Tubular Lumen Research Articles

Evaluation of subchronic exposure to triclosan on hepatorenal and reproductive toxicities in prepubertal male rats

ABSTRACTTriclosan (TCS), a common antimicrobial ingredient, is present in many consumer products, including soaps, shampoos, and toothpaste. Owing to its widespread use, potential adverse effects on animals and humans may arise from lifetime exposure, but data on chronic prepubertal exposure of TCS are still lacking. The aim of the present study was to investigate the influence of subchronic TCS exposure (0.25, 25, 250, or 750 mg/kg) on target organ toxicity in prepubertal male rats. After daily administration of TCS to rats by oral gavage for 60 d, a significant reduction in body weight and relative weights of liver, kidneys, testes, and adrenal glands was observed in the 750-mg/kg (high dose) group. Serum alanine aminotransferase and aspartate aminotransferase activities as well as levels of blood urea nitrogen, and creatinine were significantly increased at 750 mg/kg TCS. Further, TCS (750 mg/kg) elevated the protein expressions of hepatic CYP2B1, RXR/PPAR, and levels of malondialdehyde. High-dose TCS exposure induced histological changes as evidenced by reduction of Bowman’s space, occlusion of the tubular lumen, and degeneration of tubular epithelial cells in the kidney. Tubular necrosis was confirmed as evidenced by a rise in expression of high mobility group box 1 renal protein. Daily sperm production was significantly diminished by high doses of TCS with marked inhibition of androgen receptor protein expression. Our results indicated that subchronic exposure to excessively high concentrations of 750 mg/kg TCS induced hepatorenal and reproductive toxicities in prepubertal male rats; however, the biological relevance of these findings is questionable as these drug levels are not encountered in the environment.

A cross-sectional study on the relationship between hematological data and quantitative morphological indices from kidney biopsies in different glomerular diseases

BackgroundThe classical approach to the analysis of kidney biopsies is based on semi-quantitative scores of the amount of sclerosis, inflammatory infiltrate, fibrosis and vascular damage. However, advanced renal lesions may be accompanied by a paucity of clinical features and, conversely, important clinical abnormalities may be accompanied by minimal histopathological changes. The objective of this study is to correlate new, semiautomatic, quantitative features of kidney biopsies (e.g. fractal analysis) with clinical and hematological parameters using a cross-sectional design.MethodsWhole slide images from sixty-seven biopsies of patients diagnosed for diabetic nephropathy, hypertensive nephropathy, focal segmental glomerulosclerosis (FSGS) or IgA nephropathy have been used. The images have been semi-automatically quantified in the ImageJ environment, in order to derive the glomerular density, the tubular density, the number of tubules per glomerulus and the fractal dimension of the tubular lumen in the cortex (an index of complexity of the tubular lumen). For each patient, hemato-chemical data have been retrieved, including the uric acid level and the creatinine-based eGFR.ResultsA linear relationship between eGFR and glomerular density was observed in hypertension and FSGS, but not in diabetic nephropathy. Conversely, the eGFR correlated with the tubular density across different glomerular conditions. Moreover, the tubular density was linearly correlated with uric acid levels in different pathological conditions. The fractal dimension of tubular lumen was correlated with the eGFR but only in hypertensive patients. Finally, blood pressure was not correlated to any of the morphological indices tested.ConclusionsWe propose the use of the fractal dimension as a new morphological descriptor of the nephron integrity.

Kidney stone formers have more renal parenchymal crystals than non-stone formers, particularly in the papilla region

