought to drive podocyte injury, resulting in collapsing glomerulopathy as can be observed in other viral-associated nephropathies. Although in one case, the presence of virus-like particles in podocytes was observed by EM, the hypothesized mechanism of injury does not require direct kidney infection. Taken together, these observations suggest that caution should be used when addressing the etiology of kidney dysfunction in patients with COVID-19 because unequivocal evidence of direct viral infection of the kidney is still lacking in these severe and acutely ill patients. Disclosures All authors have nothing to disclose. Funding None.

Comparative histology of wild-type and p53-deficient medaka (Oryzias latipes): nephrotoxic effect of ultraviolet A radiation.

Ultraviolet radiation is an ecological factor that directly affects terrestrial organisms through suppression of immunity or damage to internal organs. The present study assessed the effects of ultraviolet A (UVA) radiation on the kidneys of both wild-type (WT) and p53-deficient medaka (Oryzias latipes) and evaluated which strain was more resistant to the effects of UVA. Fish were divided into four groups: control group 1 (Cwt and Cp53), kept for 3 days without UVA exposure; group 2 (1wt and 1p53), fish exposed daily to UVA for 1 h day-1 for 3 days; group 3 (2wt and 2p53), fish exposed daily to UVA for 2 h day-1 for 3 days; and group 4 (3wt and 3p53), fish exposed daily to UVA for 3 h day-1 for 3 days. Samples of tissues were obtained 24 h after UVA exposure. The most obvious histopathological changes induced by UVA radiation in kidney tissues of both strains of medaka (WT and p53-deficient) were high levels of vacuolation of tubular cells followed by necrosis. The tubular segments lost their normal shape which appeared like a network structure and their cells with clear cytoplasm. Necrosis of lymphoid tissues and spots of brown pigmentation (possibly melanomacrophages) were sporadically seen in interstitial lymphoid tissues, while shrinkage of glomeruli, diminution of periodic acid-Schiff staining, and increased amount of collagenous fibers were observed. Our results confirmed the harmful effects of UVA radiation on kidney tissues of both WT and p53-deficient medaka. However, WT medaka was affected more than p53-deficient medaka.

MON-023 HYPOKALEMIC NEPHROPATHY IN NEPHROTIC SYNDROME PATIENT

Hypokalemic nephropathy (HN) caused by prolonged K+ deficiency is associated with metabolic alkalosis, polydipsia, polyuria, growth retardation, hypertension, and progressive tubulointerstitial injury. Histopahologic report of HN in nephrotic syndrome (NS) patient is rare. A 27 year male suffered from weakness, especially lower leg, since two weeks prior to admission. The patients had a history of NS since childhood and cared by nephrologist. Recent condition was hemodynamically stable, laboratory examination showed potassium serum 1.85 mmol/L, albumin plasma 1.8 g/dL, serum creatinine 2.45 mg/dL, and marked dyslipidemia. The patient was clinically assesed with hypokalemia, relapse nephrotic syndrome and renal insufficiency. Intravenous potassium was given and renal biopsy was performed. Histopathologic findings showed global sclerosis. The specific findings may related to HN were mesangial proliferation and specific lesions on tubules including athrophy, vacuolization, intratubular deposition of amorphous and laminated hyaline materials and colloidisation of tubular epithelial, and interstitial nephritis. The patient was discharged at 10th day of hospitalization with potassium level 2.93 mmol/L, and serum creatinine 1.95 mg/dL. The patient was treated with oral methylprednisolone, mychophenolate mofetil, ACE-inhibitor, simvastatin and oral potassium Hypokalemic nephropathy may associate with chronic hypokalemia. Hypokalemia, especially if persistently occurs, can induce a variety of changes in renal tissue, impairing tubular transport and possibly inducing chronic tubulointerstitial disease and cyst formation. HN also associated with alterations in intrarenal vasoactive substances, leading to vasoconstriction, salt-sensitivity, and progression of interstitial fibrosis. Histopathological changes in HN, including severe tubular dilatation, intratubular deposition of amorphous and laminated hyaline materials, intratubular cellular casts, and tubular atrophy is found. More attention is paid to athrophy and vacuolar changes in renal tubular epithelium accompanied by inflammatory interstitial changes in patients with potassium losses. One function that is not impaired is the ability to appropriately conserve potassium, which can be important in distinguishing between extrarenal and renal sources of potassium losses when the cause of hypokalemia is not clear.View Large Image Figure ViewerDownload Hi-res image Download (PPT)View Large Image Figure ViewerDownload Hi-res image Download (PPT) A case with nephrotic syndrome associated with HN is reported. Chronic hypokalemia may involve in the development of hypokalemic nephropathy. Hallmark of histopathologic finding are tubular epithel athrophy, intratubular amorphous deposition and vacuolization of tubular cells, and interstitial nephritis to fibrosis.

