Effects of cytokines on vascular endothelium: their role in vascular and immune injury

Fetal Brain Damage in Human Fetuses with Congenital Cytomegalovirus Infection: Histological Features and Viral Tropism

Human cytomegalovirus (HCMV) causes congenital neurological lifelong disabilities. To date, the neuropathogenesis of brain injury related to congenital HCMV (cCMV) infection is poorly understood. This study evaluates the characteristics and pathogenetic mechanisms of encephalic damage in cCMV infection. Ten HCMV-infected human fetuses at 21 weeks of gestation were examined. Specifically, tissues from different brain areas were analyzed by: (i) immunohistochemistry (IHC) to detect HCMV-infected cell distribution, (ii) hematoxylin-eosin staining to evaluate histological damage and (iii) real-time PCR to quantify tissue viral load (HCMV-DNA). The differentiation stage of HCMV-infected neural/neuronal cells was assessed by double IHC to detect simultaneously HCMV-antigens and neural/neuronal markers: nestin (a marker of neural stem/progenitor cells), doublecortin (DCX, marker of cells committed to the neuronal lineage) and neuronal nuclei (NeuN, identifying mature neurons). HCMV-positive cells and viral DNA were found in the brain of 8/10 (80%) fetuses. For these cases, brain damage was classified as mild (n = 4, 50%), moderate (n = 3, 37.5%) and severe (n = 1, 12.5%) based on presence and frequency of pathological findings (necrosis, microglial nodules, microglial activation, astrocytosis, and vascular changes). The highest median HCMV-DNA level was found in the hippocampus (212 copies/5 ng of human DNA [hDNA], range: 10-7,505) as well as the highest mean HCMV-infected cell value (2.9 cells, range: 0-23), followed by that detected in subventricular zone (1.7 cells, range: 0-19). These findings suggested a preferential viral tropism for both neural stem/progenitor cells and neuronal committed cells, residing in these regions, confirmed by the expression of DCX and nestin in 94% and 63.3% of HCMV-positive cells, respectively. NeuN was not found among HCMV-positive cells and was nearly absent in the brain with severe damage, suggesting HCMV does not infect mature neurons and immature neural/neuronal cells do not differentiate into neurons. This could lead to known structural and functional brain defects from cCMV infection.

Delayed Septal Perforation as a Complication of COVID-19: A Case Report

BACKGROUND

There are increasing reports of the effects of SARS-CoV-2 on olfactory function, with a significant number of patients reporting anosmia as a symptom. However, our knowledge and understanding of the virus's complete impact on the nose remains poor. This report describes a unique patient case to demonstrate how COVID-19 may be associated with rhinoplasty complications such as septal perforation.

CASE REPORT

This is a case report of a previously healthy patient who underwent septorhinoplasty in 2018. She had frequent follow-up including intranasal examinations without evidence of the septal perforation for the 2 years following her operation. In March 2020, the patient was noted to have symptoms suggestive of COVID-19, but testing was not recommended by the pediatrician. Soon after her symptoms resolved, she experienced a sudden onset of whistling and physical examination revealed a perforation in the septum which rapidly enlarged over the ensuing weeks. She tested positive for the COVID-19 antibody. After confirming that she no longer had an active infection via antigen testing, she underwent repair of her septal perforation without complications.

CONCLUSION

This case report illustrates a septorhinoplasty complication that may be associated with COVID-19. Further study into this virus's impact on vascularity and wound healing, specifically in the nose, is recommended.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Ischemic Stroke among the Symptoms Caused by the COVID-19 Infection

The 2019 global pandemic of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been declared a public health emergency of international concern by the World Health Organization (WHO). The WHO recognized the spread of COVID-19 as a pandemic on 11 March 2020. Based on statistics from 10 August 2020, more than 20.2 million cases of COVID-19 have been reported resulting in more than 738,000 deaths. This completely new coronavirus has spread worldwide in a short period, causing economic crises and healthcare system failures worldwide. Initially, it was thought that the main health threat was associated with respiratory system failures, but since then, SARS-CoV-2 has been linked to a broad spectrum of symptoms indicating neurological manifestations, including ischemic stroke. Current knowledge about SARS-CoV-2 and its complications is very limited because of its rapidly evolving character. However, further research is undoubtedly necessary to understand the causes of neurological abnormalities, including acute cerebrovascular disease. The viral infection is inextricably associated with the activation of the immune system and the release of pro-inflammatory factors, that can stimulate the host organism to defend itself. However, the body’s immune response is a double-edged sword that on one hand, destroys the virus but also disrupts the homeostasis leading to serious complications, including thrombosis. Numerous studies have linked coagulopathies with COVID-19, however, there is great uncertainty regarding it functions on the molecular level. In this review, a detailed insight into the biological processes associated with ischemic stroke in COVID-19 patients and suggest a possible explanation for this phenomenon is provided.

Comparison of Hemostatic Disturbances between Patients on Capd and Patients on Hemodialysis

Objective

Disturbances in hemostasis are common findings in uremic patients. Both bleeding diathesis and thrombosis are observed. The purpose of this study was to assess whether renal replacement therapy in the form of hemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD) affects coagulation and fibrinolysis in patients with end-stage renal failure.

Design

Comparison of hemostatic measures in patients on CAPD, HD, and matched healthy controls.

Setting

Department of Nephrology and Internal Medicine, Bialystok University School of Medicine.

Patients and Methods

Twenty-four HD patients and 23 CAPD patients were evaluated with respect to platelet aggregation, hemostatic parameters, serum lipids, lipoprotein(a), and cytokines [tumor necrosis factor alpha (TNFα) and interleukin-1 (IL-1)].

Interventions

Four exchanges of CAPD per day, using 2.0 L dialysate over a period of 25 ± 31 months; or 4 – 5 hours of HD 3 times per week for a period of 31 ± 22 months.

Results

Platelet aggregation in whole blood and platelet-rich plasma was significantly impaired in both groups of dialyzed patients compared to healthy volunteers. Markers of endothelial cell injury (thrombomodulin and von Willebrand factor) were significantly higher in HD and CAPD patients compared to the control group. A similar pattern of changes was observed for lipoprotein(a), fibrinogen, tissue factor pathway activity, and factor VII activity. Activity of factor X was significantly enhanced in CAPD compared to HD patients and controls. Euglobulin clot lysis time was significantly prolonged in HD and CAPD patients over controls, being more prolonged in CAPD patients. Markers of ongoing coagulation (thrombin–antithrombin complexes and prothrombin fragments 1+2) were higher in uremic patients, significantly higher in CAPD than in HD. A marker of ongoing fibrinolysis (plasmin–antiplasmin complexes) was higher in uremic patients but was lower in CAPD than in HD patients. Concentrations of TNFα and IL-1 were higher in HD than in CAPD patients.

Conclusion

Patients on CAPD showed evidence of a higher degree of hypercoagulation than HD patients. Thus, hemostatic abnormalities in end-stage renal failure may be affected to some extent by the choice of renal replacement therapy.

A Comprehensive Study on Hemostasis in CAPD Patients Treated with Erythropoietin

Objective

Bleeding diathesis and simultaneous thrombotic complications may be seen in dialyzed patients. Erythropoietin (EPO) may shift the precarious balance of the hemostatic system toward thrombosis. Platelets and tissue factor (TF) play a major role in plug formation. Tissue factor pathway inhibitor (TFPI) appears to play a primary role in regulating TF-induced coagulation. Thrombin activatable fibrinolysis inhibitor (TAFI) is a key protein linking coagulation and fibrinolysis. The aim of the study was to assess whether 6 months of EPO therapy affects platelet function, that is, platelet aggregation and P-selectin level; moieties of the extrinsic coagulation pathway: TF, TFPI, and TFPI/Xa complexes, and factors VII and X; markers of ongoing coagulation: thrombin–antithrombin complexes (TAT) and prothrombin fragments 1+2; a marker of ongoing fibrinolysis: plasmin–antiplasmin complexes (PAP); fibrinolytic activity: euglobulin clot lysis time (ECLT); and markers of endothelial cell injury: von Willebrand factor, thrombomodulin, E-selectin, and TAFI, in continuous ambulatory peritoneal dialysis (CAPD) patients.

Patients and Methods

22 patients on CAPD were given EPO 6000 U/week. 12 patients with chronic renal failure and 12 healthy volunteers served as control groups. All parameters were studied before, and after 1, 3, and 6 months of EPO therapy.

Setting

Department of Nephrology and Internal Medicine, Medical Academy of Bialystok, Poland.