BackgroundWe investigated the renoprotective ability of healthy people against kidney stone formation. To clarify intratubular crystal kinetics and processing in human kidneys, we performed a quantitative and morphological observation of nephrectomized renal parenchyma tissues.MethodsClinical data and pathological samples from 60 patients who underwent radical nephrectomy for renal cancer were collected from June 2004 to June 2010. The patients were retrospectively classified as stone formers (SFs; n = 30, kidney stones detected by preoperative computed tomography) and non-stone formers (NSFs; n = 30, no kidney stone history). The morphology of parenchymal intratubular crystals and kidney stone-related gene and protein expression levels were examined in noncancerous renal sections from both groups.ResultsSFs had a higher smoking rate (P = 0.0097); lower red blood cell, hemoglobin, and hematocrit values; and higher urinary red blood cell, white blood cell, and bacterial counts than NSFs. Scanning electron microscopy revealed calcium-containing crystal deposits and crystal attachment to the renal tubular lumen in both groups. Both groups demonstrated crystal transmigration from the tubular lumen to the interstitium. The crystal diffusion analysis indicated a significantly higher crystal existing ratio in the medulla and papilla of SFs and a significantly higher number of papillary crystal deposits in SFs than NSFs. The expression analysis indicated relatively high osteopontin and CD68, low superoxide dismutase, and significantly lower Tamm–Horsfall protein expression levels in SFs. Multivariate logistic regression analysis involving the above factors found the presence of renal papillary crystals as a significant independent factor related to SFs (odds ratio 5.55, 95% confidence interval 1.08–37.18, P = 0.0395).ConclusionsRegardless of stone formation, intratubular crystals in the renal parenchyma seem to transmigrate to the interstitium. SFs may have reduced ability to eliminate renal parenchymal crystals, particularly those in the papilla region, than NSFs with associated gene expression profiles.

TRPV4 Channel is an Osmosensor and Mechanosensor in Proximal Tubule Cells

The proximal tubule (PT) is the first segment of the nephron and accounts for reabsorption of water and solutes filtered by the glomerulus. In addition, the proximal tubule plays a pivotal role in the endocytosis to reabsorb and metabolize proteins and other substances in glomerular filtrates. Recent studies showed that the PT functions can be modulated by mechanical forces, namely the shear stress on the apical surface and the radial stretch on tubular lumen. Since TRPV4 channel is mainly expressed at the basolateral side of the tubule, we hypothesized that TRPV4 could play a role as stretch-activated channel rather than a shear stress sensor. Patch clamp and Ca2+ imaging experiments showed that TRPV4 channel is expressed in cultured proximal tubule cells and can be activated by the specific agonist GSK1016790A and by hypotonic solution. Moreover, mechanical stretch induced by uniaxial strain in silicone stretchable chambers activated a large Ca2+ influx that was significantly reduced in Trpv4-/- PT cells. Notably, no TRPV4-dependent Ca2+ entry was observed in response to flow-induced cell deformation. Furthermore, we observed that the uptake of FITC-labeled albumin in PT cells, treated with GSK1016790A or mechanically stimulated in stretchable chambers, was significantly reduced in Trpv4-/- PT cells. Finally, we injected angiotensin II in mice, using osmotic minipumps, in order to challenge PT endocytotic activity and increase the proteinuria of mice. Our data showed a massive increase in diuresis of mice. Interestingly, we observed an increase in albuminuria in wild-type mice, and this effect was significantly higher in Trpv4-/- mice. In contrast, glucose and phosphate urinary levels, which undergo PT reabsorption as well, were not significantly affected. Taken together, these results support the view that TRPV4 channel is a mechanosensor in PT cells and modulates their endocytotic activity.

CrossTalk proposal: CNNM proteins are Na+ /Mg2+ exchangers playing a central role in transepithelial Mg2+ (re)absorption.

CrossTalk proposal: CNNM proteins are Na+ /Mg2+ exchangers playing a central role in transepithelial Mg2+ (re)absorption.

Caspase-independent programmed cell death triggers Ca2PO4 deposition in an in vitro model of nephrocalcinosis.

Nephrocalcinosis involves the deposition of microscopic crystals in the tubular lumen or interstitium. While the clinical, biochemical, and genetic aspects of the diseases causing nephrocalcinosis have been elucidated, little is known about the cellular events in this calcification process. We previously reported a phenomenon involving the spontaneous formation of Ca2PO4 nodules in primary papillary renal cells from a patient with medullary nephrocalcinosis harboring a rare glial cell-derived neurotrophic factor (GDNF) gene variant. We also demonstrated that cultivating GDNF-silenced human kidney-2 (HK-2) cells in osteogenic conditions for 15 days triggered Ca2PO4 deposits. Given the reportedly close relationship between cell death and pathological calcification, aim of the present study was to investigate whether apoptosis is involved in the calcification of GDNF-silenced HK-2 cells under osteogenic conditions. Silenced and control cells were cultured in standard and osteogenic medium for 1, 5, and 15 days, and any Ca2PO4 deposition was identified by means of von Kossa staining and environmental SEM (ESEM) analyses. Based on the results of annexin V and propidium iodide (PI) analysis, and terminal deoxynucleotidyl transferase dUTP-biotin nick end labeling (TUNEL) assay, the silenced cells in the osteogenic medium showed a significant increase in the percentage of cells in the late phase of apoptosis and an increased Ca2PO4 deposition at 15 days. The results of quantitative real-time PCR (qRT-PCR) of BAX and BCL2, and in-cell Western analysis of caspases indicated that the cell death process was independent of caspase-3, -6, -7, and -9 activation, however. Using this model, we provide evidence of caspase-independent cell death triggering the calcification process in GDNF-silenced HK-2 cells.

