Effects of low molecular weight heparin in obstructed kidneys: decrease of collagen, fibronectin and TGF-β, and increase of chondroitin/dermatan sulfate proteoglycans and macrophage infiltration

The effect of intraurethral heparin on inflammation and spongiofibrosis in a rat model of experimentally induced urethral trauma

AIM

To determine the effect of heparin administered during the early post urethral trauma period on inflammation and spongiofibrosis in rats.

MATERIALS AND METHODS

The study included 24 male rats that were randomized into 3 groups of 8 each. The urethra was traumatized using a 24-G needle sheath in all rats. Group 1 (control group) received intraurethral saline 0.9% injected b.i.d. for 27 days, group 2 received intraurethral Na-heparin (liquemine-Roche) 1500 IU kg^-1 injected b.i.d. for 27 days, and group 3 received intraurethral Na-heparin 1500 IU kg^-1 injected b.i.d and saline 0.9% s.i.d. for 27 days. On day 28 the rats' penises were degloved and penectomy was performed. Inflammation, spongiofibrosis, and congestion in the urethra were investigated in each group.

RESULTS

A statistically significant difference was found between the three groups (control, heparin, and heparin + saline) in the histopathological status of spongiofibrosis, inflammation, and congestion, respectively (P = 0.0001, P = 0.002, P = 0.0001). Severe spongiofibrosis was observed in six (75%) of the rats in group 1 (control group), whereas severe spongiofibrosis was not observed in group 2 (heparin) or group 3 (heparin + saline).

CONCLUSION

We observed that intraurethral Na-heparin 1500 IU kg^-1 injectioned during the early posturethral trauma period in rats significantly decreased inflammation, spongiofibrosis, and congestion.

Platelet-rich plasma exhibits anti-inflammatory effect and attenuates cardiomyocyte damage by reducing NF-κB and enhancing VEGF expression in isoproterenol induced cardiotoxicity model

The present study investigated the cardioprotective effects of activated platelet-rich plasma (PRP) on high dose isoproterenol (ISO) induced cardiotoxicity. ISO was injected at a dose of 85 mg/kg/day, s.c. for 2 days. Cardiac function parameters including dp/dt max/min, left ventricular end diastolic pressure (LVEDP), relaxation constant (tau) and electrocardiogram (ECG) changes, anti-oxidant and membrane bound enzymes assays, pro-inflammatory cytokine levels, collagen content, immunohistochemical staining/gene expression of vascular endothelial growth factor (VEGF), cTnI (cardiac troponin I), NF-κB (nuclear factor kappa B), Smad-2/3, TGF-β (transforming growth factor), collagen-1/3 proteins were evaluated. PRP and platelet-poor plasma (PPP) were injected intramyocardially (200 μl in each ventricle region) 3 h after first dose of ISO under anesthesia. ISO injection induced cardiac dysfunction, hypertrophy, fibrosis, necrosis due to decline in anti-oxidant capacity, enhanced NF-κB and reduced cTnI immunostaining. However, the PRP injection attenuated these cardiac pathological changes by exerting anti-inflammatory properties and promoting cardiomyocyte repair.

ILB® resolves inflammatory scarring and promotes functional tissue repair

Fibrotic disease is a major cause of mortality worldwide, with fibrosis arising from prolonged inflammation and aberrant extracellular matrix dynamics. Compromised cellular and tissue repair processes following injury, infection, metabolic dysfunction, autoimmune conditions and vascular diseases leave tissues susceptible to unresolved inflammation, fibrogenesis, loss of function and scarring. There has been limited clinical success with therapies for inflammatory and fibrotic diseases such that there remains a large unmet therapeutic need to restore normal tissue homoeostasis without detrimental side effects. We investigated the effects of a newly formulated low molecular weight dextran sulfate (LMW-DS), termed ILB^®, to resolve inflammation and activate matrix remodelling in rodent and human disease models. We demonstrated modulation of the expression of multiple pro-inflammatory cytokines and chemokines in vitro together with scar resolution and improved matrix remodelling in vivo. Of particular relevance, we demonstrated that ILB^® acts, in part, by downregulating transforming growth factor (TGF)β signalling genes and by altering gene expression relating to extracellular matrix dynamics, leading to tissue remodelling, reduced fibrosis and functional tissue regeneration. These observations indicate the potential of ILB^® to alleviate fibrotic diseases.