Results

Platelet aggregation in whole blood did not change significantly during EPO treatment. A significant rise in arachidonic acid-induced platelet aggregation in platelet-rich plasma was observed after 3 and 6 months, and in collagen-induced platelet aggregation after 6 months of EPO therapy, compared to the baseline values. The TFPI concentration decreased significantly after 6 months of EPO therapy. The activity of factor VII increased transiently after 1 month of EPO therapy, compared to the baseline values. The TAFI concentration and activity in the CAPD group were significantly higher than in the control group. Erythropoietin therapy resulted in a significant decrease in TAFI concentration and activity after 6 months of EPO treatment. The ECLT was shortened significantly as early as after 1 month of EPO therapy. Thrombomodulin, von Willebrand factor concentration and activity, PAP, TAT, TFPI/Xa complexes, prothrombin fragments 1+2, factor X activity, P-selectin, E-selectin, and lipoprotein(a) did not change significantly during EPO treatment.

Conclusion

Erythropoietin treatment has a minimal effect on hemostasis in CAPD patients. A tendency toward a decline in TAFI is of unknown clinical relevance so far, and awaits further research.

The Tumor Vascular Endothelium as Decision Maker in Cancer Therapy

Genetic and pathophysiologic criteria prearrange the uncontrolled growth of neoplastic cells that in turn initiates new vessel formation, which is prerequisite for further tumor growth and progression. This first endothelial lining is patchy, disordered in structure and thus, angiogenic tumor vessels were proven to be functionally inferior. As a result, tumors were characterized by areas with an apparent oversupply in addition to areas with an undersupply of vessels, which complicates an efficient administration of intravenous drugs in cancer therapy and might even lower the response e.g. of radiotherapy (RT) because of the inefficient oxygen supply. In addition to the vascular dysfunction, tumor blood vessels contribute to the tumor escape from immunity by the lack of response to inflammatory activation (endothelial anergy) and by repression of leukocyte adhesion molecule expression. However, tumor vessels can remodel by the association with and integration of pericytes and smooth muscle cells which stabilize these immature vessels resulting in normalization of the vascular structures. This normalization of the tumor vascular bed could improve the efficiency of previously established therapeutic approaches, such as chemo- or radiotherapy by a more homogenous drug and oxygen distribution, and/or by overcoming endothelial anergy. This review highlights the current investigations that take advantage of a proper vascular function for improving cancer therapy with a special focus on the endothelial-immune system interplay.

Unsaturated lipid bodies as a hallmark of inflammation studied by Raman 2D and 3D microscopy

Endothelial HMEC-1 cells incubated with pro-inflammatory cytokine TNF-α for 6 and 24 hours were studied as a model of inflammation using Raman imaging. Striking changes in distribution, composition and concentration of cellular lipids were observed after exposure to TNF-α compared to the control. In particular, 3D Raman imaging revealed a significant increase in the amount of lipid entities formed under inflammation. Lipid bodies were randomly distributed in the cytoplasm and two types of droplets were assembled: more saturated one, in spectral characteristics resembling phosphatidylcholine and saturated cholesteryl esters, observed also in the control, and highly unsaturated one, containing also cholesterols, being a hallmark of inflamed cells. The statistical analysis showed that the number of lipid bodies was significantly dependent on the exposure time to TNF-α. Overall, observed formation of unsaturated lipid droplets can be directly correlated with the increase in production of prostacyclins - endogenous inflammation mediators.

Cordyceps militaris fruit body extract ameliorates membranous glomerulonephritis by attenuating oxidative stress and renal inflammation via the NF-κB pathway

Membranous glomerulonephritis (MGN) is a common pathogenesis of nephritic syndrome in adult patients. Nuclear factor kappa B (NF-κB) serves as the main transcription factor for the inflammatory response mediated nephropathy. Cordyceps militaris, containing various pharmacological components, has been used as a kind of crude drug and folk tonic food for improving immunity and reducing inflammation. The current study aims to investigate the renoprotective activity of Cordyceps militaris aqueous extract (CM) in the cationic bovine serum albumin (C-BSA)-induced rat model of membranous glomerulonephritis. Significant renal dysfunction was observed in MGN rats; comparatively, 4-week CM administration strongly decreased the levels of 24 h urine protein, total cholesterol, triglyceride, blood urea nitrogen and serum creatinine, and increased the levels of serum albumin and total serum protein. Strikingly, recovery of the kidney histological architecture was noted in CM-treated MGN rats. A significant improvement in the glutathione peroxidase and superoxide dismutase levels, and a reduced malondialdehyde concentration were observed in the serum and kidney of CM-treated rats. Altered levels of inflammatory cytokines including interleukins, monocyte chemoattractant protein-1, intercellular adhesion molecule 1, vascular adhesion molecule 1, tumor necrosis factor-α, 6-keto-prostaglandin F1α, and nuclear transcriptional factor subunit NF-κB p65 reverted to normal levels upon treatment with CM. The present data suggest that CM protects rats against membranous glomerulonephritis via the normalization of NF-κB activity, thereby inhibiting oxidative damage and reducing inflammatory cytokine levels, which further provide experimental evidence in support of the clinical use of CM as an effective renoprotective agent.

In vivo neutralization of tumor necrosis factor attenuates the generalized Shwartzman reaction in the rabbit

A role for tumor necrosis factor (TNF) and TNF-induced tissue factor (TF) expression has been postulated in endotoxin (LPS)-induced diffuse intravascular coagulation (DIC). We studied the protective efficacy of goat polyclonal gammaglobulin (lgG) against recombinant human (rh)-TNF in the generalized Shwartzman reaction (GSR) in rabbits, a model of DIC. Administration of anti-rhTNF 2 h before the first, preparative, LPS injection afforded 95% neutralization of TNF released during the GSR. Compared to saline-pretreated controls, a modest attenuation of fibrin deposition in kidney, lung, liver and spleen was observed 4 h after the second provocative LPS injection. Except for the lung, fibrin deposition in the anti-rhTNF group was not attenuated compared to the non-immune goat IgG (ni-lgG)-pretreated group. Both ni-lgG and anti-rhTNF prevented LPS-induced TF expression by mononuclear cells, but not by isolated glomeruli. Other mediators than TNF and TF are involved as well in glomerular injury and fibrin deposition after LPS.

Podocytes regulate neutrophil recruitment by glomerular endothelial cells via IL-6-mediated crosstalk

Stromal cells actively modulate the inflammatory process, in part by influencing the ability of neighboring endothelial cells to support the recruitment of circulating leukocytes. We hypothesized that podocytes influence the ability of glomerular endothelial cells (GEnCs) to recruit neutrophils during inflammation. To address this, human podocytes and human GEnCs were cultured on opposite sides of porous inserts and then treated with or without increasing concentrations of TNF-α prior to addition of neutrophils. The presence of podocytes significantly reduced neutrophil recruitment to GEnCs by up to 50% when cultures were treated with high-dose TNF-α (100 U/ml), when compared with GEnC monocultures. Importantly, this phenomenon was dependent on paracrine actions of soluble IL-6, predominantly released by podocytes. A similar response was absent when HUVECs were cocultured with podocytes, indicating a tissue-specific phenomenon. Suppressor of cytokine signaling 3 elicited the immunosuppressive actions of IL-6 in a process that disrupted the presentation of chemokines on GEnCs by altering the expression of the duffy Ag receptor for chemokines. Interestingly, suppressor of cytokine signaling 3 knockdown in GEnCs upregulated duffy Ag receptor for chemokines and CXCL5 expression, thereby restoring the neutrophil recruitment. In summary, these studies reveal that podocytes can negatively regulate neutrophil recruitment to inflamed GEnCs by modulating IL-6 signaling, identifying a potential novel anti-inflammatory role of IL-6 in renal glomeruli.

Emerging role for TNF-α in erectile dysfunction

INTRODUCTION

A role for cytokines in the pathophysiology of erectile dysfunction (ED) has emerged. Cytokines induce genes that synthesize other peptides in the cytokine family and several mediators, such as prostanoids, leukotrienes, nitric oxide, bradykinin, reactive oxygen species, and platelet-activating factor, all of which can affect vascular function. Consistent with the fact that the cavernosal tissue is a complex extension of the vasculature, risk factors that affect the vasculature have been shown to affect cavernosal function as well. Accordingly, the penile tissue has been recognized as an early sentinel for atherosclerosis that underlies coronary artery disease and cardiovascular diseases (CVD).

AIM

To review the literature pertaining to the role of tumor necrosis factor-alpha (TNF-α) in ED.

METHODS

PubMed search for pertinent publications on the role of cytokines, particularly TNF-α, in CVD and ED.

MAIN OUTCOME MEASURES

Clinical and experimental evidence demonstrates that TNF-α may play a role in ED.

