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Wang Z, Sun L, Wang W, Wang Z, Shi G, Dai H, Yu A. A double-network porous hydrogel based on high internal phase emulsions as a vehicle for potassium sucrose octasulfate delivery accelerates diabetic wound healing. Regen Biomater 2024; 11:rbae024. [PMID: 38628546 PMCID: PMC11018543 DOI: 10.1093/rb/rbae024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 01/31/2024] [Accepted: 02/18/2024] [Indexed: 04/19/2024] Open
Abstract
Diabetic wounds are a difficult medical challenge. Excessive secretion of matrix metalloproteinase-9 (MMP-9) in diabetic wounds further degrades the extracellular matrix and growth factors and causes severe vascular damage, which seriously hinders diabetic wound healing. To solve these issues, a double-network porous hydrogel composed of poly (methyl methacrylate-co-acrylamide) (p(MMA-co-AM)) and polyvinyl alcohol (PVA) was constructed by the high internal phase emulsion (HIPE) technique for the delivery of potassium sucrose octasulfate (PSO), a drug that can inhibit MMPs, increase angiogenesis and improve microcirculation. The hydrogel possessed a typical polyHIPE hierarchical microstructure with interconnected porous morphologies, high porosity, high specific surface area, excellent mechanical properties and suitable swelling properties. Meanwhile, the p(MMA-co-AM)/PVA@PSO hydrogel showed high drug-loading performance and effective PSO release. In addition, both in vitro and in vivo studies showed that the p(MMA-co-AM)/PVA@PSO hydrogel had good biocompatibility and significantly accelerated diabetic wound healing by inhibiting excessive MMP-9 in diabetic wounds, increasing growth factor secretion, improving vascularization, increasing collagen deposition and promoting re-epithelialization. Therefore, this study provided a reliable therapeutic strategy for diabetic wound healing, some theoretical basis and new insights for the rational design and preparation of wound hydrogel dressings with high porosity, high drug-loading performance and excellent mechanical properties.
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Affiliation(s)
- Zhiwei Wang
- Department of Orthopedics Trauma and Microsurgery, Zhongnan Hospital of Wuhan University, Wuhan 430070, China
| | - Lingshun Sun
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Biomedical Materials and Engineering Research Center of Hubei Province, Wuhan University of Technology, Wuhan 430070, China
| | - Weixing Wang
- Department of Orthopedics Trauma and Microsurgery, Zhongnan Hospital of Wuhan University, Wuhan 430070, China
| | - Zheng Wang
- Department of Orthopedics Trauma and Microsurgery, Zhongnan Hospital of Wuhan University, Wuhan 430070, China
| | - Ge Shi
- Department of Orthopedics Trauma and Microsurgery, Zhongnan Hospital of Wuhan University, Wuhan 430070, China
| | - Honglian Dai
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Biomedical Materials and Engineering Research Center of Hubei Province, Wuhan University of Technology, Wuhan 430070, China
| | - Aixi Yu
- Department of Orthopedics Trauma and Microsurgery, Zhongnan Hospital of Wuhan University, Wuhan 430070, China
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Drakou A, Sioutis S, Zafeiris I, Soucacos F, Karampikas V, Tsatsaragkou A, Mavrogenis AF, Koulalis D. Sucralfate Prevents Pin Site Infections of External Fixators in Open Tibia Fractures. J Long Term Eff Med Implants 2024; 34:1-7. [PMID: 37938199 DOI: 10.1615/jlongtermeffmedimplants.2023044966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Pin site infections are the main complication of external fixators. The most common pathogens are Staphylococcus epidermidis and Staphylococcus aureus. The incidence of pin site infections ranges from 2% to 30%. Until now, no satisfactory prevention strategy exists. Therefore, we performed this study to assess the effect of a sucralfate gel 25% applied around the pins of external fixation systems in trauma patients with open tibia fractures. We prospectively studied two groups of patients with open tibia fractures treated with external fixators. In group A patients, pin site care was performed with the use of normal saline and plain dressings once a day. In group B patients, pin site care was performed with the use of sucralfate gel 25%. The incidence of pin site infections was 33.33% for patients of group A and 16.67% for patients of group B. Patients of group B showed significantly lower rate of pin site infections compared to patients of group A (p-value = 0.032). No patient experienced any complications related to the local application of the drug. Sucralfate significantly prevents pin site infections of external fixators in open tibia fractures. Therefore, it can be used as a preventive antimicrobial agent for pin site infections in patients with external fixators.
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Affiliation(s)
| | - Spyridon Sioutis
- First Department of Orthopaedics, National and Kapodistrian University of Athens, University Medical School, Athens, Greece
| | - Ioannis Zafeiris
- First Department of Orthopaedics, National and Kapodistrian University of Athens, School of Medicine, Athens, Greece
| | - Fotini Soucacos
- First Department of Orthopaedics, National and Kapodistrian University of Athens, School of Medicine, Athens, Greece
| | - Vasileios Karampikas
- First Department of Orthopedics, National and Kapodistrian University of Athens, ATTIKON University General Hospital, Athens, Greece
| | | | - Andreas F Mavrogenis
- First Department of Orthopaedics, National and Kapodistrian University of Athens, School of Medicine, ATTIKON University Hospital, Athens, Greece
| | - Dimitrios Koulalis
- First Department of Orthopaedics, National and Kapodistrian University of Athens, School of Medicine, Athens, Greece
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Schmid V, Wurzel A, Wetzel CH, Plössl K, Bruckmann A, Luckner P, Weber BHF, Friedrich U. Retinoschisin and novel Na/K-ATPase interaction partners Kv2.1 and Kv8.2 define a growing protein complex at the inner segments of mammalian photoreceptors. Cell Mol Life Sci 2022; 79:448. [PMID: 35876901 PMCID: PMC9314279 DOI: 10.1007/s00018-022-04409-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 05/05/2022] [Accepted: 05/30/2022] [Indexed: 11/28/2022]
Abstract
The RS1 gene on Xp 22.13 encodes retinoschisin which is known to directly interact with the retinal Na/K-ATPase at the photoreceptor inner segments. Pathologic mutations in RS1 cause X-linked juvenile retinoschisis (XLRS), a hereditary retinal dystrophy in young males. To further delineate the retinoschisin-Na/K-ATPase complex, co-immunoprecipitation was performed with porcine and murine retinal lysates targeting the ATP1A3 subunit. This identified the voltage-gated potassium (Kv) channel subunits Kv2.1 and Kv8.2 as direct interaction partners of the retinal Na/K-ATPase. Colocalization of the individual components of the complex was demonstrated at the membrane of photoreceptor inner segments. We further show that retinoschisin-deficiency, a frequent consequence of molecular pathology in XLRS, causes mislocalization of the macromolecular complex during postnatal retinal development with a simultaneous reduction of Kv2.1 and Kv8.2 protein expression, while the level of retinal Na/K-ATPase expression remains unaffected. Patch-clamp analysis revealed no effect of retinoschisin-deficiency on Kv channel mediated potassium ion currents in vitro. Together, our data suggest that Kv2.1 and Kv8.2 together with retinoschisin and the retinal Na/K-ATPase are integral parts of a macromolecular complex at the photoreceptor inner segments. Defective compartmentalization of this complex due to retinoschisin-deficiency may be a crucial step in initial XLRS pathogenesis.
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Affiliation(s)
- Verena Schmid
- Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany
| | - Alexander Wurzel
- Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany
| | - Christian H Wetzel
- Department of Psychiatry and Psychotherapy, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany
| | - Karolina Plössl
- Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany
| | - Astrid Bruckmann
- Institute of Biochemistry, Genetics and Microbiology, Protein Mass Spectrometry Group, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Patricia Luckner
- Institute of Biochemistry, Genetics and Microbiology, Protein Mass Spectrometry Group, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Bernhard H F Weber
- Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
- Institute of Clinical Human Genetics, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
| | - Ulrike Friedrich
- Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg, Germany.
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Meloni M, Giurato L, Panunzi A, Bellia A, Bohbot S, Lauro D, Uccioli L. Effectiveness of Sucrose Octasulfate Dressing in the Treatment of Neuro-Ischaemic Diabetic Foot Heel Ulcers: A Retrospective Single arm Study. INT J LOW EXTR WOUND 2022:15347346221087499. [PMID: 35287510 DOI: 10.1177/15347346221087499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The study aimed to evaluate the effectiveness of the use of sucrose octasulfate impregnated dressing (TLC-NOSF [Technology Lipido-Colloid-Nano-OligoSaccharide Factor]) in the management of persons with neuro-ischaemic heel diabetic foot ulcers (DFUs). Consecutive patients who referred for an active non-infected neuro-ischaemic heel DFU belonging to grade IC (superficial) or IIC (deep to tendons, muscle or capsule) according to Texas University Classification were included. All patients were managed by a pre-set limb salvage protocol in the respect of International guidelines and the TLC-NOSF dressing was used as primary and specific dressing. Patients were evaluated any 2 to 4 weeks until wound healing or different outcomes. Primary outcome was the rate of complete wound healing after 24 weeks of follow-up. The secondary outcomes assessed the healing time, the rate of wound regression, the re-ulceration in the case of complete healing and the safety. Thirty patients were included. The mean age was 67 ± 11 years, 17 (56.7%) were male, all of them were affected by type 2 diabetes with a mean duration of 18 ± 7 years. Twenty patients (66.7%) showed deep ulcers (grade 2 of Texas University Classification); the mean TcPO2 at the inclusion was 42 ± 7 mm Hg. Twenty-two patients (73.3%) healed by Week 24. The mean time of healing was 84 ± 32 days, 2 (6.7%) patients had ulcer relapse after healing, 28 (93.3%) had wound regression >50%, 2 (6.7%) had mild infection, 1 (3.3%) reported major amputation. No serious adverse events related to TLC-NOSF dressing or local reactions were reported. This current study showed the potential benefit of sucrose octasulfate for treating neuro-ischaemic heel DFUs in addition to the standard of care.