Antifibrotic therapy by sustained release of low molecular weight heparin from poly(lactic-co-glycolic acid) microparticles on bleomycin-induced pulmonary fibrosis in mice

Heparin and low molecular weight heparin (LMWH) have recently been considered useful treatment tools for inflammation. Heparin has antifibrotic activity, mediated by cellular secretion of hepatocyte growth factor (HGF). HGF has antifibrotic properties demonstrated in experimental models of lung, kidney, heart, skin, and liver fibrosis. The ability of LMWH for HGF secretion is similar to that of normal heparin. Poly (lactic-co-glycolic acid) (PLGA) is widely used for sustained drug release, because of its biocompatibility and low toxicity. LMWH-loaded PLGA microparticles are prepared by a conventional water-in-oil-in-water emulsion method. Interstitial pneumonia is a life-threatening pathological condition that causes respiratory failure when it progresses. In the present study, we investigated the therapeutic effect of LMWH-loaded PLGA microparticles in a mouse model of bleomycin-induced lung fibrosis. The ratios of fibrotic area to total area were significantly lower in mice administered LMWH-loaded microparticles than in mice administered bleomycin alone. The microparticle administration did not further enhance the gene expression for inflammatory cytokines. In a cell culture study, HGF secretion by mouse and human lung fibroblasts was significantly increased by LMWH addition. We conclude that LMWH showed anti-inflammatory activity, through the effects of LMWH-loaded PLGA microparticles on cells at sites of inflammation.

Differential Expression of Specific Dermatan Sulfate Domains in Renal Pathology

Dermatan sulfate (DS), also known as chondroitin sulfate (CS)-B, is a member of the linear polysaccharides called glycosaminoglycans (GAGs). The expression of CS/DS and DS proteoglycans is increased in several fibrotic renal diseases, including interstitial fibrosis, diabetic nephropathy, mesangial sclerosis and nephrosclerosis. Little, however, is known about structural alterations in DS in renal diseases. The aim of this study was to evaluate the renal expression of two different DS domains in renal transplant rejection and glomerular pathologies. DS expression was evaluated in normal renal tissue and in kidney biopsies obtained from patients with acute interstitial or vascular renal allograft rejection, patients with interstitial fibrosis and tubular atrophy (IF/TA), and from patients with focal segmental glomerulosclerosis (FSGS), membranous glomerulopathy (MGP) or systemic lupus erythematosus (SLE), using our unique specific anti-DS antibodies LKN1 and GD3A12. Expression of the 4/2,4-di-O-sulfated DS domain recognized by antibody LKN1 was decreased in the interstitium of transplant kidneys with IF/TA, which was accompanied by an increased expression of type I collagen, decorin and transforming growth factor beta (TGF-β), while its expression was increased in the interstitium in FSGS, MGP and SLE. Importantly, all patients showed glomerular LKN1 staining in contrast to the controls. Expression of the IdoA-Gal-NAc4SDS domain recognized by GD3A12 was similar in controls and patients. Our data suggest a role for the DS domain recognized by antibody LKN1 in renal diseases with early fibrosis. Further research is required to delineate the exact role of different DS domains in renal fibrosis.

Macrophage polarization in kidney diseases

Macrophage accumulation associates closely with the degree of renal structural injury and renal dysfunction in human kidney diseases. Depletion of macrophages reduces while adoptive transfer of macrophages worsens inflammation in animal models of the renal injury. However, emerging evidence support that macrophage polarization plays a critical role in the progression of a number of kidney diseases including obstructive nephropathy, ischemia-reperfusion injury, glomerulonephritis, diabetic nephropathy, and other kidney diseases. In this mini-review, we briefly summarize the macrophage infiltration and polarization in these inflammatory and fibrotic kidney diseases, discussing the results mostly from studies in animal models. In view of the critical role of macrophage in the progression of these diseases, manipulating macrophage phenotype may be a potential effective strategy to treat various kidney diseases.

The protective role of fucosylated chondroitin sulfate, a distinct glycosaminoglycan, in a murine model of streptozotocin-induced diabetic nephropathy

BACKGROUND

Heparanase-1 activation, albuminuria, and a decrease in glomerular heparan sulfate (HS) have been described in diabetic nephropathy (DN). Glycosaminoglycan (GAG)-based drugs have been shown to have renoprotective effects in this setting, although recent trials have questioned their clinical effectiveness. Here, we describe the effects of fucosylated chondroitin sulfate (FCS), a novel GAG extracted from a marine echinoderm, in experimentally induced DN compared to a widely used GAG, enoxaparin (ENX).

