A Modified Glycosaminoglycan, GM-0111, Inhibits Molecular Signaling Involved in Periodontitis

In silico approaches for better understanding cysteine cathepsin-glycosaminoglycan interactions

Cysteine cathepsins constitute the largest cathepsin family, with 11 proteases in human that are present primarily within acidic endosomal and lysosomal compartments. They are involved in the turnover of intracellular and extracellular proteins. They are synthesized as inactive procathepsins that are converted to mature active forms. Cathepsins play important roles in physiological and pathological processes and, therefore, receive increasing attention as potential therapeutic targets. Their maturation and activity can be regulated by glycosaminoglycans (GAGs), long linear negatively charged polysaccharides composed of recurring dimeric units. In this review, we summarize recent computational progress in the field of (pro)cathepsin-GAG complexes analyses.

In silico insights into procathepsin S maturation mediated by glycosaminoglycans

Procathepsins, inactive precursors of cathepsins are present in the extracellular matrix (ECM) and in lysosomes. Their active forms are involved in a number of biologically relevant processes, including bone resorption, intracellular proteolysis and regulation of programmed cell death. These processes might be mediated by glycosaminoglycans (GAGs), long unbranched periodic negatively charged polysaccharides. GAGs are also present in ECM and play important role in anticoagulation, angiogenesis and tissue regeneration. GAGs not only mediate the enzymatic activity of cathepsins but can also regulate the process of procathepsin maturation, as it was shown for procathepsin B and S. In this study, we propose the molecular mechanism underlying the biological role of GAGs in procathepsin S maturation and compare our findings with computational data obtained for procathepsin B. We rigorously analyse procathepsin S-GAG complexes in terms of their dynamics, free energy and potential allosteric regulation. We conclude that the GAG binding region might have an effect on the dynamics of procathepsin S structure and so affect its maturation by two different mechanisms.

Hyaluronic Acid in Rhinology: Its Uses, Advantages and Drawbacks-A Review

Hyaluronic acid has been increasingly involved in recent research due to its many chemical and physical properties. This is a review of the literature for studies involving the use of hyaluronic acid in rhinology. Hyaluronic acid washes and irrigation have been increasingly used in chronic sinusitis medical therapy and post-operatively with mixed results. It has also been shown to play a role in the treatment of nasal polyposis, allergic rhinitis, acute rhinosinusitis and empty nose syndrome. Its effect on biofilm in many disease entities has also been studied. HA is being recently used as ancillary treatment for several rhinologic conditions such as post-operative endoscopy care and chronic sinonasal infections. The properties of HA have intrigued researchers over the past years particularly in biofilm management, healing and inflammation.

Effect of xylitol on Porphyromonas gingivalis: A systematic review

OBJECTIVE

This review was conducted to assess the effectiveness of xylitol against Porphyromonas gingivalis anaerobic species, a key microbe contributing to periodontal disease pathogenesis.

MATERIAL AND METHODS

Relevant studies published on seven online databases (Cochrane, Ovid, Pubmed, Pubmed Central, Scopus, Google Scholar, and Web of Science) were included in accordance with the PRISMA guidelines. Inclusion criteria allowed all study designs involving xylitol and P. gingivalis, literature published since the year 2000, and all xylitol delivery forms.

RESULTS

The initial search yielded 186 papers. After the removal of duplicates, five reviewers screened every article for eligibility and seven articles were selected for data extraction. Four out of seven included studies assessed the dose-dependent effect of xylitol on P. gingivalis growth, two studies assessed the effect of xylitol on P. gingivalis-induced cytokine expression, and one study assessed both domains.

CONCLUSIONS

From the in vitro studies included in this systematic review, there is some evidence of xylitol's inhibitory effect on P. gingivalis. However, more evidence derived from in vivo studies is required to confirm its effectiveness warranting their routine use.