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Affiliation(s)
- Marco Meloni
- Department of Systems Medicine, 9318University of Rome Tor Vergata, Rome, Italy
| | - Laura Giurato
- Department of Systems Medicine, 9318University of Rome Tor Vergata, Rome, Italy
| | - Andrea Panunzi
- Department of Systems Medicine, 9318University of Rome Tor Vergata, Rome, Italy
| | - Alfonso Bellia
- Department of Systems Medicine, 9318University of Rome Tor Vergata, Rome, Italy
| | | | - Davide Lauro
- Department of Systems Medicine, 9318University of Rome Tor Vergata, Rome, Italy
| | - Luigi Uccioli
- Department of Systems Medicine, 9318University of Rome Tor Vergata, Rome, Italy
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Westra WM, Straub D, Milano F, Buttar NS, Wang KK, Krishnadath KK. Inhibition of the BMP pathway prevents development of Barrett's-associated adenocarcinoma in a surgical rat model. Dis Esophagus 2021; 35:6412930. [PMID: 34718471 PMCID: PMC9113020 DOI: 10.1093/dote/doab072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 08/30/2021] [Accepted: 09/19/2021] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Esophageal adenocarcinoma (EAC) is an aggressive cancer, associated with reflux esophagitis and intestinal metaplasia (IM). One underlying biological mechanism, which possibly drives the development of EAC, is the dysregulated expression of Bone Morphogenetic Proteins (BMPs). AIM To investigate if local delivery of Noggin, a BMP antagonist, reduced EAC. METHODS After obtaining proof of principal on local delivery of a Noggin/Sucralfate substance, a randomized controlled trial to test the effects of Noggin on EAC development was performed in a surgical rat model. In the model, an esophago-jejunostomy leads to development of reflux-esophagitis, IM and eventually EAC. Rats were treated by Noggin/Sucralfate or Sucralfate alone. Treatment was administered from 26 to 29 weeks after the operation. RESULTS Of the 112 operated rats, 52 survived beyond 26 weeks. Finally, 25 rats treated with Noggin/Sucralfate and 21 with Sucralfate, were evaluated. At the end, 39 (85%) of the animals had IM while 28 (61%) developed cancer. There were significantly more cancers in the Noggin/Sucralfate arm (50%) versus the Sucralfate group (73%) (Chi square, P < 0.05). Most cancers were mucous producing T3 adenocarcinomas. There were no significant differences in the amount of IM, size or grade of the cancers, or expression of columnar and squamous markers between the two groups. CONCLUSION In this study, we demonstrated that inhibition of BMPs by Noggin reduced development of EAC in a surgical esophagitis-IM-EAC rat model. In future, effective targeting of the BMP pathway with selective BMP-inhibitors could become an important asset to improve EAC patient outcome.
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Affiliation(s)
- Wytske M Westra
- Center for Experimental and Molecular Medicine (CEMM), AUMC, Amsterdam, The Netherlands,Department of Gastroenterology and Hepatology, Amsterdam UMC, Amsterdam, The Netherlands,Department of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Danielle Straub
- Center for Experimental and Molecular Medicine (CEMM), AUMC, Amsterdam, The Netherlands
| | - Francesca Milano
- Center for Experimental and Molecular Medicine (CEMM), AUMC, Amsterdam, The Netherlands
| | - Navtej S Buttar
- Department of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Kenneth K Wang
- Department of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Kausilia K Krishnadath
- Address correspondence to: Professor Kausilia K. Krishnadath, Department of Gastroenterology, University of Amsterdam Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands. Tel: +31 20 5666703; Fax: +31 20 6917033;
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Martinez CAR, Rodrigues MR, Sato DT, da Silva CMG, Kanno DT, Mendonça RLDS, Pereira JA. Evaluation of the anti-inflammatory and antioxidant effects of the sucralfate in diversion colitis. JOURNAL OF COLOPROCTOLOGY 2021. [DOI: 10.1016/j.jcol.2015.02.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
AbstractSucralfate enemas present good results in the treatment of colitis, however the mechanism of action of the drug is not yet fully clarified.
Objective To evaluate the anti-inflammatory and antioxidant effects of sucralfate enemas in diversion colitis model.
Method Thirty-six Wistar rats underwent intestinal bypass by end colostomy in the descending colon and distal mucous fistula. The animals were divided into 3 experimental groups according to the daily dose of enemas received containing 0.9% SF, sucralfate enemas or sucralfate enemas 1 g/kg/day or 2 g/kg/day. Each group was divided into two subgroups according to euthanasia to be performed 2–4 weeks after derivation. The tissue grade of inflammation was assessed histologically, and neutrophil infiltration by the tissue expression of myeloperoxidase (MPO) identified by immunohistochemistry and quantified by computerized morphometry. Oxidative stress was measured by tissue levels of malondialdehyde (MDA). To compare the results the Student's t test variance was used, and also the variance by ANOVA test, establishing a level of significance of 5% (p < 0.05) for both.
Results The intervention with sucralfate enemas showed improvement in the intensity of tissue inflammation related to the concentration used and the duration of the intervention. Intervention with sucralfate enemas reduced the tissue levels of MPO, independent of concentration or time of intervention (p < 0.01). There was a reduction of MDA levels in animals irrigated with sucralfate enemas, independent of concentration or duration of the intervention (p < 0.01).
Conclusion Enemas with sucralfate enemas reduce inflammation, neutrophil infiltration and oxidative stress in the excluded colon suggesting topical application of the substance to be a valid therapeutic option for the treatment of diversion colitis.
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Affiliation(s)
- Carlos Augusto Real Martinez
- Post-Graduate Program in Health Sciences, Unilversidade São Francisco (USF), Bragança Paulista, SP, Brazil
- Division of Colorectal Surgery, Medical Sciences Faculty, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | | | - Daniela Tiemi Sato
- Medicine Course, Universidade São Francisco (USF), Bragança Paulista, SP, Brazil
| | | | - Danilo Toshio Kanno
- Resident Physician, Service of Coloproctology, Hospital Universitário São Francisco na Providência de Deus, Bragança Paulista, SP, Brazil
| | - Roberta Laís dos Santos Mendonça
- Resident Physician, Service of Coloproctology, Hospital Universitário São Francisco na Providência de Deus, Bragança Paulista, SP, Brazil
| | - José Aires Pereira
- Medicine Course, Universidade São Francisco (USF), Bragança Paulista, SP, Brazil
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Pereira JA, Rodrigues MR, Sato DT, Júnior PPS, Dias AM, Silva CGD, Martinez CAR. Evaluation of sucralfate enema in experimental diversion colitis. JOURNAL OF COLOPROCTOLOGY 2021. [DOI: 10.1016/j.jcol.2013.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
AbstractDiversion colitis (DC) is an inflammatory disease that develops in segments with fecal diversion. Sucralfate (SCF) complex, which consists of sucrose octasulfate and polyaluminum hydroxide, has been demonstrated to be effective in the treatment of different forms of colitis. However, until now, the effects of SCF have not been evaluated in DC.
Objective to evaluate whether the use of enemas containing SFC improves histological findings in experimental DC.
Methods Thirty-six rats underwent right colon bypass procedure through the creation of a proximal colostomy and a distal mucous fistula. The animals were divided into two groups according to the euthanization procedure to be performed two to four weeks after surgery. Each experimental group was divided into three subgroups of six animals, which were submitted to daily application of enemas containing saline solution 0.9% or SCF at concentrations of 1.0 g/kg/day or 2.0 g/kg/day, respectively. The diagnosis of DC in segments with fecal diversion was established by histopathological study considering the following
variables epithelial loss, formation of crypt abscesses, the population of goblet cells, inflammatory infiltrate and presence of fibrosis. For statistical analysis, the nonparametric Mann-Whitney and Kruskal-Wallis tests were used, with a significance level of 5% (p <0.05).
Results It was observed that the daily application of SCF enemas decreased epithelial loss, formation of colon crypt abscesses, inflammatory infiltrate and tissue fibrosis (p <0.05), unrelated to time of intervention. The intervention with SCF preserves the goblet cell population. The effects of the substance on the preservation of colonic epithelium; the decrease in the inflammatory process and subsequent abscess formation in the colon crypts are associated with the concentration used, whereas tissue fibrosis decrease is associated with the concentration and time of intervention.
Conclusion Preventive application of SCF enemas reduces the inflammatory process in the colon with fecal diversion
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Affiliation(s)
- José Aires Pereira
- School of Medicine, Universidade São Francisco (USF), Bragança Paulista, SP, Brazil
| | | | - Daniela Tiemi Sato
- School of Medicine, Universidade São Francisco (USF), Bragança Paulista, SP, Brazil
| | | | - Alice Moreira Dias
- School of Medicine, Universidade São Francisco (USF), Bragança Paulista, SP, Brazil
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MENDONÇA RLS, KANNO DT, PEREIRA JA, CAMPOS FG, SILVA CMGD, FREITAS BZDP, MARTINEZ CAR. ENEMA DE SULCRALFATO PODE PREVENIR COLITE EM SEGMENTOS COLÔNICOS SEM TRÂNSITO FECAL? ABCD-ARQUIVOS BRASILEIROS DE CIRURGIA DIGESTIVA 2021; 34:e1630. [PMID: 35107492 PMCID: PMC8846493 DOI: 10.1590/0102-672020210002e1630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 08/18/2021] [Indexed: 11/21/2022]
Abstract
RESUMO - RACIONAL: O estresse oxidativo é um dos principais mecanismos associados à ruptura dos mecanismos de defesa que formam a barreira epitelial cólica e reduz o conteúdo tecidual das proteínas claudina-3 e ocludina principais constituintes das junções de oclusão intercelulares. O sucralfato, possui atividade antioxidante e tem sido usado para tratar diferentes formas de colite. OBJETIVO: Mensurar o conteúdo tecidual de claudina-3 e ocludina da mucosa do cólon sem trânsito fecal, submetido à intervenção com sucralfato. MÉTODO: Trinta e seis ratos foram submetidos à colostomia do cólon esquerdo e fístula mucosa distal. Os animais foram divididos em dois grupos de acordo com a eutanásia ser realizada duas ou quatro semanas após a intervenção. Cada grupo foi dividido em três subgrupos de acordo com o tipo de intervenção realizada diariamente: solução salina isolada; sucralfato a 1 g/kg/dia ou sucralfato a 2g/kg/dia. A colite foi diagnosticada por análise histológica adotando escala de validação prévia. A expressão tecidual de ambas as proteínas foi identificada por imunoistoquímica. O conteúdo das proteínas foi quantificado por análise de imagem assistida por computador. RESULTADOS: O escore inflamatório foi maior nos segmentos cólicos sem trânsito fecal e os enemas com sucralfato reduziram o escore inflamatório nesses segmentos, principalmente nos animais submetidos à intervenção com sucralfato em maior concentração e por período mais longo de intervenção. Houve aumento no conteúdo tecidual das proteínas claudina-3 e ocludina, relacionado com a concentração de sucralfato. O conteúdo tecidual de ambas as proteínas não se modificou com a duração da intervenção. CONCLUSÃO: Enemas com sucralfato reduzem a inflamação e aumentam o conteúdo tecidual de claudina-3 e ocludina na mucosa cólica sem trânsito intestinal.