Histomorphometric analysis of gonads of green turtles (chelonia mydas) stranded on the coast of Espírito Santo state, Brazil

ABSTRACT Studies on reproduction in sea turtles are important due to its life cycle, migratory patterns, high juvenile mortality and environmental impacts. This study aimed to analyse histomorphometrically gonads of C. mydas from the coastline of the Espírito Santo State, Brazil. Ovaries and testicles were collected between 2014 and 2015 from stranded animals. The material was fixed in formalin 10%, assessed macroscopically and processed for histomorphometrical evaluation. Gonads from 34 individuals were evaluated, twenty-four females and ten males. Macroscopic sexual identification presented 100% accuracy confirmed by histology. Sexual dimorphism was observed in one individual, which was considered as adult (CCL=1.023 m). Microscopy of female gonads revealed predominant previtellogenic follicles; oocyte diameter ranged between 161µm and 750µm and a positive correlation between ovarian length, largest oocyte and CCL was found. In males, autolysis was verified in five individuals. Viable testicles revealed predominant spermatogonia, primary spermatocytes and Sertoli cells in the seminiferous tubules and, Leydig cells and fibroblasts in the stroma. There was a positive correlation between tubular diameter and CCL and testicle length and CCL. Maturation of stromal tissue and a positive correlation between tubular lumen and CCL were also observed. Gonad development is proportional to individual growth.

Can Tissue Cilia Lengths and Urine Cilia Proteins Be Markers of Kidney Diseases?

The primary cilium is an organelle which consists of a microtubule in the core and a surrounding cilia membrane, and has long been recognized as a “vestigial organelle”. However, new evidence demonstrates that the primary cilium has a notable effect on signal transduction in the cell and is associated with some genetic and non-genetic diseases. In the kidney, the primary cilium protrudes into the Bowman's space and the tubular lumen from the apical side of epithelial cells. The length of primary cilia is dynamically altered during the normal cell cycle, being shortened by retraction into the cell body at the entry of cell division and elongated at differentiation. Furthermore, the length of primary cilia is also dynamically changed in the cells, as a result and/or cause, during the progression of various kidney diseases including acute kidney injury and chronic kidney disease. Notably, recent data has demonstrated that the shortening of the primary cilium in the cell is associated with fragmentation, apart from retraction into the cell body, in the progression of diseases and that the fragmented primary cilia are released into the urine. This data reveals that the alteration of primary cilia length could be related to the progression of diseases. This review will consider if primary cilia length alteration is associated with the progression of kidney diseases and if the length of tissue primary cilia and the presence or increase of cilia proteins in the urine is indicative of kidney diseases.

Role of Immunohistochemistry in the Diagnosis of Leptospirosis in Neotropical Primates

