ED1-positive Cells Research Articles

INOS expression in vascular resident macrophages contributes to circulatory dysfunction of splanchnic vascular smooth muscle contractions in portal hypertensive rats

Portal hypertension, a major complication of cirrhosis, is caused by both increased portal blood flow due to arterial vasodilation and augmented intrahepatic vascular resistance due to sinusoidal constriction. In this study, we examined the possible involvement of resident macrophages in the tone regulation of splanchnic blood vessels using bile duct ligated (BDL) portal hypertensive rats and an in vitro organ culture method. In BDL cirrhosis, the number of ED2-positive resident macrophages increased by two- to fourfold in the vascular walls of the mesenteric artery and extrahepatic portal vein compared with those in sham-operated rats. Many ED1-positive monocytes were also recruited into this area. The expression of inducible nitric oxide (NO) synthase (iNOS) mRNA was increased in the vascular tissues isolated from BDL rats, and accordingly, nitrate/nitrite production was increased. Immunohistochemistry revealed that iNOS was largely expressed in ED1-positive and ED2-positive cells. We further analyzed the effect of iNOS expression on vascular smooth muscle contraction using an in vitro organ culture system. iNOS mRNA expression and nitrate production significantly increased in vascular tissues (without endothelium) incubated with 1 μg/ml lipopolysaccharide (LPS) for 6 h. Immunohistochemistry indicated that iNOS was largely expressed in ED2-positive resident macrophages. α-Adrenergic-stimulated contractility of the mesenteric artery was greatly suppressed by LPS treatment and was restored by N(G)-nitro-L-arginine methyl ester (NO synthase inhibitor); in contrast, portal vein contractility was largely unaffected by LPS. Sodium nitroprusside (NO donor) and 8-bromo-cGMP showed greater contractile inhibition in the mesenteric artery than in the portal vein with decreasing myosin light chain phosphorylation. In the presence of an α-adrenergic agonist, the mesenteric artery cytosolic Ca(2+) level was greatly reduced by sodium nitroprusside; however, the portal vein Ca(2+) level was largely unaffected. These results suggest that the induction of iNOS in monocytes/macrophages contributes to a hypercirculatory state in the cirrhosis model rat in which the imbalance of the responsiveness of visceral vascular walls to NO (mesenteric artery >> portal vein) may account for the increased portal venous flow in portal hypertension.

Lack of protective effect of local administration of triamcinolone or systemic treatment with methylprednisolone against damages caused by optic nerve crush in rats

The purpose of the present study was to investigate the effects of administrations of triamcinolone acetonide and systemic methylprednisolone sodium succinate on optic nerves (ON) and retinal ganglion cells (RGC) in a rat model of optic nerve crush. The treated groups either received triamcinolone immediately in the form of two pieces of soaked-gelform surrounding retrobulbar optic nerves (0.5 mg/per gelform) or methylprednisolone via peritoneal injection, and control group received intra-peritoneal injection with phosphate-buffered saline (PBS) after crush experiments. RGC density was counted by retrograde labeling with Fluorogold, and visual function was assessed by flash visual-evoked potentials. Terminal transferase dUTP nick end-labeling (TUNEL) assays, Western blot analysis of serine/threonine kinase (p-Akt), extracellular signal-regulated kinases (p-ERK) and signal transducer and activator of transcription 3 (p-STAT3) and immunohistochemistry of ED1, marker of macrophage/microglia in the optic nerve were conducted. Two and four weeks after optic nerve crush experiments, neither triamcinolone nor methylprednisolone treatment rescued the RGC from death in the central and mid-peripheral retinas compared with those of the corresponding optic nerve-crushed and PBS-treated rats. Visual-evoked potentials measurements showed a prolonged latency of the P 1 wave in all treated groups (triamcinolone-treated: 123 ± 23 ms, methylprednisolone-treated: 133 ± 25 ms and PBS-treated: 151 ± 55 ms) after two weeks. TUNEL assays showed that there was no decrease in apoptotic cells in the RGC layers of both triamcinolone treated and methylprednisolone-treated retinas. Western blot analysis showed that p-AKT, p-ERK and p-Stat3 were not up-regulated in either retina of the triamcinolone or methylprednisolone treated rats. In addition, the number of ED1-positive cells was not attenuated at the lesion sites of the ON in either treatment group. Based upon these results, we conclude that neither retrobulbar administration of triamcinolone nor systemic administration of methylprednisolone has any neuroprotective effects in a rat model of optic nerve crush.