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Abstract
Historically, there has been a scarcity of evidence-based topical therapy to hasten the healing of diabetic foot ulcers. But recently new evidence-based treatments have emerged from multicentre, randomised, controlled trials. This article highlights those trials, and describes the current pharmacological management of the diabetic foot ulcer and the advances that have been made in wound therapy to date. It provides an overview of topical and systemic pharmacotherapies in current use and those in development for future use in managing the diabetic foot. For each treatment, proposed mechanisms of action and evidence available to support their clinical use are presented. There is supporting randomised, controlled evidence for sucrose octasulfate in the treatment of neuro-ischaemic ulcers, and multi-layered patch of autologous leucocytes, platelets and fibrin in ulcers with or without ischaemia. There is also evidence for placentally derived products and for topical and systemic oxygen therapy in the healing of diabetic foot ulcers. Growth factors, bio-engineered tissues, stem cell therapy, gene therapy and peptide therapy also have some supporting evidence in the healing of diabetic foot ulcers. Nonsurgical debriding agents may be useful when the optimum approach of sharp debridement is not possible, and immunomodulators may be helpful for their antimicrobial effects, but robust data is still required to strengthen the case for general use. The review does not cover antimicrobials as their primary role are as anti-infectives and not in wound healing. The development of nanotechnology has created a means of prolonging the bioavailability of target molecules at the wound site, with the use of glass/hydrogel nanoparticles, polyethylene glycol and hyaluronic acid. Looking forward, novel therapies, including traction force-activated payloads, local delivery of short-interfering RNA and finally hydrogels incorporating bioactive agents or cells may provide possibilities for pharmacotherapy in the future.
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Affiliation(s)
- Danielle Dixon
- Diabetic Foot Clinic, King's College NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK.
| | - Michael Edmonds
- Diabetic Foot Clinic, King's College NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
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Lobmann R, Grünerbel A, Lawall H, Lüdemann C, Morbach S, Tigges W, Völkel L, Rychlik RP. Impact of wound duration on diabetic foot ulcer healing: evaluation of a new sucrose octasulfate wound dressing. J Wound Care 2020; 29:543-551. [PMID: 33052796 DOI: 10.12968/jowc.2020.29.10.543] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE A common and frequent complication of diabetes is diabetic foot ulcers (DFU), which can have high treatment costs and severe adverse events. This study aims to evaluate the effects of wound duration on wound healing and the impact on costs, including treatment with a new sucrose octasulfate dressing compared with a control dressing. METHOD Based on the Explorer study (a two-armed randomised double-blind clinical trial), a cost-effectiveness analysis compared four different patient groups distinguished by their wound duration and additionally two DFU treatment options: a sucrose octasulfate dressing and a neutral dressing (as control). Clinical outcomes and total direct costs of wound dressings were evaluated over 20 weeks from the perspective of the Social Health Insurance in Germany. Simulation of long-term outcomes and costs were demonstrated by a five cycle Markov model. RESULTS The results show total wound healing rates between 71% and 14.8%, and direct treatment costs for DFU in the range of €2482-3278 (sucrose octasulfate dressing) and €2768-3194 (control dressing). Patients with a wound duration of ≤2 months revealed the highest wound healing rates for both the sucrose octasulfate dressing and control dressing (71% and 41%, respectively) and had the lowest direct treatment costs of €2482 and €2768, respectively. The 100-week Markov model amplified the results. Patients with ≤2 months' wound duration achieved wound healing rates of 98% and 88%, respectively and costs of €3450 and €6054, respectively (CE=€3520, €6864). Sensitivity analysis revealed that the dressing changes per week were the most significant uncertainty factor. CONCLUSION Based on the findings of this study, early treatment of DFU with a sucrose octasulfate dressing is recommended from a health economic view due to lower treatment costs, greater cost-effectiveness and higher wound healing rates.
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Affiliation(s)
- Ralf Lobmann
- Klinikum Stuttgart - Krankenhaus Bad Cannstatt, Stuttgart
| | | | - Holger Lawall
- Gemeinschaftspraxis Prof. Dr. med. Curt Diehm, Dr. med. Holger Lawall, Ettlingen
| | - Claas Lüdemann
- Evangelisches Waldkrankenhaus Spandau, Ein Unternehmen der Paul Gerhardt Diakonie, Berlin
| | | | | | - Lukas Völkel
- Institute of Empirical Health Economics, Burscheid, Germany
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Dissemond J, Lützkendorf S, Dietlein M, Neßeler I, Becker E, Möller U, Thomassin L, Bohbot S, Münter KC. Clinical evaluation of polyabsorbent TLC-NOSF dressings on chronic wounds: a prospective, observational, multicentre study of 1140 patients. J Wound Care 2020; 29:350-361. [DOI: 10.12968/jowc.2020.29.6.350] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Objective: The superior wound healing properties and cost-effectiveness of TLC-NOSF dressings in the local treatment of chronic wounds have already been demonstrated by several randomised controlled trials (RCTs) at a high quality level. Therefore, this study aimed to evaluate the efficacy and safety of new TLC-NOSF dressings with polyabsorbent fibres in an unselected population of patients under real-life conditions. Method: A large, prospective, multicentre, observational study with two polyabsorbent TLC-NOSF dressings (UrgoStart Plus Pad and UrgoStart Plus Border, Laboratoires Urgo, France) was conducted in Germany between July 2017 and December 2018. Main outcomes included wound healing rate, clinical assessment of wound healing progression, local tolerability and acceptance of dressings. Results: A total of 1140 patients with chronic wounds of various aetiologies (leg ulcers, diabetic foot ulcers, pressure ulcers, etc.) were treated with the investigated dressings in 130 centres, for a mean duration of 56±34 days. By the final visit, 48.5% of wounds had healed and 44.8% had improved. Similar results were reported regardless of wound aetiology or regardless of proportions of sloughy and granulation tissue at the start of treatment. According to the subgroup analysis by wound duration, the sooner the TLC-NOSF treatment was initiated, the better the clinical outcomes for all types of wounds. The dressings were very well tolerated and accepted by the patients. Conclusion: These results are consistent with those from RCTs conducted on TLC-NOSF dressings. They complete the evidence on the good healing properties and safety profile of these dressings, especially in non-selected patients treated in current practice, and regardless of the characteristics of wounds and patients. They support the use of the dressings as a first-line intervention and until wound healing in the management of chronic wounds, in association with appropriate standard of care.
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Affiliation(s)
- Joachim Dissemond
- Department of Dermatology, Venereology, and Allergology, University Hospital Essen, Essen, Germany
| | | | | | - Ingo Neßeler
- Department of Dermatology, Venereology, and Allergology, University Hospital Essen, Essen, Germany
- Medical Office Specialized on Vascular Medicine, Köln, Germany
| | | | | | | | - Serge Bohbot
- Medical Affairs Department, Laboratoires URGO Medical, Paris, France
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Lázaro-Martínez JL, Edmonds M, Rayman G, Apelqvist J, Van Acker K, Hartemann A, Martini J, Lobmann R, Bohbot S, Kerihuel JC, Piaggesi A. Optimal wound closure of diabetic foot ulcers with early initiation of TLC-NOSF treatment: post-hoc analysis of Explorer. J Wound Care 2019; 28:358-367. [DOI: 10.12968/jowc.2019.28.6.358] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Objective: In March 2018, the Explorer study, an international, double-blind, randomised controlled trial (RCT), established that adding a TLC-NOSF (UrgoStart Contact, Laboratoires Urgo, France) dressing to good local standard of care (SoC) significantly and substantially increases wound closure and reduces the healing time of neuroischaemic diabetic foot ulcers (DFU). Besides the TLC-NOSF treatment, the wound duration was the only other covariate that had an influence on the wound closure rate in the regression model used in the original study. The purpose of this work was to further document the impact of wound duration on the healing outcomes of the DFUs included in the Explorer study and to discuss complementary pragmatic observations on the TLC-NOSF effect. Method: In this post-hoc analysis of the Explorer data, the wound closure rates by week 20 are reported for the global cohort (n=240, Intention-to-treat population) and for the treated (n=126) and control groups (n=114) according to DFU duration and location. Results: For the combined group, wound closure rates decreased with the increase of wound duration at baseline (from 57% in wounds ≤2 months to 19% in wounds >11 months). Whatever the wound duration subgroups analysed, higher closure rates were reported in the TLC-NOSF group than in the control group. However, the maximal difference between the two treatments was reported in wounds with a duration of ≤2 months (71% versus 41%, 30 percentage points difference, Relative Risk 1.7, 95% Confidence Interval 1.1 to 2.8). Regarding wound location subgroup analyses, the outcomes were always in favour of the TLC-NOSF treatment, with closure rates ranging between 43% and 61% within the TLC-NOSF group, and between 25% and 40% within the control group. Conclusion: This clinical evidence supports that treating DFUs with TLC-NOSF dressing and good SoC results in higher wound closure rates than with a neutral dressing and the same good standard of care, whatever the duration and the location of the treated wounds. However, the earlier the TLC-NOSF dressing is initiated in DFU treatment, the greater the benefits.