METHODS

Diabetes mellitus (DM) was induced by streptozotocin in male Wistar rats divided into three groups: DM (without treatment), FCS (8 mg/kg), and ENX (4 mg/kg), administered subcutaneously. After 12 weeks, we measured blood glucose, blood pressure, albuminuria, and renal function. The kidneys were evaluated for mesangial expansion and collagen content. Immunohistochemical quantifications of macrophages, TGF-β, nestin and immunofluorescence analysis of heparanase-1 and glomerular basement membrane (GBM) HS content was also performed. Gene expression of proteoglycan core proteins and enzymes involved in GAG assembly/degradation were analyzed by TaqMan real-time PCR.

RESULTS

Treatment with GAGs prevented albuminuria and did not affect the glucose level or other functional aspects. The DM group exhibited increased mesangial matrix deposition and tubulointerstitial expansion, and prevention was observed in both GAG groups. TGF-β expression and macrophage infiltration were prevented by the GAG treatments, and podocyte damage was halted. The diabetic milieu resulted in the down-regulation of agrin, perlecan and collagen XVIII mRNAs, along with the expression of enzymes involved in GAG biosynthesis. Treatment with FCS and ENX positively modulated such changes. Heparanase-1 expression was significantly reduced after GAG treatment without affecting the GBM HS content, which was uniformly reduced in all of the diabetic animals.

CONCLUSIONS

Our results demonstrate that the administration of FCS prevented several pathological features of ND in rats. This finding should stimulate further research on GAG treatment for this complication of diabetes.

Heparin inhibits activation of latent transforming growth factor-β1

AIM

Besides acting as an anticoagulant, heparin has antifibrotic effects. Transforming growth factor-β1 (TGF-β1) is secreted from cells as latent TGF-β1 (LTGF-β1). LTGF-β1 consists of TGF-β1 and latency-associated peptide (LAP). To be biologically active, TGF-β1 has to be released from LAP. Heparin binds to LAP as well as TGF-β1. This study was performed to explore the biological effect of the interaction of heparin with LTGF-β1.

MATERIALS AND METHODS

TGF-β1 was measured by ELISA. Furin-like proprotein convertase activity was assayed using the fluorogenic substrate, Pyr-Arg-Thr-Lys-Arg-AMC.

RESULTS

Heparin did not interfere with the receptor binding of TGF-β1, but inhibited furin-like proprotein convertase-mediated activation of platelet LTGF-β1. This was not by inhibition of the enzyme because heparin did not inhibit the activity of furin-like proprotein convertase. In addition, heparin inhibited acid activations of recombinant small LTGF-β1, platelet LTGF-β1 and LTGF-β1s secreted in the supernatant of cultured cells. Low-molecular-weight heparins, including dalteparin, enoxaparin and nadroparin, also had inhibitory effects on furin-like proprotein convertase-mediated or acid activation of platelet LTGF-β1.

CONCLUSION

The findings suggest that heparin renders LTGF-β1 resistant to activation, possibly by binding simultaneously to TGF-β1 and LAP. Inhibition of LTGF-β1 activation by heparin may in part account for its antifibrotic effects.

Pathogenic and protective role of macrophages in kidney disease

Macrophages (MΦ) are located throughout kidney tissue, where they play important roles in homeostasis, surveillance, tolerance, and cytoprotection. MΦ are highly heterogeneous cells and exhibit distinct phenotypic and functional characteristics depending on their microenvironment and the disease type and stage. Recent studies have identified a dual role for MΦ in several murine models of kidney disease. In this review, we discuss the pathogenic and protective roles of the various MΦ subsets in experimental and human kidney diseases and summarize current progress toward the therapeutic use of MΦ in kidney diseases.