Dietary DHA/EPA supplementation ameliorates diabetic nephropathy by protecting from distal tubular cell damage.

The aim was to explore the influence of experimental diabetes mellitus type 1 (DM1) and potential protective/deleterious effects of different dietary n-6/n-3 PUFA ratios on renal phospholipid composition and pathological changes caused by DM1. Male Wistar rats were injected with 55mg/kg streptozotocin or citrate buffer (control group). Control (C) and diabetic groups (STZ) were fed with n-6/n-3 ratio of ≈ 7, STZ + N6 with n-6/n-3 ratio ≈ 60 and STZ + DHA with n-6/n-3 ratio of ≈ 1 containing 16% EPA and 19% DHA. Tissues were harvested 30days after DM1 induction. Blood and kidneys were collected and analysed for phospholipid fatty acid composition, pathohystological changes, ectopic lipid accumulation and expression of VEGF, NF-kB and special AT-rich sequence-binding protein-1 (SATB1). Pathological changes were studied also by using transmission electron microscopy, after immunostaining for VEGF. Substantial changes in renal phospholipid fatty acid composition resulted from DM1 and dietary PUFA manipulation. Extensive vacuolization of distal tubular cells (DTCs) was found in DM1, but it was attenuated in the STZ + DHA group, in which the highest renal NF-kB expression was observed. The ectopic lipid accumulation was observed in proximal tubular cells (PTCs) of all diabetic animals, but it was worsened in the STZ + N6 group. In DM1, we found disturbance of VEGF-transporting vesicular PTCs system, which was substantially worsened in STZ + DHA and STZ + N6. Results have shown that the early phase of DN is characterized with extent damage and vacuolization of DTCs, which could be attenuated by DHA/EPA supplementation. We concluded that dietary fatty acid composition can strongly influence the outcomes of DN.

The HMGB1-RAGE/TLR-TNF-α signaling pathway may contribute to kidney injury induced by hypoxia.

The hypoxia-reoxygenation process of obstructive sleep apnea (OSA) may cause oxidative stress injury of the kidney, but the molecular mechanisms are not clear. The present study aimed to investigate whether high mobility group box 1 protein (HMGB1) and its subsequent inflammatory pathway served a role in kidney injury. Adult Sprague Dawley rats were used to establish hypoxia models: Continuous hypoxia, intermittent hypoxia and intermittent hypoxia with hypercapnia. Rat kidney tissues and peripheral blood samples were obtained. Histopathological and ultrastructural changes were observed by light and electron microscopy. Immunohistochemical (IHC) staining was used to detect the distribution of HMGB1. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of HMGB1, receptor for advanced glycosylation end products (RAGE), toll-like receptor 4 (TLR4), nuclear factor kappa-light-chain-enhancer of active B cells (NF-κB) p65 subunit, tumor necrosis factor-α (TNF-α), interleukin (IL)-6, NAD-dependent protein deacetylase sirtuin-1 (SIRT1), peroxisome proliferator-activated receptor (PPAR) mRNA in renal tissues. An ELISA was used to detect the expression of soluble TLR2, TLR4, PPAR-γ, TNF-α, IL-6 in peripheral blood. Hematoxylin & eosin staining demonstrated that there was no serious injury to the kidneys due to hypoxia, with the exception of a certain degree of renal tubular epithelial cell vacuolation. By contrast, ultrastructural changes by electron microscopy were more significant in the hypoxia groups compared with the control, including foot process fusion in the glomerulus and degeneration of mitochondria in the proximal convoluted tubules. IHC also indicated increased expression of HMGB1 and nuclear translocation in the hypoxia groups. The results of the RT-qPCR demonstrated that hypoxia stimulation increased the expression of HMGB1, PPAR, RAGE and TNF-α mRNA, and decreased the expression of SIRT1 mRNA in kidney tissues (P<0.05). The results of the ELISA suggested that hypoxia stimulation increased the expression of soluble TLR4, TNF-α and IL-6 in the peripheral blood, and decreased the expression of soluble TLR2 and PPAR-γ. In summary, hypoxia stimulation may cause early renal injury at the subcellular level and increase the expression and translocation of HMGB1. Hypoxia also upregulated the mRNA expression of the HMGB1-RAGE-TNF-α pathway in kidney tissue and increased the expression of soluble TLR4, TNF-α and IL-6 in the peripheral blood. This suggested that the HMGB1-RAGE/TLR-TNF-α pathway may contribute to the molecular mechanisms of early renal injury induced by hypoxia. The pathway may contain potential markers for OSA-associated early renal injury and drug intervention targets in the future.

