Endothelial Cell Degeneration Research Articles

Histopathological, immunohistochemical, and ultrastructural evidence of spontaneous Senecavirus A-induced lesions at the choroid plexus of newborn piglets

Epidemic Transient Neonatal Losses (ETNL) is a disease of piglets caused by Senecavirus A (SVA) in which the method of dissemination and associated lesions are not well-defined. This study investigated the possible SVA-induced lesions by examining spontaneous infections in newborn piglets. Histopathology revealed ballooning degeneration of transitional epithelium, nonsuppurative meningoencephalitis, plexus choroiditis, and atrophic enteritis. RT-PCR identified SVA in all tissues evaluated and sequencing confirmed these results. Positive immunoreactivity to SVA was observed in endothelial and epithelial tissues of all organs evaluated. Semithin analysis revealed vacuolization of apical enterocytes of the small intestine, balloon degeneration and necrosis of endothelial cells of the choroid plexus (CP) and nonsuppurative choroid plexitis. Ultrathin evaluation demonstrated hydropic degeneration of apical enterocytes, degeneration and necrosis of endothelium of CP fenestrated capillaries, degeneration of ependymocytes associated with intralesional viral particles. It is proposed that SVA initially infects apical enterocytes of newborn piglets and probably enters the circulatory system with entry to the brain via the CP, by first producing an initial inflammatory reaction, with subsequent encephalitic dissemination. Consequently, SVA probably uses an enteric-neurological method of dissemination.

SLC4A11 depletion impairs NRF2 mediated antioxidant signaling and increases reactive oxygen species in human corneal endothelial cells during oxidative stress

Corneal endothelial dystrophy is a progressive disease with gradual loss of vision and characterized by degeneration and dysfunction of corneal endothelial cells. Mutations in SLC4A11, a Na+ dependent OH− transporter, cause congenital hereditary endothelial dystrophy (CHED) and Fuchs’ endothelial corneal dystrophy (FECD), the two most common forms of endothelial degeneration. Along with genetic factors, oxidative stress plays a role in pathogenesis of several corneal diseases. In this study we looked into the role of SLC4A11 in antioxidant stress response in human corneal endothelial cells (HCEnC). We found increased expression of SLC4A11 in presence of oxidative stress. Depletion of SLC4A11 using targeted siRNA, caused an increase in reactive oxygen species, cytochrome c, lowered mitochondrial membrane potential, and reduced cell viability during oxidative stress. Moreover, SLC4A11 was found to be necessary for NRF2 mediated antioxidant gene expression in HCEnC. On the other hand, over expression of SLC4A11 reduces reactive oxygen species levels and increases cell viability. Lastly, CHED tissue specimens show evidence of oxidative stress and reduced expression of NRF2. In conclusion, our data suggests a possible role of SLC4A11 in regulating oxidative stress, and might be responsible for both the etiology and treatment of corneal endothelial dystrophy.

Endothelial and Astrocytic Support by Human Bone Marrow Stem Cell Grafts into Symptomatic ALS Mice towards Blood-Spinal Cord Barrier Repair

Vascular pathology, including blood-CNS barrier (B-CNS-B) damage via endothelial cell (EC) degeneration, is a recently recognized hallmark of Amyotrophic Lateral Sclerosis (ALS) pathogenesis. B-CNS-B repair may be a new therapeutic approach for ALS. This study aimed to determine effects of transplanted unmodified human bone marrow CD34+ (hBM34+) cells into symptomatic G93A mice towards blood-spinal cord barrier (BSCB) repair. Thirteen weeks old G93A mice intravenously received one of three different doses of hBM34+ cells. Cell-treated, media-treated, and control mice were euthanized at 17 weeks of age. Immunohistochemical (anti-human vWF, CD45, GFAP, and Iba-1) and motor neuron histological analyses were performed in cervical and lumbar spinal cords. EB levels in spinal cord parenchyma determined capillary permeability. Transplanted hBM34+ cells improved behavioral disease outcomes and enhanced motor neuron survival, mainly in high-cell-dose mice. Transplanted cells differentiated into ECs and engrafted within numerous capillaries. Reduced astrogliosis, microgliosis, and enhanced perivascular end-feet astrocytes were also determined in spinal cords, mostly in high-cell-dose mice. These mice also showed significantly decreased parenchymal EB levels. EC differentiation, capillary engraftment, reduced capillary permeability, and re-established perivascular end-feet astrocytes in symptomatic ALS mice may represent BSCB repair processes, supporting hBM34+ cell transplantation as a future therapeutic strategy for ALS patients.