Sulfated Hyaluronan Binds to Heparanase and Blocks Its Enzymatic and Cellular Actions in Carcinoma Cells

We examined whether sulfated hyaluronan exerts inhibitory effects on enzymatic and biological actions of heparanase, a sole endo-beta-glucuronidase implicated in cancer malignancy and inflammation. Degradation of heparan sulfate by human and mouse heparanase was inhibited by sulfated hyaluronan. In particular, high-sulfated hyaluronan modified with approximately 2.5 sulfate groups per disaccharide unit effectively inhibited the enzymatic activity at a lower concentration than heparin. Human and mouse heparanase bound to immobilized sulfated hyaluronan. Invasion of heparanase-positive colon-26 cells and 4T1 cells under 3D culture conditions was significantly suppressed in the presence of high-sulfated hyaluronan. Heparanase-induced release of CCL2 from colon-26 cells was suppressed in the presence of sulfated hyaluronan via blocking of cell surface binding and subsequent intracellular NF-κB-dependent signaling. The inhibitory effect of sulfated hyaluronan is likely due to competitive binding to the heparanase molecule, which antagonizes the heparanase-substrate interaction. Fragment molecular orbital calculation revealed a strong binding of sulfated hyaluronan tetrasaccharide to the heparanase molecule based on electrostatic interactions, particularly characterized by interactions of (−1)- and (−2)-positioned sulfated sugar residues with basic amino acid residues composing the heparin-binding domain-1 of heparanase. These results propose a relevance for sulfated hyaluronan in the blocking of heparanase-mediated enzymatic and cellular actions.

SAGE: Novel Therapy to Reduce Inflammation in a Naturally Occurring-Dog Model of Periodontal Disease

Objective

Methods

Results

Conclusion

An Oligomeric Sulfated Hyaluronan and Silk-Elastinlike Polymer Combination Protects against Murine Radiation Induced Proctitis

Semisynthetic glycosaminoglycan ethers (SAGEs) are short, sulfated hyaluronans which combine the natural properties of hyaluronan with chemical sulfation. In a murine model, SAGEs provide protection against radiation induced proctitis (RIP), a side effect of lower abdominal radiotherapy for cancer. The anti-inflammatory effects of SAGE have been studied in inflammatory diseases at mucosal barrier sites; however, few mechanisms have been uncovered necessitating high throughput methods. SAGEs were combined with silk-elastinlike polymers (SELPs) to enhance rectal accumulation in mice. After high radiation exposure to the lower abdominal area, mice were followed for 3 days or until they met humane endpoints, before evaluation of behavioral pain responses and histological assessment of rectal inflammation. RNA sequencing was conducted on tissues from the 3-day cohort to determine molecular mechanisms of SAGE–SELP. After 3 days, mice receiving the SAGE–SELP combination yielded significantly lowered pain responses and amelioration of radiation-induced rectal inflammation. Mice receiving the drug–polymer combination survived 60% longer than other irradiated mice, with a fraction exhibiting long term survival. Sequencing reveals varied regulation of toll like receptors, antioxidant activities, T-cell signaling, and pathways associated with pain. This investigation elucidates several molecular mechanisms of SAGEs and exhibits promising measures for prevention of RIP.

Therapeutic potential of a novel semi-synthetic-sulfated-polysaccharide to suppress inflammatory mediators in P. gingivalis LPS stimulated human monocytes/macrophages

BACKGROUND

Chronic periodontitis is associated with an increased risk for systemic conditions such as cardiovascular disease, diabetes, and osteoporosis. During chronic periodontitis, endotoxin (lipopolysaccharide, LPS) produced by P. gingivalis provokes monocyte accumulation and differentiation into macrophages and increased secretion of pro-inflammatory cytokines and matrix metalloproteases (MMPs). While normal levels of MMPs are important in cellular function, increased levels of cytokines and MMPs can cause connective tissue destruction.

