Morphological Changes In Kidney Research Articles

Zinc Supplementation Attenuates Metallothionein and Oxidative Stress Changes in Kidney of Streptozotocin-Induced Diabetic Rats

Zinc is an element that under physiological conditions preferentially binds to and is a potent inducer of metallothionein under physiological conditions. The present study was conducted to explore whether zinc supplementation morphologically and biochemically protects against diabetic nephropathy through modulation of kidney metallothionein induction and oxidative stress in streptozotocin-induced diabetic rats. Thirty-two Wistar albino male rats were equally divided into four groups. The first group was used as untreated controls and the second group was supplemented with 30mg/kg/day zinc as zinc sulfate. The third group was treated with streptozotocin to induce diabetes and the fourth group was treated with streptozotocin and supplemented with zinc as described for group 2. The blood glucose and micro-albuminuria levels, body and kidney weights were measured during the 42-day experimental period. At the end of the experiment, the kidneys were removed from all animals from the four groups. Diabetes resulted in degenerative kidney morphological changes. The metallothionein immunoreactivity level was lower and the kidney lipid peroxidation levels were higher in the diabetes group than in the controls. The metallothionein immunoreactivity levels were higher in the tubules of the zinc-supplemented diabetic rats as compared to the non-supplemented diabetic group. The zinc and metallothionein concentrations in kidney tissue were higher in the supplemented diabetic group compared to the non-supplemented diabetes group. The activity of glutathione peroxidase did not change in any of the four groups. In conclusion, the present study shows that zinc has a protective effect against diabetic damage of kidney tissue through stimulation of metallothionein synthesis and regulation of the oxidative stress.

Intrinsic proinflammatory signaling in podocytes contributes to podocyte damage and prolonged proteinuria

Inflammation conveys the development of glomerular injury and is a major cause of progressive kidney disease. NF-κB signaling is among the most important regulators of proinflammatory signaling. Its role in podocytes, the epithelial cells at the kidney filtration barrier, is poorly understood. Here, we inhibited NF-κB signaling in podocytes by specific ablation of the NF-κB essential modulator (NEMO, IKKγ). Podocyte-specific NEMO-deficient mice (NEMO(pko)) were viable and did not show proteinuria or overt changes in kidney morphology. After induction of glomerulonephritis, both NEMO(pko) and control mice developed significant proteinuria. However, NEMO(pko) mice recovered much faster, showing rapid remission of proteinuria and restoration of podocyte morphology. Interestingly, quantification of infiltrating macrophages, T-lymphocytes, and granulocytes at day 7 revealed no significant difference between wild-type and NEMO(pko). To further investigate the underlying mechanisms, we created a stable NEMO knockdown mouse podocyte cell line. Again, no overt changes in morphology were observed. Translocation of NF-κB to the nucleus after stimulation with TNFα or IL-1 was sufficiently inhibited. Moreover, secretion of proinflammatory chemokines from podocytes after stimulation with TNFα or IL-1 was significantly reduced in NEMO-deficient podocytes and in glomerular samples obtained at day 7 after induction of nephrotoxic nephritis. Collectively, these results show that proinflammatory activity of NF-κB in podocytes aggravates proteinuria in experimental glomerulonephritis in mice. Based on these data, it may be speculated that immunosuppressive drugs may not only target professional immune cells but also podocytes directly to convey their beneficial effects in various types of glomerulonephritis.

Functional and Morphological Changes in Kidneys From Marginal Donors

Despite the increased number of cadaver donors and overall organ transplantations, we have observed a dramatic increase in the waiting list. We evaluated transplantations performed using marginal (n = 63) and “ideal” or optimal donors (n = 86). Donor and recipient functional and histopathological data were studied at 1 and 5 years after transplantation. Among the marginal donor group, we investigated whether the age or pre-existent hypertension in the donor showed a strong impact on the functional deterioration of the grafts. Twenty-three graftectomies were performed in marginal, and 39 in ideal recipients (P = .002). Evaluating graft function, at 5 years, we observed the serum creatinine level (P = .0001) and the estimated glomerular filtration rate (P = .003) are significantly different between the two groups. At this time there was a significant difference in the serum creatinine level of patients who were older than the age of 55 years compared with those who showed hypertension (P = .0003). Evaluating morphological changes in the kidneys, acute rejection episodes (P = .0004) and interstitial fibrosis/tubular atrophy (P = .002) were significantly greater among the marginal versus the ideal groups. At 1 year after kidney transplantation, despite no significant difference regarding renal function, they were significant in the histology of marginal versus ideal donor kidneys.