Liver Microvascular Injury and Thrombocytopenia of Antibody-Calicheamicin Conjugates in Cynomolgus Monkeys-Mechanism and Monitoring.

Purpose: Adverse reactions reported in patients treated with antibody-calicheamicin conjugates such as gemtuzumab ozogamicin (Mylotarg) and inotuzumab ozogamicin include thrombocytopenia and sinusoidal obstruction syndrome (SOS). The objective of this experimental work was to investigate the mechanism for thrombocytopenia, characterize the liver injury, and identify potential safety biomarkers.Experimental Design: Cynomolgus monkeys were dosed intravenously at 6 mg/m2/dose once every 3 weeks with a nonbinding antibody-calicheamicin conjugate (PF-0259) containing the same linker-payload as gemtuzumab ozogamicin and inotuzumab ozogamicin. Monkeys were necropsied 48 hours after the first administration (day 3) or 3 weeks after the third administration (day 63).Results: PF-0259 induced acute thrombocytopenia (up to 86% platelet reduction) with nadirs on days 3 to 4. There was no indication of effects on megakaryocytes in bone marrow or activation of platelets in peripheral blood. Microscopic evaluation of liver from animals necropsied on day 3 demonstrated midzonal degeneration and loss of sinusoidal endothelial cells (SECs) associated with marked platelet accumulation in sinusoids. Liver histopathology on day 63 showed variable endothelial recovery and progression to a combination of sinusoidal capillarization and sinusoidal dilation/hepatocellular atrophy, consistent with early SOS. Among biomarkers evaluated, there were early and sustained increases in serum hyaluronic acid (HA) that correlated well with serum aspartate aminotransferase and liver microscopic changes, suggesting that HA may be a sensitive diagnostic marker of the liver microvascular injury.Conclusions: These data support the conclusion that target-independent damage to liver SECs may be responsible for acute thrombocytopenia (through platelet sequestration in liver sinusoids) and development of SOS. Clin Cancer Res; 23(7); 1760-70. ©2016 AACR.

Endothelial Degeneration of Parkinson's Disease is Related to Alpha-Synuclein Aggregation

Objective: We previously reported that the ability of vascular remodelling is impaired in human Parkinson’s disease, leading to endothelial degeneration and vascular dysfunction. Aggregation of α-synuclein is a hallmark of neurodegeneration in Parkinson’s disease and inflammation and autophagy may contribute to secondary neuronal degeneration. The current study examined the association between these characteristic pathologies and endothelial cell degeneration in Parkinson’s disease. Methods: The study used the post-mortem grey matter from middle frontal gyrus (MFG) of human Parkinson’s disease and age-matched control cases. Immunohistochemical staining of phosphorylated α-synuclein, p62 for autophagy, Human Leukocyte Antigen-antigen D Related (HLA-DR) for activated microglia, Factor VIII for endothelial cells and Neuronal Nuclei for neurons were performed using either tissue microarray or free-floating sections. The expression of these factors were quantified by analysing the images of the stained sections and compared between the Parkinson’s disease and the age-matched control groups. Results: Compared to the control cases the expression of phosphorylated α-synuclein and p62 was increased in Parkinson’s disease, whereas both neurons and endothelial cells were significantly reduced, with no changes in the number of microglial cells. The density of phosphorylated α-synuclein was negatively correlated with the total length of endothelial cell associated blood vessels when compared across normal and Parkinson’s disease cases combined. However, using double label immunohistochemistry we found that the degree of endothelial cell degeneration in Parkinson’s disease was not directly related to the degree of neuronal degeneration and accumulation of phosphorylated α-synuclein. Conclusion: α-synuclein and autophagy are associated with endothelial degeneration in Parkinson’s disease. The degree of endothelial degeneration was not related to the extent of neuronal degeneration, both of which were copathological changes in PD brains. Alpha-synuclein-associated endothelial degeneration was also age-related pathology.

