Expression Of Receptor For HA-mediated Motility Research Articles

Upregulation of hyaluronan-mediated motility receptor in hepatocellular carcinoma predicts poor survival.

Hepatocellular carcinoma (HCC) is one of the most common types of cancer across the world. Hyaluronic acid (HA) has been reported to serve an important role in tumor extension, progression, migration and invasion. In addition, the receptor for HA-mediated motility (RHAMM) has been demonstrated to be overexpressed in different types of cancer. However, whether the upregulation of RHAMM contributes to hepatocarcinogenesis of HCC remains unclear. The present study examined the RHAMM expression in 187 HCC patients by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry (IHC). RHAMM expression was significantly upregulated in liver cancer tissues compared with that observed in adjacent normal liver tissues. The IHC analysis demonstrated that RHAMM was overexpressed in 18 (72.0%) of the 25 HCC tissues. Furthermore, overexpression of RHAMM was associated with tumor-node-metastasis (TNM), the presence of vascular invasion and recurrence. Notably, the present study indicated that the overexpression of RHAMM was closely associated with the shorter disease-free and overall survival, so it may be a potential independent predictor for disease-free and overall survival of HCC patients. In conclusion, the upregulation of RHAMM is associated with HCC progression and prognosis; and it may be a potential independent predictor of disease-free and overall survival of HCC following surgical resection.

Extrinsic ageing in the human skin is associated with alterations in the expression of hyaluronic acid and its metabolizing enzymes

Extrinsic skin ageing or 'photoageing', as opposed to intrinsic skin ageing, is the result of exposure to external factors, mainly ultraviolet irradiation. Glycosaminoglycans (GAG) and particularly hyaluronic acid (HA) are major components of the cutaneous extracellular matrix involved in tissue repair. However, their involvement in extrinsic skin ageing remains elusive. In this study, we investigated the expression of HA and its metabolizing enzymes in photoexposed and photoprotected human skin tissue specimens, obtained from the same patient. Total GAG were isolated, characterized using specific GAG-degrading enzymes and separated by electrophoresis on cellulose acetate membranes and polyacrylamide gels. Quantitation of HA in total GAG was performed using ELISA. Gene expression of hyaluronan synthases (HAS), hyaluronidases (HYAL) and HA receptors CD44 and receptor for HA-mediated motility (RHAMM) was assessed by RT-PCR. We detected a significant increase in the expression of HA, of lower molecular mass, in photoexposed skin as compared with photoprotected skin. This increase was associated with a significant decrease in the expression of HAS1 and an increase in the expression of HYAL1-3. Furthermore, the expression of HA receptors CD44 and RHAMM was significantly downregulated in photoexposed as compared with photoprotected skin. These findings indicate that extrinsic skin ageing is characterized by distinct homoeostasis of HA. The elucidation of the role of HA homoeostasis in extrinsic skin ageing may offer an additional approach in handling cutaneous ageing.

Expression of hyaluronan synthases and corresponding hyaluronan receptors is differentially regulated during oocyte maturation in cattle.

In response to the gonadotropin surge, the compact cumulus-oocyte complex (COC) undergoes expansion by synthesis of the mucopolysaccharide hyaluronan (HA) accompanying oocyte maturation. The objective of the present study was to quantify mRNA transcripts of the HA synthase (HAS) 1, HAS2, and HAS3 and the HA-receptors CD44 and RHAMM (receptor for HA-mediated motility). Additionally, we determined the histological localization of HA and its receptor, CD44, in maturing bovine COCs and cultured granulosa cells (GCs). Full-length transcript of bovine HAS2 and a part of the bovine RHAMM sequence has been made available. Real-time reverse transcriptase-polymerase chain reaction was used for individual mRNA expressions of bovine COCs in comparison to follicular GC gonadotropin treatment. Localization of CD44 and HA were done by immunohistochemistry and biotinylated HA-binding protein, respectively. Gonadotropins caused a rapid, 120-fold increase of HAS2 mRNA, whereas a delayed, 2-fold up-regulation of HAS3 mRNA was observed. The HAS1 transcripts were barely detected. Expression of CD44 mRNA greatly increased during in vitro maturation of COCs, indicating an important role when compared to an unchanged, steady-state RHAMM expression. As a consequence, HA was locally enriched after COC expansion, but only limited change was observed in the GCs. In cultured GCs, HAS2 expression was stimulated through FSH application, followed by the effective treatments of FSH+LH and LH. Treatment with LH induced the highest increase of the CD44 receptor, followed by FSH and FSH+LH treatments. These results suggest that HAS2 is mainly responsible for rapid HA synthesis in bovine COCs and GCs. In bovine COCs, the transcriptional up-regulation of both HAS2 and the receptor CD44 appear to be important prerequisites for initiating HA-mediated effects during final oocyte development and sperm-egg interaction.