Mitochondria-Targeted Drugs Synergize with 2-Deoxyglucose to Trigger Breast Cancer Cell Death

Cancer cells are long known to exhibit increased aerobic glycolysis, but glycolytic inhibition has not offered a viable chemotherapeutic strategy in part because of the systemic toxicity of antiglycolytic agents. However, recent studies suggest that a combined inhibition of glycolysis and mitochondrial function may help overcome this issue. In this study, we investigated the chemotherapeutic efficacies of mitochondria-targeted drugs (MTD) in combination with 2-deoxy-d-glucose (2-DG), a compound that inhibits glycolysis. Using the MTDs, termed Mito-CP and Mito-Q, we evaluated relative cytotoxic effects and mitochondrial bioenergetic changes in vitro. Interestingly, both Mito-CP and Mito-Q synergized with 2-DG to decrease ATP levels in two cell lines. However, with time, the cellular bioenergetic function and clonogenic survival were largely restored in some cells. In a xenograft model of human breast cancer, combined treatment of Mito-CP and 2-DG led to significant tumor regression in the absence of significant morphologic changes in kidney, liver, or heart. Collectively, our findings suggest that dual targeting of mitochondrial bioenergetic metabolism with MTDs and glycolytic inhibitors such as 2-DG may offer a promising chemotherapeutic strategy.

The evolutionary origin of the vasopressin/V2-type receptor/aquaporin axis and the urine-concentrating mechanism

In this mini-review, current evidence for how the vasopressin/V2-type receptor/aquaporin axis developed co-evolutionary as a crucial part of the urine-concentrating mechanism will be presented. The present-day human kidney, allowing the concentration of urine up to a maximal osmolality around 1200 mosmol kg(-1)-or urine to plasma osmolality ratio around 4-with essentially no sodium secreted is the result of up to 3 billion years evolution. Moving from aquatic to terrestrial habitats required profound changes in kidney morphology, most notable the loops of Henle modifying the kidneys from basically a water excretory system to a water conserving system. Vasopressin-like molecules has during the evolution played a significant role in body fluid homeostasis, more specifically, the osmolality of body liquids by controlling the elimination/reabsorption of fluid trough stimulating V2-type receptors to mobilize aquaporin water channels in the renal collector tubules. Recent evidence supports that all components of the vasopressin/V2-type receptor/aquaporin axis can be traced back to early precursors in evolutionary history. The potential clinical and pharmacological implications of a better phylogenetic understanding of these biological systems so essential for body fluid homeostasis relates to any pathological aspects of the urine-concentrating mechanism, in particular deficiencies of any part of the vasopressin-V2R-AQP2 axis causing central or nephrogenic diabetes insipidus-and for broader patient populations also in preventing and treating disturbances in human circadian regulation of urine volume and osmolality that may lead to enuresis and nocturia.

English

The aim of the study is to investigate the effect of Echinacea on kidney and liver against oxidative stress during renal ischemia-reperfusion (I/R) injury, by determining biochemical parameters and evaluating histological examinations. Adult male Sprague-Dawley rats were evaluated in five groups (each group consists of 8 animals). Group 1 (Control; non-ischemic animals); Group 2 (renal I/R injury+saline), Group 3 (renal I/R injury + Echinacea, 25 mg/kg), Group 4 (renal I/R injury + Echinacea, 50 mg/kg) Group 5 (renal I/R injury+ Echinacea, 100 mg/kg) were designed to evaluate effects of Echinacea in renal I/R injury on the morphological changes in kidney and liver. A right nephrectomy was performed for I/R injury. On the 15th day following nephrectomy, ischemia and reperfusion was performed. Echinacea was administered intraperitoneally. Left kidney and liver were taken after 24 h of reperfusion period for histopathological examinations. The malondialdehyde (MDA) levels, superoxide dismutase (SOD) and catalase (CAT) enzyme activities were determined from tissue homogenates. In the study, Echinacea administration in renal ischemia-reperfusion decreased MDA in kidney and liver. SOD activity was decreased with low and high doses of Echinacea treatment in both kidney and liver. Echinacea administration decreased CAT levels in kidney and no difference was observed between Echinacea doses. CAT was increased in liver low dose group. But CAT was decreased in high doses of Echinacea. Histopathological examinations showed partial improvement in the damages seen in I/R injury after Echinacea administration at both kidney and liver. Echinacea may be effective in preventing oxidative injury.   Key words: Echinacea, ischemia-reperfusion, kidney, liver, antioxidant enzyme.