Acute renal injury induced by valacyclovir hydrochloride: A case report.

Acyclovir has been a frequently used antiviral agent in the clinical treatment of leukemia, acute encephalitis, malignant tumor and herpes simplex. The adverse effects of this drug have been widely described in clinical practice. In the present study, a case of a 35-year-old female patient diagnosed with herpes simplex, who developed acute renal injury following treatment with valacyclovir hydrochloride, is described. Kidney biopsy, light microscopy and laboratory examination were performed, and all findings revealed the signs of evident vacuolar degeneration of capillary endothelial and renal tubular epithelial cells, erythrocyte aggregation in partial renal tubule and microvilli exfoliation from epithelial cells. Renal interstitial edema was clearly identified. The clinical evidence observed from this female patient indicated that renal functions should be closely monitored during valacyclovir hydrochloride administration. A variety of effective measures, such as hydration, alkalizing urine, promoting the discharge of medication and the use of antagonists are recommended following the administration of antiviral agents.

Erroneus measurement of the intraocular pressure with the goldmann aplanation tonometry in fuchs endothelial corneal dystrophy

PurposeFuchs endothelial corneal dystrophy (FECD) is a bilateral, progressive, disease of the corneal endothelium. It's caused by an abnormal collagen deposition in Descemet membrane leading to progressive degeneration of endothelial cells. The loss of endothelial cells prevents the removal of water from the cornea, causing corneal edema. Later stages involve other layers corneal layers. It is most frequently a spontaneous disease although several autosomal dominant mutations have been reported.It has been described that corneal thickness influences the corneal biomechanics properties, leading to an erroneous measurement of the intraocular pressure (IOP) with the Goldmannn aplanation tonometry.MethodsWe report a patient diagnosed with FECD and his IOP was measured with Goldamann applanation tonometry (GAT) and Ocular Response Analyser (ORA). As well as corneal hysteresis (CH), corneal resistance factor (CRF) were recorded with the ORA. We have followed this patient for several years we also carried out corneal topographic maps and spectral domain optical coherence tomography (SD‐OCT) to complete the study.ResultsThe evolution of our patient showed a corneal edema related to an abnormal endothelium. We noticed that compensated IOP was significantly higher than GAT IOP and Goldmann IOP due to biomechanic changes secondary to corneal edema.ConclusionsIOP in patients with FECD and edema should be measured with ORA so compensated IOP is registered avoiding the underestimation of only GAT.

In Vivo Imaging of Corneal Endothelial Dystrophy in Boston Terriers: A Spontaneous, Canine Model for Fuchs' Endothelial Corneal Dystrophy.

PurposeBoston Terriers (BTs) have a greater prevalence of corneal endothelial dystrophy (CED), in comparison to other canine breeds. Similar to Fuchs' endothelial corneal dystrophy (FECD), this condition is characterized by endothelial cell degeneration with secondary corneal edema. This study assessed corneal morphology using in vivo confocal microscopy (IVCM) and Fourier-domain optical coherence tomography (FD-OCT) in BTs with and without CED.MethodsThe corneas of 16 BTs with CED and 15 unaffected, age-matched BTs underwent clinical evaluation and were imaged using IVCM and FD-OCT. A two-sample t-test or Mann-Whitney rank sum test were used to statistically compare parameters between groups. Data are presented as mean ± SD or median (range).ResultsMean age did not significantly differ between affected and unaffected dogs at 10.0 ± 2.0 and 10.6 ± 2.4 years, respectively (P = 0.437). Females (69%) were overrepresented among the CED-affected dogs. In CED patients, IVCM demonstrated endothelial polymegathism and pleomorphism. Corneal endothelial density was significantly less (P < 0.001) in dogs with CED (1026 ± 260 cells/mm2) versus age-matched controls (2297 ± 372 cells/mm2). Fourier-domain OCT demonstrated a significant increase (P < 0.01) in central corneal and endothelium-Descemet's complex thickness in dogs with CED versus age-matched controls at 1019 (485–1550) or 536 (464–650) μm and 32 (22–56) or 25 (15–34) μm, respectively.ConclusionsCorneal endothelial dystrophy in BTs is a bilateral, adult-onset condition that shares many similarities with FECD. Thus, CED could serve as a spontaneous disease model to study the pathogenesis of and develop novel treatments for FECD.