RESULTS

In the current study, we investigated the therapeutic capability of a novel semi-synthetic sulfated polysaccharide (SAGE) on the production of cytokines and MMPs by cultured human mononuclear cells and macrophages stimulated with endotoxin LPS produced by P. gingivalis, a periodontally-relevant cell culture model. Our research demonstrated SAGE inhibited the LPS induced synthesis of inflammatory mediators including TNF-α, IL-1β, PGE₂, and MMP-9 in this periodontal-relevant cell culture model. In addition, TLR-2 and TLR-4 levels were also reduced with the SAGE treatment.

CONCLUSIONS

The therapeutic potential of this novel semi-synthetic sulfated polysaccharide compound may help to prevent tissue damage and bone loss in patients with periodontal disease or other inflammatory diseases.

Silk-elastinlike copolymers enhance bioaccumulation of semisynthetic glycosaminoglycan ethers for prevention of radiation induced proctitis

Radiation-induced proctitis (RIP) is a debilitating adverse event that occurs commonly during lower abdominal radiotherapy. The lack of prophylactic treatment strategies leads to diminished patient quality of life, disruption of radiotherapy schedules, and limitation of radiotherapy efficacy due to dose-limiting toxicities. Semisynthetic glycosaminoglycan ethers (SAGE) demonstrate protective effects from RIP. However, low residence time in the rectal tissue limits their utility. We investigated controlled delivery of GM-0111, a SAGE analogue with demonstrated efficacy against RIP, using a series of temperature-responsive polymers to compare how distinct phase change behaviors, mechanical properties and release kinetics influence rectal bioaccumulation. Poly(lactic acid)-co-(glycolic acid)-block-poly(ethylene glycol)-block-poly(lactic acid)-co-(glycolic acid) copolymers underwent macroscopic phase separation, expelling >50% of drug during gelation. Poloxamer compositions released GM-0111 cargo within 1 h, while silk-elastinlike copolymers (SELPs) enabled controlled release over a period of 12 h. Bioaccumulation was evaluated using fluorescence imaging and confocal microscopy. SELP-415K, a SELP analogue with 4 silk units, 15 elastin units, and one elastin unit with lysine residues in the monomer repeats, resulted in the highest rectal bioaccumulation. SELP-415K GM-0111 compositions were then used to provide localized protection from radiation induced tissue damage in a murine model of RIP. Rectal delivery of SAGE using SELP-415K significantly reduced behavioral pain responses, and reduced animal mass loss compared to irradiated controls or treatment with traditional delivery approaches. Histological scoring showed RIP injury was ameliorated for animals treated with GM-0111 delivered by SELP-415K. The enhanced bioaccumulation provided by thermoresponsive SELPs via a liquid to semisolid transition improved rectal delivery of GM-0111 to mice and radioprotection in a RIP model.

Polysulfated Hyaluronan GlycoMira-1111 Inhibits Elastase and Improves Rheology in Cystic Fibrosis Sputum

Cystic fibrosis (CF) lung disease is marked by high concentrations of neutrophil elastase (NE) and DNA polymers; both factors contribute to airway disease. Although inhaled recombinant human dornase alfa reduces the frequency of CF pulmonary exacerbations, it also increases free NE activity in the sputum. There are no approved anti-NE therapies for patients with CF. We investigated whether synthetic, low-molecular weight polysulfated hyaluronan GlycoMira-1111 (GM-1111) would be effective as an anti-NE drug using ex vivo CF sputum. Anti-NE activity of GM-1111 was tested in CF sputum in the presence or absence of dornase alfa and/or hypertonic saline using a spectrophotometric assay specific for human NE and was compared with unfractionated heparin. We tested whether GM-1111 disaggregated DNA from CF sputum (using gel electrophoresis analysis) or modified CF sputum viscoelastic properties (using a dynamic rheometer). GM-1111 and unfractionated heparin had near equivalent anti-NE activity in CF sputum in the presence of dornase alfa. Both GM-1111 and unfractionated heparin retained anti-NE activity in hypertonic saline but with decreased activity. GM-1111 increased the release of soluble DNA in CF sputum, resulting in improved depolymerization efficacy of dornase alfa. GM-1111 decreased CF sputum elasticity. GM-1111 inhibited NE activity, enhanced DNA depolymerization by deoxyribonuclease, and decreased viscoelastic properties of CF sputum, similar to effects reported previously for unfractionated heparin. Unlike heparins, GM-1111 is synthetic, with minimal anticoagulant activity, and is not derived from animal products. These key attributes provide advantages over unfractionated heparin as a potential therapeutic for CF.