Stromal Cell-Derived Factor-1 Is Essential for Photoreceptor Cell Protection in Retinal Detachment

Stromal cell-derived factor-1 (SDF-1) causes chemotaxis of CXCR4-expressing bone marrow-derived cells. SDF-1 is involved in the pathogenesis of various vascular diseases, including those of the eye. However, the role of SDF-1 in neuronal diseases is not completely understood. Here, we show higher SDF-1 levels in the vitreous humor of patients with retinal detachment (RD) compared with normal patients. SDF-1 correlated positively with the duration as well as the extent of RD. Furthermore, SDF-1 correlated significantly with levels of interleukin-6 and interleukin-8, but not with vascular endothelial growth factor. Western blot analysis results showed significant SDF-1 up-regulation in detached rat retinas compared with normal animals. Immunohistochemistry data showed that SDF-1 was co-localized with the glial cells of the detached retina. SDF-1 blockade with a neutralizing antibody increased photoreceptor cell loss and macrophage accumulation in the subretinal space. The retinal precursor cell line R28 expressed CXCR4. SDF-1 rescued serum starvation-induced apoptosis in R28 cells and enhanced their ability to participate in wound closure in a scratch assay. Our results indicate a surprising, protective role for SDF-1 in RD. This effect may be mediated directly or indirectly through other cell types.

Scaffolds containing growth factors and extracellular matrix induce hepatocyte proliferation and cell migration in normal and regenerating rat liver

Intrahepatic drug delivery from implantable scaffolds is being developed as a strategy to modulate growth and enhance regeneration at the time of liver resection. In this study we examine the effects of scaffolds containing hepatocyte growth factor, epidermal growth factor, fibroblast growth factor 1, fibroblast growth factor 2, and liver-derived extracellular matrix (L-ECM) when implanted into normal and partially hepatectomized rat livers. Scaffolds loaded with combinations of growth factors and L-ECM were implanted into normal livers (controls=L-ECM, polymer or sham) and livers following partial hepatectomy (controls=partial hepatectomy or sham). The primary end points were hepatocyte DNA synthesis and liver tissue penetration into scaffolds. Secondary end points included non-parenchymal cell DNA synthesis, liver weight analysis, liver function, and histological characterisation of the peri-implant parenchyma. Four days after implantation in normal livers, there was significantly more hepatocyte proliferation around growth factor scaffolds than controls. Seven days after implantation, there was significantly more tissue penetration into growth factor scaffolds than control scaffolds. ED-1 and desmin positive cells were present in the pores of scaffolds. Two days after partial hepatectomy, there was significantly more hepatocyte proliferation around scaffold implanted livers than after partial hepatectomy alone. Growth factors and L-ECM accelerated non-parenchymal cell migration into scaffolds and increased hepatocyte and non-parenchymal cell proliferation around them. These results demonstrate the potential for intrahepatic implantation of scaffolds containing growth factors and L-ECM to modulate growth in the normal and regenerating liver.