Hyaluronan receptor expression increases in fetal excisional skin wounds and correlates with fibroplasia

Background/Purpose: The midgestation fetus heals incisional skin wounds scarlessly, whereas large excisional wounds scar. High concentrations of hyaluronan (HA) are associated with scarless fetal as opposed to scar-forming adult wound repair. Because expression of the HA receptors, CD44 and RHAMM (Receptor for HA-Mediated Motility), has been associated with adult wound fibroplasia, the authors postulated that fetal excisional wounds would show increased expression of CD44 and RHAMM as compared with incisional wounds. Methods: Two models of fetal wound healing were examined. Fetal skin from human abortuses was heterotrans-planted subcutaneously into severe combined immunodeficient (SCID) mice. Fourteen days after grafting, incisional or 2-mm excisional wounds were created (n = 6 per time-point). In addition, incisional and excisional (6 to 10 mm) wounds (n = 5 per time-point) were created on the backs of 70- to 75-day fetal lambs (term, 145 days). Tissue from both models was harvested at sequential time-points after injury. Wounds were studied histologically for fibroplasia and assayed for their HA content. CD44 and RHAMM expression were analyzed by immunohistochemistry and immunoblotting. Results: As expected, in both models, incisional wounds healed scarlessly, whereas excisional wounds showed fibroplasia. Incisional wounds of fetal lambs maintained a significantly higher HA content than excisional wounds 3 days after injury. Between 1 and 7 days in either human or sheep fetal wounds, immunostaining for CD44 and RHAMM markedly increased along the margins of excisional wounds as compared with incisional wounds and unwounded skin. Immunoblot analysis confirmed this increased HA receptor expression in both models. Conclusions: HA receptor expression increased in both human and sheep fetal excisional wounds and correlated with fibroplasia and a reduced HA content. The authors speculate that strategies to limit the expression or function of HA receptors during postnatal wound repair may modify the development of scar.

Inhibiting the Differentiation of Myocardiocytes by Hyaluronic Acid

Background. In vitroexperimentation found that wounded midgestation fetal mouse hearts heal scarlessly. Scarless repair occurs in an environment enriched in hyaluronic acid (HA), while in the absence of HA and the inclusion of hyaluronidase (HAdase), repair by scarring occurs. Excess HA downregulates the expression of the specific HA receptor, RHAMM (receptor for HA-mediated motility). The expression of RHAMM and the migration of cardiac cells from fetal heart explants were investigated in the presence of excess HA and added HAdase.Method.Hearts from Gestational Day 15 fetal mice (term = 20) were cut into four fragments, established as explant cultures, and assigned to one of three treatment groups: 400 μg/ml HA, 50 U/ml HAdase, or saline. Cellular outgrowth was recorded at Day 7. The character of the migrating cells (fibroblast-like or myocardiocyte) was determined by immunostaining for filamentous actin (f-actin, microfilaments) or desmin (intermediate filaments). The expression of RHAMM was documented also.Results.The inclusions of HA stimulated cell migration and proliferation, perpetuated cells as immature myocardiocytes, and blocked the expression of RHAMM. The inclusion of HAdase limited cell migration and proliferation, promoted the differentiation of cells into myocardiocytes, and increased the number of cells expressing RHAMM.Conclusion.Increased concentrations of HA promoted the proliferation and migration of an immature population of myocardiocytes. On the other hand the inclusion of HAdase inhibits the migration and proliferation of cells and promotes the appearance of myocardiocytes with a fibroblast-like morphology. The speculation is that excess HA may promote proliferation and migration of immature myocardiocytes into a heart defect, leading to replacement of lost myocardium with contractile tissue rather than dysfunctional scar.