Glycosaminoglycans as Multifunctional Anti-Elastase and Anti-Inflammatory Drugs in Cystic Fibrosis Lung Disease

Neutrophil elastase (NE) is a major protease in the airways of patients with cystic fibrosis (CF) that activates airway inflammation by several mechanisms. NE stimulates epithelial toll like receptors (TLR) resulting in cytokine upregulation and release, upregulates MUC5AC, a major airway mucin, degrades both phagocytic receptors and opsonins resulting in both neutrophil and macrophage phagocytic failure, generates oxidative stress via extracellular generation and uptake of heme free iron, and activates other proteases. Altogether, these mechanisms create a significant inflammatory challenge that impairs innate immune function and results in airway remodeling. Currently, a major gap in our therapeutic approach to CF lung disease is the lack of an effective therapeutic strategy targeting active NE and its downstream pro-inflammatory sequelae. Polysulfated glycosaminoglycans (GAGs) are potent anti-elastase drugs that have additional anti-inflammatory properties. Heparin is a prototype of a glycosaminoglycan with both anti-elastase and anti-inflammatory properties. Heparin inhibits NE in an allosteric manner with high potency. Heparin also inhibits cathepsin G, blocks P-selectin and L-selectin, hinders ligand binding to the receptor for advanced glycation endproducts, and impedes histone acetyltransferase activity which dampens cytokine transcription and High Mobility Group Box 1 release. Furthermore, nebulized heparin treatment improves outcomes for patients with chronic obstructive pulmonary disease (COPD), asthma, acute lung injury and smoke inhalation. However, the anticoagulant activity of heparin is a potential contraindication for this therapy to be developed for CF lung disease. Therefore, modified heparins and other GAGs are being developed that retain the anti-elastase and anti-inflammatory qualities of heparin with minimal to no anticoagulant activity. The modified heparin, 2-O, 3-O desulfated heparin (ODSH), maintains anti-elastase and anti-inflammatory activities in vitro and in vivo, and has little residual anticoagulant activity. Heparan sulfate with O-sulfate residues but not N-sulfate residues blocks allergic asthmatic inflammation in a murine model. Polysulfated hyaluronic acid abrogates allergen- triggered rhinosinusitis in a murine model. Finally, nonsaccharide glycosaminoglycan mimetics with specific sulfate modifications can be designed to inhibit NE activity. Altogether, these novel GAGs or GAG mimetics hold significant promise to address the unmet need for inhaled anti-elastase and anti-inflammatory therapy for patients with CF.

Temperature-responsive silk-elastinlike protein polymer enhancement of intravesical drug delivery of a therapeutic glycosaminoglycan for treatment of interstitial cystitis/painful bladder syndrome

Interstitial cystitis (IC), also known as painful bladder syndrome, is a debilitating chronic condition with many patients failing to respond to current treatment options. Rapid clearance, mucosal coating, and tight epithelium create strong natural barriers that reduce the effectiveness of many pharmacological interventions in the bladder. Intravesical drug delivery (IDD) is the administration of therapeutic compounds or devices to the urinary bladder via a urethral catheter. Previous work in improving IDD for IC has focused on the sustained delivery of analgesics within the bladder and other small molecule drugs which do not address underlying inflammation and bladder damage. Therapeutic glycosaminoglycans (GAG) function by restoring the mucosal barrier within the bladder, promoting healing responses, and preventing irritating solutes from reaching the bladder wall. There is an unmet medical need for a therapy that provides both acute relief of symptoms while alleviating underlying physiological sources of inflammation and promoting healing within the urothelium. Semi-synthetic glycosaminoglycan ethers (SAGE) are an emerging class of therapeutic GAG with intrinsic anti-inflammatory and analgesic properties. To reduce SAGE clearance and enhance its accumulation in the bladder, we developed a silk-elastinlike protein polymer (SELP) based system to enhance SAGE IDD. We evaluated in vitro release kinetics, rheological properties, impact on bladder function, pain response, and bladder inflammation and compared their effectiveness to other temperature-responsive polymers including Poloxamer 407 and poly(lactic-co-glycolic acid)-poly(ethylene glycol). SAGE delivered via SELP-enhanced intravesical delivery substantially improved SAGE accumulation in the urothelium, provided a sustained analgesic effect 24 h after administration, and reduced inflammation.