Effects of TJN-598, a new selective phosphodiesterase type IV inhibitor on anti-Thy1 nephritis in rats

Phosphodiesterase type IV (PDEIV) plays an important role in the immune response and inflammation. However, it is well known that classical PDEIV inhibitors have systemic side effects, so the clinical and chronic use of these agents as therapy for glomerulonephritis is difficult. This study was performed to elucidate the anti-nephritic effects of TJN-598, a new chemical compound derived from herbal components, on experimental mesangial proliferative glomerulonephritis. We first examined the effects of TJN-598 and captopril on mesangial expansion induced by anti-Thy1 serum in rats. Second, to investigate the effects of TJN-598 and rolipram, which are typical PDEIV inhibitors, on the production of tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-β1, glomeruli were isolated from rats with anti-Thy1 nephritis and incubated with the test drugs in vitro for 48 h. Treatment with TJN-598 prevented an increase in the mesangial area/total glomerular area, in the number of cells in the glomerular cross section and matrix index. TJN-598 also inhibited the increases in the expression of α-smooth muscle actin, the TGF-β1-positive area, in the number of ED-1 positive cells and proliferating cell nuclear antigen-positive cells in the glomeruli. Furthermore, administration of TJN-598 inhibited increases in the levels of TGF-β1 protein derived from glomeruli with anti-Thy-1 nephritis. The addition of both TJN-598 and rolipram to the culture supernatant inhibited both increased expression of TGF-β1 and increases in levels of TNF-α in glomeruli isolated from rats with anti-Thy1 nephritis in a dose-dependent manner. These results suggest that TJN-598, a PDEIV inhibitor, is effective against expansion of mesangial cells, via the suppression of secretion of TGF-β1 and TNF-α from inflamed glomeruli.

Relationship between inflammatory reaction and ischemic injury of caudate-putamen in rats: inflammatory reaction and brain ischemia

Inflammatory response after middle cerebral artery occlusion (MCAO) has been a focus of research recently, but the effect of inflammatory cells on ischemic neurons remains unclear. In order to study the effect of the inflammatory reaction on brain ischemic injury, we observed the morphology, number and distribution of CD3-, CD8-, ED1- and ED2-positive cells systematically in the caudate-putamen of rats in a MCAO model. The present results show that all four types of inflammatory cells first infiltrated the ischemic penumbra and then migrated into the center of the ischemic area, but the morphological changes and infiltration processes differed significantly; the infiltration of CD3- and CD8-positive cells into the ischemic area started at 3days postischemia, and their number peaked at 1week; however, although ED1- and ED2-positive cells were also observed at 3days after ischemia, they reached their maximum number at 2 and 4weeks, respectively. Moreover, ED1-and ED2-positive cells showed evident hyperplasia and hypertrophy in morphology. Our results also showed that the response of CD3-, CD8-, ED1- and ED2-positive cells in the ischemic area and the pathological changes in ischemic brain tissue could be inhibited by cyclosporine A. The results suggest that the infiltration and reaction of inflammatory cells are involved in the pathological process of ischemic brain injury.

OP08 Evidence for early astrocyte activation, cellular stress and compensatory microglial related transforming growth factor-α responses in bile-duct ligated rats

IntroductionInflammation and ammonia are important mediators in the pathogenesis of hepatic encephalopathy and though the mechanisms are unclear astrocytes are thought to have a central role. Recently Microglia, which also...

Repeated administration of bone marrow-derived mesenchymal stem cells improved the protective effects on a remnant kidney model

Mesenchymal stem cell (MSC) has been implied to have the therapeutic potential on chronic kidney disease (CKD). However, the underlying mechanism is still unclear and administration frequency of MSCs could be an issue in a chronic disease model. We evaluated the effect of repeated administration of MSCs on a remnant kidney model. MSCs from 5-week male Sprague–Dawley rats were infused by tail vein into 7-week female 5/6 nephrectomized rats after tagging with a fluorescent probe, chloromethyl-1,1-dioctadecyl-3,3,3′,3′-tetramethyl- indocarbocyanine perchlorate (CM-Dil). Effect of weekly administration of MSCs was compared with the effect of once injection of MSCs and mesangial cells (MCs) at 1 and 5 weeks, respectively. Engraftment of MSCs into the kidney was evaluated by the presence of CM-Dil fluorescence or SRY gene expression. Weekly MSCs administration showed significant improvement in systolic blood pressure (SBP), urinary protein excretion amount, and serum creatinine level at 5 weeks, whereas once MSCs or MCs administration did not. Although once MSCs administration attenuated glomerulosclerosis and infiltration of ED-1 positive cells at 5 weeks as compared with MCs, weekly MSC administration led to a more significant improvement. Renal SRY gene expression and presence of CM-Dil-tagged cells could be confirmed at 1 week after injection of MSCs or weekly injected group, but not at 5 weeks after once injection. MSCs attenuated cortical expression of interleukin (IL)-6 and elevated the expression of IL-10, but these effects were only sustained in the weekly group. Thus, repeated administration of MSCs improves the protective effect on remnant kidney injury, but primarily via the paracrine effect rather than differentiation.