Abstract LB-202: Liver microvascular injury and thrombocytopenia of antibody-calicheamicin conjugates: mechanism and monitoring

Abstract Gemtuzumab ozogamicin (Mylotarg, GO) and inotuzumab ozogamicin (IO) are antibody-drug conjugates (ADCs) comprised of different humanized monoclonal antibodies (against CD33 and CD22 antigen, respectively) and of the same acid-labile linker and calicheamicin payload. GO and IO are developed for the treatment of acute myeloid leukemia and acute lymphoblastic leukemia, respectively. Adverse events reported with these 2 drugs in patients include thrombocytopenia and liver toxicity, which is characterized by increases in serum aminotransferases and bilirubin along with occasional cases of sinusoidal obstruction syndrome (SOS). The platelet and liver effects were seen in patients with conjugates targeting unrelated antigens and are likely target-independent. Since the specific mechanisms of these toxicities remain elusive, an investigative study was performed in cynomolgus monkeys with a non-binding ADC containing the same linker and payload as GO and IO, PF-0259, with the objectives to investigate the mechanism for thrombocytopenia, characterize the liver injury and identify potential safety biomarkers. Cynomolgus monkeys were dosed intravenously with PF-0259 at 6 mg/m2/dose once every 3 weeks for up to 3 doses and were necropsied 48 hours after the 1st administration (Day 3) or 3 weeks after the 3rd administration (Day 63). PF-0259 induced acute thrombocytopenia (up to 86% reduction in platelet count) in monkeys with nadirs on Days 3-4. There was no indication of effects on megakaryocytes in bone marrow or activation of platelets in peripheral blood. Microscopic evaluation of liver samples from animals necropsied on Day 3 demonstrated midzonal degeneration and loss of sinusoidal endothelial cells (SECs) associated with marked platelet accumulation in sinusoids. Liver histopathology on Day 63 showed variable endothelial cell recovery and progression to a combination of sinusoidal capillarization and sinusoidal dilation/hepatocellular atrophy, consistent with early SOS. Among biomarkers evaluated, there were early and sustained increases in serum hyaluronic acid (HA) that correlated well with AST levels and liver microscopic changes, suggesting that HA could be a sensitive diagnostic marker of the liver microvascular injury. In conclusion, this work has demonstrated that target-independent damage to liver SECs was responsible for acute thrombocytopenia (through platelet sequestration in the liver) and development of early SOS in monkeys. The translation of these observations to humans has not been evaluated. We further hypothesize that this toxicity mechanism may operate for other types of non-calicheamicin based ADCs in patients where adverse events of thrombocytopenia, increased liver enzymes and liver microvascular disorders (including nodular regenerative hyperplasia) have been observed. Citation Format: Magali Guffroy, Hadi Falahatpisheh, Kathleen Biddle, John Kreeger, Leslie Obert, Karen Walters, Richard Goldstein, Germaine Boucher, Timothy Coskran, William Reagan, Danielle Sullivan, Sharon Sokolowski, Richard Giovanelli, Hans-Peter Gerber, Martin Finkelstein, Nasir Khan. Liver microvascular injury and thrombocytopenia of antibody-calicheamicin conjugates: mechanism and monitoring. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-202.