Hypoxia-Inducible Transcription Factors Stabilization in the Thick Ascending Limb Protects against Ischemic Acute Kidney Injury

Hypoxia-inducible transcription factors (HIF) protect cells against oxygen deprivation, and HIF stabilization before ischemia mitigates tissue injury. Because ischemic acute kidney injury (AKI) often involves the thick ascending limb (TAL), modulation of HIF in this segment may be protective. Here, we generated mice with targeted TAL deletion of the von Hippel-Lindau protein (Vhl), which mediates HIF degradation under normoxia, using Tamm-Horsfall protein (Thp)-driven Cre expression. These mice showed strong expression of HIF-1α in TALs but no changes in kidney morphology or function under control conditions. Deficiency of Vhl in the TAL markedly attenuated proximal tubular injury and preserved TAL function following ischemia-reperfusion, which may be partially a result of enhanced expression of glycolytic enzymes and lactate metabolism. These results highlight the importance of the thick ascending limb in the pathogenesis of AKI and suggest that pharmacologically targeting the HIF system may have potential to prevent and mitigate AKI.

Gender-dependent effects of aging on the kidney

It is well known that the kidney plays an important role in the development of cardiovascular diseases such as hypertension. The normal aging process leads to changes in kidney morphology, hemodynamics and function, which increase the incidence of cardiovascular events in the elderly population. These disturbances are influenced by several factors, including gender. In general, females are protected by the effects of estrogens on the cardiorenal system. Several studies have demonstrated the beneficial effects of estrogens on renal function in the elderly; however, the relationships between androgens and kidney health during one's lifetime are not well understood. Sex steroids have many complex actions, and the decline in their levels during aging clearly influences kidney function, decreases the renal reserve and facilitates the development of cardiovascular disorders. Therefore, in this review, we discuss the cellular, biochemical, and molecular mechanisms by which sex hormones may influence renal function during the aging process.

Factors Influencing Rat Survival in a Warm Renal Ischemia Model: Time to Adapt the Protocols

Introduction Survival in warm renal ischemia models is not only dependent on the treatment or surgical technique being evaluated, but also on factors inherent to the model itself. Use of rats of various strains in previous studies makes interstudy comparison difficult when trying to design an appropriate model control that would yield intermediate survival. In this study, impact of rat strain on survival after prolonged warm renal ischemia in the setting of delivery-controlled inhalational anesthesia was evaluated. Materials and methods Under general delivery-controlled inhalation anesthesia with isoflurane, Dahl salt-sensitive, Wistar-Furth, Sprague-Dawley, and spontaneously hypertensive rats (n = 66 rats) were subjected to 150 minutes of unilateral renal warm ischemia time, subsequent reperfusion, and contralateral nephrectomy. Animals were followed up for 1 month, after which survivors were euthanized and morphologic changes in kidneys were scored. Results Thirty-day survival was: Dahl salt sensitive, 78%; Wistar-Furth, 67%; Sprague-Dawley, 55%; and spontaneously hypertensive rats, 0% ( P < .0001). Histologic acute injury scores were higher for non-survivors versus 30-day survivors ( P < .0001). Conclusion Our data strongly suggest that rat strain is a major factor influencing survival and that strain and warm ischemia time selections must be considered together when designing a model control yielding intermediate survival. Further study is warranted in order to compare the effect of delivery-controlled inhalational versus historical anesthesia methods on animal survival.