New anti-fibrotic mechanisms of n-acetyl-seryl-aspartyl-lysyl-proline in silicon dioxide-induced silicosis

Aims We previously reported that tetrapeptide N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) inhibited pulmonary inflammation and fibrosis in SiO 2-induced silicosis. This study aimed to explore the precise mechanism involved. Main methods Rats were divided into 3 groups: 1) sham (saline), 2) silicosis + vehicle, and 3) silicosis + Ac-SDKP [800 μg/(kg d)]. SiO 2 particles or saline were administered by tracheal instillation and Ac-SDKP or vehicle (saline) via a miniosmotic pump planted into the abdominal cavity 48 h before instillation. Animals were observed for 4 weeks. Silicotic nodule fraction (SNF) and macrophage infiltration (ED-1 positive cells) were measured by hematoxylin and eosin (H.E.) and immunohistochemical staining respectively. Collagen I and III, transforming growth factor-β1 (TGF-β1) proteins and monocyte chemotactic protein-1 (MCP-1) mRNA were detected by Western Blot (WB) and real-time RT-PCR respectively. In vitro, pulmonary fibroblasts were stimulated by TGF-β1 (5 μg/ml) with or without Ac-SDKP. Phosphorylated c-Jun N-terminal Kinase (p-JNK) was detected by WB and p-JNK nuclear translocation by confocal analysis. Key findings SiO 2 significantly increased the SNF, collagen I and III proteins, TGF-β1, MCP-1 mRNA and macrophage infiltration. All these pathological changes were inhibited by Ac-SDKP. TGF-β1 resulted in fibroblast proliferation, increased expression of collagen I and III proteins, p-JNK and its subsequent nuclear translocation. Addition of Ac-SDKP markedly suppressed these changes. Significance These data indicate that the anti-fibrotic effect of Ac-SDKP in silicosis is mediated by inhibiting chronic inflammation, TGF-β1 production, and TGF-β1-induced pulmonary fibroblast proliferation and collagen synthesis.

Brief Exposure to Damaging Light Causes Focal Recruitment of Macrophages, and Long-Term Destabilization of Photoreceptors in the Albino Rat Retina

Purpose: To characterize the long-term spatiotemporal features of light-mediated retinal degeneration.Methods: Sprague–Dawley rats were exposed to 1000 lux for 24 h, then kept in dim light (5 lux), for up to 56 days. Animals were killed at 0, 3, 7, 28, and 56 days post-exposure, and retinas were prepared for immunohistochemistry. Outer nuclear layer (ONL) thickness and TUNEL labeling were used to quantify photoreceptor death. Antibodies to opsins, glial fibrillary acidic protein (GFAP), fibroblast growth factor-2 (FGF-2), and ED1 were used to assess the retina.Results: At 0 days post-exposure, we detected photoreceptor death 2 mm superior to the optic disc (the “hotspot”), and ED1-positive macrophages in the retinal vasculature and underlying choroid. By 3 days, the ONL was thinner and there was gliosis in the outer retina, where ED1 positive macrophages were also present. Few ED1 positive cells remained at 28 days. At 56 days, there were TUNEL-positive nuclei in the penumbra, and increased FGF-2, and GFAP expression by Müller cells (MCs). In inferior retina, outer segment length was initially reduced, but recovered to near-normal by 28 days.Conclusions: Short exposure to damaging light destabilizes the retina adjacent to a hotspot of degeneration, so that the damaged region expands in size over time. Recruitment of macrophages is associated with the early phase of damage, but not with the longer term photoreceptor loss in the penumbra. Features of the focal and progressive retinal damage in this model are reminiscent of the progression of age-related macular degeneration (AMD).