Na+, K+-ATPase dysfunction causes cerebrovascular endothelial cell degeneration in rat prefrontal cortex slice cultures

Cerebrovascular endothelial cell dysfunction resulting in imbalance of cerebral blood flow contributes to the onset of psychiatric disorders such as depression, schizophrenia and bipolar disorder. Although decrease in Na+, K+-ATPase activity has been reported in the patients with schizophrenia and bipolar disorder, the contribution of Na+, K+-ATPase to endothelial cell dysfunction remains poorly understood. Here, by using rat neonatal prefrontal cortex slice cultures, we demonstrated that pharmacological inhibition of Na+, K+-ATPase by ouabain induced endothelial cell injury. Treatment with ouabain significantly decreased immunoreactive area of rat endothelial cell antigen-1 (RECA-1), a marker of endothelial cells, in a time-dependent manner. Ouabain also decreased Bcl-2/Bax ratio and phosphorylation level of glycogen synthase kinase 3β (GSK3β) (Ser9), which were prevented by lithium carbonate. On the other hand, ouabain-induced endothelial cell injury was exacerbated by concomitant treatment with LY294002, an inhibitor of phosphoinositide 3- (PI3-) kinase. We also found that xestospongin C, an inhibitor of inositol triphosphate (IP3) receptor, but not SEA0400, an inhibitor of Na+, Ca2+ exchanger (NCX), protected endothelial cells from cytotoxicity of ouabain. These results suggest that cerebrovascular endothelial cell degeneration induced by Na+, K+-ATPase inhibition resulting in Ca2+ release from endoplasmic reticulum (ER) and activation of GSK3β signaling underlies pathogenesis of these psychiatric disorders.

Abstract 13846: Factor Xa Inhibition Prevents Cardiac Remodeling Induced by Intermittent Hypoxia in Sleep Apnea Model Mice

Introduction: We have reported that intermittent hypoxia (IH) relevant to sleep apnea increases oxidative stress causing vascular remodeling and heart failure. The serine protease factor Xa in the coagulation cascade elicits inflammatory responses in endothelial cells. Hypothesis: We hypothesize that rivaroxaban might attenuate cardiac remodeling induced by IH in sleep apnea model mice. Methods: Male C57BL/6J mice at 8 weeks of age were exposed to IH (repeated cycles of 1.5 minute of 5% oxygen followed by 5 minutes of 21% oxygen) for 56 days with/without treatment by rivaroxaban (1.2 g riv./kg chow). After echocardiography, heart was examined by light and electron microscopy, immunohistochemistry, and RT-PCR. HPAECs were cultured under hypoxic conditions (37%, 1% O 2 , 5% CO 2 ) with/without rivaroxaban (1 μM). Results: IH caused cardiac remodeling (Figure), associated with both systolic and diastolic dysfunction compared with those of normoxia (IH vehicle vs. Normoxia; EF: 51.8% vs. 59.4% and E/e’: 29.4 vs. 22.3), which were attenuated by rivaroxaban (EF: 55.8%, E/e’: 24.6). In right atrial myocardium, IH caused endothelial cell degeneration, dissociation of intercalated discs, vacuolar formation and loss of ANP specific granules. Furthermore, 4-hydroxy-2-nonenal protein adducts and the expression of protease-activated receptor-1 (PAR-1) and NF-kB mRNA were increased by IH. Treatment with rivaroxaban significantly suppressed PAR-1 and NF-kB mRNA expression, increased ANP granules and reduced perivascular fibrosis, preventing cardiac remodeling due to IH. Conclusions: Rivaroxaban may attenuate atrial and ventricular remodeling induced by IH at least partly through its anti-inflammatory effect in sleep apnea model mice.