Screening effective parts of combination of Astragali Radix and Angelicae Sinensis Radix (A&amp;A) for its renoprotective effects

The decoction of Astragali Radix and Angelicae Sinensis Radix (A&A) has shown antifibrotic effects in rats with unilateral ureteral obstruction (UUO). The aim of this study was to track the effective parts of A&A for its renoprotective effects, according to the improvement of renal function and renal tubulointerstitial damage. A&A was sequentially extracted by using different solvents for three times and eleven different parts were gained. Wistar rats were randomly divided into Sham, UUO and the treatment groups with A&A or each part of A&A. After administration of A&A or its parts for 10 days, the levels of serum creatinin (Scr) and urea were measured. The morphological changes of kidneys were also semi-quantitatively analyzed by HE, Masson stained tissue sections, which including interstitial cell infiltration, tubular atrophy and interstitial fibrosis. The levels of Scr, urea were significantly increased, accompanied with severe renal damage in rats with UUO. As same as A&A, the part I in the first extraction and part IC in the second extraction were all shown to decrease the levels of Scr and urea and the index of renal interstitial damage. However, the following 4 parts extracted from IC in the third extraction were shown no effect on the above indexes. The extract part I and part IC could be considered as the predominant parts of A&A for its renoprotective effects, due to their improvement of renal damage in interstitial nephropathy.

A New Technique for Ureteral Defect Lesion Reconstruction Using an Autologous Vein Graft and a Biodegradable Endoluminal Stent

Ureteral defect lesions are severe complications caused by iatrogenic lesions or trauma. For ureteral defect lesions elaborate surgical intervention is needed, such as autotransplantation or ureteral replacement with small bowel. Thus, we developed a new technique for ureteral defect reconstruction in a pig model using an autologous vein graft splinted by an endoluminal biodegradable poly-L-lactic acid stent (Institute of Textile Technology and Process Engineering, Denkendorf, Germany). In 42 pigs we removed the external jugular vein and used it as an autologous vein graft. After median laparotomy a 3 cm segment was resected from the proximal ureter and replaced by the vein with or without an endoluminal biodegradable poly-L-lactic acid stent. As controls, we used 14 pigs. We observed survival, kidney function, and neoureteral and kidney morphological changes for 7 days and for 6 months. After 6 months the stent material was completely broken down and the vein graft was relined with urothelium. It resembled native ureter with cytokeratin-7 positive columnar epithelium and newly formed capillaries in the ureteral wall. All animals had normal kidney function without renal pelvis congestion. This new technique for ureteral defect reconstruction using an autologous vein graft and a biodegradable endoluminal stent is feasible. It is an interesting alternative in the clinic due to the preservation of physiological urine passage and the antireflux mechanism.

Prenatal Dexamethasone Exposure Does Not Alter Blood Pressure and Nephron Number in the Young Adult Marmoset Monkey

The influence of prenatal factors on the development of arterial hypertension has gained considerable interest in recent years. Prenatal dexamethasone exposure was found to induce hypertension and to alter nephron number and size in rodents and sheep. However, it is not clear whether these findings are applicable to nonhuman primates. Thus, we examined the effects of prenatal dexamethasone treatment on blood pressure (BP) and nephron number in marmoset monkeys. Fifty-two marmosets were allotted to 3 groups according to the gestational stage during which their mothers were exposed to oral 5-mg/kg dexamethasone for 7 days (gestation period: 20 weeks): (1) the early dexamethasone group at week 7; (2) the late dexamethasone group at week 13; and (3) the control group. BP was determined by telemetric (n=12) or cuff measurements (n=30), along with cystatin C, proteinuria, and body weight. All of the animals were euthanized at the age of 24 months, and glomerular number and volume were determined. Prenatal exposure to dexamethasone did not lead to a significant difference between the groups with regard to BP, kidney morphology and function, or body weight. BP correlated significantly with body weight, relative kidney weight, and mean glomerular volume and the body weight with the glomerular volume regardless of dexamethasone treatment. In conclusion, prenatal exposure to dexamethasone in marmosets does not, in contrast to other mammals studied, result in hypertension or changes in kidney morphology. Our data support the role of body weight as a predictor of elevated glomerular volume and BP development rather than prenatal dexamethasone exposure.

Involvement of the V2 Vasopressin Receptor in Adaptation to Limited Water Supply

Mammals adapted to a great variety of habitats with different accessibility to water. In addition to changes in kidney morphology, e.g. the length of the loops of Henle, several hormone systems are involved in adaptation to limited water supply, among them the renal-neurohypophysial vasopressin/vasopressin receptor system. Comparison of over 80 mammalian V2 vasopressin receptor (V2R) orthologs revealed high structural and functional conservation of this key component involved in renal water reabsorption. Although many mammalian species have unlimited access to water there is no evidence for complete loss of V2R function indicating an essential role of V2R activity for survival even of those species. In contrast, several marsupial V2R orthologs show a significant increase in basal receptor activity. An increased vasopressin-independent V2R activity can be interpreted as a shift in the set point of the renal-neurohypophysial hormone circuit to realize sufficient water reabsorption already at low hormone levels. As found in other desert mammals arid-adapted marsupials show high urine osmolalities. The gain of basal V2R function in several marsupials may contribute to the increased urine concentration abilities and, therefore, provide an advantage to maintain water and electrolyte homeostasis under limited water supply conditions.