5/6腎摘除慢性腎不全モデルラットの血圧, 腎機能および腎病変に対する長期的運動, 低タンパク食, アンジオテンシンII受容体拮抗薬の併用効果

A low protein diet(LPD) has been prescribed to alleviate uremic symptoms, and to delay the aggravation of chronic renal failure(CRF). However, it has been suggested that LPD treatment causes malnutrition and attenuation of muscle power. On the other hand, it also has been suggested that appropriate long-term exercise training(EX) may lead to improvement of the physical fitness and quality of life (QOL) in patients with CRF. However, there is no definitive conclusion as to whether EX has any renal protective effect or not. We assessed the effects of combination therapy with LPD and EX. We also assessed the effects of a combination of these therapies and the angiotensin II receptor antagonist, olmesartan (OLS). Male Wistar Kyoto rats that were five-sixth-nephrectomized were divided into 6 groups; 1) normal-protein diet(NPD); 2) NPD and EX with treadmill running(1 h/day, 5 days/week for 12 weeks)(NPD + EX); 3) LPD; 4) LPD + EX; 5) LPD + EX with OLS( 10 mg/kg/day for 12 weeks) (LPD + EX + OLS); and 6) Sham-operated(S). Systolic blood pressure(SBP) in the NPD + EX, LPD + EX, LPD + EX + OLS, and S groups was significantly lower than in the NPD group. Moreover, SBP in the LPD + EX + OLS was significantly lower than in all the other groups. LPD, LPD + EX, and LPD + EX + OLS induced a significant decrease in UP, Scr and BUN compared with the NPD group. UP in the LPD + EX, LPD + EX + OLS, and S groups was significantly lower than in the LPD group. The index of glomerular sclerosis (IGS) and relative interstitial volume(RIV) in the NPD + EX, LPD, LPD + EX, LPD + EX + OLS, and S groups were significantly lower than the values in the NPD group. IGS and RIV in the LPD, LPD + EX, LPD + EX + OLS, and S groups were significantly lower than the values in the NPD + EX and LPD groups. Glomerular ED-1 positive cells in the LPD + EX, LPD + EX + OLS, and S groups was significantly fewer than in the NPD groups. These results indicate that LPD and EX have renoprotective effects, and suggest that the combination therapy with LPD and EX provides greater renoprotective effects than LPD alone. Moreover simultaneous treatment of OLS and LPD + EX provides greater antihypertensive and antiproteinuric effects than treatment with LPD + EX.

Quercetin attenuates inflammatory processes after spinal cord injury in an animal model

We have shown earlier that administration of the flavonoid quercetin significantly contributed to recovery of motor function after spinal cord compression injury in the adult rat. Using the same animal model, we have now designed a set of experiments to test the hypothesis that quercetin attenuates oxidative stress-related inflammatory processes early after spinal cord trauma. Mid-thoracic spinal cord compression injury in adult male Wistar rats was caused by extradural application and closure of a 50 g calibrated aneurysm clip for 5 s. Myeloperoxidase (MPO) levels were determined in spinal cord tissue and serum of quercetin-treated animals and controls at 6, 12, 24 and 72 h after injury. The white blood count was followed until 72 h after injury. In quercetin-treated animals, MPO activity was significantly decreased in tissue at 12 and 24 h and in serum at 6, 12 and 24 h after injury, compared with saline controls. In quercetin-treated animals, the prevalence of ED-1 and MPO positive cells was significantly lower than in saline controls. White blood count in venous blood was significantly decreased in quercetin-treated animals at 12 and 24 h after injury. Quercetin attenuated the recruitment of neutrophils to the site of injury. The resulting lower MPO release in the injured tissue is likely to decrease the extent of secondary injury and might at least partially explain the neuroprotective effect of the flavonoid quercetin.