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Affiliation(s)
| | | | - Gerry Rayman
- The Ipswich Diabetic Foot Unit, Diabetes Centre, The Ipswich Hospital NHS Trust, Ipswich, Suffolk, UK
| | - Jan Apelqvist
- Department of Endocrinology, University Hospital of Malmö, Malmö, Sweden
| | | | - Agnès Hartemann
- Department of Diabetology, Pitié-Salpêtrière University Hospital, Paris, France
| | - Jacques Martini
- Department of Endocrinology, Rangueil University Hospital, Toulouse, France
| | - Ralf Lobmann
- Department of Endocrinology, Diabetology and Geriatrics, Klinikum Stuttgart, Germany
| | - Serge Bohbot
- Medical Affairs Department, Laboratoires URGO, Paris, France
| | | | - Alberto Piaggesi
- Department of Endocrinology and Metabolism, University of Pisa, Pisa, Italy
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Ousey K, Chadwick P, Jawień A, Tariq G, Nair HKR, Lázaro-Martínez JL, Sandy-Hodgetts K, Alves P, Wu S, Moore Z, Pokorná A, Polak A, Armstrong D, Sanada H, Hong JP, Atkin L, Santamaria N, Tehan P, Lobmann R, Fronzo C, Webb R. Identifying and treating foot ulcers in patients with diabetes: saving feet, legs and lives. J Wound Care 2018; 27:S1-S52. [DOI: 10.12968/jowc.2018.27.sup5.s1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
| | | | - Arkadiusz Jawień
- Collegium Medicum, University of Nicolaus Copernicus, Bydgoszcz, Poland
| | - Gulnaz Tariq
- Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates
| | | | | | | | - Paulo Alves
- Institute of Health Sciences, Catholic University of Portugal, Portugal
| | - Stephanie Wu
- Dr William M. Scholl College of Podiatric Medicine at Rosalind Franklin University of Medicine and Science, United States
| | - Zena Moore
- Royal College of Surgeons in Ireland, Dublin, Republic of Ireland
| | | | - Anna Polak
- Jerzy Kukuczka Academy of Physical Education in Katowice, Poland
| | - David Armstrong
- Keck School of Medicine of University of Southern California, United States
| | | | - Joon Pio Hong
- Asan Medical Centre, University of Ulsan, South Korea
| | | | - Nick Santamaria
- University of Melbourne and Royal Melbourne Hospital, New South Wales, Australia
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Effectiveness of Topical Sucralfate in the Management of Pressure Ulcer in Hospitalized Patients: A Prospective, Randomized, Placebo-Controlled Trial. Am J Ther 2018; 26:e5-e11. [PMID: 29642075 DOI: 10.1097/mjt.0000000000000531] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The aim of this study was to evaluate the effectiveness of topical sucralfate in the management of pressure ulcer (PU) in hospitalized patients. METHODS Forty hospitalized patients with stage II PU were included in this prospective, double-blind, randomized, placebo-controlled trial and were randomly divided into 2 groups receiving either sucralfate gel or placebo, on a daily basis. The patients were visited every day for 14 days, the ulcer was evaluated using the Pressure Ulcer Scale for Healing (PUSH) and changes to the measured scores over time were used as an indicator of wound healing. RESULTS There were no statistically significant differences in any of the demographic characteristics between both groups. Both of the interventions reduced the average PUSH score, and at the end of the trial, all but 2 patients were healed. One in each group discontinued the trial because of exacerbation of the ulcer. No significant between-group difference in the average PUSH score reduction was observed (6.36 ± 2.11 vs. 5.89 ± 1.41, P = 0.42). Although the average healing time was less in the sucralfate group (6.05 ± 2.17 vs. 7.78 ± 3.42), the difference was not statistically significant (P = 0.07). CONCLUSIONS Sucralfate gel does not improve healing of PU compared with placebo.
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Edmonds M, Lázaro-Martínez JL, Alfayate-García JM, Martini J, Petit JM, Rayman G, Lobmann R, Uccioli L, Sauvadet A, Bohbot S, Kerihuel JC, Piaggesi A. Sucrose octasulfate dressing versus control dressing in patients with neuroischaemic diabetic foot ulcers (Explorer): an international, multicentre, double-blind, randomised, controlled trial. Lancet Diabetes Endocrinol 2018; 6:186-196. [PMID: 29275068 DOI: 10.1016/s2213-8587(17)30438-2] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 11/08/2017] [Accepted: 11/09/2017] [Indexed: 12/17/2022]
Abstract
BACKGROUND Diabetic foot ulcers are serious and challenging wounds associated with high risk of infection and lower-limb amputation. Ulcers are deemed neuroischaemic if peripheral neuropathy and peripheral artery disease are both present. No satisfactory treatment for neuroischaemic ulcers currently exists, and no evidence supports one particular dressing. We aimed to assess the effect of a sucrose octasulfate dressing versus a control dressing on wound closure in patients with neuroischaemic diabetic foot ulcers. METHODS We did a randomised, double-blind clinical trial (Explorer) in 43 hospitals with specialised diabetic foot clinics in France, Spain, Italy, Germany, and the UK. Eligible participants were inpatients or outpatients aged 18 years or older with diabetes and a non-infected neuroischaemic diabetic foot ulcer greater than 1 cm2 and of grade IC or IIC (as defined by the University of Texas Diabetic Wound Classification system). We excluded patients with a severe illness that might lead to them discontinuing the trial and those who had surgical revascularisation in the month before study entry. We randomly assigned participants (1:1) via a computer-generated randomisation procedure (concealed block size two); stratified by study centre and wound area (1-5 cm2 and 5-30 cm2), to treatment with either a sucrose octasulfate wound dressing or a control dressing (the same dressing without sucrose octasulfate) for 20 weeks. Both groups otherwise received the same standard of care for a 2-week screening period before randomisation and throughout the 20-week trial. Dressings were applied by nursing staff (or by instructed relatives for some outpatients). Frequencies of dressing changes were decided by the investigator on the basis of the clinical condition of the wound. Patients were assessed 2 weeks after randomisation, then monthly until week 20 or occurrence of wound closure. The primary outcome, assessed by intention-to-treat, was proportion of patients with wound closure at week 20. This trial is registered with ClinicalTrials.gov, number NCT01717183. FINDINGS Between March 21, 2013, and March 31, 2016, we randomly assigned 240 individuals to treatment: 126 to the sucrose octasulfate dressing and 114 to the control dressing. After 20 weeks, wound closure occurred in 60 patients (48%) in the sucrose octasulfate dressing group and 34 patients (30%) in the control dressing group (18 percentage points difference, 95% CI 5-30; adjusted odds ratio 2·60, 95% CI 1·43-4·73; p=0·002). In both groups, the most frequent adverse events were infections of the target wound: 33 wound infections in 25 (20%) patients of 126 in the sucrose octasulfate dressing group and 36 in 32 (28%) patients of 114 in the control dressing group. Minor amputations not affecting the wound site were also reported in one (1%) patient in the sucrose octasulfate dressing group and two (2%) patients in the control dressing group. Three (2%) patients assigned to the sucrose octasulfate dressing and four (4%) assigned to the control dressing died, but none of the deaths were related to treatment, procedure, wound progression, or subsequent to amputation. INTERPRETATION A sucrose octasulfate dressing significantly improved wound closure of neuroischaemic diabetic foot ulcers without affecting safety after 20 weeks of treatment along with standard care. These findings support the use of sucrose octasulfate dressing as a local treatment for neuroischaemic diabetic foot ulcers. FUNDING Laboratoires Urgo Medical.
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Affiliation(s)
| | | | | | - Jacques Martini
- Department of Endocrinology, Rangueil University Hospital, Toulouse, France
| | - Jean-Michel Petit
- Department of Endocrinology, Diabetology and Metabolism, François Mitterrand University Hospital, Dijon, France
| | - Gerry Rayman
- The Ipswich Diabetic Foot Unit, Diabetes Centre, The Ipswich Hospital NHS Trust, Ipswich, Suffolk, UK
| | - Ralf Lobmann
- Department of Endocrinology, Diabetology and Geriatrics, Klinikum Stuttgart, Germany
| | - Luigi Uccioli
- Department of Internal Medicine, University of Tor Vergata, Roma, Italy
| | | | | | | | - Alberto Piaggesi
- Department of Endocrinology and Metabolism, University of Pisa, Pisa, Italy
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Lewis LM, Guo J, Torres E, Wang J, Billones H, Kolhe P, Young AL, Bates D, Parker A, Rigby-Singleton S. Ex Situ and In Situ Characterization of Vaccine Suspensions in Pre-Filled Syringes. J Pharm Sci 2017; 106:2163-2167. [DOI: 10.1016/j.xphs.2017.04.055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/03/2017] [Accepted: 04/24/2017] [Indexed: 01/12/2023]
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Alvandipour M, Ala S, Tavakoli H, Yazdani Charati J, Shiva A. Efficacy of 10% sucralfate ointment after anal fistulotomy: A prospective, double-blind, randomized, placebo-controlled trial. Int J Surg 2016; 36:13-17. [PMID: 27765686 DOI: 10.1016/j.ijsu.2016.10.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Revised: 09/25/2016] [Accepted: 10/03/2016] [Indexed: 11/19/2022]
Abstract
INTRODUCTION The most frequent problems after anal fistulotomy are pain, bleeding, and delayed or impaired wound healing. Topical Sucralfate preparation has been used to treat a wide variety of wounds. In this study, we investigate effects of 10% sucralfate ointment on wound healing and postoperative pain after fistulotomy. METHODS AND MATERIALS A total of 41 patients undergoing anorectal fistulotomy were included in this randomized, blinded, controlled trial and were randomly allocated to either sucralfate ointment (every 12 h) or placebo. The patients were visited weekly for up to 5 weeks. The intensity of pain and the wound healing were assessed. RESULTS The sucralfate group had significantly less pain at rest (1.92 ± 0.88 vs 2.96 ± 0.98; P = 0.002) and on defecation (1.68 ± 0.92 vs 3.08 ± 1.12; p < 0.001) than the placebo group from 1st to 5th post-operative visits. Complete wound healing was achieved after 8.15 ± 1 weeks in placebo group versus 5.9 ± 0.8 weeks in sucralfate group (p < 0.001). There were no significant differences in the frequencies of postoperative complications between the two groups. CONCLUSION Compared with placebo, sucralfate ointment reduced postoperative pain at rest and on defecation and improves wound healing in patients undergoing fistulotomy.
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Affiliation(s)
- Mina Alvandipour
- Department of Surgery, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, Sari, Mazandaran Province, Iran
| | - Shahram Ala
- Department of Clinical Pharmacy, Pharmaceutical Sciences Research Center, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Mazandaran Province, Iran.
| | - Hasan Tavakoli
- Department of Surgery, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, Sari, Mazandaran Province, Iran
| | - Jamshid Yazdani Charati
- Department of Biostatics, Health Sciences Research Center, Faculty of Health, Mazandaran University of Medical Sciences, Sari, Mazandaran Province, Iran
| | - Afshin Shiva
- Department of Clinical Pharmacy, Nephrology and Kidney Transplant Research Center, Faculty of Pharmacy, Urmia University of Medical Sciences, Urmia, Iran
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Bonassa CEG, Pereira JA, Campos FGCMD, Rodrigues MR, Sato DT, Chaim FDM, Martinez CAR. Tissue content of sulfomucins and sialomucins in the colonic mucosa, without fecal stream, undergoing daily intervention with sucralfate. Acta Cir Bras 2015; 30:328-38. [DOI: 10.1590/s0102-865020150050000004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 04/15/2015] [Indexed: 12/20/2022] Open
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McCullough RW. High-potency sucralfate prevents and rapidly reverses chemo-radiation mucositis in a patient with stage 4b head and neck cancer. World J Transl Med 2013; 2:13-21. [DOI: 10.5528/wjtm.v2.i2.13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 04/27/2013] [Indexed: 02/05/2023] Open
Abstract
AIM: To study usefulness of high-potency sucralfate (HPS) in a patient with chemoradiation mucositis and discuss its mechanism of action.