Coagulation and coagulation signalling in fibrosis

Following tissue injury, a complex and coordinated wound healing response comprising coagulation, inflammation, fibroproliferation and tissue remodelling has evolved to nullify the impact of the original insult and reinstate the normal physiological function of the affected organ. Tissue fibrosis is thought to result from a dysregulated wound healing response as a result of continual local injury or impaired control mechanisms. Although the initial insult is highly variable for different organs, in most cases, uncontrolled or sustained activation of mesenchymal cells into highly synthetic myofibroblasts leads to the excessive deposition of extracellular matrix proteins and eventually loss of tissue function. Coagulation was originally thought to be an acute and transient response to tissue injury, responsible primarily for promoting haemostasis by initiating the formation of fibrin plugs to enmesh activated platelets within the walls of damaged blood vessels. However, the last 20years has seen a major re-evaluation of the role of the coagulation cascade following tissue injury and there is now mounting evidence that coagulation plays a critical role in orchestrating subsequent inflammatory and fibroproliferative responses during normal wound healing, as well as in a range of pathological contexts across all major organ systems. This review summarises our current understanding of the role of coagulation and coagulation initiated signalling in the response to tissue injury, as well as the contribution of uncontrolled coagulation to fibrosis of the lung, liver, kidney and heart. This article is part of a Special Issue entitled: Fibrosis: Translation of basic research to human disease.

Preparation of gelatin hydrogels incorporating low-molecular-weight heparin for anti-fibrotic therapy

The objective of this study is to design biodegradable hydrogels for the controlled release of low-molecular-weight heparin (LMWH) and evaluate the biological activity. Gelatin was cationized by chemically introducing ethylene diamine into the carboxyl groups in different conditions to obtain cationized gelatins. The cationized gelatin was mixed with the LMWH in aqueous solution to form the complex. Gelatin, together with the complex of LMWH and cationized gelatin, was dehydrothermally cross-linked for different time periods to prepare the gelatin hydrogel-incorporating complex. The hydrogel-incorporating complex was neither degraded in phosphate-buffered saline solution (PBS) at 37 °C nor did it release the LMWH complex. When placed in PBS containing collagenase, the hydrogel was enzymatically degraded to release the LMWH complex. The time profile of hydrogel degradation and the LMWH release depended on the condition of hydrogel cross-linking. The longer the cross-linking time period, the slower the hydrogel degradation and the subsequent LMWH release. The half-life period of LMWH release was in good correspondence with that of hydrogel degradation. It is possible that the LMWH was released as the result of hydrogel degradation. When applied to the mouse model of abdominal membrane fibrosis, the hydrogel system of LMWH release showed a promising anti-fibrotic effect.

Dermatan sulfate reduces monocyte chemoattractant protein 1 and TGF-β production, as well as macrophage recruitment and myofibroblast accumulation in mice with unilateral ureteral obstruction

Selectins play an essential role in most inflammatory reactions, mediating the initial leukocyte-rolling event on activated endothelium. Heparin and dermatan sulfate (DS) bind and block P- and L-selectin function in vitro. Recently, we reported that subcutaneous administration of DS inhibits colon inflammation in rats by reducing macrophage and T-cell recruitment and macrophage activation. In the present study, we examined the effect of porcine intestinal mucosa DS on renal inflammation and fibrosis in mice after unilateral ureteral obstruction (UUO). Twenty-four adult male Swiss mice weighing 20-25 g were divided into 4 groups: group C (N = 6) was not subjected to any surgical manipulation; group SH (N = 6) was subjected to surgical manipulation but without ureter ligation; group UUO (N = 6) was subjected to unilateral ureteral obstruction and received no treatment; group UUO plus DS (N = 6) was subjected to UUO and received DS (4 mg/kg) subcutaneously daily for 14 days. An immunoblot study was also performed for TGF-β. Collagen (stained area ~3700 µm(2)), MCP-1 (stained area ~1700 µm(2)), TGF-β (stained area ~13% of total area), macrophage (number of cells ~40), and myofibroblast (stained area ~1900 µm(2)) levels were significantly (P < 0.05) higher in the UUO group compared to control. DS treatment significantly (P < 0.05) reduced the content of collagen (stained area ~700 µm(2)), MCP-1 (stained area ~160 µm(2)) and TGF-β (stained area ~5% of total area), in addition to myofibroblast (stained area ~190 µm(2)) and macrophage (number of cells ~32) accumulation in the obstructed kidney. Overall, these results indicate that DS attenuates kidney inflammation by reducing macrophage recruitment, myofibroblast population and fibrosis in mice submitted to UUO.