Arterial Function and Flow Related Arterial Remodeling during DOCA‐salt Hypertension

HypothesisThe DOCA‐salt Hypertensive rat (DOCA), a model of enhanced function of endothelin‐1 (ET‐1), displays: 1. Increased importance of endogenous ET‐1 in vasoreactivity 2. Altered flow‐related arterial remodeling.Methods1. 2nd order rat mesenteric artery (MrA) reactivity was assessed using wire‐myography. 2. Flow modifying surgery was performed as described by Pourageaud and De Mey (1997) and arteries were analysed by pressure arteriography and histology.Results1. the endothelin‐receptor antagonist Bosentan endothelium‐dependently reduced contractile responses to K+‐induced depolarization in arteries of DOCA but not SHAM. 2. No outward hypertrophic remodeling occurred in high flow (HF) arteries of DOCA. Arteries exposed to low flow (LF) conditions, showed inward remodeling, hypertrophy, and infiltration of ED‐1 (monocyte/macrophage‐marker) positive cells. DOCA MrA's showed a marked reduction in calculated distensibility. α‐Smooth muscle actin staining of LF vessels showed development of “collaterals” in the adventitia.ConclusionDOCA MrA's show increased contribution of endogenous ET‐1 to K+‐induced vasomotor responses, impaired outward remodeling, arterial stiffening and hypertrophy. LF MrA's show infiltration of inflammatory cells and development of “collaterals” in the adventitia.This study was performed within project T2–108 of the Dutch Top Institute Pharma.

Integrins and Monocyte Migration to the Ischemic Myocardium

ABSTRACTAims: Characterize mononuclear cell migration after acute-myocardial infarction (MI).Material and Methods: Male Lewis rats underwent a left thoracotomy and ligation of the left anterior descending coronary artery (MI group). Control animals underwent thoracotomy without ligation (Sham group). Animals were sacrificed at 0, 2, 4, or 24 hr after the onset of ischemia. Leukocyte migration was assessed using isolated and In111 labeled mononuclear cells (injected at the onset of ischemia) and γ-count determined at 24 hours. Inhibition of migration was evaluated with monoclonal anti α4 and/or β2 antibodies. Results: Serum troponin was significantly elevated in animals with MI as compared with Sham (p = .017). Labeled mononuclear cell migration was five-fold higher in MI-treated animals than in Sham (p = .006). ED-1 positive mononuclear cells were confirmed in the left myocardium after 24 hr of ischemia. MCP-1 mRNA was significantly elevated in the left myocardium at 2 hr and 4 hr and peaked at 24 hr (p <.05). In addition, α4 integrin blockade inhibited labeled mononuclear cell migration by 22%. Blockade of β2 integrin inhibited mononuclear cell migration by 48%, while the combined α4+β2 blockade resulted in 59% inhibition of labeled mononuclear cell migration compared with treatment with isotype control antibody (p = .001). Conclusions: Significant ED1+ mononuclear cell migration within 24 hr of MI correlated with peak MCP-1 mRNA. Monoclonal antibody blockade suggested that early mononuclear cell migration is dependent only in part on α4 and β2 integrins.

Higher expression of vascular endothelial growth factor (VEGF) and its receptor VEGFR-2 (Flk-1) and metalloproteinase-9 (MMP-9) in a rat model of peritoneal endometriosis is similar to cancer diseases

