Renal Tubular Epithelium Research Articles

Effect of cultured white soft cheese on the histopathological changes in the kidneys and liver of albino rats

Three different types of lactic acid bacteria (Lactobacillus helveticus, Lactobacillus rhamnosus and Streptococcus thermophilus S3855) were used to manufacture white soft cheese. The resultant white soft cheeses were pickled for 28 days at refrigerator temperatures and were fed to the experimental rats. The chemical and microbiological analyses of white soft cheese were conducted at different storage periods (fresh, 7 days, 14 days, 21 days, and 28 days). The pH values and protein content of white soft cheese gradually decreased during the storage peroid. Conversely, the moisture content, titratable acidity, and fat/DM % of white soft cheese were found to increase with of the increase in pickling periods of up to 28 days. Microbiologically, the total viable count of bacteria in the control samples was lower than that in the other treatments. Furthermore, the treatments containing the L. helveticus and L. rhamnosus strains had the highest lactoacilli counts whereas the treatment containing the S. thermophilus strain had the highest streptococci counts. Twenty-five male Albino rats were used for experiemntal technique. Rats were fed with 70% basal diet with addition of 30% white soft cheese. Several pathological findings were present in all experimental groups apart from the control rats, and the kidney samples exhibited renal vascular congestion especially in the cortical area. The changes of the glomeruli comprise atrophy, distortion, hypocellularity of the glomerular tuft, and focal lymphoid cell reactions. The renal tubular epithelium showed a series of degenerative changes ranging up to necrosis. The liver samples showed variable hepatic injury in the form of thickening in the Glisson capsule, as well as dissociation and disorganization of hepatic cords. Hepatocellular vacuolar degeneration, presence of focal areas of nodular hyperplasia, the hyperplastic cells mixed with lymphocytic infiltration, congestion in the portal vein, periportal fibrosis and edema with the presence of newly formed nonfunctional bile ductulus. Based on the histopathology scores, the severity of renal and hepatic changes was significantly increased (P ≤ 0.05) in all of the experimental groups compared with the control group. Generally, the chemical composition, microbiological analysis and vital organs were significantly affected by using cultured white soft cheese.

Recurrent Metachronous Metastatic Renal Cell Carcinoma to the Breast- Think Kidney! Case report and Literature Review

Background: Metastases to the breast from non-mammary primary tumours are uncommon and account for 0.5-2.0% of all breast malignancies. Renal cell carcinomas (RCC) (historically also known as hypernephroma or Grawitz tumour) are primary malignant adenocarcinomas derived from the renal tubular epithelium and are the most common malignant renal tumour. Metastatic renal cell carcinoma to the breast is very rare, with 23 cases published in the literature. We present a patient with a history of previous RCC treated surgically who has developed three recurrences of metastatic RCC to the same breast.

A Combination of Iohexol Treatment and Ionizing Radiation Exposure Enhances Kidney Injury in Contrast-Induced Nephropathy by Increasing DNA Damage.

Contrast media has been shown to induce nephropathy (i.e., contrast-induced nephropathy) after various types of radiological examinations. The molecular mechanism of contrast-induced nephropathy has been unclear. In this study, we investigated the mechanism of contrast-induced nephropathy by examining the effects of combined treatment of contrast medium and ionizing radiation on kidney cells in vitro and kidney tissue in vivo. In human renal tubular epithelium cells, immunofluorescence analysis revealed that iohexol increased the numbers of radiation-induced γH2AX nuclear foci. The numbers of γH2AX nuclear foci remained high at 24 h, suggesting that some radiation-induced double-strand breaks remain unrepaired in the presence of iohexol. We established a mouse model of contrast-induced nephropathy, then showed that iohexol and ionizing radiation synergistically reduced renal function and induced double-strand breaks. Importantly, iohexol induced significant macrophage accumulation and oxidative DNA damage in the kidneys of contrast-induced nephropathy model mice in the absence of ionizing radiation; these effects were amplified by ionizing radiation. The results suggest that underlying inflammation and oxidative DNA damage caused by iohexol contribute to the enhancement of radiation-induced double-strand breaks, leading to contrast-induced nephropathy.