Background: Leptospirosis is considered the most widespread zoonosis worldwide, occurring more frequently in tropical and developing regions. The aim of the present study was to detect the presence of Leptospira spp. in different primate tissues, using immunohistochemical (IHC) assays, taking advantage of the considerable number of necropsies compatible with a diagnosis of leptospirosis in neotropical primates at the Animal Pathology Laboratory (APL) of the University of Passo Fundo (UPF) in the northern region of Rio Grande do Sul.Materials, Methods & Results: Paraffin-embedded primate tissue samples were selected from necropsy examinations and subjected to IHC. The streptavidin-biotin-peroxidase method was used with diaminobenzidine chromogen (DAB) to verify immunostaining. Of the101 primates tested for Leptospira spp., 51.48% were positive; taining was distributed between lung (76.92%), liver (44.23%), and kidney (32.69%) tissue. Analysis of the combined anatomopathological verification data of the studied organs revealed a high frequency of lesions commonly observed in the tissues of animals exposed to the pathogen. For complementary diagnosis, an anti-Leptospira spp. antibody test was performed in primates at the UPF-Zoo, from which a population of the necropsied animals originated. The microscopic agglutination test (MAT) was utilized, which demonstrated 90.47% positivity in 21 individuals; sejroe and panama were the most frequent serovars.Discussion: Different intensities of tissue immunostaining were observed. Areas of fragmented or diffuse staining were considered to indicate equal positivity to that indicated by areas of staining with preserved morphology. Of 52 Leptospirapositive primates, most presented some degree of staining in lung samples, which shows a high level of involvement for this organ in primate leptospirosis. Conventional pathological diagnostic methods do not allow fort issue antigen recognition, thus making the IHC technique important to facilitate conclusive antigen sample verification. In the liver, leptospires were detected mostly between the sinusoids, hepatocytes, and Kupffer cells. In kidney tissues, staining indicated small agglomerates in the tubular lumen, interstitium, and glomeruli. All these forms of presentation have been previously reported. Considering that we detected the highest number of positive samples in lung tissue, followed by those from liver and kidney tissue, we argue that the IHC technique, when applied to samples of these three tissues, decreases the chance of false negatives. Anatomopathological studies of primate leptospirosis are scarce. In dogs, renal lesions are characterized by the necrosis and degeneration of tubular epithelium, cellular debris, and hyaline cylinders. In the liver, hepatocyte cord dissociation and biliary pigment accumulation within the canaliculi and hepatocellular necrosis are observed. These findings are similar to those from our study. In the lung, diffuse alveolar lesions are reported, with hemorrhage and edema, in addition to capillaritis. The high frequency of Leptospira-positive animals determined by serological examination was consistent with the IHC findings, thus confirming the pathogen’s high prevalence in neotropical primate populations in the studied region. Serological surveys on primate populations have already been carried out and have revealed frequency and serovar variations between regions. Immunohistochemical examination allows the detection of leptospires in various tissues and should be used based on the characteristics of the investigated case.

Ivermectin acute administration impaired the spermatogenesis and spermiogenesis of adult rats

Ivermectin (IVM) is an antiparasitic agent widely used in agricultural, domestic animals and in human clinical practice. In the present study, the temporal effects of therapeutic doses of IVM in the morphometric and histological assessment of testis were studied to verify if IVM acute administration impaired the spermatogenesis and spermiogenesis of adult rats, if these effects are reversible. The testosterone levels and the plasmatic IVM levels were assessed. The results show: 1) IVM acute exposure, mainly in the higher dose, reduced the testicular volume, the tubular diameter and the germinal epithelium height; 2) no interferences on Leydig cells frequency; 3) histological studies show that tubular sections containing several histological changes indicative of spermatogenesis interruption, such as disorganization of germinal epithelium, vacuolar degeneration of the germ cells and sloughing of cells into the tubular lumen; 4) no differences in testosterone levels; 5) The IVM plasmatic levels were significantly reduced at 72h after the 0.2mg/kg. It was concluded that acute IVM impaired the spermatogenesis and spermiogenesis of rats. Probably these effects were not consequence of IVM at the Leydig cells because no effects were observed at this level. Finally, our results suggest that some testicular effects are reversible and correlated with the plasmatic levels of IVM.

Effects of profenofos induced histopathology and recovery patterns in silver barb (Barbonymus gonionotus)

Histopathology is promising field for research in aquatic toxicology as it provides the real picture of the toxic effects of xenobiotics in vital functions of a living organism. The present study aims to evaluate the toxic effect of pesticide namely profenofos on silver barb. Liver and kidney of silver barb were examined histologically after exposure to sublethal concentrations (0.01 ppm, 10% of LC50 and 0.05 ppm, 50% of LC50) of profenofos for 0, 7, 15 and 30 days. Histological recovery was also studied by maintaining the pesticide‐exposed fish in a freshwater system for an additional 7, 15 and 30 day. Kidney and liver of exposed individuals exhibited some remarkable changes in their histology in comparison to control and recovery group. Hepatic lesions in the liver tissues of fish were characterized by cloudy swelling of hepatocytes, lipoid vacuoles, pycnotic nuclei and focal necrosis. Epithelial hypertrophy, narrowing of the tubular lumen, atrophy of the glomerulus, broader Bowman's capsule, necrosis in the epithelial cells and pycnosis in the hematopoietic tissue were observed in kidney tissues of experimental fish. These lesions grew with increasing concentration. Although some of the changes were reversible, the rest were less pronounced after a recovery period.Progressive Agriculture 28 (3): 240-248, 2017

Assembly of RGD-Modified Hydrogel Micromodules into Permeable Three-Dimensional Hollow Microtissues Mimicking in Vivo Tissue Structures.