N-acetylcysteine protects against diabetic nephropathy through control of oxidative and nitrosative stress by recovery of nitric oxide in rats

The diabetes mellitus (DM) induces several changes, with substantial increase of reactive oxygen species (ROS). The ROS cause damage to systemic and renal microvasculature, which could be one of the mechanisms involved in the development of diabetic nephropathy (DN). The ROS modulate other substances like the nitric oxide (NO), a vasodilator with important role in the renal function. N-acetylcysteine (NAC) is an antioxidant that acts replenishing intracellular cysteine levels, which is essential for glutathione formation. The aim of this study was to evaluate the effect of early or late NAC treatment on oxidative/nitrosative stress in DN progression. All rats were submitted to unilateral nephrectomy and diabetes was induced with streptozotocin. The animals were allocated into six groups: controls that received water (CTL) or NAC (CTL + NAC); diabetic groups that received early or late, water (DM-E; DM-L) or NAC (DM + NAC-E; DM + NAC-L), started on 5th day (early) or 4th week (late) after diabetes induction, during 8 weeks. After NAC treatment, the rats were placed in individual metabolic cages to obtain urine and blood samples for analysis of metabolic profile, renal function, thiobarbituric acid reactive substances (TBARS) and NO. At the end of the protocol, the renal cortex was removed for TBARS, NOS evaluation, antioxidants markers and histology. The DM-E group compared to CTL showed a significant increase in glycemia and proteinuria and impaired renal function; there was a significant increase of TBARS in plasma, urine and renal tissue, and also a significant decrease in plasma NO, which were reverted after early NAC treatment. The eNOS was decreased and iNOS was increased in DM-E vs. CTL, p < 0.05. The early NAC treatment in DM rats reduced proteinuria, creatinine, urea, TBARS and iNOS and, increased creatinine clearance, NO and eNOS, increasing significantly the antioxidant defenses, promoting elevated catalase and glutathione compared to DM-E group, all p < 0.05. The late NAC treatment in diabetic rats vs.DM-E showed reduced proteinuria and TBARS excretion and higher values of creatinine clearance and NO, all statistically significant. Histological analysis of the animals in DM-E or DM-L showed significant tubular changes with degeneration and vacuolization in tubular cells, dilated tubular lumen, intense glycosidic degeneration, and discreet mesangial expansion with interstitial fibrosis area. The DM + NAC-E group showed moderate glycosidic degeneration, however, did not present tubular degeneration or fibrosis. The DM + NAC-L group showed severe glycosidic degeneration, moderate tubular cell degeneration, light and focal dilatation of the tubules, with no fibrosis. Our study showed that NAC protected the diabetic rats against renal injury, probably due to the control of oxidative stress via recovery of the NO bioavailability, showing that early NAC was more effective than late treatment. All these data suggest that NAC may be useful in the adjuvant treatment in a safe way, in the early phase of the disease. Eventually, prolonged treatment, even if it is started later, could change the natural history of the disease, delaying the complications of diabetes in renal tissue.