BackgroundEndometriosis is a common disease characterized by the presence of a functional endometrium outside the uterine cavity, causing pelvic pain, dysmenorrheal, and infertility. This disease has been associated to development of different types of malignancies; therefore new blood vessels are essential for the survival of the endometrial implant. Our previous observations on humans showed that angiogenesis is predominantly found in rectosigmoid endometriosis, a deeply infiltrating disease. In this study, we have established the experimental model of rat peritoneal endometriosis to evaluate the process of angiogenesis and to compare with eutopic endometrium.MethodsWe have investigated the morphological characteristics of these lesions and the vascular density, VEGF and its receptor Flk-1 and MMP-9 expression, and activated macrophage distribution, using immunohistochemistry and RT-PCR.ResultsAs expected, the auto-transplantation of endometrium pieces into the peritoneal cavity is a well-established method for endometriosis induction in rats. The lesions were cystic and vascularized, and demonstrated histological hallmarks of human pathology, such as endometrial glands and stroma. The vascular density and the presence of VEGF and Flk-1 and MMP-9 were significantly higher in endometriotic lesions than in eutopic endometrium, and confirmed the angiogenic potential of these lesions. We also observed an increase in the number of activated macrophages (ED-1 positive cells) in the endometriotic lesions, showing a positive correlation with VEGF.ConclusionThe present endometriosis model would be useful for investigation of the mechanisms of angiogenesis process involved in the peritoneal attachment of endometrial cells, as well as of the effects of therapeutic drugs, particularly with antiangiogenic activity.

Proposed protective mechanism of the pancreas in the rat

BackgroundHeparan sulphate is known to have various functions in the animal body, including surveillance of tissue integrity. Administered intraperitoneally, it induces a systemic inflammatory response syndrome and when given locally in the pancreas it initiates a protective inflammatory response. The aim of the present study was to investigate the underlying mechanisms behind cell recruitment following intra-ductal infusion of heparan sulphate.MethodsRats were subjected to intraductal-infusion of heparan sulphate, lipopolysaccharide and phosphate buffered saline into the pancreas. Pancreatic tissue was harvested 1, 3, 6, 9 or 48 hours after infusion and stained immunohistochemically for myeloperoxidase, ED-1, CINC-1 and MCP-1, as well as using eosin hematoxylin staining. Furthermore, MPO activity and MCP-1 and CINC-1 concentrations of tissue homogenates were measured. All differences were analyzed statistically using the Mann-Whitney U-test.ResultsDuring HS infusion, a rapid influx of macrophages/monocytes, as visualized as ED-1 positive cells, was seen reaching a maximum at 6 hours. After 48 hours, the same levels of ED-1 positive cells were noted in the pancreatic tissue, but with different location and morphology. Increased neutrophil numbers of heparan sulphate treated animals compared to control could be detected only 9 hours after infusion. The number of neutrophils was lower than the number of ED-1 positive cells. On the contrary, LPS infusion caused increased neutrophil numbers to a larger extent than heparan sulphate. Furthermore, this accumulation of neutrophils preceded the infiltration of ED-1 positive cells. Chemokine expression correlates very well to the cell infiltrate. MCP-1 was evident in the ductal cells of both groups early on. MCP-1 preceded monocyte infiltration in both groups, while the CINC-1 increase was only noticeable in the LPS group.ConclusionsOur data suggest that heparan and LPS both induce host defense reactions, though by using different mechanisms of cell-recruitment. This implies that the etiology of pancreatic inflammation may influence how the subsequent events will develop.

Neonatal Dexamethasone Treatment in the Rat Leads to Kidney Damage in Adulthood

Recently, concern has been raised that corticosteroid treatment of preterm neonates might be associated with adverse effects later in life, including early development of hypertension. Here, we investigate the impact of neonatal dexamethasone (Dex) treatment on early renal cell proliferation and nephron number. We analyzed mitotic activity in renal cortex of rat pups neonatally treated with Dex. Nephron number was measured and possible renal damage was quantified by counting inflammatory foci, ED-1 positive cells (macrophages), and the desmin score (activated podocytes). Mitotic activity was 34 and 29% lower on d 2 and 4 in Dex-treated rats compared with saline-treated controls. The number of glomeruli was lower at 4 wk, but nephron size was unchanged after Dex treatment, as calculated from glomerular density and (lower) body- and kidney weight. At wk 50, the glomerular number was significantly lower in Dex-treated rats, whereas body and kidney weight were the same as in Sal controls. Dex rats also showed more kidney damage, manifested by a approximately 3.5-fold increase in inflammation foci/mm and in ED-1 positive cells/mm and a approximately 4.3-fold increased desmin score. Temporary suppression of mitotic activity during neonatal Dex treatment leads to reduction of nephron number and more kidney damage later in life. :