RESULTS

TNF-α has been shown to play an important role in CVD, mainly due to its direct effects on the vasculature. In addition, high levels of TNF-α were demonstrated in patients with ED. In this review, we present a short description of the physiology of erection and the cytokine network. We focus on vascular actions of TNF-α that support a role for this cytokine as a potential candidate in the pathophysiology of ED, particularly in the context of CVD. A brief overview of its discovery, mechanisms of synthesis, receptors, and its main actions on the systemic and penile vasculature is also presented.

CONCLUSIONS

Considering that ED results from a systemic arterial defect not only confined to the penile vasculature, implication of TNF-α in the pathophysiology of ED offers a humoral linking between CVD and ED.

Acute urticaria[corrected]-like lesions in allergen-unexposed cutaneous tissues in a mouse model of late allergic rhinitis

The mechanisms of distant manifestation after a local allergic reaction are largely unknown. This study examined the development of cutaneous lesions in a mouse model of late allergic rhinitis (LAR). BALB/c mice were sensitized by ovalbumin (OVA) intraperitoneally two times (on days 0 and 10) and challenged by OVA intranasally on day 14. Four days after OVA challenge, nasal and cutaneous lesions including helper T (Th) responses, expression of adhesion molecules and presence of OVA and IgE were examined, and compared with unsensitized and unchallenged (control) mice. Compared with the control group, the LAR group developed LAR characterized by infiltration of lymphocytes and eosinophils, increased IgE values and increased productions of IL-4 and IL-5, but not IFN-gamma. A dominant infiltration of eosinophils and increase in mast cells, attachment of eosinophils to endothelium, intense expression of VCAM-1 on endothelium in venules and VLA-4 expression on eosinophils and mast cells were recognized in the cutaneous tissues. There were no differences in the expression of ICAM-1 on vascular endothelium and LFA-1 on infiltrated leucocytes between the two groups. CLA expression on lymphocytes was not detected, and the binding of OVA and IgE on mast cells and eosinophils was found in the cutaneous lesions in the LAR group, but not in the control group. This study suggests that acute urticaria[corrected]-like lesions in OVA-unexposed cutaneous tissues may be induced by immediate allergic reaction due to the systemic development of Th2-type response in a mouse model of LAR.

The role of alveolar macrophages in the pathogenesis of aspiration pneumonitis

RATIONALE

A robust TNFalpha response is seen following aspiration of food particles, while there is only a modest response to acid.

OBJECTIVES

To examine the direct effects of acid and particulate components of gastric content on local and systemic macrophages.

METHODS

Pathogen-free Long-Evans rats were injured with intratracheal instillation of normal saline (SHAM), low pH saline (ACID), small non-acidic particles (SNAP) or acidified particles (CASP). The alveolar (local) and the peritoneal (systemic) macrophages were harvested following the injury.

MEASUREMENTS

We examined the phagocytic activity and TNFalpha release by the alveolar and peritoneal macrophages following in vivo and in vitro exposure to acid and/or food particles. TNFalpha release by macrophages was examined in response to E. coli lipopolysaccharide (LPS) stimulation.

MAIN RESULTS

In rats injured with gastric particles, the number of the mononuclear cells was higher than those obtained from acid-injured animals. Both in vivo and in vitro exposure of the alveolar macrophages to SNAP resulted in increased production of TNFalpha within 8 hours. Transient exposure of the alveolar macrophages to a low pH environment suppressed LPS-induced production of this cytokine. Additionally, the phagocytic activity of the alveolar macrophages was inhibited by in vitro exposure of the macrophages to acid.

CONCLUSIONS

We conclude that the two components of gastric aspiration have diverse effects on local and systemic macrophages. Although there is a synergy between acid and gastric particulate in producing an acute lung injury, the modulatory effects of these injuries on the alveolar macrophages are averse.

Thyroid Function, Endothelium, and Inflammation in Hemodialyzed Patients: Possible Relations?

OBJECTIVE

Renal function affects the thyroid gland in many ways. Disturbances in hemostasis and inflammation are common complications of kidney diseases. Endothelial dysfunction may link these two processes.

DESIGN AND PATIENTS

A cross-sectional study on thyroid hormones in relation to markers of endothelial damage and inflammation in 96 hemodialyzed (HD) patients and 39 healthy volunteers was performed.

SETTING

The study took place in the dialysis unit at a university hospital.

INTERVENTION

Thyroid hormones, markers of endothelial damage (von Willebrand factor, thrombomodulin, intracellular adhesion molecule, and CD146), markers of inflammation (high-sensitivity C-reactive protein, tumor necrosis factor alpha), other hemostatic parameters (thrombin-antithrombin complexes, prothrombin fragments 1 + 2 - F1 + 2, plasmin-antiplasmin complexes, tissue plasminogen activator and its inhibitor, tissue factor pathway inhibitor, and platelet glycoprotein V) were measured using commercially available kits.

RESULTS

Free T3 and total T3 were lower in HD patients compared with controls. Markers of endothelial dysfunction and inflammation were significantly elevated in HD patients compared with controls. In multiple regression analysis T3 was independently related to time on dialyses, albumin, iron, ferritin, C-reactive protein (CRP), and F1 + 2 in HD patients. Free T3 was also independently related to total protein, total calcium, and triglycerides. In patients with CRP less than 6 mg/L in multiple regression analysis the only correlates of T3 were albumin and ferritin, whereas the only correlates of free T3 were albumin and time on dialyses. Multiple regression analysis showed that in HD patients with CRP greater than equal to 6 mg/L predictors of free T3 were CRP, F1 + 2, and dose of erythropoietin. In healthy volunteers T3 was related to tissue factor pathway inhibitor and platelet glycoprotein V was related to thyroid-stimulating hormone.

CONCLUSIONS

We described novel relations between thyroid hormones and markers of endothelial dysfunction and inflammation in HD patients. Thyroid dysfunction is related to time on dialyses, endothelial damage, and inflammatory state, frequently encountered in uremia. Therefore, the relations between thyroid axis and endothelium in HD subjects merit additional studies.

Possible Relations Between Thyroid Function, Endothelium, and Kidney and Liver Function in Kidney Allograft Recipients

BACKGROUND

Renal function affects the thyroid gland in many ways. Disturbances in hemostasis and endothelial damage are common complications of kidney disease. Endothelial dysfunction may link these two processes.

AIM AND METHODS

This cross-sectional study examined thyroid hormones in relation to markers of endothelial damage and inflammation among 80 kidney allograft recipients and 29 healthy volunteers. Thyroid hormones, markers of endothelial damage (vWF, thrombomodulin, intracellular adhesion molecule [ICAM] vascular adhesion molecule [VCAM], CD146), markers of inflammation (hsCRP), other hemostatic parameters (thrombin-antithrombin complexes [TAT], prothrombin fragments 1 + 2 [F1 + 2], plasmin-antiplasmin complexes, tissue plasminogen activator and its inhibitor, platelet glycoprotein [V-GPV]) as well as P-selectin were measured using commercially available kits.

RESULTS

Total T3 was significantly lower among kidney allograft recipients, whereas markers of endothelial dysfunction and inflammation were significantly elevated over controls. In kidney allograft recipients total T3 was independently related to PAI-1, ICAM, and eGFR, whereas free T3 was independently related to thrombomodulin, aspartate, and alanine aminotransferases, hemoglobin, urea, eGFR, dose of cyclosporine and treatment with mycophenolate mofetil/azathioprine. Total T4 was related to aspartate and alanine aminotransferases, dose of cyclosporine, PAI-1, and ICAM. In multiple regression analysis the only correlates of T3 were PAI-1 and ICAM, whereas the only correlates of free T3 were thrombomodulin, aspartate aminotransferase, eGFR, and cyclosporine dose. In healthy volunteers GPV was related only to TSH.

CONCLUSIONS

We described novel relations between thyroid hormones and markers of endothelial dysfunction in kidney transplant recipients. In kidney transplant recipients thyroid function metrics were associated with endothelial damage, immunosuppressive treatment, liver and kidney function. Therefore, the relations between thyroid axis and endothelium in kidney allograft recipients merit additional studies.

Retinal endovascular lysis in ischemic central retinal vein occlusion: one-year results of a pilot study

PURPOSE

Retinal endovascular lysis is a new therapeutic option for patients with central retinal vein occlusion (CRVO). In this procedure, a fibrinolytic agent is injected directly into a cannulated retinal vein after pars plana vitrectomy.

DESIGN

Prospective interventional case series.

PARTICIPANTS

Thirteen strictly defined patients with ischemic CRVO.

METHODS

Patients with a decimal visual acuity (VA) of 0.2 or worse were scheduled for surgery within the first 5 months after onset of CRVO. A full ocular examination, determination of VA (Early Treatment Diabetic Retinopathy Study charts), and fluorescein angiography were done preoperatively and 6, 12, 26, and 52 weeks postoperatively.