Involvement of ZEB1 and Snail1 in excessive production of extracellular matrix in Fuchs endothelial corneal dystrophy

Fuchs endothelial corneal dystrophy (FECD) due to corneal endothelial cell degeneration is a major cause of corneal transplantation. It is characterized by abnormal deposition of extracellular matrix (ECM), such as corneal guttae, accompanied by a loss of endothelial cells. Although recent studies have revealed several genomic factors, the molecular pathophysiology of FECD has not yet been revealed. In this study, we establish a cellular in vitro model by using immortalized corneal endothelial cells obtained from late-onset FECD and control patients and examined the involvement of epithelial mesenchymal transition (EMT) on excessive ECM production. We demonstrate that the EMT-inducing genes ZEB1 and SNAI1 were highly expressed in corneal endothelial cells in FECD and were involved in excessive production of ECM proteins, such as type I collagen and fibronectin through the transforming growth factor (TGF)-β signaling pathway. Furthermore, we found that SB431542, a specific inhibitor of TGF-β type I ALK receptors, suppressed the expression of ZEB1 and Snail1 followed by reduced production of ECM. These findings suggest that increased expression levels of ZEB1 and Snail1 in FECD cells were responsible for an increased responsiveness to TGF-β present in the aqueous humor and excessive production of ECM. In addition, these results suggest that the regulation of EMT-related genes by blocking the TGF-β signaling pathway may be a feasible therapeutic strategy for FECD.

Structural and functional changes in retinal vasculature induced by retinal ischemia-reperfusion in rats

Recent studies have shown retinal blood vessel damage in experimental models of retinal degeneration. The present study aimed to provide a detailed description of the structural and functional changes in retinal vasculature induced by retinal ischemia-reperfusion (I/R) in rats. Retinal ischemia was induced for 60 min by raising the intraocular pressure to 130 mmHg. Morphological changes in vascular components (endothelial cells, pericytes, and basement membranes), the patency and perfusion of blood vessels, and expression of vascular endothelial growth factor (VEGF) were assessed in the retinas at 2, 7, and 14 days after I/R. Significant reductions in vascular densities were observed at 7 and 14 days after I/R. Pericyte loss occurred after the appearance of endothelial cell degeneration, whereas the vascular basement membranes remained unchanged. Some vessels showed no perfusion in damaged retina. A decrease in the immunoreactivity of VEGF in the region extending from the ganglion cell layer to the outer plexiform layer was evident 2 days after I/R. In retinal I/R model, retinal ganglion cells are rapidly (<2 day) damaged following reperfusion, therefore, the current results suggest that neuronal cell damage precedes capillary degeneration, and neuronal cells may play an important role in maintaining vascular structure and function through the production and release of endothelial cell survival factors, including VEGF. Neuronal cell damage could be an additional cause of progression of ischemic retinal damage by reducing blood supply to the retinal neurons due to the destruction of the blood vessel network.

Severe pre-eclampsia complicated by HELLP syndrome alterations in the structure of the umbilical cord (morphometric and immunohistochemical study)

The aim of this study was to evaluate the morphometric and immunohistochemistry in umbilical cords from patients with severe pre-eclampsia with and without haemolysis, elevated liver enzymes and low platelets (HELLP) syndrome. The patient and control groups were similar according to baseline obstetric characteristics. White blood cell count in patients with HELLP syndrome and the control group was significantly increased among patients with HELLP syndrome (p < 0.001). Morphometric examination and endothelial core length were significantly different between the groups. In the umbilical cord cross-section of the HELLP group, endothelial cell degeneration in the vessel wall and basement membrane thickening were observed. In the muscle layer of blood vessels, the following disorders were found: increased collagen fibres in the muscle cell, hyperplasia and separation of muscle fibres as well as edema in the intermediate connective tissue. Immunohistochemical analysis showed that endothelial cells, basal membrane and fibroblast cells in the HELLP group expressed high levels of CD44. Vessel wall and amniotic epithelial basement membrane thickening were observed in the HELLP group. Matrix metalloproteinase 9 (MMP9) was expressed. Fibroblast and smooth muscle cells were fusiform and showed a positive reaction to immunohistochemical staining of α-actin smooth muscle.

Effect of fluid shear stress on portal vein remodeling in a rat model of portal hypertension.