Co-Expression and Functional Interactions of Death Receptor 3 and E-Selectin in Clear Cell Renal Cell Carcinoma

Similar to the behavior of inflamed tubular epithelial cells, clear cell renal cell carcinoma (ccRCC) cells express death receptor 3 (DR3 or TNFSFR25) in situ, and expression increases with tumor grade. Surprisingly, E-selectin, which can be induced in endothelial cells by DR3 signaling, is also expressed by ccRCC cells and increases with tumor grade. In ccRCC organ cultures, addition of tumor necrosis factor-like 1A (TL1A or TNFSF15), the ligand for DR3, activates NF-κB and mitogen-activated protein kinases, induces both DR3 and E-selectin expression in an NF-κB-dependent manner, and promotes cell cycle entry. DR3 immunoprecipitated from ccRCC tissue contains sialyl Lewis X moieties (the ligand recognized by E-selectin), proximity ligation assays reveal DR3, and E-selectin interacts on ccRCC cells. Similar to that with the addition of TL1A, the addition of soluble E-selectin to ccRCC organ cultures activates NF-κB and mitogen-activated protein kinases in ccRCC cells and increases both DR3 and E-selectin expression and cell-cycle entry. In contrast, normal renal tubular epithelium, which poorly expresses DR3, is minimally responsive to either of these ligands. These data suggest a functional role for autocrine/paracrine DR3/E-selectin interactions in ccRCC and its progression, revealing a potential new target for therapeutic intervention.

Effects of alternative splicing events and transcriptome changes on kidney stone formation

During the development of urinary stone disease, the formation of tiny crystals that adhere to the renal tubular epithelium induces epithelial cell damage. This damage and repair of the epithelium is associated with the establishment of more crystal adhesion sites, which in turn stimulates further crystal adhesion and, eventually, stone formation. Deposited crystals typically cause changes in epithelial cell gene expression, such as transcriptome changes and alternative splicing events. Although considered important for regulating gene expression, alternative splicing has not been reported in studies related to kidney stones. To date, whether alternative splicing events are involved in the regulation of stone formation and whether crystallographic cell interactions are regulated by alternative splicing at the transcriptional level have remained unknown. Therefore, we conducted RNA sequencing and alternative splicing-related bioassays by modeling the in vitro stone environment. Many alternative splicing events were associated with crystallographic cell interactions. Moreover, these events regulated transcription and significantly affected the capacity of crystals to adhere to renal tubular epithelial cells and regulate apoptosis.

Kidney-Targeted Redox Scavenger Therapy Prevents Cisplatin-Induced Acute Kidney Injury.

Cisplatin-induced acute kidney injury (CI-AKI) is a significant co-morbidity of chemotherapeutic regimens. While this condition is associated with substantially lower survival and increased economic burden, there is no pharmacological agent to effectively treat CI-AKI. The disease is hallmarked by acute tubular necrosis of the proximal tubular epithelial cells primarily due to increased oxidative stress. We investigated a drug delivery strategy to improve the pharmacokinetics of an approved therapy that does not normally demonstrate appreciable efficacy in CI-AKI, as a preventive intervention. In prior work, we developed a kidney-selective mesoscale nanoparticle (MNP) that targets the renal proximal tubular epithelium. Here, we found that the nanoparticles target the kidneys in a mouse model of CI-AKI with significant damage. We evaluated MNPs loaded with the reactive oxygen species scavenger edaravone, currently used to treat stroke and ALS. We found a marked and significant therapeutic benefit with edaravone-loaded MNPs, including improved renal function, which we demonstrated was likely due to a decrease in tubular epithelial cell damage and death imparted by the specific delivery of edaravone. The results suggest that renal-selective edaravone delivery holds potential for the prevention of acute kidney injury among patients undergoing cisplatin-based chemotherapy.

“Elucidation of the Shared Pathophysiology between Diabetes and COVID-19”