Establishment of a timeline of morphological changes in kidney tissue during progression of diabetes

The effects and progression of diabetes mellitus can be studied through an examination of the glomerulus. When diabetes is present, glomerular filtration rate is lowered, filtration selectivity is altered and membrane proteins accumulate. Our hypothesis is that biochemical changes precede morphological changes in the kidney. If the hypothesis is correct, ultimately, these changes might be utilized to predict individuals at risk for development of kidney complications. In this study, we are interested in establishing a timeline of measurable changes in kidney morphology during progression of diabetes. Kidney sections were prepared from both diabetic and non‐diabetic BBZDR/Wor rats, animals that mimic type 2 human diabetes, between 26‐395 days of age. Damage analyses were performed independently using a visual semi‐quantitative estimation of overall sclerotic damage and glomerular damage, and a quantitative measurement of glomerular diameters. Diabetic rats showed retraction within the glomerulus, increased collagen expression and increased interstitial space when compared to non‐diabetic rats. Glomerular diameters increased in diabetic rats as early as 34 days of age. Glomeruli analyses showed a positive correlation between the glomerular diameter and the glomerular damage in both groups, but more so in the diabetic group.

Veränderungen der Nierenfunktion im Alter – Weitreichende Folgen für die Nierentransplantation und die Behandlung Nierenkranker

Renal aging is associated with changes in kidney morphology, a decline in kidney function and an increased susceptibility to renal diseases. Age-related changes of kidney morphology comprise mainly the development of interstitial fibrosis, loss of functioning tubuli, sclerosis and loss of glomeruli as well as arterio-arteriolosclerosis. These structural alterations with aging are accompanied by a decrease in kidney function. These age-related changes of the kidney were accelerated or aggravated by systemic diseases like hypertension, diabetes mellitus, etc. which in itself increase with age. In addition, decreased regeneration capacity of the kidney in situations of acute or chronic kidney injury are attributed to increasing age. Thus, it is not astonishing that chronic kidney diseases (CKD) increase with increasing age. The marked increase in life expectancy in the Western world and the developing countries then further increase the prevalence of CKD. Thus, it is clear that age-related renal changes directly affect the pathogenesis and progression as well as the treatment of acute and chronic kidney injury. This is most evident with respect to the old-for-old kidney transplantation program. Better knowledge and understanding of kidney aging, in particular its separation from kidney damage, is essential for treating elderly patients.

Fasudil, a Rho-kinase inhibitor, reverses L-NAME exacerbated severe nephrosclerosis in spontaneously hypertensive rats

In this study, we tested the hypothesis that long-term Rho-kinase inhibition would reverse nitro-L-arginine methyl ester-exacerbated nephrosclerosis in spontaneously hypertensive rats and attempted to elucidate the mechanism involved. Five groups (each n = 8) were studied: untreated spontaneously hypertensive rats; nitro-L-arginine methyl ester (50 mg/l in drinking water, for 3 weeks)-treated spontaneously hypertensive rats; nitro-L-arginine methyl ester with fasudil (10 mg/kg/day)-treated spontaneously hypertensive rats; nitro-L-arginine methyl ester for 3 weeks followed by fasudil for 3 weeks-treated spontaneously hypertensive rats (same doses), and nitro-L-arginine methyl ester for 3 weeks followed by untreated for 3 weeks. We examined renal function, blood pressure, histological features, oxidative stress markers, and mRNA expression in the renal cortex. Nitro-L-arginine methyl ester-treated spontaneously hypertensive rats had higher blood pressure, proteinuria, and serum creatinine and lower creatinine clearance, urinary NO3/NO2 ratio, and urinary cGMP excretion compared with control spontaneously hypertensive rats (all Ps < 0.05). Nitro-L-arginine methyl ester-treated spontaneously hypertensive rats also had increased free radical metabolites and abnormal morphological findings with increased nicotinamide adenine dinucleotide phosphate oxidase activity, phosphorylation of myosin phosphatase targeting subunit-1, and mRNA expression of RhoA, RhoB, RhoC, collagen I and III, transforming growth factor-beta, nicotinamide adenine dinucleotide phosphate subunit, endothelial nitric oxide synthase, plasminogen activator inhibitor, and intercellular adhesion molecule-1 in the renal cortex compared with control spontaneously hypertensive rats. Long-term co-treatment with fasudil slightly improved these indices, but most of them were not statistically significant. Late fasudil treatment significantly improved kidney function, morphological changes, and alterations of mRNA expression in the renal cortex, although late untreated controls did not show any improvement. These results suggest that Rho-kinase inhibition partly reverses hypertensive glomerulosclerosis. The renoprotective effect of the Rho-kinase inhibitor may have multiple mechanisms including inhibition of extracellular matrix production, oxidative stress, adhesion molecule production, and antifibrinolysis.