METHODS: HPS, a non-covalently cross-link of sucralfate, cations and bidentate anionic chelators, has a maintains a surface concentration of sucralfate 3 h following administration that is 7-23 fold that possible with standard-potency sucralfate. The accelerated mucosal healing and pain alleviation of HPS in patients with erosive esophageal reflux, prompted its use in this patient with chemoradiation mucositis of the oropharynx and alimentary tract. A literature-based review of the immuno-modulatory effects of sucralfate is discussed.
RESULTS: Within 48 h of intervention: (1) there was complete disappearance of oral mucositis lesions; tenderness with (2) patient-reported disappearance of pain, nausea and diarrhea; patient required (3) no opiate analgesia and (4) no tube-feeding supplements to regular diet. Dysgeusia and xerostomia persisted. A modified Naranjo Questionnaire score of 10 supported the likelihood that HPS intervention caused the observed clinical effects. No adverse reactions noted.
CONCLUSION: In this patient HPS was useful to treat chemo-radiation mucositis of the oropharynx and alimentary tract. HPS may directly or indirectly facilitate an immunomodulatory mechanism involving accelerated growth factor activation, which may be a new target for therapeutic intervention in such patients.
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Fannon M, Forsten-Williams K, Zhao B, Bach E, Parekh PP, Chu CL, Goerges-Wildt AL, Buczek-Thomas JA, Nugent MA. Facilitated diffusion of VEGF165 through descemet's membrane with sucrose octasulfate. J Cell Physiol 2012; 227:3693-700. [PMID: 22378222 DOI: 10.1002/jcp.24077] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Vascular endothelial growth factor A (VEGF-A) is a promoter of neovascularization and thus a popular therapeutic target for diseases involving excessive growth of blood vessels. In this study, we explored the potential of the disaccharide sucrose octasulfate (SOS) to alter VEGF165 diffusion through Descemet's membrane. Descemet's membranes were isolated from bovine eyes and used as a barrier between two chambers of a diffusion apparatus to measure VEGF transport. Diffusion studies revealed a dramatic increase in VEGF165 transport in the presence of SOS, with little diffusion of VEGF165 across the membrane over a 10-h time course in the absence of SOS. Diffusion studies with VEGF121, a non-heparin binding variant of VEGF, showed robust diffusion with or without SOS. To determine a possible mechanism, we measured the ability of SOS to inhibit VEGF interactions with extracellular matrix (ECM), using cell-free and cell surface binding assays. Binding studies showed SOS had no effect on VEGF165 binding to either heparin-coated plates or endothelial cell surfaces at less than mg/ml concentrations. In contrast, we show that SOS inhibited VEGF165 binding to fibronectin in a dose dependent manner and dramatically accelerated the rate of release of VEGF165 from fibronectin. SOS also inhibited the binding of VEGF165 to fibronectin-rich ECM deposited by vascular smooth muscle cells. These results suggest that fibronectin-rich extracellular matrices serve as barriers to VEGF165 diffusion by providing a network of binding sites that can trap and sequester the protein. Since the content of Descemet's membrane is typical of many basement membranes it is possible that they serve throughout the body as formidable barriers to VEGF165 diffusion and tightly regulate its bioavailability and distribution within tissues.
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Affiliation(s)
- Michael Fannon
- Department of Ophthalmology and Visual Sciences, University of Kentucky, Lexington, KY 40536-0305, USA.
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Cheng W, Joshi SB, He F, Brems DN, He B, Kerwin BA, Volkin DB, Middaugh CR. Comparison of High-Throughput Biophysical Methods to Identify Stabilizing Excipients for a Model IgG2 Monoclonal Antibody: Conformational Stability and Kinetic Aggregation Measurements. J Pharm Sci 2012; 101:1701-20. [DOI: 10.1002/jps.23076] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 01/06/2012] [Accepted: 01/18/2012] [Indexed: 12/12/2022]
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Kamerzell TJ, Esfandiary R, Joshi SB, Middaugh CR, Volkin DB. Protein-excipient interactions: mechanisms and biophysical characterization applied to protein formulation development. Adv Drug Deliv Rev 2011; 63:1118-59. [PMID: 21855584 DOI: 10.1016/j.addr.2011.07.006] [Citation(s) in RCA: 348] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 07/19/2011] [Accepted: 07/26/2011] [Indexed: 12/18/2022]
Abstract
The purpose of this review is to demonstrate the critical importance of understanding protein-excipient interactions as a key step in the rational design of formulations to stabilize and deliver protein-based therapeutic drugs and vaccines. Biophysical methods used to examine various molecular interactions between solutes and protein molecules are discussed with an emphasis on applications to pharmaceutical excipients in terms of their effects on protein stability. Key mechanisms of protein-excipient interactions such as electrostatic and cation-pi interactions, preferential hydration, dispersive forces, and hydrogen bonding are presented in the context of different physical states of the formulation such as frozen liquids, solutions, gels, freeze-dried solids and interfacial phenomenon. An overview of the different classes of pharmaceutical excipients used to formulate and stabilize protein therapeutic drugs is also presented along with the rationale for use in different dosage forms including practical pharmaceutical considerations. The utility of high throughput analytical methodologies to examine protein-excipient interactions is presented in terms of expanding formulation design space and accelerating experimental timelines.
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Affiliation(s)
- Tim J Kamerzell
- Cardiovascular Research Institute, University of Kansas Medical Center, Kansas City, KS 66160, USA.
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Interactions of formulation excipients with proteins in solution and in the dried state. Adv Drug Deliv Rev 2011; 63:1053-73. [PMID: 21756953 DOI: 10.1016/j.addr.2011.06.011] [Citation(s) in RCA: 263] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 06/18/2011] [Accepted: 06/23/2011] [Indexed: 12/12/2022]
Abstract
A variety of excipients are used to stabilize proteins, suppress protein aggregation, reduce surface adsorption, or to simply provide physiological osmolality. The stabilizers encompass a wide variety of molecules including sugars, salts, polymers, surfactants, and amino acids, in particular arginine. The effects of these excipients on protein stability in solution are mainly caused by their interaction with the protein and the container surface, and most importantly with water. Some excipients stabilize proteins in solution by direct binding, while others use a number of fundamentally different mechanisms that involve indirect interactions. In the dry state, any effects that the excipients confer to proteins through their interactions with water are irrelevant, as water is no longer present. Rather, the excipients stabilize proteins through direct binding and their effects on the physical properties of the dried powder. This review will describe a number of mechanisms by which the excipients interact with proteins in solution and with various interfaces, and their effects on the physical properties of the dried protein structure, and explain how the various interaction forces are related to their observed effects on protein stability.
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Abstract
BACKGROUND Sucralfate is a cytoprotective agent which adheres to mucoproteins and forms a protective barrier at wound sites. In oral form it is a common ulcer medication, and as a topical preparation it has been used to treat a wide variety of wounds. OBJECTIVE The present study was designed to evaluate the effectiveness and safety of topical sucralfate in wound healing after anal fistulotomy. DESIGN Double-blind, randomized controlled study comparing topical application of sucralfate or placebo. SETTING Private outpatient clinic specializing in anorectal disease in Nagpur, India. PATIENTS Patients with a wound length of at least 5 cm after low anal fistulotomy were eligible for the study. INTERVENTION Patients were randomly assigned to receive ointment containing 7% sucralfate or a placebo ointment consisting of petroleum jelly. Patients were instructed to apply approximately 3 g of ointment to the wound twice daily after a sitz bath for 6 weeks or until the wound had healed. MAIN OUTCOME MEASURES The wounds were examined by a blinded independent observer at 2, 4, and 6 weeks after the operation. The primary end point was the proportion of patients with wounds that had completely healed. Secondary end points included amount of mucosal covering (scored by the observer), adverse events, and postoperative pain (self-rated on a visual analog scale). RESULTS Of 80 participants (29 women, 51 men; median age, 23 (range, 17-49) years), 76 participants completed the trial (sucralfate, 39; placebo, 37). At 6-week follow-up, complete wound healing was achieved in 37 patients (95%) in the sucralfate group and 27 patients (73%) in the placebo group (P = .009). Mucosal coverage of the wound was significantly greater with sucralfate than with placebo at each measurement point (P = .01). No adverse events were observed. Postoperative pain scores were significantly lower for sucralfate than for placebo at 2 and 4 weeks after the start of treatment. LIMITATIONS Wound tissue specimens were not available for morphological and ultrastructural analysis. CONCLUSIONS The results of this study add support to the evidence that topical sucralfate is a safe and effective method for promoting mucosal healing and for providing analgesia during wound treatment. Patients undergoing anal fistulotomy can benefit from the use of topical application of sucralfate.
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Yang IS, Kim TG, Park BS, Cho KJ, Lee JH, Park Y, Kim KH. Crystal structures of aprotinin and its complex with sucrose octasulfate reveal multiple modes of interactions with implications for heparin binding. Biochem Biophys Res Commun 2010; 397:429-35. [PMID: 20529698 DOI: 10.1016/j.bbrc.2010.05.113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Accepted: 05/24/2010] [Indexed: 11/17/2022]
Abstract
The crystal structures of aprotinin and its complex with sucrose octasulfate (SOS), a polysulfated heparin analog, were determined at 1.7-2.6A resolutions. Aprotinin is monomeric in solution, which associates into a decamer at high salt concentrations. Sulfate ions serve to neutralize the basic amino acid residues of aprotinin to stabilize the decameric aprotinin. Whereas SOS interacts with heparin binding proteins at 1:1 molar ratio, SOS was surprisingly found to induce strong agglutination of aprotinins. Five molecules of aprotinin interact with one molecule of the sulfated sugar, which is stabilized by electrostatic interactions between the positively charged residues of aprotinin and sulfate groups of SOS. The multiple binding modes of SOS with five individual aprotinin molecules may represent the diverse patterns of potential heparin binding to aprotinin, reflecting the interactions of densely packed protein molecules along the heparin polymer.