Background: COVID-19 is a rapidly spreading communicable disease worldwide. It varies widely in its spectrum of manifestations, from being mild self-limiting disease, to fulminant disease, often leading to complications and death. Diabetes is an important co-morbidity linked to severity of infection by SARSCoV- 2, which predisposes them to severe pneumonia. Poor glycaemic control is associated with worse outcomes. The disease burden of COVID-19 is continuously increasing, and with a high prevalence of diabetes, it is all the more important to understand the vital aspects of COVID-19 infection in diabetic population. Hence, we try to provide close insights into its pathophysiology, clinical characteristics, recommendations on management and prevention and possible avenues for improving disease outcomes. Methods: PubMed database and Google Scholar were searched using the key terms ‘COVID-19’, ‘SARS CoV- 2’, ‘Corona’ and ‘diabetes’. Full texts of the retrieved articles were accessed and referred. Three main mechanisms which influence COVID-19 disease manifestation in diabetics include: (a) Entry of virus via ACE-2 receptors (b) Action through Dipeptidyl-peptidase-4, and (c) Elevation of glucose concentration in airways by elevated blood glucose.ACE-2 is expressed in alveolar epithelial cells, heart, renal-tubular and intestinal epithelia and pancreas. S-Glycoprotein on the surface of SARS-CoV-2 binds to this ACE-2 and undergoes a conformational change. This allows its’ proteolytic digestion by host cell proteases TMPRSS2 and Furin, leading to internalization of virus. Viral entry into cells triggers an inflammatory response by T-helper-cells and at times, a ‘cytokine storm’, resulting in organ damage. Apart from diminishing neutrophil chemotaxis and reducing phagocytosis, by which diabetes predisposes individuals to infections, there are several specific factors with respect to SARS-CoV2: (i) Increased ACE-2 expression (ii) Raised Furin (iii) Diminished T-cell functioning, and (iv) Increased IL-6 levels. Movement restrictions, increased stress due to social isolation and lack of physical activity further complicates the issue. It is therefore, much essential to raise awareness among front-line workers. Finally, the current situation emphasizes the need for more clinical investigation and define best practices for optimum outcomes. Bangladesh Journal of Medical Science Vol. 21(1) 2022 Page : 19-23

Homoarginine test for evaluation of metabolic renal dysfunction

Low plasma L-homoarginine (hArg) concentration is an independent predictor of adverse cardiovascular outcomes and overall mortality, as well as the progression of chronic kidney disease (CKD). The enzyme L-arginine:glycinamidinotransferase (AGAT, EC 2.1.4.1) acts in the mitochondrial membrane of the renal tubular epithelium, forming the precursor of creatine, guanidinoacetic acid, and additionnaly by-product hArg. As it was shown recently, there is a decreased level of hArg in the late stages of CKD, however, the the level of hArg in the early stages of CKD remained unexplored. The aim of this study was to determine the diagnostic threshold levels of hArg in the blood of patients with stages 1 and 2 of CKD. In patients with the initial stages of CKD (n = 44) at the age of 58 (45-67) years, compared with the group of donors of 55 (42-58) years (n = 30), a significant decrease of hArg level was found. In the subgroup with stage CKD 2, the cut-off point of 1.59 μM threshold was characterized by greater sensitivity and specificity than in the subgroup with stage CKD 1 with 1.66 μM threshold level of hArg. For the full group, the hArg cut-off threshold was 1.60 μM, which is about to 0.2 μM lower than the lower limit of the reference interval for healthy individuals. It can be assumed that even before the formation of symptoms of proteinuria and albuminuria, a significant part of individuals from population cohort develops a state of decreased AGAT activity, since the expression of this enzyme is associated with a certain regulatory feedback inhibition at the body level. As a result of the study, it can be noted that in patients with early stages of CKD in the age group 45-67 years, there is a disturbance of the kidneys metabolic function. These metabolic changes can be detected by testing the level of hArg.

Protective Role of Different Local Spices on Lambda Cyhalothrin Induced Nephrotoxicity in Male Mice

Aim: This study was aimed at evaluating the protective role of different local spices on lambda cyhalothrin induced nephrotoxicity in male mice
 Experimental Design: A completely randomized experimental design using standard methods for analysis.
 Place and Duration of Study: This study was carried out in the Animal house, Department of Animal and Environmental Biology of Rivers State University, Nkpolu-Oroworukwo Port Harcourt, Nigeria. GPS 4o47'50''N 6o58'49''E. This study lasted for 35days.
 Methodology: The experimental animals were separated into 6 groups (A-F) of seven mice each. Group A served as the control and Group B – F served as the test groups. At the end of the 35 day treatment period, feed was withdrawn from the mice 24 hours before termination of the experiment. Blood samples for analysis of kidney function test were collected from each mouse by ocular puncture into plain tubes. The blood was allowed to clot and centrifuged at 2500g to separate the serum from the cells. Total protein was analyzed using the spectrophotometric method of biuret, Bradford and erythrosine – b, albumin was estimated, creatinine and urea was done using enzymatic method. Vital organs were removed and weighed for organosomatic indices. Histological sections of the kidney were mounted on slides, stained with hematoxylin and eosin (H&E). Photomicrographs were generated.
 Results: There is no significant difference (P=0.05) between the organ weight and bodyweight in group A compared with the treatment groups. The values of Albumin, total protein, urea, creatinine and total bilirubin increased significantly in group B administered lambda cyhalothrin alone but decreased in groups administered the local spices. Histopathological analysis of the kidney shows the regular structure of the kidney architecture in group A, tubular degeneration and several vacuolations were observed in group B. However, less degeneration of the epithelial cells, regeneration of renal tubular epithelium were observed in groups C- F.
 Conclusion: Based on the results from liver biomarkers and histological micrographs from this study, pronounced degeneration was observed in the kidney cells exposed to lambda-cyhalothrin only. Moreover, all spices used had a regenerating ability on the kidney tubules. It is advocated therefore that consumption of this spices either singly or in combination should be encouraged especially for those exposed to insecticides poisoning

Detection of PKD1 and PKD2 Somatic Variants in Autosomal Dominant Polycystic Kidney Cyst Epithelial Cells by Whole-Genome Sequencing.

Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder characterized by the development of multiple cysts in the kidneys. It is often caused by pathogenic mutations in PKD1 and PKD2 genes that encode polycystin proteins. Although the molecular mechanisms for cystogenesis are not established, concurrent inactivating germline and somatic mutations in PKD1 and PKD2 have been previously observed in renal tubular epithelium (RTE). To further investigate the cellular recessive mechanism of cystogenesis in RTE, we conducted whole-genome DNA sequencing analysis to identify germline variants and somatic alterations in RTE of 90 unique kidney cysts obtained during nephrectomy from 24 unrelated participants. Kidney cysts were overall genomically stable, with low burdens of somatic short mutations or large-scale structural alterations. Pathogenic somatic "second hit" alterations disrupting PKD1 or PKD2 were identified in 93% of the cysts. Of these, 77% of cysts acquired short mutations in PKD1 or PKD2 ; specifically, 60% resulted in protein truncations (nonsense, frameshift, or splice site) and 17% caused non-truncating mutations (missense, in-frame insertions, or deletions). Another 18% of cysts acquired somatic chromosomal loss of heterozygosity (LOH) events encompassing PKD1 or PKD2 ranging from 2.6 to 81.3 Mb. 14% of these cysts harbored copy number neutral LOH events, while the other 3% had hemizygous chromosomal deletions. LOH events frequently occurred at chromosomal fragile sites, or in regions comprising chromosome microdeletion diseases/syndromes. Almost all somatic "second hit" alterations occurred at the same germline mutated PKD1/2 gene. These findings further support a cellular recessive mechanism for cystogenesis in ADPKD primarily caused by inactivating germline and somatic variants of PKD1 or PKD2 genes in kidney cyst epithelium.

Clinical and pathomorphological analysis of deaths from COVID-19 in 2020

The aim of the work – to conduct clinical and pathomorphological analysis of deaths from COVID-19 in 2020. Materials and methods. We analyzed 41 case histories and results of pathological-anatomical examination of patients who were died of COVID-19 during 2020. Results. The lethal outcome of COVID-19 disease was recorded at day 22 (16; 27) of the disease. Among the dead, there is a high percentage of men (73.2 %), early old age and middle old age patients (75.6 %) with comorbid pathology (92.7 %). Early lung damage with COVID-19 in the deceased was determined by pronounced interstitial and interstitial-alveolar edema, the presence of erythrocyte stasis in the pulmonary microvessels, blood clots and hypoperfusion leukocyte stasis, as well as the presence of erythrocytes in the alveoli. Bilateral polysegmental subtotal viral pneumonia in 90.2 % of dead patients was characterized by significant edema and thickening of the alveolar walls with their moderate infiltration by lymphocytes, focal peribronchial and perivascular inflammatory polymorphonuclear infiltration, multiple and small exfoliated alveolar epithelium (87.8 %), as well as metaplasia of a few alveolocytes preserved on the luminal surface of the alveoli (82.9 %). Every tenth person who died of COVID-19 had signs of secondary bacterial microflora. In 85.4 % of patients who died on day 22–27 of the disease focal or sublobar pneumofibrosis was diagnosed. In those who died due to COVID-19, multiorgan failure was characterized by focal necrosis of the renal tubular epithelium (73.2 %), focal lymphocytic-leukocyte infiltration (12.2 %) and renal microvascular thrombosis (17.1 %), focal centro-lobular necrosis (90.2 %) and focal lymphocytic-leukocyte infiltration of lobes (7.3 %) of the liver. Thrombotic complications were confirmed in 22.0 % of deceased patients: ischemic cerebral infarction, transmural myocardial infarction, pulmonary embolism, deep vein thrombosis of the lower extremities under the pathology. These thrombotic complications were not diagnosed during life in all patients. The majority of deaths due to COVID-19 had morphological signs of chronic cardiovascular pathology. Ischemic heart disease and hypertension during the life of patients were not diagnosed in all cases. Conclusions. Early lung damage in COVID-19 in the deceased was determined by pronounced interstitial-alveolar edema, blood clots and leukocyte stasis in microvessels, less often – the presence of “hyaline membranes”. In 90.2 % of the dead patients bilateral polysegmental subtotal pneumonia with edema and lymphocytic infiltration of the pulmonary interstitium, inflammatory peribronchial and perivascular focal polymorphonuclear infiltrates, foci of atelectasis and dyscryphaseses was found. In 9.7 % of patients bilateral subtotal viral-bacterial fibrinous-purulent bronchopneumonia developed. In those who died on the 22nd–27th day of the disease focal pneumofibrosis was determined. Pathomorphologically, thrombotic complications, which were not diagnosed in all patients during their lifetime, were confirmed in 22.0 % of deceased patients. Most deaths from COVID-19 had morphological signs of chronic cardiovascular disease.