Relationship between blood and urine indexes and morphological changes of kidney in acute cadmium exposed rats

目的 观察急性镉中毒大鼠尿液、血清指标与肾病理学改变的关系,以判断.肾功能损害Ζ的程度.方法 将SD健康雄性大鼠随机分成空白对照组和高、中、低3个剂量染镉组(染毒剂量分别为1.6、0.8、0.4 mg/kg,每天1次,连续染毒5 d),每组6只动物.分别测定各组血肌酐(Cr)、尿素氮(BUN)、尿β-N-乙酰葡萄糖苷酶(NAG)、肾皮质镉含量;光学显微镜、电子显微镜下观察肾组织形态学变化.结果 3个染镉组中,高剂量组血Cr及尿NAG水平较对照组升高,差异有统计学意义(P＜0.05),病理学观察相应出现肾小球萎缩,大量近曲小管上皮细胞明显肿胀,部分坏死,管腔狭窄甚至消失;尿NAG动态观察发现,中剂量组在第5天出现峰值,与对照组比较,差异有统计学意义(P＜0.05),该组可见到部分肾近曲小管上皮细胞肿胀变性,管腔萎缩.结论 急性染镉引起的肾功能生化指标变化与组织形态学变化一致,中、低剂量组的损伤为可逆的。

The histopathology of septic acute kidney injury: a systematic review

IntroductionSepsis is the most common trigger of acute kidney injury (AKI) in critically ill patients; understanding the structural changes associated with its occurrence is therefore important. Accordingly, we systematically reviewed the literature to assess current knowledge on the histopathology of septic AKI.MethodsA systematic review of the MEDLINE, EMBASE and CINHAL databases and bibliographies of the retrieved articles was performed for all studies describing kidney histopathology in septic AKI.ResultsWe found six studies reporting the histopathology of septic AKI for a total of only 184 patients. Among these patients, only 26 (22%) had features suggestive of acute tubular necrosis (ATN). We found four primate studies. In these, seven out of 19 (37%) cases showed features of ATN. We also found 13 rodent studies of septic AKI. In total, 23% showed evidence of ATN. In two additional studies performed in a dog model and a sheep model there was no evidence of ATN on histopathologic examination. Overall, when ATN was absent, studies reported a wide variety of kidney morphologic changes in septic AKI – ranging from normal (in most cases) to marked cortical tubular necrosis.ConclusionThere are no consistent renal histopathological changes in human or experimental septic AKI. The majority of studies reported normal histology or only mild, nonspecific changes. ATN was relatively uncommon.

Morphological Changes Produced by Aminoglycoside Induced Nephrotoxicity - An Experimental Study

Aminoglycosides are very commonly used antibiotics to treat life threatening infections because they display many highly desirable properties. The major limitations to their uses being their adverse effects, such as nephrotoxicity. The purpose of present study was to see and compare the morphological changes in kidneys caused by the use of aminoglycosides in animal model. The study was conducted on eighteen male local breed rabbits weighing 1 to 1.75 Kg and age ranging from 8 to 10 months for the period of 20 days. These animals were divided in three groups at random with 6 animals in each group. Two groups (G & A) were given Aminoglycosides namely Gentamicin and Amikacin in doses 10 times larger than corresponding human clinical dose to produce experimental nephrotoxicity while third group being control was injected only isotonic saline. After sacrificing the animals the histological examination of the kidneys revealed morphological changes mainly involving the renal tubules which show patchy necrosis along with hyaline and granular casts in their lumina. Dropped out tubular cells were also seen in the lumina of some of the renal tubules. The lining epithelial cells show hydropic changes with cytoplasmic vacuoles at some areas while regeneration at others. The glomerulae showed mild hypercellularity and congestion in most of the sections. The renal interstitium showed infiltration by polymorphonuclear leukocytes, lymphocytes, plasma cells and macrophages while the renal vascular changes were limited to focal congestion only but the changes were more pronounced in gentamicin treated group. It is concluded that Aminoglycosides cause nephrotoxicity by producing damaging effects on renal tubules especially at higher does, so their administration should carefully be monitored for early detection and prevention of toxic effects.