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Affiliation(s)
- In Seok Yang
- Department of Biotechnology & Bioinformatics, Korea University, Chungnam 339-700, Republic of Korea
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Sarilla S, Habib SY, Kravtsov DV, Matafonov A, Gailani D, Verhamme IM. Sucrose octasulfate selectively accelerates thrombin inactivation by heparin cofactor II. J Biol Chem 2010; 285:8278-89. [PMID: 20053992 DOI: 10.1074/jbc.m109.005967] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Inactivation of thrombin (T) by the serpins heparin cofactor II (HCII) and antithrombin (AT) is accelerated by a heparin template between the serpin and thrombin exosite II. Unlike AT, HCII also uses an allosteric interaction of its NH(2)-terminal segment with exosite I. Sucrose octasulfate (SOS) accelerated thrombin inactivation by HCII but not AT by 2000-fold. SOS bound to two sites on thrombin, with dissociation constants (K(D)) of 10 +/- 4 microm and 400 +/- 300 microm that were not kinetically resolvable, as evidenced by single hyperbolic SOS concentration dependences of the inactivation rate (k(obs)). SOS bound HCII with K(D) 1.45 +/- 0.30 mm, and this binding was tightened in the T.SOS.HCII complex, characterized by K(complex) of approximately 0.20 microm. Inactivation data were incompatible with a model solely depending on HCII.SOS but fit an equilibrium linkage model employing T.SOS binding in the pathway to higher order complex formation. Hirudin-(54-65)(SO(3)(-)) caused a hyperbolic decrease of the inactivation rates, suggesting partial competitive binding of hirudin-(54-65)(SO(3)(-)) and HCII to exosite I. Meizothrombin(des-fragment 1), binding SOS with K(D) = 1600 +/- 300 microm, and thrombin were inactivated at comparable rates, and an exosite II aptamer had no effect on the inactivation, suggesting limited exosite II involvement. SOS accelerated inactivation of meizothrombin 1000-fold, reflecting the contribution of direct exosite I interaction with HCII. Thrombin generation in plasma was suppressed by SOS, both in HCII-dependent and -independent processes. The ex vivo HCII-dependent process may utilize the proposed model and suggests a potential for oversulfated disaccharides in controlling HCII-regulated thrombin generation.
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Affiliation(s)
- Suryakala Sarilla
- Department of Pathology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
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A surface plasmon resonance-based solution affinity assay for heparan sulfate-binding proteins. Glycoconj J 2008; 26:577-87. [DOI: 10.1007/s10719-008-9210-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2008] [Revised: 10/05/2008] [Accepted: 10/27/2008] [Indexed: 12/15/2022]
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Kamerzell TJ, Russell Middaugh C. The Complex Inter-Relationships Between Protein Flexibility and Stability. J Pharm Sci 2008; 97:3494-517. [DOI: 10.1002/jps.21269] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Joshi SB, Kamerzell TJ, McNown C, Middaugh CR. The Interaction of Heparin/polyanions with Bovine, Porcine, and Human Growth Hormone**Sangeeta B. Joshi and Tim J. Kamerzell contributed equally to this work. J Pharm Sci 2008; 97:1368-85. [PMID: 17705152 DOI: 10.1002/jps.21056] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The interaction of polyanions with proteins is of potential pharmaceutical and cellular significance. A partial thermodynamic description of the interaction of four representative polyanions with human, bovine, and porcine growth hormone is described. A heparin bead-binding assay confirms all growth hormones bind to heparin but to varying extents. Moderate-binding constants and high ratios of bound protein to the more extended polyanions, heparin, and dextran sulfate were measured by isothermal titration calorimetry and dynamic light scattering. The binding constants and ratio of protein bound to ligand were significantly smaller for the low molecular weight polyanions phytic acid and sucrose octasulfate (SOS). The effect of polyanion binding on the bovine, porcine, and human growth hormone's (hGH) structural and colloidal stability was also explored. Heparin and dextran sulfate inhibit porcine somatotropin (pST) and bovine somatotropin (bST) aggregation to the greatest extent, as compared to phytic acid and SOS, while decreasing secondary and tertiary structural stability as measured by the temperature dependence of their circular dichroism and intrinsic fluorescence. Somewhat surprisingly, the polyanions do not appear to affect the structure or stability of hGH. The potential biological significance of growth hormone polyanion interactions is discussed.
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Affiliation(s)
- Sangeeta B Joshi
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047, USA
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Lin X, Zamora PO, Takahashi K, Lui Y. Alleviation of experimental ulcerative colitis with the synthetic peptide, F2A4-K-NS (Fibratide). Dig Dis Sci 2007; 52:2054-62. [PMID: 17404850 DOI: 10.1007/s10620-006-9641-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2006] [Accepted: 10/09/2006] [Indexed: 12/09/2022]
Abstract
Recombinant fibroblast growth factors (FGFs) maintain the integrity of the gut epithelium and reduce mucosal injury in experimental inflammatory bowel disease (IBD). Chemically synthesized FGF mimetics could potentially extend the utility of FGFs by tailoring them for optimal bioactivity and oral administration, for example. Here, F2A4-K-NS (Fibratide), a synthetic FGF mimetic peptide, alleviated dextran sulfate sodium (DSS)-induced ulcerative colitis in mice when delivered systemically and, to a lesser extent, orally. Intraperitoneal injection of Fibratide (1 or 5 mg/kg/day) ameliorated DSS-induced ulcerative colitis, resulting in reduced weight loss, decreased colon wall thickening, and increased colon length. Fibratide also improved epithelial integrity by reducing histological-detectable crypt damage and inflammation. Orally administered Fibratide (1 mg/kg/day) was also effective in ameliorating symptoms with effects generally similar to those of intraperitoneal injection. In vitro studies were conducted to help clarify how Fibratide might act in vivo. Fibratide exhibited a modest enhancement of epithelial cell proliferation. On the other hand, Fibratide doubled the rate of epithelial cells migration and restitution in a cell culture model of wound repair. Collectively, the results indicate that Fibratide reduced the severity of experimental ulcerative colitis and may be potentially useful in the treatment of IBD.
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Affiliation(s)
- Xinhua Lin
- BioSurface Engineering Technologies, Inc., 9430 Key West Avenue, Suite 220, Rockville, Maryland 20850, USA.
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31
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Kamerzell TJ, Joshi SB, McClean D, Peplinskie L, Toney K, Papac D, Li M, Middaugh CR. Parathyroid hormone is a heparin/polyanion binding protein: binding energetics and structure modification. Protein Sci 2007; 16:1193-203. [PMID: 17525467 PMCID: PMC2206658 DOI: 10.1110/ps.062613807] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Revised: 01/17/2007] [Accepted: 02/22/2007] [Indexed: 10/23/2022]
Abstract
The interaction of four representative polyanions with parathyroid hormone (PTH) residues 1-84 has been investigated utilizing a variety of spectroscopic and calorimetric techniques. Each of the polyanions employed demonstrate enthalpically driven binding to PTH (1-84) with significant affinity. The polyanions heparin, dextran sulfate, phytic acid, and sucrose octasulfate induce alpha-helical structure in PTH to varying extents depending on the ratio of polyanion to protein employed. Intrinsic and extrinsic fluorescence spectroscopy suggests significant protein tertiary structure alteration upon polyanion binding. Although structural modification occurred upon polyanion binding, PTH colloidal stability was increased depending on the ratio of polyanion to protein used. Nevertheless, the bioactivity of PTH in the presence of various ratios of heparin was not altered. The potential biological significance of PTH/polyanion interactions is discussed.
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Affiliation(s)
- Tim J Kamerzell
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047, USA
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Queneau Y, Jarosz S, Lewandowski B, Fitremann J. Sucrose Chemistry and Applications of Sucrochemicals. Adv Carbohydr Chem Biochem 2007; 61:217-92. [DOI: 10.1016/s0065-2318(07)61005-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Kamerzell TJ, Unruh JR, Johnson CK, Middaugh CR. Conformational Flexibility, Hydration and State Parameter Fluctuations of Fibroblast Growth Factor-10: Effects of Ligand Binding. Biochemistry 2006; 45:15288-300. [PMID: 17176051 DOI: 10.1021/bi061712q] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Differential effects of ligand binding on local and global fibroblast growth factor-10 (FGF-10) flexibility and stability have been investigated utilizing a variety of experimental and computational techniques. Normal mode analysis was used to predict the low frequency motions and regional flexibility of FGF-10. Similarly, regional variations in local folding/unfolding equilibria were characterized with the COREX/BEST algorithm. Experimental adiabatic and isothermal compressibilities of FGF-10 alone and in the presence of polyanions are compared. Furthermore, the effect of polyanions on the coefficient of thermal expansion is compared. Measurements of density, heat capacity, compressibility, and expansibility were combined to calculate experimentally determined volume and enthalpy fluctuations. Global effects of polyanions on FGF-10 flexibility, thermodynamic fluctuations, and hydration vary depending on the size and charge density of the polyanion. Local effects of polyanions were investigated utilizing time-resolved fluorescence spectroscopy and red edge excitation spectroscopy (REES). Increased rigidity of the protein matrix or an increased solvent response surrounding the Trp residues is observed in the presence of polyanions. Similarly, time-resolved spectroscopy reveals increased ground state heterogeneity and increased dipole relaxation on the time scale of fluorescence for FGF-10 in the presence of polyanions. These polyanions increase heterogeneity, global flexibility, and fluctuations while increasing the melting temperature (Tm) of FGF-10.
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Affiliation(s)
- Tim J Kamerzell
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047, USA
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Arisawa T, Shibata T, Kamiya Y, Nagasaka M, Nakamura M, Fujita H, Hasegawa S, Harata M, Nakamura M, Mizuno T, Tahara T, Ohta Y, Nakano H. EFFECTS OF SUCRALFATE, CIMETIDINE AND RABEPRAZOLE ON MUCOSAL HYDROXYPROLINE CONTENT IN HEALING OF ETHANOL-HCL-INDUCED GASTRIC LESIONS. Clin Exp Pharmacol Physiol 2006; 33:628-32. [PMID: 16789931 DOI: 10.1111/j.1440-1681.2006.04418.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
1. No general consensus has been reached on the treatment of acute gastric lesions. The aims of the present study were to clarify the effects of sucralfate, cimetidine and rabeprazole monotherapies and combination therapies on acute gastric lesions from the viewpoint of connective tissue regeneration. 2. Gastric lesions were experimentally created by the oral administration of 50% ethanol-0.15 mol/L HCl to rats. After 30 min, the anti-ulcer agents sucralfate (100 mg/kg), cimetidine (20 mg/kg) and rabeprazole (2 mg/kg) were administered separately or in combination and the stomach was excised at different times to measure the level of hydroxyproline in the gastric mucosa and determine lesion index. Immunostaining against prolylhydroxylase was performed on some specimens. 3. In the control group, lesion index decreased linearly from 30 min after ethanol-HCl administration and the level of mucosal hydroxyproline peaked between 2 and 4 h later. Although sucralfate significantly promoted lesion healing, it had no effect on mucosal hydroxyproline level. Cimetidine suppressed increases in mucosal hydroxyproline and prolonged lesion healing, but these findings were reversed by combining cimetidine and sucralfate. Rabeprazole had no significant effect on lesion healing, but promoted lesion healing in combination with sucralfate. Immunohistochemical analysis showed that prolylhydroxylase was expressed in spindle cells that lined the glandular cells in a boundary area between normal and injured tissues. 4. Under conditions in which the effects of intragastric pH are minimal, sucralfate is superior to antisecretory agents in promoting the healing of acute gastric lesions.