Fabricated microscale tissues that replicate in vivo architectures have shown huge potential in regenerative medicine and drug discovery. Owing to the spatial organization of cell-encapsulated hydrogel microstructures, three-dimensional (3D) tissue structures have been broadly applied as novel pathological or pharmacological models. However, the spatial reorganization of arbitrary microstructures with tissue-specific shapes into 3D in vitro microtissues that mimic the physiological morphology and nutrient diffusion of native tissues presents a major challenge. Here, we develop a versatile method that engineers permeable 3D microtissues into tissue-specific microscopic architectures. The customized, arbitrarily shaped hollow micromodules are prepared by photocopolymerizing poly(ethylene glycol) diacrylate (PEGDA) with acryloyl-PEG-Arg-Gly-Asp-Ser (RGDS). These micromodules are spatially reorganized and self-aligned by a facile assembly process based on hydrodynamic interactions, forming an integrated geometry with tissue-specific morphology and a vessel-mimetic lumen. The RGD linkages create cell-adhesive structures in the PEGDA hydrogel, greatly increasing the long-term cell viability in 3D microtissue cultures. Meanwhile, the mechanical properties for fast cell spreading inside the microstructures can be optimized by modulating the PEGDA concentration. The 3D microtissues, with their different geometries and permeable tubular lumens, maintained cell proliferation over 14 days. The cell viabilities exceeded 98%. We anticipate that our method will regenerate complex tissues with physiological importance in future tissue engineering.

Early detection of acute tubulointerstitial nephritis in the genesis of Mesoamerican nephropathy

Mesoamerican nephropathy is a devastating disease of unknown etiology that affects mostly young agricultural workers in Central America. An understanding of the mechanism of injury and the early disease process is urgently needed and will aid in identification of the underlying cause and direct treatment and prevention efforts. We sought to describe the renal pathology in Mesoamerican nephropathy at its earliest clinical appearance in prospectively identified acute case patients in Nicaragua. We considered those with elevated (or increased at least 0.3 mg/dL or 1.5-fold from baseline) serum creatinine, leukocyturia, and either leukocytosis or neutrophilia for inclusion in this biopsy study. Renal tissue was obtained by ultrasound-guided biopsy for examination by light, immunofluorescence, and electron microscopy. All 11 individuals who underwent renal biopsy showed tubulointerstitial nephritis, with varying degrees of inflammation and chronicity. Interstitial cellular infiltrates (predominantly T lymphocytes and monocytes), mostly in the corticomedullary junction; neutrophilic accumulation in the tubular lumens; largely preserved glomeruli; few mild ischemic changes; and no immune deposits were noted. The acute components of tubulointerstitial nephritis were acute tubular cell injury, interstitial edema, and early fibrosis. Chronic tubulointerstitial nephritis included severe tubular atrophy, thickened tubular basement membrane, and interstitial fibrosis. Thus, renal histopathology in Mesoamerican nephropathy reveals primary interstitial disease with intact glomeruli.

A nephron model for study of drug-induced acute kidney injury and assessment of drug-induced nephrotoxicity