Toxicological studies of aqueous and ethanol leaf extract of Spondias purpurea (red plum) in rats

BackgroundSpondias purpurea is a flowering plant of the cashew family commonly found in South Western Nigeria. The plant is used in folk medicine for treatment of gastric disorders and diarrhoea. The purpose of the study was to investigate the haematological and histopathological effects of aqueous and ethanol leaf extract of S. purpurea (red plum) in rats.MethodsFemale wistar rats weighing (121.5 ± 30.41 g) were administered 500, 1000 and 1500 mg/kg body weight of aqueous and ethanol extracts of S. purpurea leaf (orally) daily for 14 days, while the control group was administered 0.5 ml of normal saline (vehicle). At the end of the study, the rats were euthanized; blood samples were collected for haematological parameters. The liver, kidney and spleen were harvested from the rats for photomicrographic examination.ResultThe result of the acute toxicity test revealed no death with dose up to 5000 mg/kg body weight. The administration of the extracts showed no significant difference (p > 0.05) in the hematologic parameters of the animals. The liver sections showed congestion, mononuclear infiltration, widened sinusoidal space and congestions with hemosiderin. Similar changes were observed in the kidney showing slight necrosis of renal tubular epithelium, widened Bowman’s space, and collapsed renal tubules and adhesion of the parietal layer of glomerulus to the Bowman’s space. The spleen showed congestion, lymphocyte proliferation at the germinal centre.ConclusionsThe result of this study showed that the alterations observed in the organs intensified with increase in the doses of the extracts administered. It can be inferred that the prolonged consumption of S. purpurea leaf maybe associated with significant tissue damage of some vital organs.

Histopathological changes in kidney and pancreas induced by energy drinks in adult male rats

The study aims to assess the impact of various doses of red bull on kidney and pancreas of male albino rats. Thirty male albino rats were assigned to three groups (10 animals/ group). Control group (1) received standard diet and water, group 2 and group 3 received daily oral doses of 10 ml/kg/rat and 20 ml/kg/rat of the energy drink (red bull) respectively for 30 days. Under light microscope no tissue changes were seen in kidney and pancreas of control group. In group 2 red bull causes vacuolar degeneration as well as coagulative necrosis of renal tubular epithelium, vascular congestion in the glomeruli and in the interstitial space of the kidney, in addition to atrophy of the glomeruli, as regard to pancreas it causes vascular congestion of the islets of Langerhans, increase in the size of the islets, besides, necrosis of Langerhans cells. In group 3 red bull leads to more atrophic glomeruli, massive coagulative necrosis of renal tubular epithelium, marked vascular dilatation and congestion in the interstitial space and degenerative changes of the renal tubular epithelium, whereas the pancreatic tissue revealed reduction in the size of the islets of Langerhans, vacuolation and degeneration of their cells, necrosis of other islets with mononuclear inflammatory cells infiltration and degenerative changes of pancreatic acini. It is concluded that administration of red bull to rats for 30 days will affect the histological structure of kidney as well as pancreas and this effect is a dose dependent.

Post-mortem assessment of vimentin expression as a biomarker for renal tubular regeneration following acute kidney injury.