A synthetic glycosaminoglycan reduces sinonasal inflammation in a murine model of chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is characterized by sustained mucosal inflammation, impaired mucociliary clearance, loss of cilia and epithelial barrier breakdown, and tissue remodeling. Certain glycosaminoglycans inhibit various inflammatory mediators, suppress bacterial growth, and provide important functions in mucosal tissue repair and mucociliary clearance. Herein, we evaluated the effects of a synthetic glycosaminoglycan, GM-1111, on the clinical signs and inflammatory tissue changes associated with CRS in mice. CRS was generated by repeated intranasal applications of Aspergillus fumigatus (A. fumigatus) extracts over 4 weeks. Mice were then intranasally administered GM-1111 (600 μg per dose, 5 times a week) or vehicle (phosphate buffered saline, PBS) for an additional 4 weeks while still being given A. fumigatus extracts to maintain a chronic inflammatory environment with acute exacerbations. Clinical signs indicative of sinonasal inflammation were recorded throughout the study. After 9 weeks, whole blood and sinonasal tissues were harvested for hematological, histological, and biochemical examination. The clinical signs, white blood cell counts, tissue markers of sinonasal inflammation, and histological changes caused by A. fumigatus extract administration were compared to the healthy (PBS vehicle) and GM-1111-treated groups (n = 12 per treatment group). Compared to vehicle-treated animals, animals treated with GM-1111 demonstrated significant reductions in clinical signs (p<0.05), degenerative tissue changes, goblet cell hyperplasia, inflammatory cell infiltration (p<0.01), innate immunity- (tlr2, tlr4, myd88, il1b, tnfa, il6, and il12) and adaptive immunity-associated (ccl11, ccl24, ccl5, il4, il5, and il13) cytokine gene expression (p<0.05 to p<0.0001) in sinonasal tissues, and serum IgE levels (p<0.01). Our data suggest that GM-1111 significantly reduces local and systemic effects of CRS-associated sinonasal inflammation.

[Effect of injectable composites of calcium sulfate and hyaluronate in enhancing osteogenesis]

Objective

To fabricate an injectable composite bone substitute with hyaluronic acid (HA) and calcium sulfate and to evaluate the biocompatibility and effect of the composite on cell proliferation, osteogenic differentiation in vitro and osteogenic capability in vivo.

Methods

Calcium sulfate powder was mixed with HA solution, cross-linked HA solution, and phosphate buffer solution (PBS) in a ratio of 2∶1 ( W/ V) to get composites of CA+HA, CA+HAC, and CA. The standard extracts from above 3 materials were prepared according to ISO10993-5, and were used to culture mouse MC3T3-E1 cells. The composite biocompatibility and cell proliferation in different concentrations of extract were tested with cell counting kit-8 (CCK-8). The cells were cultured with standard medium as a control. The optimal concentration was selected for osteogenic differentiation test, and ELISA Kit was used to determine the alkaline phosphatase (ALP), collagen type I (COL-I), and osteocalcin (OCN). The femoral condylar bone defect was made on New Zealand white rabbits and repaired with CA+HA, CA+HAC, and CA. Micro-CT was done to evaluate new bone formation with bone volume/tissue volume (BV/TV) ratio at 6 and 12 weeks. HE staining was used to observe bone formation.