Diabetes results in structural alteration of chondroitin sulfate/dermatan sulfate in the rat kidney: effects on the binding to extracellular matrix components

Chondroitin sulfate (CS)/dermatan sulfate (DS) is a group of sulfated polymers, which play an essential role in various biological phenomena. In the kidney, they are present in small but significant amounts. Studies on their structure-function relationship in the kidney and their changes during diabetic conditions have not been rigorously looked into, which is the focus of this paper. The CS/DS content decreased significantly (14%) during diabetic conditions. This was accompanied by a decrease in the CS/heparan sulfate ratio. Disaccharide composition analysis revealed fine structural changes especially with respect to the E unit [glucuronic acid β1-3 N-acetyl d-galactosamine (4,6-O-sulfate)] and the degree of sulfation. The mRNA expression levels of major enzymes involved in the synthesis of the "E"-disaccharide unit showed a decrease during diabetes. The changes in CS/DS had implications on ligand-binding properties when tested in vitro for binding to major extracellular matrix (ECM) components such as type IV collagen, laminin and fibronectin. Thus, this study provides insights into the structure-function relationship of CS/DS in the kidney during diabetes and alterations of which could aggravate conditions such as diabetic nephropathy by virtue of them being a part of ECM components.

Fucosylated chondroitin sulfate attenuates renal fibrosis in animals submitted to unilateral ureteral obstruction: a P-selectin-mediated event?

Fibrosis is the end point of most renal diseases, and several glycosaminoglycans have been shown to attenuate this process. Marine invertebrate glycosaminoglycans with unique structures have opened the possibility to test these new compounds on renal fibrosis. The effect of a fucosylated chondroitin sulfate from an echinoderm marine species is reported with the use of a model of renal fibrosis in rats, termed unilateral ureteral obstruction. Animals were given 4 mg/kg body wt of fucosylated chondroitin sulfate intraperitoneally, once a day. After 14 days, their kidneys were examined by histological, immunohistochemical, and biochemical methods. Compared with control mice, collagen deposition decreased in the course of renal fibrosis in the animals receiving fucosylated chondroitin sulfate, as revealed by Sirius red staining and hydroxyproline content. The cellularity related to myofibroblasts and macrophages was also reduced, as was the production of transforming growth factor (TGF)-β. The glycosaminoglycan content increased in the renal interstitium of animals submitted to unilateral ureteral obstruction compared with the control contralateral kidney, mostly due to an increase of chondroitin sulfate content. Interestingly, no change in the pattern of glycosaminoglycan deposition was observed after administration of fucosylated chondroitin sulfate. Fibrosis induced by unilateral ureteral obstruction is attenuated in P-selectin-deficient mice, which also do not respond to the invertebrate glycosaminoglycan. In conclusion, fucosylated chondroitin sulfate attenuates renal fibrosis on a ureteral obstruction model in mice preponderantly through a P-selectin-mediated mechanism.

Paraquat (PQ)-induced pulmonary fibrosis increases exercise metabolic cost, reducing aerobic performance in rats

Rats exposed to the quaternary herbicide paraquat (PQ) exhibit oxidative stress and lung injury. In the present study, we investigated the effect of multiple exposures to PQ on aerobic performance during progressive exercise on a treadmill in rats. PQ was dissolved in saline (SAL) (10 mg/ml) and administered intraperitoneally 7 mg/kg body wt to Wistar rats (n = 5) once a week for one month. Control rats received SAL (0.7 ml/kg body wt., intraperitoneally, n = 5) over the same time period. The animals were submitted to aerobic evaluation on a treadmill using a progressive protocol until fatigue prior to the administration of the first dose of PQ or SAL and repeated at 1 week and 40 days following the last dose of the herbicide. Twenty-four hours after the last performance tests, the animals were sacrificed, lungs removed and divided in two groups: PQ and SAL for histopathological analysis. The animals exposed to PQ exhibited decrease in aerobic performance and mechanical efficiency (ME) as well as increase in oxygen consumption during exercise in comparison to the controls forty days after the last dose of PQ. Lung histologic changes included atelectasis, interstitial edema, and inflammation cells in PQ group. The collagen system fibers, fraction area of alveolar collapse and influx of polymorphonuclear (PMN) cells in lung parenchyma were higher in PQ compared to SAL. In conclusion, multiple exposures to PQ induce pulmonary fibrosis, reduce the aerobic performance and mechanical efficiency and increase the metabolic cost of exercise in rats.