Necrotic Cells Induce Systemic Autoimmune Disease in vivo by Activation of Dendritic Cells (DCs)

RATIONALE: The mechanism for autoantibody production in systemic lupus erythematosus remains unclear. Dying cells are likely to be a source of autoantigens. We hypothesized that DCs may take up dying cells and induce autoimmunity.METHODS: Bone-marrow-derived DCs were co-cultured with syngeneic necrotic (freezing-thawing) or apoptotic (UV-irradiated) splenocytes. After 24 co-culture, DCs capturing dying cells were injected into female 11-week-old MRL/MP-+/+ mice. Blood was taken at two-week interval and was determined by ELISA for autoantibody level. Morphological changes in kidney were examined by immunofluorescent staining and transmission electron microscopy. T-cell stimulatory capacity of DCs was determined by mixed leukocyte reaction.RESULTS: Compared with DCs with apoptotic cells, DCs phagocytosing necrotic cells induced significantly higher serum levels of anti-double-stranded DNA antibodies IgG and IgG2a, (n = 3∼5, P<0.01), and higher level of proteinuria (P<0.05). Immunofluorescent staining showed strong immune complex deposition in kidney, which was further confirmed by transmission electron microscopy. Mice receiving DCs with necrotic cells developed subsequently a ‘butterfly’ facial skin lesion similar to that observed in human lupus. Flow cytometry analysis demonstrated that necrotic cells upregulated expression of surface MHC class II, CD80, CD86 and CD40 of DCs comparably to apoptotic cells. In response to lipopolysaccharide, DCs that have captured necrotic cells significantly secreted substantial TH1 cytokine INF-g at 24, 48, 72 hours (P<0.01). DCs that have phagocytosed necrotic cells significantly increased the proliferation of C57BL/6N and MRL/+ T cells (P<0.05).CONCLUSIONS: Activation of DCs by necrotic cells might promote TH1 autoimmune responses, leading to the systemic autoimmune disease in vivo. RATIONALE: The mechanism for autoantibody production in systemic lupus erythematosus remains unclear. Dying cells are likely to be a source of autoantigens. We hypothesized that DCs may take up dying cells and induce autoimmunity. METHODS: Bone-marrow-derived DCs were co-cultured with syngeneic necrotic (freezing-thawing) or apoptotic (UV-irradiated) splenocytes. After 24 co-culture, DCs capturing dying cells were injected into female 11-week-old MRL/MP-+/+ mice. Blood was taken at two-week interval and was determined by ELISA for autoantibody level. Morphological changes in kidney were examined by immunofluorescent staining and transmission electron microscopy. T-cell stimulatory capacity of DCs was determined by mixed leukocyte reaction. RESULTS: Compared with DCs with apoptotic cells, DCs phagocytosing necrotic cells induced significantly higher serum levels of anti-double-stranded DNA antibodies IgG and IgG2a, (n = 3∼5, P<0.01), and higher level of proteinuria (P<0.05). Immunofluorescent staining showed strong immune complex deposition in kidney, which was further confirmed by transmission electron microscopy. Mice receiving DCs with necrotic cells developed subsequently a ‘butterfly’ facial skin lesion similar to that observed in human lupus. Flow cytometry analysis demonstrated that necrotic cells upregulated expression of surface MHC class II, CD80, CD86 and CD40 of DCs comparably to apoptotic cells. In response to lipopolysaccharide, DCs that have captured necrotic cells significantly secreted substantial TH1 cytokine INF-g at 24, 48, 72 hours (P<0.01). DCs that have phagocytosed necrotic cells significantly increased the proliferation of C57BL/6N and MRL/+ T cells (P<0.05). CONCLUSIONS: Activation of DCs by necrotic cells might promote TH1 autoimmune responses, leading to the systemic autoimmune disease in vivo.