In this study, we developed a multilayer microfluidic device to simulate nephron, which was formed by “glomerulus”, “Bowman's capsule”, “proximal tubular lumen” and “peritubular capillary”. In this microdevice, artificial renal blood flow was circulating and glomerular filtrate flow was single passing through, mimicking the behavior of a nephron. In this dynamic artificial nephron, we observed typical renal physiology, including the glomerular size-selective barrier, glomerular basement membrane charge-selective barrier, glucose reabsorption and para-aminohippuric acid secretion. To demonstrate the capability of our microdevice, we used it to investigate the pathophysiology of drug-induced acute kidney injury (AKI) and give assessment of drug-induced nephrotoxicity, with cisplatin and doxorubicin as model drugs. In the experiment, we loaded the doxorubicin or cisplatin in the “renal blood flow”, recorded the injury of primary glomerular endothelial cells, podocytes, tubular epithelial cells and peritubular endothelial cells by fluorescence imaging, and identified the time-dependence, dose-dependence and the death order of four types of renal cells. Then by measuring multiple biomarkers, including E-cadherin, VEGF, VCAM-1, Nephrin, and ZO-1, we studied the mechanism of cell injuries caused by doxorubicin or cisplatin. Also, we investigated the effect of BSA in the “renal blood flow” on doxorubicin-or-cisplatin-induced nephrotoxicity, and found that BSA enhanced the tight junctions between cells and eased cisplatin-induced nephrotoxicity. In addition, we compared the nephron model and traditional tubule models for assessment of drug-induced nephrotoxicity. And it can be inferred that our biomimetic microdevice simulated the complex, dynamic microenvironment of nephron, yielded abundant information about drug-induced-AKI at the preclinical stage, boosted the drug safety evaluation, and provided a reliable reference for clinical therapy.

Effect of adipose-derived mesenchymal stem cell transplantation on vascular calcification in rats with adenine-induced kidney disease

Previous studies have investigated the use of mesenchymal stem cells (MSCs) to treat damaged kidneys. However, the effect of adipose-derived MSCs (ASCs) on vascular calcification in chronic kidney disease (CKD) is still poorly understood. In the present study, we explored the potential of ASCs for the treatment of CKD and vascular calcification. CKD was induced in male Sprague-Dawley rats by feeding them a diet containing 0.75% adenine for 4 weeks. ASCs transplantation significantly reduced serum inorganic phosphorus (Pi) as compared to that in the control. The histopathology of the kidneys showed a greater dilation of tubular lumens and interstitial fibrosis in the control group. Calcium and Pi contents of the aorta in the ASCs transplantation group were lower than those in the control group. Von Kossa staining of the thoracic aorta media revealed that ASCs transplantation suppressed vascular calcification. Thus, this study revealed that autogenic ASCs transplantation inhibits kidney damage and suppresses the progression of vascular calcification in the CKD rat model, suggesting that autogenic ASCs transplantation is a novel approach for preventing the progression of CKD and vascular calcification.

A novel ability of endocytoscopy to diagnose histological grade of differentiation in T1 colorectal carcinomas.

Endocytoscopic images closely resemble histopathology. We assessed whether endocytoscopy could be used to determine T1 colorectal cancer histological grade. Endocytoscopic images of 161 lesions were divided into three types: tubular gland lumens, unclear gland lumens, and fused gland formations on endocytoscopy (FGFE). We retrospectively compared endocytoscopic findings with histological grade in the resected specimen superficial layer, and examined the incidence of risk factors for lymph node metastasis. Of the 118 eligible lesions, the sensitivity, specificity, accuracy, negative predictive value, and positive likelihood ratio of tubular or unclear gland lumens to identify well-differentiated adenocarcinomas were 91.0 %, 93.1 %, 91.5 %, 77.1 %, and 13.20, respectively. To identify moderately differentiated adenocarcinomas for FGFE, these values were 93.1 %, 91.0 %, 91.5 %, 97.6 %, and 10.36, respectively. In the 35 lesions with FGFE, the rates of massive invasion, lymphovascular infiltration, and tumor budding were 97.1 %, 60.0 %, and 37.1 %, respectively. Endocytoscopy could be used to diagnose T1 colorectal cancer histological grade, and FGFE was a marker for recommending surgery.

Germ cell proliferation and apoptosis during testicular regression in a seasonal breeding fish kept in captivity.

Cell proliferation and apoptosis regulate germ cells stock and sperm production, eliminate anomalous gametes, and are essential parameters to consider in fish farming. Herein, spermatogenic activity as well as germ cell proliferation and apoptosis were assessed in Leporinus taeniatus, a seasonal breeding species from the São Francisco River basin, Brazil. Testes of 24 adult fishes from a farming station were sampled between December and July and processed for light and transmission electron microscopy and immunohistochemistry for PCNA and TUNEL assay. The gonadosomatic index and seminiferous tubule diameters presented higher values during the breeding season (December/January and February/March), and then significantly reduced during the regression and resting stages (April/May and June/July). Phagocytosis of spermatozoa by Sertoli cells was evident during gonadal regression, but a significant number (up to 30%) remained at the tubular lumen during the resting stage. A higher PCNA/TUNEL ratio occurred in the breeding period, leading to an elevated proportion (%) of spermatogonia (GA and GB) in resting. Moreover, a higher TUNEL/PCNA ratio indicates the contribution of apoptosis to the reduction of germ cells during testicular regression. Together, these results indicate a shift in the balance between cell proliferation and apoptosis that contributes to the regulation of the spermatogenic cycle and germ cells pool of L. taeniatus kept in captivity.