Nitric Oxide (NO) Regulates the Production and Receptor-Mediated Internalization of Hyaluronan (HA) During Macrophage Chemotaxis. † 1586

Macrophage chemotaxis, a critical component of the inflammatory response to lung injury, has previously been shown to be attenuated by inhibitors of NO synthase. Hyaluronan (HA), a glycosaminoglycan that accumulates in the lung during pulmonary inflammation, regulates cell locomotion through interaction with cell receptors such as RHAMM (Receptor for HA-Mediated Motility). Since NO has been implicated in pulmonary damage, we hypothesized that NO would regulate the expression of both HA and RHAMM during stimulation of macrophage chemotaxis. We used a murine macrophage cell line (S1) in a modified Boyden chamber assay. HA stimulated macrophage chemotaxis in a bell-shaped, dose-dependent manner, with maximal effect at 0.1 μg/ml. L-N-arginine methyl ester (L-NAME), a blocker of NO synthase, failed to inhibit HA-stimulated chemotaxis over a large range of concentrations (0.1-5 mM). Sodium nitroprusside (SNP), a NO donor, stimulated macrophage chemotaxis in a dose-dependent manner with maximal effect at 0.5 nM. This concentration of SNP also maximally upregulated the expression of RHAMM and HA. The HA-binding region of aggrecan and synthetic HA-binding peptides inhibited NO-stimulated macrophage chemotaxis, as did an anti-RHAMM antiserum previously shown to interfere with RHAMM:HA interactions. Interestingly, addition of L-NAME to quiescent S1 cells down-regulated RHAMM and increased the media content of HA suggesting a block of receptor-mediated internalization of HA. We conclude that NO regulates the normal homeostasis of the RHAMM:HA axis in quiescent cells, but, at higher concentrations, increases the expression of RHAMM and HA, stimulating macrophage chemotaxis through the interaction of HA with RHAMM. We speculate that regulation of HA content after lung injury may provide a useful means of limiting pulmonary inflammation and subsequent fibrosis.

NITRIC OXIDE-MEDIATED MACROPHAGE CHEMOTAXIS IS DEPENDENT ON HYALURONAN (HA) AND THE HA RECEPTOR RHAMM. † 1989

Previous work has implicated the interaction of hyaluronan (HA) with its receptor RHAMM (Receptor for HA-Mediated Motility) in the regulation of macrophage motility during bleomycin-induced pulmonary inflammation in rats. Further, growth factor-mediated cell locomotion is mediated by RHAMM and HA. Since nitric oxide (NO) has also been implicated in macrophage chemotaxis and in pulmonary inflammation, we hypothesized that the RHAMM:HA interaction is also required for NO-mediated macrophage chemotaxis. We investigated macrophage chemotaxis using a murine macrophage cell line (S1) in a modified Boyden chamber assay. HA stimulated macrophage chemotaxis in a bell-shaped, dose-dependent manner, with maximal effect at 0.1 μg/ml. L-N-arginine methyl ester (L-NAME), a blocker of nitric oxide synthase, failed to inhibit HA-stimulated chemotaxis over a large range of concentrations (0.1 mM - 5 mM). Sodium nitroprusside (SNP), a NO donor, stimulated macrophage chemotaxis in a dose-dependent manner with maximal effect at 0.5 nM. This concentration of SNP also maximally upregulated the expression of RHAMM and HA in S1 cells. The HA-binding region of aggrecan, isolated from bovine nasal cartilage, inhibited NO-mediated chemotaxis by 80%, while synthetic HA-binding peptides (2 mg/ml), previously shown to inhibit macrophage motility, were able to inhibit NO-mediated macrophage chemotaxis by 50% as compared to scrambled peptide controls. We conclude that NO increases the expression of RHAMM and HA, and that RHAMM:HA interaction is required for NO-mediated macrophage chemotaxis. We speculate that regulation of HA content may provide a useful means of limiting pulmonary inflammation after lung injury.