MAIN OUTCOME MEASURE

Visual acuity 1 year after retinal endovascular lysis. Secondary study end points were (1) correlation of VA and successful recombinant tissue plasminogen activator injection into a retinal vein, (2) complication rate, and (3) number of additional surgical procedures within the first year after retinal endovascular lysis.

RESULTS

All patients had an ischemic CRVO and completed the 1-year follow-up visit. Preoperative decimal VA was 0.063 +0.025/-0.018 (VA range, light perception [LP]-0.2); 6-week postoperative VA, 0.049 +0.024/-0.016 (LP-0.4); 3-month postoperative VA, 0.043 +0.019/-0.014 (LP-0.3); 6-month postoperative VA, 0.035 +0.022/-0.013 (blindness-0.4); and 12-month postoperative VA, 0.04 +0.026/-0.016 (blindness-0.4). Visual acuity changed 1 year after retinal endovascular lysis by -1.923+/-1.619 lines (+6 to -16 lines; P = 0.258). We considered the retinal endovascular lysis procedure to have been technically successful in 10 eyes. Visual changes did not depend on successful lysis. Six eyes developed neovascular glaucoma, of which 2 globes ended up with painful phthisis and had to be removed. Retinal detachment was found in 3 eyes and cataract in 4. Together, the 13 eyes needed 22 additional surgical procedures. Preoperative and postoperative angiographic examinations showed no significant changes.

CONCLUSION

Ischemic CRVO patients did not profit from retinal endovascular lysis in this pilot study. Visual results and the risk of developing iris neovascularization and neovascular glaucoma took the natural course. Although these results may be due to the overall bad prognosis of these particular ischemic eyes, the number of postoperative complications is unacceptably high.

High TNF-α and low IL-2 producing T cells characterize active disease in Takayasu's arteritis

We have investigated intracellular production by T cells and plasma levels of TNF-alpha, IL-2 and IFN-gamma in 12 active and 10 inactive Takayasu's arteritis (TA) patients and 12 healthy controls. The active TA compared to inactive TA and controls had higher TNF-alpha (52.7 +/- 22.3% vs. 32.9 +/- 14.2% and 35.2 +/- 14.5%, respectively; P = 0. 020), lower IL-2 (19.6 +/- 13.2% vs. 36.1 +/- 10.1% and 31.2 +/- 10.3%, respectively; P = 0.010) and comparable IFN-gamma (38.6 +/- 13.9% vs. 34.2 +/- 12.4% and 34.9 +/- 11.1%, respectively; P = 0.581) producing CD3+ T cells. There was no difference in the plasma levels of the cytokines between active TA, inactive TA and controls (TNF-alpha: 79.1 +/- 94.5 vs. 72.9 +/- 120.0 and 9.5 +/- 6.7 pg/ml, P = 0.110; IL-2: 4.3 +/- 4.8 vs. 6.6 +/- 4.7 and 8.6 +/- 4.5 pg/ml, P = 0.094 and IFN-gamma: 10.1 +/- 11.3 vs. 8.8 +/- 8.7 and 8.2 +/- 6.5 pg/ml, P = 0.871, respectively). The data show an important role of these high TNF-alpha and low IL-2 producing T cells in TA.

Cytokine mRNA repertoire of peripheral blood mononuclear cells in Takayasu's arteritis

We have investigated constitutive and phytohaemagglutinin (PHA) + phorbol 12-myristate 13-acetate (PMA)-induced gene expression of tumour necrosis factor (TNF)-alpha, interferon (IFN)-gamma, interleukin (IL)-2, IL-3, IL-4, IL-10, IL-12 and granulocyte macrophage colony-stimulating factor (GM-CSF) in peripheral blood mononuclear cells (PBMCs) of 10 patients with Takayasu's arteritis (TA) and 10 healthy controls by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). The constitutive mRNA expression of TNF-alpha (69.0 +/- 4.0%versus 27.5 +/- 18.0%; P = 0.001) and IL-4 (60.0 +/- 10.0%versus 0%; P = 0.001) was significantly higher in patients than controls; that of IL-3 was comparable in both groups (38.0 +/- 6.0%versus 32.0 +/- 5.0%; P = 0.651) while no constitutive mRNA expression was observed for the other cytokines studied. The stimulated PBMCs of patients, as compared with the controls, had higher mRNA gene expression of TNF-alpha (127.0 +/- 16.0%versus 54.0 +/- 6.0%; P = 0.001), IFN-gamma (93.0 +/- 13.0%versus 57.0 +/- 5.0%; P = 0.032), IL-2 (109.0 +/- 13.0%versus 68.0 +/- 6.0%; P = 0.015), IL-3 (60.0 +/- 8.0%versus 21.2 +/- 3.0%; P = 0.045) and IL-4 (68.0 +/- 7.0%versus 27.0 +/- 7.2%; P = 0.01) The mRNA expression of IL-10 was lower in patients than controls (35.0 +/- 8.0%versus 75.0 +/- 12.0%; P = 0.022). The GM-CSF mRNA was similar (102.0 +/- 6.0%versus 89.0 +/- 5.0%; P = 0.475) in both groups. Stimulation of cells with PHA + PMA showed no IL-12 expression but stimulation with lipopolysaccharide induced higher IL-12 mRNA in patients than controls (83.0 +/- 14.0%versus 33.0 +/- 4.0%; P = 0.005). Our data suggest that an inflammatory cytokine signature exists in TA with a key role for TNF-alpha, IL-4, IL-10 and IL-12 in different pathological processes of the disease.

Uraemic medium accelerates proliferation but does not induce apoptosis of endothelial cells in culture

BACKGROUND

Chronic renal failure patients exhibit accelerated atherosclerosis, which is associated with a high incidence of cardiovascular death. We investigated the potential effect of uraemic medium on cell proliferation and apoptosis of endothelial cells in culture (ECs), two key processes in the development of atherosclerosis. Phosphorylation kinetics of the mitogen-activated protein kinase (MAPK) p42/44 and p38 were also evaluated.

METHODS

ECs were cultured with growth media supplemented with pooled sera from healthy donors. Semiconfluent ECs were incubated for 24 h with media supplemented with pools of control or uraemic sera. Cell proliferation was assessed through morphometric analysis and by flow cytometry evaluation of cell cycle. To investigate if uraemic medium induces apoptosis in ECs, we used a combination of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) assay and activation of caspase-3 using flow cytometry. Changes in the phosphorylation levels of MAPK were evaluated in cell lysates by western blotting.

RESULTS

Exposure to uraemic media caused an alteration in the morphology of ECs, showing irregular shape and size. The number of ECs at S+G(2)M phase in the cell cycle was found to be increased when exposed to uraemic media for 24 h (28.4+/-2.9 vs 20.2+/-2.6% in control ECs). There was a transient increase in levels of phosphorylation of MAPK in both cells, although these levels were significantly higher in ECs exposed to uraemic media, especially after 5 min. In contrast, no signs of apoptosis were observed in ECs incubated with uraemic medium at the conditions applied.

CONCLUSIONS

Under our experimental conditions, uraemic medium accelerates proliferation of ECs, but it does not seem to induce apoptosis. The increased proliferation observed could be related to a higher MAPK activity in these cells. Although the enhanced atherosclerosis cannot be explained on the basis of an apoptotic process, the proliferative status could contribute to intimal proliferation, which is considered to be an earlier step in the development of atherosclerosis.

Unique sensitivities to cytokine regulated expression of adhesion molecules in human heart-derived endothelial cells

The expression of adhesion molecules by endothelial cells is crucial in many inflammatory processes and plays an active role in the development of reperfusion injury, acute and chronic rejection. The expression of adhesion molecules in different parts of the coronary tree to cytokine stimulation is not known. We describe here a detailed study of the effects of the inflammatory cytokines TNFalpha and IL-1beta on the expression of adhesion molecules vascular cell adhesion molecule-1 (VCAM-1), E-selectin and intracellular cell adhesion molecule-1 (ICAM-1) on human aortic root (HAEC), coronary artery (HCAEC) and heart microvascular (HHMEC)) endothelial cells in culture, using flow cytometry. We found constitutive levels of both VCAM-1 and E-Selectin on HCAEC and HHMEC (approximately 20%) which were significantly higher compared to HAEC (approximately 3%). There was an extreme sensitivity of HCAEC and HHMEC to 0.002 ng/ml TNFalpha: (VCAM-1 approximately 40%, E-Selectin approximately 25%) respectively, compared to HAEC (VCAM-1 approximately 5%, E-selectin approximately 5%). IL-1beta showed a similar pattern of expression at low doses (5 U/ml), but was less potent. We also observed prolonged expression of these adhesion molecules, especially on the HHMEC (>48 hours) compared to HAEC. There was also increased binding of peripheral blood mononuclear cells (PBMC) to both non-stimulated and TNFalpha stimulated HCAEC and HHMEC compared to HAEC. This data suggest that endothelial cells in different regions of the coronary tree express different patterns of basal and cytokine-stimulated adhesion molecule expression.