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Affiliation(s)
- Tomiyasu Arisawa
- Department of Gatroenterology, Fujita Health University, School of Medicine, Kutsukake-cho, Toyoake, Japan.
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35
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Mohammadi M, Olsen SK, Ibrahimi OA. Structural basis for fibroblast growth factor receptor activation. Cytokine Growth Factor Rev 2005; 16:107-37. [PMID: 15863029 DOI: 10.1016/j.cytogfr.2005.01.008] [Citation(s) in RCA: 531] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
FGF signaling plays a ubiquitous role in human biology as a regulator of embryonic development, homeostasis and regenerative processes. In addition, aberrant FGF signaling leads to diverse human pathologies including skeletal, olfactory, and metabolic disorders as well as cancer. FGFs execute their pleiotropic biological actions by binding, dimerizing and activating cell surface FGF receptors (FGFRs). Proper regulation of FGF-FGFR binding specificity is essential for the regulation of FGF signaling and is achieved through primary sequence variations among the 18 FGFs and seven FGFRs. The severity of human skeletal syndromes arising from mutations that violate FGF-FGFR specificity is a testament to the importance of maintaining precision in FGF-FGFR specificity. The discovery that heparin/heparan sulfate (HS) proteoglycans are required for FGF signaling led to numerous models for FGFR dimerization and heralded one of the most controversial issues in FGF signaling. Recent crystallographic analyses have led to two fundamentally different models for FGFR dimerization. These models differ in both the stoichiometry and minimal length of heparin required for dimerization, the quaternary arrangement of FGF, FGFR and heparin in the dimer, and in the mechanism of 1:1 FGF-FGFR recognition and specificity. In this review, we provide an overview of recent structural and biochemical studies used to differentiate between the two crystallographic models. Interestingly, the structural and biophysical analyses of naturally occurring pathogenic FGFR mutations have provided the most compelling and unbiased evidences for the correct mechanisms for FGF-FGFR dimerization and binding specificity. The structural analyses of different FGF-FGFR complexes have also shed light on the intricate mechanisms determining FGF-FGFR binding specificity and promiscuity and also provide a plausible explanation for the molecular basis of a large number craniosynostosis mutations.
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Affiliation(s)
- Moosa Mohammadi
- Department of Pharmacology, New York University School of Medicine, 550 First Avenue, MSB 425, New York, NY 10016, USA.
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36
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Chen P, Guo M, Wygle D, Edwards PA, Falck JR, Roman RJ, Scicli AG. Inhibitors of cytochrome P450 4A suppress angiogenic responses. THE AMERICAN JOURNAL OF PATHOLOGY 2005; 166:615-24. [PMID: 15681843 PMCID: PMC1602331 DOI: 10.1016/s0002-9440(10)62282-1] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Cytochrome P450 enzymes of the 4A family (CYP4A) convert arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE) in blood vessels of several vascular beds. The present study examined the effects of inhibiting the formation of 20-HETE with N-hydroxy-N'-(4-butyl-2-methylphenol) formamidine (HET0016) on the mitogenic response of vascular endothelial growth factor (VEGF) in human umbilical vein endothelial cells (HUVECs) in vitro, and on growth factor-induced angiogenesis in the cornea of rats in vivo. HET0016 (10 micromol/L and 20 microg, respectively) abolished the mitogenic response to VEGF in HUVECs and the angiogenic response to VEGF, basic fibroblast growth factor, and epidermal growth factor in vivo by 80 to 90% (P < 0.001). Dibromododecenyl methylsulfonimide (DDMS), a structurally and mechanistically different inhibitor of 20-HETE synthesis, also abolished angiogenic responses when tested with VEGF. Additionally, administration of the stable 20-HETE agonist, 20-hydroxyeicosa-6(Z) 15(Z)-dienoic acid (WIT003) induced mitogenesis in HUVECs and angiogenesis in the rat cornea in vivo. We studied the ability of HET0016 to alter the angiogenic response in the rat cornea to human glioblastoma cancer cells (U251). When administered locally into the cornea, HET0016 (20 microg) reduced the angiogenic response to U251 cancer cells by 70%. These results suggest that a product of CYP4A product, possibly 20-HETE, plays a critical role in the regulation of angiogenesis and may provide a useful target for reduction of pathological angiogenesis.
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Affiliation(s)
- Ping Chen
- Eye Care Services, Henry Ford Health System, One Ford Place, 4 D, Detroit, MI 48202-3450, USA
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Brych SR, Dubey VK, Bienkiewicz E, Lee J, Logan TM, Blaber M. Symmetric Primary and Tertiary Structure Mutations within a Symmetric Superfold: A Solution, not a Constraint, to Achieve a Foldable Polypeptide. J Mol Biol 2004; 344:769-80. [PMID: 15533444 DOI: 10.1016/j.jmb.2004.09.060] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Revised: 09/17/2004] [Accepted: 09/21/2004] [Indexed: 11/16/2022]
Abstract
In previous studies designed to increase the primary structure symmetry within the hydrophobic core of human acidic fibroblast growth factor (FGF-1) a combination of five mutations were accommodated, resulting in structure, stability and folding kinetic properties similar to wild-type (despite the symmetric constraint upon the set of core residues). A sixth mutation in the core, involving a highly conserved Met residue at position 67, appeared intolerant to substitution. Structural analysis suggested that the local packing environment of position 67 involved two regions of apparent insertions that distorted the tertiary structure symmetry inherent in the beta-trefoil architecture. It was postulated that a symmetric constraint upon the primary structure within the core could only be achieved after these insertions had been deleted (concomitantly increasing the tertiary structure symmetry). The deletion of these insertions is now shown to permit mutation of position 67, thereby increasing the primary structure symmetry relationship within the core. Furthermore, despite the imposed symmetric constraint upon both the primary and tertiary structure, the resulting mutant form of FGF-1 is substantially more stable. The apparent inserted regions are shown to be associated with heparin-binding functionality; however, despite a marked reduction in heparin-binding affinity the mutant form of FGF-1 is surprisingly approximately 70 times more potent in 3T3 fibroblast mitogenic assays. The results support the hypothesis that primary structure symmetry within a symmetric protein superfold represents a possible solution, rather than a constraint, to achieving a foldable polypeptide.
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Affiliation(s)
- Stephen R Brych
- Kasha Laboratory, Institute of Molecular Biophysics and Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306-4380, USA
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Abstract
The behavior of the proteome reflects spatial and temporal organization both within and without cells. We propose that various macromolecular entities possessing polyanionic character such as proteoglycans, lipid bilayer surfaces, microtubules, microfilaments, and polynucleotides may provide a functional network that mediates a variety of cellular phenomena. The interaction of proteins with this array of polyanions is characterized by a lower degree of specificity than seen with most commonly recognized macromolecular interactions. In this commentary, potential roles for this polyanion network in diverse functions such as protein/protein interactions, protein folding and stabilization, macromolecular transport, and various disease processes are all considered, as well as the use of polyanions as therapeutic agents. The role of small polyanions in the regulation of protein/polyanion interactions is also postulated. We provide preliminary experimental analysis of the extent to which proteins interact with polyanions inside cells using a combination of two-dimensional chromatographic and electrophoretic methods and antibody arrays. We conclude that many hundreds to thousands of such interactions are present in cells and argue that future understanding of the proteome will require that the "polyanion world" be taken into account.
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Affiliation(s)
- LaToya S Jones
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66047-3729, USA
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Hung KW, Kumar TKS, Chi YH, Chiu IM, Yu C. Molecular cloning, overexpression, and characterization of the ligand-binding D2 domain of fibroblast growth factor receptor. Biochem Biophys Res Commun 2004; 317:253-8. [PMID: 15047176 DOI: 10.1016/j.bbrc.2004.03.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2004] [Indexed: 11/25/2022]
Abstract
Fibroblast growth factors (FGFs) regulate a wide range of important cellular processes. The biological activities of FGFs are mediated by cell surface receptors (FGFRs). In the present study for the first time we report the cloning, expression, and characterization of the ligand (FGF)-binding D2 domain of human FGFR2. D2 domain is expressed in Escherichia coli in high yields (10 mg/L) as inclusion bodies. The protein is recovered by dissolving the inclusion bodies in 8 M urea and subsequently refolding on nickel affinity column. The protein is purified (to approximately 97% purity) to homogeneity using heparin-Sepharose affinity column. Far-UV circular dichroism data and chemical shift index plot based on 1H-alpha, 13C-alpha, 13C-beta, and 13carbonyl group chemical shifts suggest that D2 domain is an all beta-sheet protein consisting of 9 beta-strands. Isothermal titration calorimetry and equilibrium urea unfolding experiments show that recombinant D2 domain is in a biologically active conformation and binds strongly to its ligand (FGF) and to the heparin analog, sucrose octasulfate (SOS). Using a variety of triple resonance NMR experiments, complete assignment of 1H, 15N, and 13C resonances in D2 domain has been accomplished. The findings of the present study not only pave way for an in-depth investigation of the molecular mechanism(s) underlying the activation of FGF signaling but also provide avenues for the rational design of potent inhibitors against FGF-mediated pathogenesis.