Results

CA+HA and CA+HAC were better in injectability and stability in PBS than CA. The biocompatibility test showed that absorbance ( A) value of CA group was significantly lower than that of control group ( P<0.05) at 6, 12, and 24 hours after culture, but no significant difference was found in A values between CA+HA group or CA+HAC group and control group ( P>0.05). The proliferation test showed 25% and 50% extract of all 3 materials had significantly higher A value than control group ( P<0.05). For 75% and 100% extract, only CA+HA group had significantly higher A value than control group ( P<0.05). And 50% extract was selected for osteogenic differentiation test. At 14 and 21 days, ALP, COL-I and OCN concentrations of CA+HA group and CA+HAC group were significantly higher than those of CA group and control group ( P<0.05). Micro-CT results showed higher BV/TV in CA+HA group and CA+HAC group than CA group at 6 and 12 weeks ( P<0.05), but no significant difference was found between CA+HA group and CA+HAC group ( P>0.05). HE staining revealed that a little bone tissue was seen in CA+HA group and CA+HAC group, but there was no bone formation in CA group at 6 weeks; more streak bone tissue in CA+HA group and CA+HAC group than CA group at 12 weeks.

Conclusion

Composites prepared with calcium sulfate and HA or with cross-linked HA are stable, injectable, and biocompatible. The materials have excellent effect on proliferation and differentiation of mouse MC3T3-E1 cells. They also show good osteogenic capability in vivo. So it is a potential bone substitutes for bone defective diseases.

Prevention of sinonasal inflammation by a synthetic glycosaminoglycan

BACKGROUND

Glycosaminoglycans (GAGs) are polysaccharides that are distributed on respiratory epithelial cells, endothelial cells, and submucosal glands. Uniquely positioned, certain GAGs exhibit anti-inflammatory properties in respiratory diseases and serve important roles in repairing mucosal surfaces and modulating mucociliary clearance. We hypothesized that topical administration of a synthetic GAG (GM-0111) would prevent sinonasal inflammation in a mouse model of rhinosinusitis (RS).

METHODS

To test our hypothesis, C57BL/6 mice were intranasally administered fluorescent GM-0111, and sinonasal tissues were examined for coating and penetration ability. To test therapeutic feasibility, mice (n = 6) were given GM-0111 or hyaluronic acid (HA; 800 μg dose) prior to inducing RS with inflammatory molecule LL-37 (115 μg dose). After 24 hours, sinonasal tissues were harvested for histological and biochemical analysis of inflammatory markers (inflammatory cell infiltration, lamina propria [LP] thickening, and neutrophil enzyme myeloperoxidase [MPO]) and cell death.

RESULTS

GM-0111 was observed within sinonasal tissues 1 hour and 24 hours after intranasal administration, indicating rapid and effective coating and penetration. GM-0111 prevented sinonasal tissues from developing inflammatory changes, with significant reductions in mast cell infiltration (p < 0.05), LP thickening (p < 0.001), and MPO levels (p < 0.01) when compared to tissues treated with LL-37 and those pretreated with HA. GM-0111 reduced cell death within sinonasal tissues in contrast to LL-37-treated tissues.

CONCLUSION

We report a new synthetic GAG (GM-0111) that uniformly coats and penetrates into the sinonasal mucosa to prevent sinonasal inflammation and cell death in a mouse model of RS.

Establishing the UK DNA Bank for motor neuron disease (MND)

In 2003 the Motor Neurone Disease (MND) Association, together with The Wellcome Trust, funded the creation of a national DNA Bank specific for MND. It was anticipated that the DNA Bank would constitute an important resource to researchers worldwide and significantly increase activity in MND genetic research. The DNA Bank houses over 3000 high quality DNA samples, all of which were donated by people living with MND, family members and non-related controls, accompanied by clinical phenotype data about the patients. Today the primary focus of the UK MND DNA Bank still remains to identify causative and disease modifying factors for this devastating disease.