Circulating levels of plasminogen activator inhibitor type-1, tissue plasminogen activator, and thrombomodulin in hemodialysis patients: biochemical correlations and role as independent predictors of coronary artery stenosis

This study investigated the relationship between the circulating levels of the endothelial cell glycoproteins plasminogen activator inhibitor type 1 (PAI-1), tissue plasminogen activator (TPA), and thrombomodulin (TM) and the major vascular risk factors described in dialysis patients. In addition, the role of these endothelial cell products as independent predictors of coronary artery disease (CAD) was analyzed. Levels of TM, TPA antigen (Ag), TPA activity, PAI-1 Ag, PAI-1 activity, TPA/PAI complexes, thrombin-antithrombin complexes, fibrinopeptide A, C-reactive protein (CRP), interleukin-1beta and tumor necrosis factor-alpha, lipids, apoproteins A1 and B, and albumin were measured in a group of 200 nondiabetic dialysis patients and 100 healthy matched volunteers. When compared with healthy controls, dialysis patients showed increased levels of CRP, TM, TPA, and PAI-1 and evidence of increased thrombin-dependent fibrin formation. Increased levels of active PAI-1 were associated to a great extent with major classic vascular risk factors and to a lesser extent with CRP and serum triglycerides. Forty-six patients (23%) had evidence of CAD. Variables associated with CAD in the univariate analysis included age, time on dialysis, male gender, number of packs of cigarettes per year, high BP, fibrinogen, apolipoprotein B, albumin, PAI-1 activity, CRP, thrombin-antithrombin complexes, and fibrinopeptide A. Logistic regression analysis found age, high-density lipoprotein cholesterol, gender, high BP, CRP, time on dialysis, and PAI-1 activity to be independent predictors of CAD. This model classified correctly 85% of patients as having CAD and showed adequate goodness of fit for all risk categories. Our data support a pathogenic link among activated inflammatory response, endothelial injury, and CAD in hemodialysis patients and suggest that assessment of circulating PAI-1 levels could be an additional tool to identify dialysis patients who are at risk for developing atheromatous cardiovascular disease.

Rejection of peritubular capillaries in renal allo- and xeno-graft

The microvasculature plays an important role in the pathogenesis of humoral- and cell-mediated renal allo- and xeno-graft rejection. Peritubular capillary (PTC) endothelium expresses the major histocompatibility complex (MHC) class I and II antigens in the resting phase, as does the glomerular capillary endothelium, suggesting that these cells may be major immune targets. However, the role of PTCs in renal allo- and xeno-graft rejection is unclear. In this review, we discuss injury and subsequent remodeling of PTCs in both humoral- and cell-mediated rejection in allo- and xeno-grafts. Recent evidence suggests that PTC injury and endothelial cell death occur during both cell- and humoral-mediated rejection. Severe PTC rejection contributes to deterioration of graft function and acute graft loss. The mild but recurrent form of PTC rejection is associated with progressive interstitial fibrosis and chronic rejection. Following endothelial injury, the remaining PTC endothelium activates with up-regulation of allo-antigens and adhesion molecules, and down-regulation of anti-coagulant proteins. Subsequent to this, more severe rejection and graft dysfunction occur. Therefore, a careful analysis of cellular- and antibody-mediated rejection in PTCs is important in the diagnosis of rejection, prediction of graft prognosis, and in further development of new anti-rejection therapies.

Genetically modified bone marrow-derived vehicle cells site specifically deliver an anti-inflammatory cytokine to inflamed interstitium of obstructive nephropathy

In this study, we used genetically modified bone marrow-derived CD11b(+)CD18(+) vehicle cells to deliver IL-1 receptor antagonist (IL-1ra) for treatment of inflamed renal interstitium in an animal model of unilateral ureteral obstruction (UUO). Vehicle cells that expressed the ICAM-1 ligands, CD11b and CD18, were obtained from bone marrow cells of DBA/2j mice and adenovirally transduced with the IL-1ra gene or glucocerebrosidase (GC) gene ex vivo. In kidneys treated to develop UUO, levels of ICAM-1, IL-1 beta, and IL-1R expression increased within 3 days compared with contralateral untreated kidneys in the same mice. Similarly, the macrophage infiltration in the cortical interstitium increased after 3 days in UUO kidneys, but not untreated kidneys. After UUO developed, DBA/2j mice were injected i.v. with either IL-1ra(+) vehicle cells (IL-1ra-treated mice) or GC(+) vehicle cells (GC-treated mice) at 24 h after UUO. Six days after the injection of these vehicle cells, marked increase of CD11b(+) IL-1ra(+) vehicle cells was observed in the ICAM-1-positive interstitium of UUO kidneys from IL-1ra-treated mice. In contrast, no CD11b(+) IL-1ra(+) cells appeared in ICAM-1-negative contralateral kidneys from these mice. Furthermore, the infiltration of macrophages (p < 0.001), expression of ICAM-1 (p < 0.005), and presence of alpha-smooth muscle actin (p = 0.005) in the interstitium of UUO kidneys were significantly decreased in IL-1ra-treated mice compared with GC-treated mice. These findings suggest that IL-1 may contribute to the development of renal interstitial injury and that our method can deliver a functioning gene encoding an antiinflammatory cytokine gene specifically at that site by interacting with local adhesion molecules.

Peritoneal dialysis in diabetic patients

Diabetes mellitus is the fastest growing cause of end-stage renal disease (ESRD) and has become the leading cause of such ESRD worldwide. In the United States, between 1984 and 1997, the proportion of new patients starting renal replacement therapies whose ESRD was caused by diabetes increased from 27% to 44.4%. Canada saw an increase from 16.5% in 1984 to 28.9% in 1997, and many European countries had similar increases. Among the modes of renal replacement, many clinicians have favored continuous ambulatory peritoneal dialysis (CAPD) for the treatment of diabetic ESRD for several reasons. Many studies have compared clinical outcomes in diabetic patients undergoing CAPD, and nondiabetic patients undergoing CAPD, or diabetic patients undergoing peritoneal dialysis (PD) and those undergoing hemodialysis (HD). However, only a small number of diabetic dialysis patients have been followed up for more than 5 years, largely because of the presence of several comorbid conditions at the start of dialysis and the coexistence of far-advanced target-organ damage at dialysis initiation and its progression during the course of dialysis. Diabetic patients undergoing PD and HD probably have similar survival, and those undergoing CAPD have lower survival and technique success rates than nondiabetic patients of comparable age. This article reviews the literature and our experience with diabetic patients undergoing PD and compares clinical outcomes in diabetic patients undergoing PD and HD.

Facioscapulohumeral muscular dystrophy

A decade's progress in facioscapulohumeral muscular dystrophy genetics has been marked by the discovery of novel genetic phenomena such as crossover of subtelomeric DNA between chromosomes 4 and 10 in normal individuals and by the recognition that the facioscapulohumeral muscular dystrophy deletion-mutation may cause a position variegation effect on more proximal DNA. The mutated DNA itself is probably not transcribed. Larger deletions tend to cause more severe disease. Antenatal diagnosis, based on detection of the short fragment of mutated DNA, is possible in between 95 and 100% of cases, depending on the precise nature of the parental facioscapulohumeral muscular dystrophy mutation. Yet remarkably, the nature of the gene product(s) of the affected proximal gene(s), as well as of the molecular pathogenesis of facioscapulohumeral muscular dystrophy muscle, retinal and cochlear disease, is completely unknown. Marked perivascular inflammation is often present in facioscapulohumeral muscular dystrophy muscle biopsies. The expression of facioscapulohumeral muscular dystrophy within reported monozygotic twinships differs greatly. This raises the question of whether variations in expression of the T-cell receptor gene repertoire or of other immune genes play an important modifying role in determining the severity of facioscapulohumeral muscular dystrophy. A focus on traditional scientific disciplines may now be appropriate. Symptomatic treatments, for instance of scapular winging and of lagophthalmos, are important, and timely photocoagulation of the retinal exudates which are a very rare, but real, complication of retinal telangiectasis can curtail visual loss. The results of collobarative trials of pharmacological agents such as albuterol which affect muscle mass and development are awaited.