Aims. To explore the effects and mechanisms of fluid shear stress on portal vein remodeling in a rat model of portal hypertension. Methods. Subcutaneous injections of CCl4 were given to establish a rat model of liver cirrhosis and portal hypertension. Biomechanical technology was adopted to determine the dynamic changes of haemodynamic indices and fluid shear stress. Nitric oxide (NO), synthase (NOS), and endothelin-1 (ET-1) of the portal vein blood were measured. Changes in geometric structure and ultrastructure of the portal vein were observed using optical and electron microscopy. Results. After the CC14 injections, rat haemodynamics were notably altered. From week 4 onwards, PVP, PVF, and PVR gradually and significantly increased (P < 0.05 versus baseline). The fluid shear stress declined from week 4 onwards (P < 0.01 versus control group). NO, NOS, and ET-1 increased after repeated CCI4 injections. Hematoxylin and eosin staining showed thickened portal vein walls, with increased inside and outside diameters. Electron microscopy revealed different degrees of endothelial cell degeneration, destruction of basement membrane integrity, proliferating, and hypertrophic smooth muscle cells. Conclusions. Fluid shear stress not only influenced the biomechanical environment of the portal vein but also participated in vascular remodeling.

Vascular mechanism of axonal degeneration in peripheral nerves in hemiplegic sides after cerebral hemorrhage: An experimental study

BackgroundThough retrograde neuronal death and vascular insufficiency have been well established in plegics following intracerebral hemorrhage, the effects of plegia on arterial nervorums of peripheral nerves have not been reported. In this study, the histopathological effects of the intracerebral hemorrhage on the dorsal root ganglions and sciatic nerves via affecting the arterial nervorums were investigated.MethodsThis study was conducted on 13 male hybrid rabbits. Three animals were taken as control group and did not undergo surgery. The remaining 10 subjects were anesthetized and were injected with 0.50 ml of autologous blood into their right sensory-motor region. All rabbits were followed-up for two months and then sacrificed. Endothelial cell numbers and volume values were estimated a three dimensionally created standardized arterial nervorums model of lumbar 3. Neuron numbers of dorsal root ganglions, and axon numbers in the lumbar 3 nerve root and volume values of arterial nervorums were examined histopathologically. The results were analyzed by using a Mann-Whitney-U test.ResultsLeft hemiplegia developed in 8 animals. On the hemiplegic side, degenerative vascular changes and volume reduction in the arterial nervorums of the sciatic nerves, neuronal injury in the dorsal root ganglions, and axonal injury in the lumbar 3 were detected. Statistical analyses showed a significant correlation between the normal or nonplegic sides and plegic sides in terms of the neurodegeneration in the dorsal root ganglions (p < 0.005), axonal degeneration in the lumbar 3 nerve roots (p < 0.005), endothelial cell degeneration in the arterial nervorums (p < 0.001), and volume reduction in the arterial nervorums (p < 0.001).ConclusionIntracerebral hemorrhage resulted in neurodegeneration in the dorsal root ganglion and axonolysis in the sciatic nerves, endothelial injury, and volume reduction of the arterial nervorums in the sciatic nerves. The interruption of the neural network connection in the walls of the arterial nervorums in the sciatic nerves may be responsible for circulation disorders of the arterial nervorums, and arterial nervorums degeneration could result in sciatic nerves injury.

Endothelial keratoplasty versus penetrating keratoplasty for Fuchs endothelial dystrophy

Endothelial keratoplasty versus penetrating keratoplasty for Fuchs endothelial dystrophy

Blood-CNS Barrier Impairment in ALS patients versus an animal model

Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease with a complicated and poorly understood pathogenesis. Recently, alterations in the blood–Central Nervous System barrier (B-CNS-B) have been recognized as a key factor possibly aggravating motor neuron damage. The majority of findings on ALS microvascular pathology have been determined in mutant superoxide dismutase (SOD1) rodent models, identifying barrier damage during disease development which might similarly occur in familial ALS patients carrying the SOD1 mutation. However, our knowledge of B-CNS-B competence in sporadic ALS (SALS) has been limited. We recently showed structural and functional impairment in postmortem gray and white matter microvessels of medulla and spinal cord tissue from SALS patients, suggesting pervasive barrier damage. Although numerous signs of barrier impairment (endothelial cell degeneration, capillary leakage, perivascular edema, downregulation of tight junction proteins, and microhemorrhages) are indicated in both mutant SOD1 animal models of ALS and SALS patients, other pathogenic barrier alterations have as yet only been identified in SALS patients. Pericyte degeneration, perivascular collagen IV expansion, and white matter capillary abnormalities in SALS patients are significant barrier related pathologies yet to be noted in ALS SOD1 animal models. In the current review, these important differences in blood–CNS barrier damage between ALS patients and animal models, which may signify altered barrier transport mechanisms, are discussed. Understanding discrepancies in barrier condition between ALS patients and animal models may be crucial for developing effective therapies.