The preventive effects of heparin-superoxide dismutase on carbon tetrachloride-induced acute liver failure and hepatic fibrosis in mice

In this study, the effects of heparin-superoxide dismutase conjugate (heparin-SOD) on carbon tetrachloride (CCl4)-induced acute liver failure and hepatic fibrosis were evaluated. To investigate the effects of heparin-SOD on acute liver failure, heparin-SOD was administered to CCl4-treated mice by intravenous injection. Biochemical indicators, such as glutamic oxaloacetic transaminase/glutamic pyruvic transaminase (GOT/GPT), GSH (glutathione), lactate dehydrogenase (LDH), and malondialdehyde (MDA) were determined 24 h after CCl4 treatment. The development of CCl4-induced acute liver failure altered the redox state with a decreased hepatic GSH and increased formation of lipid peroxidative products, which were partially normalized by treatment with heparin-SOD or heparin + SOD. Compared with other groups, the acute liver injury of heparin-SOD group was significantly lessened (reduced activities of GOT/GPT, MDA, and increased activities of GSH). To investigate the effects of heparin-SOD on hepatic fibrosis, heparin-SOD and CCl4 were co-administered by intraperitoneal injection twice a week for 12 weeks. Histological and hepatic hydroxyproline examination revealed that heparin-SOD could significantly prevent the progression of hepatic fibrosis. Moreover, real-time PCR was used to determine transforming growth factor-beta1 (TGF-beta1), metalloproteinase-2 (MMP-2), fibronectin, and collagen-I expression. Significantly, greater fibrosis and TGF-beta1, MMP-2, fibronectin, and collagen-I expression were found in the liver of CCl4-induced mice at the end of 12th week. Heparin-SOD could markedly attenuate the mRNA expression of TGF-beta1, MMP-2, and collagen-I. Western blots of tissue homogenates revealed that the protein expression of TGF-beta1 was substantially reduce also by heparin-SOD treatment. These results demonstrate that administration of heparin-SOD may be useful in the treatment and prevention of acute liver failure and hepatic fibrosis.

Effect of Sulodexide on Plasma Transforming Growth Factor-β1 in Healthy Volunteers

It is unknown whether the glycosaminoglycan drug sulodexide interferes with transforming growth factorβ1—a member of heparin-binding family and a potent regulator of human biology and diseases. Hence, a 2-week pilot study was performed in 11 healthy men. Sulodexide was initially administered intravenously in a single dose, then—orally for 12 days and—again intravenously on study completion. Initial injection had no effect on activated form of the growth factor measured in plasma after 10 and 120 min; no change was also observed after 120 min from drug ingestion on day 7. On final intravenous administration, the growth factor levels increased by almost 60% after 10 min and remained elevated; the 120-min levels directly correlated with sulodexide dosage. Baseline cytokine levels decreased during the 2-week trial by more than 50%. In conclusion, transforming growth factor-β1 release and likely downregulation of its expression may constitute novel pharmacological effects of sulodexide.

Pleiotropic Effects of Heparin and Heparinoids in Peritoneal Dialysis

Unfractionated heparin, low-molecular-weight heparins, and sulodexide belong to the family of glycosaminoglycans. Recent studies report on properties other than anticoagulant activities of these medications. They include modulation of cell growth and proliferation via actions on numerous growth factors affecting the immune system and matrix molecules production and degradation. Long-term peritoneal dialysis remarkably influences peritoneal cavity homeostasis by mechanisms mediated by growth factors. They initiate progression of pathological processes and further account for morphological and functional alterations of the peritoneal membrane. The best-recognized pathologies in peritoneal cavity under these conditions encompass inflammation, fibrosis, and vasculopathy, often leading to fatal encapsulating peritoneal sclerosis. Intraperitoneal heparin and its derivatives, by their pleiotropic actions, may influence these crucial processes and improve the peritoneal dialysis technique survival in a complex and so far understudied way. These issues, novel medical approaches, and their likely mechanisms have been reviewed.