TNF-alpha, not CD154 (CD40L), plays a major role in SEB-dependent, CD4(+) T cell-induced endothelial cell activation in vitro

CD4(+) T cell effector molecules, in particular TNF-alpha and CD154, activate endothelial cells. However, the relative contributions of TNF-alpha and CD154 in mediating endothelial cell activation during complex Ag-driven CD4(+) T cell-endothelial cell interactions are not known. We utilized an in vitro model of CD4(+) T cell-endothelial cell interactions to characterize the contributions of TNF-alpha and CD154 in mediating upregulation of adhesion molecules CD54, CD62E, and CD106 on human umbilical vein endothelial cells (HUVEC). HUVEC were first treated with IFN-gamma to upregulate MHC Class II expression. IFN-gamma minimally effects HUVEC adhesion molecule expression but renders them capable of MHC class II restricted interactions with CD4(+) T cells. Coculturing MHC class II+ HUVEC and CD4(+) T cells with the superantigen SEB induces a rapid and marked upregulation of CD54, CD62E, and CD106 expression on HUVEC, as shown by FACS analysis. To study the effector molecules mediating SEB-driven, CD4(+) T cell-dependent endothelial cell activation, similar experiments were performed in the presence of neutralizing anti-CD154, anti-TNF-alpha, or anti-IL1 antibodies, as well as combinations of these antibodies. In contrast to the anti-CD154 or anti-IL-1 antibodies, the anti-TNF-alpha mAb markedly inhibited SEB-dependent, CD4(+) T cell-induced HUVEC activation. We conclude that TNF-alpha, not CD154, plays the major role in SEB-driven, CD4(+) T cell-induced endothelial cell activation in vitro.

Potential role of hepatocyte growth factor in the maintenance of renal structure: anti-apoptotic action of HGF on epithelial cells

BACKGROUND

Mesangial cells (MC) are known to secrete various vasoactive substances that may control endothelial and epithelial cell growth. Therefore, the cell-cell interactions among these cells may be important in the control of renal function. However, the exact mechanisms of maintaining the cell-cell interactions are not yet understood. We have focused on the role of hepatocyte growth factor (HGF) in the regulation of cell-cell interactions, since HGF has many protective functions in the kidney. To investigate the role of HGF in renal injury, we examined (1) the effects of HGF on epithelial injury induced by serum deprivation, and (2) the role of local HGF production in the maintenance of renal structure.

METHODS

Apoptotic changes in epithelial cells were assessed by nuclear morphology and DNA fragmentation assay. Transfection of human HGF vector into epithelial cells was performed by a highly efficient viral-liposome method. The effects of secreted HGF on the growth of renal cells were examined using a co-culture system.

RESULTS

The addition of recombinant HGF (rHGF) stimulated the growth of rat and porcine epithelial cells. Moreover, the decrease in number of epithelial cells by serum deprivation was significantly attenuated by rHGF. Interestingly, apoptotic changes in epithelial cells induced by serum deprivation were also significantly attenuated by rHGF (P < 0.01). As a model of gene therapy, the effects of overexpression of human HGF gene in epithelial cells on apoptosis induced by serum deprivation were examined. Transfection of human HGF vector into epithelial cells also attenuated epithelial cell death induced by serum deprivation through the inhibition of apoptosis, accompanied by increased HGF production (P < 0.01). In addition, HGF also prevented endothelial injury induced by tumor necrosis factor-alpha and dexamethasone. Given the presence of a local HGF system, we measured local HGF secreted from renal cells. Immunoreactive HGF was observed in the conditioned medium of MC, but not epithelial cells, while the specific receptor of HGF, c-met, was expressed in epithelial cells. Of importance, co-culture of MC with epithelial cells resulted in a significant increase in number of epithelial cells, which was significantly abolished by neutralizing anti-HGF antibody.

CONCLUSIONS

Overall, these results demonstrate that local production of HGF in MC may maintain the growth of epithelial and endothelial cells through its anti-apoptotic action.

A new model of renal microvascular injury

The vascular endothelial injury with its consequent activation is actively involved in inflammation and promotion of a procoagulant state, which are likely to be of major importance in the pathogenesis of various disorders, including renal thrombotic microangiopathy. This study briefly reviews the consequences of glomerular endothelial cell injury or activation, as shown by recent experimental data.

Potential role of a novel vascular modulator, hepatocyte growth factor (HGF), in cardiovascular disease: characterization and regulation of local HGF system

Since endothelial cells (EC) are known to secrete various anti-proliferative and vasodilating factors, an agent that promotes seeding or regeneration of EC may have potential therapeutic value against vascular smooth muscle cell (VSMC) proliferation. To seek an endothelium specific growth factor, we have focused on hepatocyte growth factor (HGF). HGF is belonged to a member of endothelium specific growth factors, whose mitogenic action on EC was most potent among growth factors. Moreover, the presence of local HGF system (HGF and its specific receptor, c-met) was observed in EC and VSMC of rat and human in vitro as well as in vivo. Production of local HGF production in vascular cells was regulated by various cytokines including transforming growth factor (TGF)-beta and angiotensin II (Ang II). Furthermore, HGF may be a therapeutic growth factor for the treatment of restenosis after angioplasty and arteriosclerosis obliterance, etc., as gene therapy. From these characteristics of HGF, we hypothesized that HGF might contribute to the protection or repair of vascular endothelial cells. Indeed, serum HGF concentration was significantly correlated with blood pressure, suggesting that HGF secretion might be elevated in response to high blood pressure as a counter-system against endothelial dysfunction. In this review, we discussed that HGF is a member of the endothelium specific growth factors whose serum concentration is significantly associated with blood pressure.

Dysregulation of cytokine expression in tubulointerstitial nephritis associated with murine malaria

We examined the circulating levels of the proinflammatory cytokines tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1 alpha, IL-6, granulocyte macrophage-colony stimulating factor (GM-CSF), and the anti-inflammatory cytokine IL-10, and their expression in kidneys acutely infected with murine malaria parasite P. berghei ANKA in C57BL/6J mice. Groups of six mice sacrificed on days 5, 10, 15, and 20, and normal controls were used for cytokine analysis. High concentrations of TNF-alpha and IL-10 were detected in plasma as shown by ELISA, and elevated levels of mRNA specific for TNF-alpha and IL-10 in infected kidneys were demonstrated by reverse transcription-polymerase chain reaction (RT-PCR) analysis. Kidney sections stained with antibodies against TNF-alpha, IL-1 alpha, IL-6, GM-CSF and IL-10 for immunohistochemistry showed markedly enhanced staining for TNF-alpha, and progressively increased staining for IL-1 alpha and IL-6 both in the tubules and the walls of arteries during the course of infection. The endothelia of blood vessels and inflammatory cells located around small arteries showed positive staining for GM-CSF from day 10 onwards. Unlike the staining for proinflammatory cytokines, the anti-inflammatory cytokine IL-10 showed strongly positive staining in normal tubules and walls of arteries, especially in the brush border of proximal tubules, but the staining intensity decreased dramatically after day 15 post-infection. A strongly positive correlation was found between the antibody staining for TNF-alpha/IL-1 alpha in tubules, and the severity of proteinuria. In contrast, there was an inverse correlation between the staining for IL-10 with TNF-alpha/IL-1 alpha, and the degree of proteinuria. Plenty of pigmented macrophages showed positive staining both for proinflammatory and anti-inflammatory cytokines in the tubulointerstitium. Our findings imply that the up-regulation of proinflammatory cytokines and the dysregulation of anti-inflammatory cytokines are involved in the pathogenesis of tubulointerstitial nephritis associated with malaria.

A new model of renal microvascular endothelial injury

Although the importance of injury with consequent activation of endothelium is well-recognized in diseases affecting the glomerular endothelial cell (GEN), research on GEN injury in vivo has been hampered by the lack of adequate animal models. Here we report the establishment and characterization of a new GEN injury model in rats. This model was induced by selective renal artery perfusion with anti-GEN IgG and resulted in the severe acute renal failure with marked platelet deposition and development of a thrombotic microangiopathy involving glomeruli. Peritubular capillary endothelial cells were also damaged that was associated with severe tubular necrosis. Although the glomerular changes were severe, half of the glomeruli recovered by day 10, while interstitial changes remained throughout our observation time course. Proliferation of GEN was observed during the recovery phase. An increased expression of endothelial nitric oxide synthase in GEN was also observed, and may be an adaptive mechanism to counteract the thrombosis and ischemia. This model should be useful to investigate the pathophysiology of renal microvascular diseases and the mechanisms of GEN injury, activation and recovery in vivo.