SYSTEMIC AND INTRATRACHEAL STEROIDS DECREASE THE PRODUCTION OF HYALURONAN(HA) AND REDUCE THE EXPRESSION OF THE HA RECEPTOR RHAMM DURING BLEOMYCIN-INDUCED PULMONARY INFLAMMATION. ▴ 1975

We have previously shown that hyaluronan (HA) and its receptor RHAMM(Receptor for HA-Mediated Motility) regulate macrophage motility during bleomycin-induced pulmonary inflammation. Since steroid therapy has been used to limit inflammation in this model, and may limit the severity of bronchopulmonary dysplasia in premature infants, we hypothesized that, in addition to reducing the inflammatory response, steroids would reduce the expression of RHAMM and HA after bleomycin-induced lung injury in rats. Sprague-Dawley rats (n=5/group) were treated with either 30 mg/kg solumedrol intramuscularly (IM), or 1 mg budesonide intratracheally (IT) 1 day prior to and daily for 4 days after intratracheal bleomycin. Control animals received an equal volume of normal saline by the same routes. Four days after injury, bronchoalveolar lavage (BAL) was performed. The cells from the BAL were separated from the lavage fluid by centrifugation. The HA content of the lavage fluid was measured using an ELISA-like assay, while the cells were analyzed for RHAMM content by western blot, and macrophage content by glucosaminidase activity. Steroid treatment decreased HA content of the lavage fluid by 40%, and decreased RHAMM expression by 40% (IM) and 90% (IT) as compared to controls. Both treatments resulted in a 40% reduction in macrophage accumulation in the lungs of injured animals. We conclude that, in addition to decreasing pulmonary inflammation after intratracheal bleomycin, steroids decrease the expression of RHAMM and HA in vivo. We speculate that the anti-inflammatory action of steroids in lung injury may be explained in part by the inhibition of RHAMM and HA.

RHAMM, a Receptor for Hyaluronan-Mediated Motility, on Normal Human Lymphocytes, Thymocytes and Malignant B Cells: a Mediator in B cell Malignancy?

RHAMM (Receptor for HA Mediated Motility) is a novel HA receptor that has been linked to regulating cell locomotion and density dependent contact inhibition of fibroblasts, smooth muscle cells, macrophages, lymphocytes, astrocytes and sperm. The ubiquitous expression of RHAMM suggests the existence of multiple isoforms, and indeed, RHAMM is found in various cellular compartments, namely nuclear, cytosolic, membrane-bound and extracellular. In this review, we emphasize the evolving role of RHAMM in B cell malignancies, and examine the function of RHAMM in T cell development in the thymic microenvironment. Both the motile behaviour of progenitor thymocytes (CD3-CD4-CD8-) and malignant B cells from multiple myeloma (MM), plasma cell leukemia, and hairy cell leukemia was blocked by monoclonal antibodies to RHAMM, suggesting that motility may correlate with increased expression of RHAMM at the cell surface. Interestingly, the soluble form of RHAMM is able to inhibit fibroblast locomotion, and it is likely that a balance between expression of both forms determines, in part the motility of cells. RHAMM appears to play a fundamental role in the immune system and the ability of RHAMM to function as a motility receptor is likely to be due to complex variables including the extent to which soluble RHAMM is secreted. RHAMM expression characterizes circulating monoclonal B cells as abnormal. potentially invasive and/or metastatic components of myeloma and may underlie the malignant behavior of these cells.