Tubulointerstitial heparan sulfate proteoglycan changes in human renal diseases correlate with leukocyte influx and proteinuria

Heparan sulfate proteoglycans (HSPGs) are well known for their proposed role in glomerular filtration. In addition, HSPGs can bind the leukocyte adhesion molecule l-selectin and chemokines, suggesting a role in inflammation. We examined a panel of biopsies representing different human primary kidney diseases for l-selectin and monocyte chemoattractant protein-1 (MCP-1) binding. In various renal diseases, l-selectin and MCP-1 binding to interstitial perivascular matrix HSPGs is increased, which is significantly associated with leukocyte influx. In proteinuric diseases, including membranous glomerulopathy, minimal change disease, but also IgA nephropathy and lupus nephritis, increased binding of l-selectin and MCP-1 to tubular epithelial cell (TEC) HSPGs is observed, which colocalizes with increased basolateral syndecan-1 and anti-heparan sulfate 10E4 staining. Short-hairpin RNA-mediated silencing demonstrates that syndecan-1 on TECs indeed mediates l-Selectin binding. Increased TEC expression of IL-8 in biopsies of proteinuric patients suggests that the increase in luminal protein may activate TECs to increase expression of l-selectin and MCP-1 binding syndecan-1. Strikingly, urinary syndecan-1 from proteinuric patients is less capable of binding l-selectin compared with urinary syndecan-1 from healthy controls, although syndecan-1 concentrations are similar in both groups. Together, our data show pronounced tubulointerstitial HSPG alterations in primary kidney disease, which may affect the inflammatory response.

Kinetics of mobilization and differentiation of lymphohematopoietic cells during experimental murine schistosomiasis in galectin-3−/−mice

Galectin-3 (gal-3), a beta-galactoside-binding animal lectin, plays a role in cell-cell and cell-extracellular matrix interactions. Extracellular gal-3 modulates cell migration and adhesion in several physiological and pathological processes. Gal-3 is highly expressed in activated macrophages. Schistosoma mansoni eggs display a large amount of gal-3 ligands on their surface and elicit a well-characterized, macrophage-dependent, granulomatous, inflammatory reaction. Here, we have investigated the acute and chronic phases of S. mansoni infection in wild-type and gal-3(-/-) mice. In the absence of gal-3, chronic-phase granulomas were smaller in diameter, displaying thinner collagen fibers with a loose orientation. Schistosoma-infected gal-3(-/-) mice had remarkable changes in the monocyte/macrophage, eosinophil, and B lymphocyte subpopulations as compared with the infected wild-type mice. We observed a reduction of macrophage number, an increase in eosinophil absolute number, and a decrease in B lymphocyte subpopulation (B220(+/high) cells) in the periphery during the evolution of the disease in gal-3(-/-) mice. B lymphopenia was followed by an increase of plasma cell number in bone marrow, spleen, and mesenteric lymph nodes of the infected gal-3(-/-) mice. The plasma IgG and IgE levels also increased in these mice. Gal-3 plays a role in the organization, collagen distribution, and mobilization of inflammatory cells to chronic-phase granulomas, niches for extramedullary myelopoiesis, besides interfering with monocyte-to-macrophage and B cell-to-plasma cell differentiation.

Low molecular weight heparin prevents hepatic fibrogenesis caused by carbon tetrachloride in the rat

BACKGROUND/AIMS

In this study, we investigated the effect of dalteparin sodium, a low molecular weight (LMW)-heparin, on hepatic fibrogenesis caused by chronic carbon tetrachloride (CCl4) administration in the rat.

METHODS

Female Wistar rats were given a single, or repeated intraperitoneal injections of CCl4 (1ml/kg, twice per week) and dalteparin (50IU/kg, daily) for 7 weeks.

RESULTS

Dalteparin did not prevent acute CCl4-induced hepatic necrosis and elevation in serum aminotransferases levels; however, proliferating cell nuclear antigen (PCNA)-positive hepatocytes were dramatically increased 24h after simultaneous administration of CCl4 and dalteparin. Interestingly, serum hepatocyte growth factor (HGF) levels 12h after injection of CCl4 were almost doubled when dalteparin was given simultaneously. Hepatic fibrosis following 7-week CCl4 treatment was markedly ameliorated by daily co-administration of dalteparin. Indeed, dalteparin largely inhibited CCl4-induction of smooth muscle alpha-actin expression, alpha1(I)procollagen and transforming growth factor (TGF)-beta1 mRNA levels in the liver. Further, dalteparin blunted platelet-derived growth factor (PDGF)-induced increases in 5-bromo-2'deoxyuridine (BrdU) uptake in 3-day cultured hepatic stellate cells (HSCs) in a dose-dependent manner.

CONCLUSIONS

Dalteparin enhances hepatic regeneration and minimizes hepatic fibrogenesis caused by chronic CCl4 treatment. The mechanism underlying these effects most likely involves both up-regulation of HGF and inhibition of HSC proliferation.