Glomerular sequence of events concerning monocyte/macrophage accumulation and ICAM-1 expression during experimental serum sickness nephritis in the rat

Serum sickness nephritis was induced in Fischer rats by preimmunization and repeated immunization with chicken egg albumin. This experimental model is characterized by marked accumulation of monocytes/macrophages (MO) and deposition of immune complexes (IC) in glomeruli during the inflammatory stage and, thereafter, the advancement to glomerulosclerosis. The correlations between glomerular tissue damage, MO participation, intercellular adhesion molecule-1 (ICAM-1) expression and IC deposition were analyzed during the long-term disease process. The grade of ICAM-1 expression was well correlated with MO accumulation and IC deposition, and its distribution was observed on the glomerular endothelial layer, mesangium, and along the parietal epithelial layer of the Bowman's capsule. It is suggested that glomerular MO accumulation is largely affected by the ICAM-1 expression on glomeruli and, underneath such adhesion molecules, MO may play a role in subendothelial or mesangial migration, mesangial cell activation, inducing sclerosis and monocytic-epithelial crescent formation.

Effects of TNF alpha on verocytotoxin cytotoxicity in purified human glomerular microvascular endothelial cells

In the pathogenesis of the hemolytic uremic syndrome (HUS), endothelial damage of glomeruli and arterioles of the kidney appears to play a central role. Previous studies have shown that verocytotoxin-1 (VT-1) cytotoxicity on human vein endothelial cells require additional stimuli, in particular the inflammatory mediator tumor necrosis factor alpha (TNF alpha). In this study the effects of VT on human glomerular microvascular endothelial cells (GMVEC) were examined. A reproducible method was developed for the isolation and purification of large numbers of highly purified GMVEC. The obtained GMVEC were over 99% pure; their endothelial origin was demonstrated by the expression of the endothelial antigens von Willebrand factor, EN-4, PECAM-1 and V,E-cadherin. Upon stimulation with TNF alpha the cells expressed the endothelial-specific adhesion molecule E-selectin. A limited number of fenestral structures was observed by scanning electron microscopy (SEM), suggesting glomerular origin of the endothelial cells. Cytotoxicity of VT-1 to GMVEC was evaluated by determination of the number of viable adherent cells and by assay of overall protein synthesis after exposure to varying concentrations of VT-1. In non-stimulated GMVEC, cytotoxicity of VT-1 was inversely related to the degree and duration of confluence, subconfluent cells being the most sensitive. In highly confluent GMVEC, VT cytotoxicity required pre-exposure of the cells to the inflammatory mediator TNF alpha, which induced an increase in the number of VT receptors on GMVEC. Thin layer chromatography of extracted glycolipids from the GMVEC showed binding of VT-1 to globotriaosylceramide (Gb3), known to be the functional receptor for VT. There were no major differences in protein synthesis inhibition with equal concentrations VT-1 and VT-2. In conclusion, in this study we provide a reproducible method to isolate, purify and culture well characterized human GMVEC on a routine basis. In vitro studies with these GMVEC demonstrate that VT cytotoxicity depends on the degree of confluence and the additional preexposure to the inflammatory mediator TNF alpha. These observations provide further insight into the complex events that may occur in glomeruli in the pathogenesis of HUS.

Loss of ATP diphosphohydrolase activity with endothelial cell activation

Quiescent endothelial cells (EC) regulate blood flow and prevent intravascular thrombosis. This latter effect is mediated in a number of ways, including expression by EC of thrombomodulin and heparan sulfate, both of which are lost from the EC surface as part of the activation response to proinflammatory cytokines. Loss of these anticoagulant molecules potentiates the procoagulant properties of the injured vasculature. An additional thromboregulatory factor, ATP diphosphohydrolase (ATPDase; designated as EC 3.6.1.5) is also expressed by quiescent EC, and has the capacity to degrade the extracellular inflammatory mediators ATP and ADP to AMP, thereby inhibiting platelet activation and modulating vascular thrombosis. We describe here that the antithrombotic effects of the ATPDase, like heparan sulfate and thrombomodulin, are lost after EC activation, both in vitro and in vivo. Because platelet activation and aggregation are important components of the hemostatic changes that accompany inflammatory diseases, we suggest that the loss of vascular ATPDase may be crucial for the progression of vascular injury.

Expression of adhesion molecules in rat renal cortex during experimental hydronephrosis

Unilateral ureteral obstruction (UUO) is associated with an early and steadily increasing infiltration of macrophages into the renal cortical interstitium. As adhesion molecules may play an important role in macrophage recruitment following the mechanical disturbance after UUO, we delineated the time course of intercellular adhesion molecule (ICAM)-1 and vascular adhesion molecule (VCAM)-1 mRNA and protein expression. A significant 6.6- (P < 0.001), 2.6- (P < 0.025), 2.6- (P < 0.01), and 2.0-fold (P < 0.005) increase in ICAM-1 mRNA expression was observed at 12, 24, 48, and 96 hours after obstruction, respectively, in comparison to the contralateral unobstructed kidney (CUK). Despite an apparent relief of obstruction, four weeks following reversal of obstruction mRNA levels of ICAM-1 remained equivalent to the 96-hour obstructed kidney group. No significant difference in VCAM-1 mRNA expression was observed between the obstructed kidneys and CUK specimens. Immunohistochemistry revealed focal labeling of ICAM-1 on the apical and basolateral surface of the renal tubules, peritubular interstitium, and vessels of the renal cortex by 12 hours after UUO. In contrast, only faint staining for ICAM-1 protein was observed in the cortex from CUK specimens. The obstructed and CUK specimens exhibited diffuse immunolocalization of VCAM-1 in the cortical tubules and Bowman's capsular epithelium. In situ hybridization showed mRNA transcription for ICAM-1 localized in the peritubular interstitium and cortical tubules from obstructed kidneys. To lend mechanistic insight into the response of ICAM-1 to the mechanical disturbance after UUO, the expression of ICAM-1 mRNA was examined when freshly isolated proximal tubules were exposed to angiotensin II (1 to 100 microM) immediately after preparation. Levels of ICAM-1 mRNA were elevated 1.4-, 7.1-, and 3.7-fold when exposed to 10 microM, 100 microM, and 1000 microM of angiotensin II for one hour, respectively, when compared to control cultures. The addition of losartan to proximal tubules for one hour prior to angiotensin II stimulation decreased ICAM-1 levels to control values. In summary, this investigation demonstrates that ICAM-1 is important in the initiation of macrophage recruitment into the renal cortex of the obstructed kidney. These findings provide evidence that angiotensin II, produced after ureteral ligation as a result of tubular injury and dysfunction, may play a central role in the release of ICAM-1 from the proximal tubule epithelial cells.

Effective treatment of painful bone crises in type I gaucher's disease with high dose prednisolone

In type I Gaucher's disease, episodes of severe disabling bone pain, the so called bone crises, may be resistant to all analgesics, including narcotics. The demonstration of subperiosteal oedema on magnetic resonance imaging (MRI) led to an attempt to use steroids to relieve the oedema and thereby the pain. On eight occasions, five patients with documented bone crises received conventional dose steroids (20 mg/m2/day) with considerable shortening of the attacks. On six occasions five further patients received high dose methylprednisolone (30 mg/kg intravenously or 1 g/m2 orally daily for two days), which was followed by oral prednisone for three to five days on the last four occasions. In this later group, pain relief was evident within several hours. Three treatments were given on an ambulatory basis. The MRI scan of one of these patients showed no subperiosteal fluid collection five days after high dose steroids had been started, and on subsequent x ray examination, there was no periosteal elevation. This treatment should be considered in cases of Gaucher's disease with bone crises.

Delayed xenograft rejection

Despite considerable progress in understanding the mechanisms of discordant xenograft rejection, and overcoming hyperacute rejection through targeting of complement or antibody, vascularized xenografts are typically rejected within days. Here, Fritz Bach and colleagues discuss the importance of endothelial cell activation, platelet aggregation and other aspects of thrombosis, as well as the contribution of host natural killer cell and monocyte activation in overcoming this next barrier to prolonged xenograft survival.