BackgroundAcute kidney injury (AKI) is a common cause of morbidity and mortality. It mainly targets the renal tubular epithelium with pathological changes, referred to as acute tubular injury. The latter is followed by a regenerative response that is difficult to visualize on routine hematoxylin and eosin (H&E) stains. In this study, we examined the regenerative capacity of renal tubules by correlating vimentin (VIM) immunohistochemical (IHC) expression and pathological findings of AKI and renal tubular regeneration (RTR) on H&E.MethodsWe reviewed 23 autopsies performed in the clinical setting of AKI and RTR. VIM expression was scored in the renal cortical tubular epithelium using a statistical cutoff ≥ 3% for high expression and < 3% for low expression.ResultsOf the 23 kidney tissues examined, seven (30.4%) had low VIM expression, and 16 (69.6%) had high VIM expression. Kidney tissues with evidence of AKI and RTR had significantly higher VIM expression. Renal peritubular microenvironment features showing regenerative changes on H&E were associated with high VIM expression. In the univariate model, kidney tissues with RTR were 18-fold more likely to have high VIM expression.ConclusionsIn conclusion, our findings suggest that VIM could serve as an IHC marker for RTR following AKI. However, correlation with H&E findings remains critical to excluding chronic tubular damage. Collectively, our preliminary results pave the way for future studies including a larger sample size to validate the use of VIM as a reliable biomarker for RTR.

VX-765 ameliorates renal injury and fibrosis in diabetes by regulating caspase-1-mediated pyroptosis and inflammation.

IntroductionAs a lytic inflammatory cell death, pyroptosis has been recently described but has not been unequivocally elucidated in diabetic nephropathy (DN). VX‐765 is a safe and effective inhibitor of caspase‐1, that was well tolerated in a phase II clinical trial in patients with epilepsy, but its application in DN is still undefined.Materials and MethodsImmunoblot, co‐immunoprecipitation, confocal microscope and flow cytometry were used to analyze the effects of glucose on pyroptosis in renal tubular epithelia (HK‐2). In vitro, selective caspase‐1 inhibitors VX‐765 and Z‐YVAD‐FMK were administered. Pyroptosis and fibrogenesis were determined by immunoblot, ELISA, cytotoxicity assay and flow cytometry. In vivo, diabetic mice were administered with 100 mg/kg VX‐765. Renal function, pathological changes, and the expressions of NLRC4, GSDMD, IL‐1β, collagen I, fibronectin and CD45 in renal cortex were evaluated.ResultsWe identified NLRC4 as a sensor for caspase‐1 activation. Moreover, we provided morphological and molecular evidence for pyroptosis in glucose‐stressed tubular cells, including ballooned cell membrane, caspase‐1 immunoreactivity, GSDMD cleavage, and the release of inflammatory cytokine and cellular contents. All these effects were prevented by treatment with VX‐765 or Z‐YVAD‐FMK, confirming that caspase‐1 effectively regulates the occurrence of pyroptosis in HK‐2 cells. In vivo, treatment of diabetic animals with VX‐765 ameliorated renal function, suppressed inflammatory cell infiltration and pyroptosis‐associated protein expression, and mitigated tubulointerstitial fibrosis.ConclusionsThis work revealed that caspase‐1‐mediated pyroptosis drives renal inflammation and fibrosis in diabetes. Our results are the first demonstration of VX‐765 representing a promising therapeutic opportunity for alleviating the progression of DN.

Ovine gammaherpesvirus-2 infection associated with chronic interstitial pneumonia in a sheep