Structural evaluation of the peritubular sheath of rat's testes after administration of ribavirin: A possible impact on the testicular function.

Effects of ribavirin on the structure of peritubular sheath (PS) of seminiferous tubules and on testicular functions were studied. We found that ribavirin at a dose of 4 mg/kg/day for 4 weeks produced a significant reduction in testosterone level (6.3 ± 0.2; P < 0.001) and in spermatogenic score count (3.8 ± 0.2; P < 0.001) compared to control values. The thickness of PS (17.8 ± 1.13) and tubular lumen perimeter (1024.7 ± 67) was significantly increased compared to controls (10.7 ± 0.70; P < 0.001 and 808 ± 25; P = 0.004, respectively). The length of germinal epithelium (411.8 ± 39) and tubular external diameters (1661.8 ± 115) was significantly reduced compared to control values (708.4 ± 40; P < 0.001 and 2358.8 ± 169; P < 0.001, respectively). The basement membranes (BMs) were thickened with great deposition of collagen. Myoid cells showed altered structure and extracellular matrix revealed disorganization by excessive collagen I and IV accumulation. Testicular damage was established histologically. Evidence of apoptosis was detected in germ cells. There was a significant increase in integrated density of Casp-3 expression (38,121,743 ± 1,763,420; P < 0.001) in seminiferous tubules compared to control (24,788,409 ± 1,900,140). It is concluded that ribavirin can cause alterations of the testicular function and structure with increased apoptosis in the tissues after 4 weeks of administration. The damaging effect could be persuaded by destruction of the peritubular sheath.

Early involvement of cellular stress and inflammatory signals in the pathogenesis of tubulointerstitial kidney disease due to UMOD mutations

Autosomal dominant tubulointerstitial kidney disease (ADTKD) is an inherited disorder that causes progressive kidney damage and renal failure. Mutations in the UMOD gene, encoding uromodulin, lead to ADTKD-UMOD related. Uromodulin is a GPI-anchored protein exclusively produced by epithelial cells of the thick ascending limb of Henle’s loop. It is released in the tubular lumen after proteolytic cleavage and represents the most abundant protein in human urine in physiological condition. We previously generated and characterized a transgenic mouse model expressing mutant uromodulin (TgUmodC147W) that recapitulates the main features of ATDKD-UMOD. While several studies clearly demonstrated that mutated uromodulin accumulates in endoplasmic reticulum, the mechanisms that lead to renal damage are not fully understood. In our work, we used kidney transcriptional profiling to identify early events of pathogenesis in the kidneys of TgUmodC147W mice. Our results demonstrate up-regulation of inflammation and fibrosis and down-regulation of lipid metabolism in young TgUmodC147W mice, before any functional or histological evidence of kidney damage. We also show that pro-inflammatory signals precede fibrosis onset and are already present in the first week after birth. Early induction of inflammation is likely relevant for ADTKD-UMOD pathogenesis and related pathways can be envisaged as possible novel targets for therapeutic intervention.

Effect of gentamicin on the histology of renal tubules in different doses, Experimental study

The present study showed that the gentamicin cause a mild effect to the proximal convoluted tubules at dose of 5 mg/kg for 14 days represented by loss of brush border. Vacuoles of various sizes appeared with flattening and dilatation of the tubules, condensation of nuclear chromatin was observed, with partial detachment of the cells from the basement membrane. In comparison the more clear effect of gentamicin appears at 10 mg/kg dose that included loss of apical surface and detachment of cells from the basement membrane, with nearly complete loss of brush border and increase in number &amp; size of the cytoplasmic vacuoles. Many nuclei with condensed chromatin and nuclear fragmented cells (apoptosis) were located in tubular lumen. The study concluded that gentamicin has adverse effect on the kidney and renal tubules histology especially in the high dose administration, comparison with low dose that reveal to mild damage.