Dual Roles for Perivascular Macrophages in Immune-to-Brain Signaling

Cytokines produced during infection/inflammation activate adaptive central nervous system (CNS) responses, including acute stress responses mediated by the hypothalamo-pituitary-adrenal (HPA) axis. The mechanisms by which cytokines engage HPA control circuitry remain unclear, though stimulated release of prostanoids from neighboring vascular cells has been implicated in this regard. How specific vascular cell types, endothelial cells (ECs) versus perivascular cells (PVCs; a subset of brain-resident macrophages), participate in this response remains unsettled. We exploited the phagocytic activity of PVCs to deplete them in rats by central injection of a liposome-encapsulated proapoptotic drug. This manipulation abrogated CNS and hormonal indices of HPA activation under immune challenge conditions (interleukin-1) that activated prostanoid synthesis only in PVCs, while enhancing these responses to stimuli (lipopolysaccharide) that engaged prostanoid production by ECs as well. Thus, PVCs provide both prostanoid-mediated drive to the HPA axis and an anti-inflammatory action that constrains endothelial and overall CNS responses to inflammatory insults.

Tranilast Attenuates Chronic Cyclosporine Nephrotoxicity in Rats

Our aim was to explore the effects of the anti-allergic and antifibrotic agent tranilast on chronic cyclosporine (CsA) nephrotoxicity in rats. Methods Eighteen Sprague-Dawley rats were randomized to be given the following daily treatments by gavage for 4 weeks: (1) controls, olive oil; (2) CsA group, CsA 25 mg/kg; (3) CsA plus tranilast group, CsA 25 mg/kg and tranilast 400 mg/kg. We examined the body weights and the effects of tranilast on histopathology, macrophage (Mϕ) infiltration, and expression of osteopontin (OPN). Results The administration of tranilast improved body weight gain by CsA-treated rats (232 ± 24 vs 203 ± 6 g; P < .05). This treatment reduced the expression of OPN protein and infiltration of macrophages (9.14 ± 2.7 vs 22.44 ± 5.68 ED-1 positive cells per high power field, P < .05). Furthermore compared with the CsA alone group, it ameliorated tubulointerstitial fibrosis scores (1.18 ± 0.08 vs 2.57 ± 0.21, P < .05). Conclusion Tranilast attenuated tubulointerstitial fibrosis through decreased expression of OPN protein and macrophage infiltration, showing renal protective effects in rats with chronic CsA nephrotoxicity.

Prolonged Administration Enhances the Renoprotective Effect of Pentoxifylline via Anti-Inflammatory Activity in Streptozotocin-Induced Diabetic Nephropathy

The beneficial effects of pentoxifylline (PTX), which has an anti-inflammatory and renoprotective effect in diabetic nephropathy, are not completely understood. This study investigates whether prolonged administration of PTX (40 mg/kg, per oral) is effective in streptozotocin-induced diabetic nephropathy. The amount of urinary protein was higher in the diabetic rats than in the control rats. The amount remained unchanged after 4 weeks and decreased after 8 weeks of PTX treatment. Accumulation of monocyte chemoattractant peptide-1 (MCP-1) and mouse monoclonal anti-monocyte/macrophage antibody (ED-1) positive cells was higher in untreated diabetic rats than in the control rats. PTX administration ameliorated the urinary MCP-1 excretion and interstitial infiltration of ED-1 positive cells at 4 weeks. Further, in diabetic rats, administration of PTX for 4 weeks inhibited the renal inflammatory reaction, and when administration for 8 weeks, it prevented proteinuria. These findings support the hypothesis that prolonged administration enhances the protective effects of PTX.