Sheep Associated-Malignant Catarrhal Fever (SA-MCF) is severe, frequently lethal, lymphoproliferative disease predominantly of ruminants, that is caused by ovine gammaherpesvirus-2 (OvHV-2), a member of the MCF virus (MCFV) complex. However, SA-MCF in sheep is a rare entity with few demonstrations of natural diseases worldwide. This report documents the clinical, radiographical, pathological, immunohistochemical, and molecular findings of SA-MCF in a sheep. A 4-year-old, female, mixed-breed sheep with progressive emaciation for at least one month was humanely euthanized due to poor prognosis. Clinically, the animal had tachypnea, ruminal hypomotility, productive coughing with bilateral muffling sounds during pulmonary auscultation. Radiographical evaluation revealed alveolar opacity of the cranioventral pulmonary region. Grossly, there were distinct rib impressions on the pleural surface of the lungs, suggestive of interstitial pneumonia. Histopathologic evaluation of the lungs revealed several disease patterns including 1) chronic interstitial pneumonia with vasculitis and proliferating vascular lesions, and thrombosis; 2) pulmonary abscesses associated with embolic dissemination of Corynebacterium pseudotuberculosis from superficial lymph node due to caseous lymphadenitis, CLA; 3) granulomatous pneumonia associated with pulmonary nematodes; and 4) chronic pleuritis, probably due to caseous lymphadenitis. Additional significant histologic findings included widespread lymphocytic vasculitis and proliferating vascular lesions in multiple tissues, atrophic enteritis, segmental degeneration of myocardial fibers with lymphocytic pericarditis, lymphocytic interstitial nephritis, and non-suppurative encephalitis. An immunohistochemistry (IHC) assay, based on the monoclonal antibody 15A (MAb-15A), that is specific to all MCFV known to cause MCF, revealed positive, intracytoplasmic, intralesional immunoreactivity, predominantly within bronchial and bronchiolar epithelial cells of the lungs and cryptal epithelial cells of the small intestine, followed by the renal tubular epithelium, cardiomyocytes, and with patchy immunolabelling within neurons of the cerebral cortex. Molecular testing done to detect a wide range of bacterial and viral agents of ruminant diseases, only amplified OvHV-2 DNA from fresh tissue fragments of the lungs, kidney, liver, spleen, and cerebrum. Direct sequencing confirmed that the PCR amplicon derived from the pulmonary fragments had 99.2–99.7% nucleotide sequence identity with OvHV-2 reference strains and strains of OvHV-2 from Brazil. The clinical, radiographical, gross, histopathologic, IHC, and molecular findings in the lungs are consistent with chronic interstitial pneumonia associated with infection by OvHV-2. Furthermore, the non-detection of other viral agents associated with pulmonary diseases in ruminants suggest that OvHV-2 was directly associated with the development of chronic pneumonia in this sheep. Additionally, the dental alterations, CLA, and the pulmonary nematode may have contributed towards the reduced immunological statue of the animal and facilitated the occurrence of SA-MCF. These findings may indicate that OvHV-2 may be a major participant in the pathogenesis of pulmonary disease of sheep under special conditions. Moreover, the proliferating vascular lesions identified in multiple tissues are additional evidence of chronic manifestations of OvHV-2 infections as described in chronic SA-MCF of cattle, while the widespread vasculitis is consistent with SA-MCF. Additionally, the IHC findings using the MAb-15A confirmed that this diagnostic approach is efficient to identify intralesional antigens of OvHV-2.

Low-dose rapamycin does not impair vascular integrity and tubular regeneration after kidney transplantation in rats

mTOR inhibitors offer advantages after kidney transplantation including antiviral and antitumor activity besides facilitating low calcineurin inhibitor exposure to reduce nephrotoxicity. Concerns about adverse effects due to antiproliferative and antiangiogenic properties have limited their clinical use particularly early after transplantation. Interference with vascular endothelial growth factor (VEGF)-A, important for physiologic functioning of renal endothelial cells and tubular epithelium, has been implicated in detrimental renal effects of mTOR inhibitors. Low doses of Rapamycin (loading dose 3 mg/kg bodyweight, daily doses 1.5 mg/kg bodyweight) were administered in an allogenic rat kidney transplantation model resulting in a mean through concentration of 4.30 ng/mL. Glomerular and peritubular capillaries, tubular cell proliferation, or functional recovery from preservation/reperfusion injury were not compromised in comparison to vehicle treated animals. VEGF-A, VEGF receptor 2, and the co-receptor Neuropilin-1 were upregulated by Rapamycin within 7 days. Rat proximal tubular cells (RPTC) responded in vitro to hypoxia with increased VEGF-A and VEGF-R1 expression that was not suppressed by Rapamycin at therapeutic concentrations. Rapamycin did not impair proliferation of RPTC under hypoxic conditions. Low-dose Rapamycin early posttransplant does not negatively influence the VEGF network crucial for recovery from preservation/reperfusion injury. Enhancement of VEGF signaling peritransplant holds potential to further improve outcomes.

Differential localization patterns of claudin 10, 16, and 19 in human, mouse, and rat renal tubular epithelia.