Angiotensin II is mitogenic for cultured rat glomerular endothelial cells

Angiotensin II (Ang II) has growth-stimulatory properties on different renal cell types. However, possible growth effects of this vasoactive peptide on endothelial cells isolated from the glomerular microvasculature have not been formally investigated. Therefore, we isolated and characterized primary cultures of rat glomerular endothelial cells. We used a simple technique in which collagenase-treated glomeruli were sparsely plated in several 96-well culture plates and microscopically screened for cobblestone-like outgrowth. After two limiting dilutions, homogeneous cultures were obtained. Cells were characterized by positive staining for the endothelial markers factor VIII, CD 31, endothelial leukocyte adhesion molecule-1, and the lectin Bandeiraea simplificifolia. Ang II stimulated the synthesis and release of endothelin-1 in culture supernatants. Moreover, in contrast to syngeneic mesangial cells, glomerular endothelial cells expressed angiotensin-converting enzyme. Ang II stimulated a mild but significant proliferation of quiescent cells, as measured by [3H]thymidine incorporation and direct cell counting. This mitogenesis was transduced by losartan-blockade angiotensin type 1 receptors. Moreover, Ang II mediated phosphorylation of mitogen-activated protein kinase 2 and induction of transcripts for the immediate early gene Egr-1. Our results indicate that Ang II is a moderate mitogen for primary cultures of rat glomerular endothelial cells and activation of these metabolically active cells may play a role in the pathophysiology of several types of glomerulonephritis. Moreover, remodeling of glomerular endothelial cells by Ang II may be important in the progression of structural renal damage during the course of hypertensive injury.

Intracerebral vascular occlusion in familial erythrophagocytic lymphohistiocytosis: a case report of two siblings

Neuropathological findings in two siblings with familial erythrophagocytic lymphohistiocytosis (FEL) are reported. Case 1 showed the typical neuropathological findings of FEL with lymphohistiocytic infiltration of the leptomeninges and perivascular spaces. A characteristic erythrophagocytosis was detected in inguinal lymph nodes, lung and bone marrow. Case 2 revealed calcification and necrotic lesions in the brain. In the necrotic areas, parenchymal calcification, vascular medial calcification, and occlusion of many vessels due to subendothelial fibrosis were detected. The areas of necrosis correlated with the distribution of occluded vessels. These changes were most prominent in putamen, internal capsule, thalamus and dentate nucleus. Hypercytokinemia is suspected to be the underlying mechanism for the clinical and laboratory findings in patients with FEL, although the relationship to the vascular pathology is unclear.

Low-density lipoprotein stimulates the expression of macrophage colony-stimulating factor in glomerular mesangial cells

Disordered lipoprotein metabolism and the enhanced influx and accumulation of circulating mononuclear leukocytes into vascular tissue are common pathobiological phenomena associated with both atherosclerosis and glomerulosclerosis. Since atherogenic lipoproteins (such as low density lipoprotein, LDL) have been implicated in monocyte migration and proliferation into the glomerular mesangium, we examined the effect of LDL on mesangial cell expression of macrophage colony-stimulating factor (M-CSF), a cytoregulatory peptide associated with monocyte chemoattraction, differentiation and proliferation. Mesangial cell M-CSF gene expression, protein synthesis and secretion, and its biological activity to induce progenitor colony formation and monocyte proliferation were studied in murine mesangial cells. Incubation of either primary cultures or SV-40 transformed murine mesangial cells with LDL (0 to 200 micrograms/ml) induced M-CSF steady-state mRNA expression, in a dose-dependent manner (52 to 183% of control) when Northern blots were analyzed quantitatively by densitometric scanning. Similarly, Western blot analysis showed that LDL-activated SV-40 transformed mesangial cells increased M-CSF protein synthesis and secretion in a dose-dependent manner. The conditioned media obtained by incubating mesangial cells with LDL induced bone marrow progenitor colony formation that could be inhibited by specific neutralizing antibodies against murine M-CSF. Finally, the biological activity of M-CSF secreted by LDL-activated mesangial cells was further confirmed by its enhanced ability to induce monocyte proliferation. These data indicate that LDL, by activating mesangial cells to induce M-CSF and possibly other monocyte chemoattractants, may regulate the migration and proliferation of cells of mononuclear leukocytic origin into the mesangium supporting a pathobiological role for LDL in glomerular injury.

Renal dysfunction in obstructive jaundice

The association between renal dysfunction and obstructive jaundice is well established. Despite a substantial number of clinical reviews and prospective studies, the exact incidence and extent of the problem has not been determined accurately. Various pathogenic mechanisms and therapeutic strategies have been proposed but renal dysfunction remains a persistent problem in hepatobiliary practice. The intention of this review is to determine the current extent of the problem, outline the proposed pathophysiological mechanisms and assess the current therapeutic options.

Biologic control of the tumor necrosis factor and interleukin-1 signaling cascade

It is clear that activation of the proinflammatory cytokine cascade is both the cause and the consequence of renal injury. Recently, it has been appreciated that a rich network of signaling pathways contributes to modulation of tumor necrosis factor-alpha (TNF) and interleukin-1 (IL-1) bioactivity, both in vitro and in vivo. Insight into the checks and balances that intervene or temper endogenous cytokine effector mechanisms has arisen from an explosion of new information on the cell biology of proinflammatory cytokines. Novel mechanisms of cytokine regulation are currently being described and hold promise for therapeutic potential: soluble cytokine receptors, endogenous receptor antagonists, and anti-inflammatory cytokines such as IL-4, IL-10, and IL-13.

Nitric oxide and endothelin in pathophysiological settings

The role of the endothelium is now known to encompass the generation of many potent cytokines which impact endothelial cells, adjacent tissue such as smooth muscle cells, and distant sites in an autocrine, paracrine, and endocrine manner, respectively. This review addresses two of these cytokines, nitric oxide and endothelin, and describes how each effects the functions of endothelial cells, including regulation of platelet aggregation and coagulation, regulation of vasomotor tone, modulation of inflammation, and the regulation of cellular proliferation. The emphasis is on the increasingly recognized importance of the autocrine and paracrine mechanisms by which nitric oxide and endothelin act. In particular, autoinduction of endothelin is proposed as a central mechanism underlying endothelin's renowned effects. Additionally, specific nitric oxide/endothelin interactions are discussed by which each cytokine modulates the production and actions of the other. The net effect observed in a variety of physiological and pathophysiological settings, therefore, reflects a balance of these opposing functions.

Passive dual immunization against tumour necrosis factor-alpha (TNF-alpha) and IL-1 beta maximally ameliorates acute aminonucleoside nephrosis

Rats receiving a single dose (10 mg/100 g) of aminonucleoside of puromycin (PAN) develop heavy proteinuria and acute interstitial nephritis (AIN). Whole isolated glomeruli from rats injected with PAN secreted both TNF-alpha and IL-1 beta cytokines. TNF-alpha secretion was first and maximally detected on day 3, whereas IL-beta activity was found on day 7, when rats were heavily proteinuric and AIN developed. In vivo treatment with either anti-TNF-alpha or anti-IL-1 beta antibodies produced a drastic and simultaneous reduction in both levels of proteinuria and intensity of interstitial cell infiltrate. These effects improved when both antibodies were administered together. Our studies demonstrate the effectiveness of immunosuppressive therapy against these two cytokines in rats with PAN-induced nephrosis.

A distinct coagulopathy associated with interleukin-2 therapy

We studied the coagulation profiles of 14 patients with advanced malignancies treated with Interleukin-2 (IL-2). A 43% prolongation of the PTT (P < 0.001) and a significant decrease in functional levels of factors II, IX, X, XI, and XII were observed 6 h post IL-2 treatment in comparison to pretreatment values. These parameters normalized within 2-3 d following IL-2 administration. The PT, factors V, VII, VIII, fibrinogen and D-dimer levels were unchanged with IL-2 treatment. This pattern of coagulopathy has not previously been reported.

The importance of E-selectin as a marker for renal transplant rejection

Vascular endothelial cells express membrane bound adhesion molecules which play a direct role in the localization and subsequent movement of leucocytes from the blood into sites of inflammation. E-Selectin is a cytokine induced adhesion molecule, known to be expressed by endothelial cells in inflammatory conditions, which binds to various leucocyte subpopulations. In a prospective study we have investigated the expression and distribution of E-selectin on renal allograft needle biopsies taken from 16 pretransplant kidneys and 119 post-transplant kidneys. Post-transplant biopsies were taken at times of graft dysfunction and at times of normal graft function. Formal histology was also performed and assessed independently. E-Selectin was found predominantly on the intertubular endothelium and on the endothelium of larger vessels. E-Selectin was present, at low intensity, in some pretransplant biopsies and also some post-transplant biopsies which were reported histologically as normal. In post-transplant biopsies taken for dysfunction E-selectin was present in the majority of cases. Expression was strong in biopsies showing acute cellular rejection and this was associated with a CD4 positive cellular infiltrate. Biopsies showing other causes of dysfunction, in particular acute tubular necrosis, also were E-selectin and CD4 positive with lower intensity than those with acute cellular rejection. These results suggest that E-selectin is a good marker for endothelial activation in renal transplant biopsies. Its presence in histologically apparently normal biopsies suggests that its in vivo kinetics may differ from previously reported in vitro kinetics. E-Selectin may be a potential target for therapeutic intervention.