Stroke-induced opposite and age-dependent changes of vessel-associated markers in co-morbid transgenic mice with Alzheimer-like alterations

The pathophysiological concept of ischaemic stroke was recently expanded to a more comprehensive perspective, focussing on the vasculature as well as peri- and juxtavascular cells including astrocytes. Increasing evidence also supports a role of the vasculature in Alzheimer's disease (AD), but causal relationships are poorly understood. The purpose of this study was to examine vascular alterations due to cerebral ischaemia in aged wildtype (WT) mice and in the triple-transgenic (3xTg) mouse model of AD. Three- and 12-month-old WT and 3xTg mice underwent permanent middle cerebral artery occlusion. One day after ischaemia onset, expression of collagen IV and laminin as basement membrane constituents, and Solanum tuberosum lectin (STL) as endothelial marker was quantified in the ischaemic neocortex, striatum and hippocampus. Further, CD31- and aquaporin-4-immunoreactivity served for coverage of endothelium and astrocyte endfeet. Ischaemia resulted in strong upregulation of collagen IV and laminin in the neocortex of 3-month-old WT and 3xTg mice, while STL appeared unaffected. Quantification confirmed collagen IV upregulation in the ischaemic neocortex of 3- and 12-month-old WT and 3xTg mice, whereas striatal changes were limited to young WT mice. However, collagen IV expression in the hippocampus appeared nearly unaltered. Qualitative and quantitative data evidenced more severe degeneration of endothelial cells and astrocyte endfeet in 3xTg mice. In conclusion, this study supports the critical impact of the vasculature in the aged and AD brain by showing an age- and genetic background-dependent response of basement membranes to cerebral ischaemia, and a pronounced endothelial and astrocytic degeneration in the AD-like brain.

Histological study on conjunctival and corneal reactions in rabbits induced by chronic topical application of latanoprost and travoprost

Introduction: Chronic topical glaucoma therapy was reported to cause deleterious changes tothe ocular surface epithelial layer. Aim of the work: The aim of this study was to compare the histological changes in the cornea after chronic exposure to latanoprost preserved with 0.02% benzalkonium chloride(BAK) eye drops, travoprost preserved with sofZia eye drops and preservative-free artificial tears. Materials and methods Fifteen white rabbits were randomized into three groups (five animals each). They received once-daily topical application of one of the three treatments for 30 days. The first group (the control group) received preservative-free artificial tears (Refresh Plus). The second group received travoprost preserved with SofZia (Travatan Z).The third group received latanoprost preserved with 0.02% BAK (Xalatan). Enucleation was performed at the end of the experiment. Corneal samples were processed for light and transmission electron microscopic studies and conjunctival samples for light microscopic study. The mean epithelial height of the corneal epithelium, the mean number of goblet cells in the conjuctival epithelium and the mean area% of PAS-positive goblet cells were measured using an image analyzer. These results were statistically analysed using analysis of variance and the t-test. Results: Latanoprost eye drops preserved in BAK produced toxic changes in the form of degeneration and desquamation of the superficial epithelial cells in the cornea, separation of Descemet’s membrane and degeneration of endothelial cells, in addition to decreased number of goblet cells in the conjunctiva. Travoprost eyedrops preserved in sofZia were safer and produced slight changes on the rabbit’s ocular surface compared with latanoprost eye drops preserved in BAK. Conclusion It was concluded that antiglaucomatous drugs preserved with sofZia produced less corneal and conjunctival changes than those preserved with BAK.