Functional properties of the paracellular pathway depend critically on the set of claudins (CLDN) expressed at the tight junction. Two syndromes are causally linked to loss-of-function mutations of claudins: hypohidrosis, electrolyte imbalance, lacrimal gland dysfunction, ichthyosis, and xerostomia (HELIX) syndrome caused by genetic variations in the CLDN10 gene and familial hypomagnesemia with hypercalciuria and nephrocalcinosis caused by genetic variations in the CLDN16 or CLDN19 genes. All three genes are expressed in the kidney, particularly in the thick ascending limb (TAL). However, localization of these claudins in humans and rodents remains to be delineated in detail. We studied the segmental and subcellular expression of CLDN10, CLDN16, and CLDN19 in both paraffin-embedded and frozen kidney sections from the adult human, mouse, and rat using immunohistochemistry and immunofluorescence, respectively. Here, CLDN10 was present in a subset of medullary and cortical TAL cells, localizing to basolateral domains and tight junctions in human and rodent kidneys. Weak expression was detected at the tight junction of proximal tubular cells. CLDN16 was primarily expressed in a subset of TAL cells in the cortex and outer stripe of outer medulla, restricted to basolateral domains and tight junctional structures in both human and rodent kidneys. CLDN19 predominantly colocalized with CLDN16 in tight junctions and basolateral domains of the TAL but was also found in basolateral and junctional domains in more distal sites. CLDN10 expression at tight junctions almost never overlapped with that of CLND16 and CLDN19, consistent with distinct junctional pathways with different permeation profiles in both human and rodent kidneys.NEW & NOTEWORTHY This study used immunohistochemistry and immunofluorescence to investigate the distribution of claudin 10, 16, and 19 in the human, mouse, and rat kidney. The findings showed distinct junctional pathways in both human and rodent kidneys, supporting the existence of different permeation profiles in all species investigated.

Renal Tubular Epithelial Subnuclear Vacuolization in Hypothermia and Diabetic Ketoacidosis-A Retrospective Autopsy Study.

Subnuclear vacuolization of the renal tubular epithelium refers to discrete lipid vacuoles displacing the nuclei toward the lumen. This phenomenon has been associated with conditions sharing fatal ketoacidosis as a common denominator. This retrospective study aimed to investigate renal tubular epithelial subnuclear vacuolization and other postmortem examination findings in fatal hypothermia and diabetic ketoacidosis (DKA) cases.Fourteen cases with hypothermia and 19 cases with DKA were included. More cases with DKA had focal or diffuse subnuclear vacuolization compared with hypothermia cases (89% vs 43%; P = 0.007). In 6 cases with DKA, formalin pigment was detected within subnuclear vacuoles, whereas no case with hypothermia had formalin pigment deposition. Comparative analyses of hypothermia and DKA cases revealed further differences: Vitreous beta-hydroxybutyrate was higher in the DKA group compared with the hypothermia group (P = 0.044), whereas blood ethanol concentrations were higher in the latter (P = 0.008). Hypothermia cases were older compared with the DKA cases (P = 0.022).When all cases were included in the statistical analysis, cases with subnuclear vacuolization had higher vitreous beta-hydroxybutyrate and blood ethanol concentrations (P = 0.029 and 0.023, respectively). The findings corroborate the results of previous studies suggesting a link between subnuclear vacuolization and increased levels of ketoacidosis.

Urinary Dickkopf-3 and Contrast-Associated Kidney Damage

BackgroundAdministration of iodinated contrast medium (CM) during invasive cardiovascular procedures may be associated with impairment of kidney function. ObjectivesUrinary dickkopf-3 (DKK3), a stress-induced renal tubular epithelium–derived glycoprotein, has been identified as a biomarker predicting both acute kidney injury (AKI) and persistent kidney dysfunction. MethodsUrinary DKK3/creatinine ratio (uDKK3/uCr), urine and serum neutrophil gelatinase-associated lipocalin (uNGAL, sNGAL) and serum cystatin C (sCyC) were assessed in 458 patients with chronic kidney disease scheduled for invasive cardiovascular procedures requiring CM administration with universal adoption of nephroprotective interventions. Contrast-associated AKI (CA-AKI) was defined as serum creatinine increase ≥0.3 mg/dl at 48 h after CM administration. Persistent kidney dysfunction was defined as persistent estimated glomerular filtration rate reduction ≥25% at 1 month compared with baseline. ResultsCA-AKI occurred in 64 or the 458 patients (14%), and baseline uDKK3/uCr ≥491 pg/mg was the best threshold for its prediction. Net reclassification improvement (NRI) was significantly increased by adding baseline uDKK3/uCr to the Mehran, Gurm, and National Cardiovascular Data Registry (NCDR) scores (all p < 0.05), and the same applied to integrated discrimination improvement (IDI) when adding uDKK3/uCr to the Gurm and NCDR scores (p < 0.001). Persistent kidney dysfunction occurred in 57 of the 458 patients (12%) and baseline uDKK3/uCr ≥322 pg/mg appeared as the best threshold for its prediction. Adding baseline uDKK3/uCr to the Mehran, Gurm, and NCDR scores significantly increased IDI and NRI (all p < 0.001). ConclusionsBaseline uDKK3/uCr seems to be a reliable marker for improving the identification of patients with chronic kidney disease undergoing invasive coronary and peripheral procedures at risk for AKI and persistent kidney dysfunction.