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MESH Headings
- Amino Acid Sequence
- Calorimetry/methods
- Circular Dichroism
- Cloning, Molecular
- Escherichia coli/metabolism
- Fibroblast Growth Factors/metabolism
- Humans
- Molecular Sequence Data
- Nuclear Magnetic Resonance, Biomolecular
- Protein Denaturation
- Protein Renaturation
- Protein Structure, Secondary
- Protein Structure, Tertiary
- Receptor Protein-Tyrosine Kinases/biosynthesis
- Receptor Protein-Tyrosine Kinases/chemistry
- Receptor Protein-Tyrosine Kinases/genetics
- Receptor Protein-Tyrosine Kinases/metabolism
- Receptor, Fibroblast Growth Factor, Type 2
- Receptors, Fibroblast Growth Factor/biosynthesis
- Receptors, Fibroblast Growth Factor/chemistry
- Receptors, Fibroblast Growth Factor/genetics
- Receptors, Fibroblast Growth Factor/metabolism
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Sucrose/analogs & derivatives
- Sucrose/metabolism
- Urea/chemistry
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Affiliation(s)
- Kuo-Wei Hung
- Department of Chemistry, National Tsing Hua University, Hsinchu 300, Taiwan, ROC
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Srimathi T, Kumar TKS, Chi YH, Chiu IM, Yu C. Characterization of the structure and dynamics of a near-native equilibrium intermediate in the unfolding pathway of an all beta-barrel protein. J Biol Chem 2002; 277:47507-16. [PMID: 12226076 DOI: 10.1074/jbc.m203407200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The structure and dynamics of equilibrium intermediate in the unfolding pathway of the human acidic fibroblast growth factor (hFGF-1) are investigated using a variety of biophysical techniques including multidimensional NMR spectroscopy. Guanidinium hydrochloride (GdnHCl)-induced unfolding of hFGF-1 proceeds with the accumulation of a stable intermediate state. The transition from the intermediate state to the unfolded state(s) is cooperative without the accumulation of additional intermediate(s). The intermediate state induced maximally in 0.96 m GdnHCl is found to be obligatory in the folding/unfolding pathway of hFGF-1. Most of the native tertiary structure interactions are preserved in the intermediate state. (1)H-(15)N chemical shift perturbation data suggest that the residues in the C-terminal segment including those located in the beta-strands IX, X, and XI undergo the most discernible structural change(s) in the intermediate state in 0.96 m GdnHCl. hFGF-1 in the intermediate state (0.96 m GdnHCl) does not bind to its ligand, sucrose octasulfate. Limited proteolytic digestion experiments and hydrogen-deuterium exchange monitored by (15)N heteronuclear single quantum coherence (HSQC) spectra show that the conformational flexibility of the protein in the intermediate state is significantly higher than in the native conformation. (15)N spin relaxation experiments show that many residues located in beta-strands IX, X, and XI exhibit conformational motions in the micro- to millisecond time scale. Analysis of (15)N relaxation data in conjunction with the amide proton exchange kinetics suggests that residues in the beta-strands II, VIII, and XII possibly constitute the stability core of the protein in the near-native intermediate state.
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Arunkumar AI, Srisailam S, Kumar TKS, Kathir KM, Chi YH, Wang HM, Chang GG, Chiu IM, Yu C. Structure and stability of an acidic fibroblast growth factor from Notophthalmus viridescens. J Biol Chem 2002; 277:46424-32. [PMID: 12205097 DOI: 10.1074/jbc.m207814200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The three-dimensional solution structure of an acidic fibroblast growth factor (nFGF-1) from the newt (Notophthalmus viridescens) is determined using multidimensional NMR techniques. Complete assignment of all the atoms ((1)H, (15)N, and (13)C) has been achieved using a variety of triple resonance experiments. 50 structures were calculated using hybrid distance geometry-dynamical simulated annealing technique with a total of 1359 constraints. The atomic root mean square distribution for the backbone atoms in the structured region is 0.60 A. The secondary structural elements include 12 beta-strands arranged antiparallely into a beta-barrel structure. The protein (nFGF-1) exists in a monomeric state upon binding to the ligand, sucrose octa sulfate (SOS), in a stoichiometric ratio of 1:1. The SOS binding site consists of a dense cluster of positively charged residues located at the C-terminal end of the molecule. The conformational stabilities of nFGF-1 and its structural and functional homologue from the human source (hFGF-1) are drastically different. The differential stabilities of nFGF-1 and hFGF-1 are attributed to the differences in the number of hydrogen bonds and the presence of solvent inaccessible cavities in the two proteins.
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42
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Nayar R, Manning MC. High throughput formulation: strategies for rapid development of stable protein products. PHARMACEUTICAL BIOTECHNOLOGY 2002; 13:177-98. [PMID: 11987752 DOI: 10.1007/978-1-4615-0557-0_8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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43
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Yeh BK, Eliseenkova AV, Plotnikov AN, Green D, Pinnell J, Polat T, Gritli-Linde A, Linhardt RJ, Mohammadi M. Structural basis for activation of fibroblast growth factor signaling by sucrose octasulfate. Mol Cell Biol 2002; 22:7184-92. [PMID: 12242295 PMCID: PMC139814 DOI: 10.1128/mcb.22.20.7184-7192.2002] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sucrose octasulfate (SOS) is believed to stimulate fibroblast growth factor (FGF) signaling by binding and stabilizing FGFs. In this report, we show that SOS induces FGF-dependent dimerization of FGF receptors (FGFRs). The crystal structure of the dimeric FGF2-FGFR1-SOS complex at 2.6-A resolution reveals a symmetric assemblage of two 1:1:1 FGF2-FGFR1-SOS ternary complexes. Within each ternary complex SOS binds to FGF and FGFR and thereby increases FGF-FGFR affinity. SOS also interacts with the adjoining FGFR and thereby promotes protein-protein interactions that stabilize dimerization. This structural finding is supported by the inability of selectively desulfated SOS molecules to promote receptor dimerization. Thus, we propose that SOS potentiates FGF signaling by imitating the dual role of heparin in increasing FGF-FGFR affinity and promoting receptor dimerization. Hence, the dimeric FGF-FGFR-SOS structure substantiates the recently proposed "two-end" model, by which heparin induces FGF-FGFR dimerization. Moreover, the FGF-FGFR-SOS structure provides an attractive template for the development of easily synthesized SOS-related heparin agonists and antagonists that may hold therapeutic potential.
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Affiliation(s)
- Brian K Yeh
- Departments of Pharmacology. Medicine, New York University School of Medicine, New York, New York 10016, USA
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Arunkumar AI, Kumar TKS, Kathir KM, Srisailam S, Wang HM, Leena PST, Chi YH, Chen HC, Wu CH, Wu RT, Chang GG, Chiu IM, Yu C. Oligomerization of acidic fibroblast growth factor is not a prerequisite for its cell proliferation activity. Protein Sci 2002; 11:1050-61. [PMID: 11967362 PMCID: PMC2373565 DOI: 10.1110/ps.2270102] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2001] [Revised: 01/23/2002] [Accepted: 01/29/2002] [Indexed: 10/14/2022]
Abstract
Oligomerization of fibroblast growth factors (FGFs) induced on binding to heparin or heparan sulfate proteoglycan is considered to be crucial for receptor activation and initiation of biological responses. To gain insight into the mechanism of activation of the receptor by FGFs, in the present study we investigate the effect(s) of interaction of a heparin analog, sucrose octasulfate (SOS), on the structure, stability, and biological activities of a recombinant acidic FGF from Notophthalmus viridescens (nFGF-1). SOS is found to bind to nFGF-1 and significantly increase the thermodynamic stability of the protein. Using a variety of techniques such as size-exclusion chromatography, sedimentation velocity, and multidimensional nuclear magnetic resonance (NMR) spectroscopy, it is shown that binding of SOS to nFGF-1 retains the protein in its monomeric state. In its monomeric state (complexed to SOS), n-FGF-1 shows significant cell proliferation activity. (15)N and (1)H chemical shift perturbation and the intermolecular nuclear Overhauser effects (NOEs) between SOS and nFGF-1 reveal that the ligand binds to the dense, positively charged cluster located in the groove enclosed by beta-strands 10 and 11. In addition, molecular modeling based on the NOEs observed for the SOS-nFGF-1 complex, indicates that SOS and heparin share a common binding site on the protein. In conclusion, the results of the present study clearly show that heparin-induced oligomerization of nFGF-1 is not mandatory for its cell proliferation activity.
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45
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Volkin DB, Middaugh CR. The characterization, stabilization, and formulation of acidic fibroblast growth factor. PHARMACEUTICAL BIOTECHNOLOGY 2002; 9:181-217. [PMID: 8914192 DOI: 10.1007/0-306-47452-2_3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- D B Volkin
- Department of Vaccine Pharmaceutical Research, Merck Research Laboratories, West Point, Pennsylvania 19486, USA
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46
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Chi Y, Kumar TK, Chiu IM, Yu C. 15N NMR relaxation studies of free and ligand-bound human acidic fibroblast growth factor. J Biol Chem 2000; 275:39444-50. [PMID: 10982816 DOI: 10.1074/jbc.m007205200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
15N NMR relaxation data have been used to characterize the backbone dynamics of the human acidic fibroblast growth factor (hFGF-1) in its free and sucrose octasulfate (SOS)-bound states. (15)N longitudinal (R(1)), transverse (R(2)) relaxation rates and (1H)-(15)N steady-state nuclear Overhauser effects were obtained at 500 and 600 MHz (at 25 degrees C) for all resolved backbone amide groups using (1)H- detected two-dimensional NMR experiments. Relaxation data were fit to the extended model free dynamics for each NH group. The overall correlation time (tau(m)) for the free and SOS-bound forms were estimated to be 10.4 +/- 1.07 and 11.1 +/- 1.35 ns, respectively. Titration experiments with SOS reveals that the ligand binds specifically to the C-terminal domain of the protein in a 1:1 ratio. Binding of SOS to hFGF-1 is found to induce a subtle conformational change in the protein. Significant conformational exchange (R(ex)) is observed for several residues in the free form of the protein. However, in the SOS-bound form only three residues exhibit significant R(ex) values, suggesting that the dynamics on the micro- to millisecond time scale in the free form is coupled to the cis-trans-proline isomerization. hFGF-1 is a rigid molecule with an average generalized parameter (S(2)) value of 0.89 +/- 0.03. Upon binding to SOS, there is a marked decrease in the overall flexibility (S(2) = 0.94 +/- 0.02) of the hFGF-1 molecule. However, the segment comprising residues 103-111 shows increased flexibility in the presence of SOS. Significant correlation is found between residues that show high flexibility and the putative receptor binding sites on the protein.
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Affiliation(s)
- Y Chi
- Department of Chemistry, National Tsing Hua University, Hsinchu 30043, Taiwan
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47
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Zhou H, Casas-Finet JR, Heath Coats R, Kaufman JD, Stahl SJ, Wingfield PT, Rubin JS, Bottaro DP, Byrd RA. Identification and dynamics of a heparin-binding site in hepatocyte growth factor. Biochemistry 1999; 38:14793-802. [PMID: 10555961 DOI: 10.1021/bi9908641] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hepatocyte growth factor (HGF) is a heparin-binding, multipotent growth factor that transduces a wide range of biological signals, including mitogenesis, motogenesis, and morphogenesis. Heparin or closely related heparan sulfate has profound effects on HGF signaling. A heparin-binding site in the N-terminal (N) domain of HGF was proposed on the basis of the clustering of surface positive charges [Zhou, H., Mazzulla, M. J., Kaufman, J. D., Stahl, S. J., Wingfield, P. T., Rubin, J. S., Bottaro, D. P., and Byrd, R. A. (1998) Structure 6, 109-116]. In the present study, we confirmed this binding site in a heparin titration experiment monitored by nuclear magnetic resonance spectroscopy, and we estimated the apparent dissociation constant (K(d)) of the heparin-protein complex by NMR and fluorescence techniques. The primary heparin-binding site is composed of Lys60, Lys62, and Arg73, with additional contributions from the adjacent Arg76, Lys78, and N-terminal basic residues. The K(d) of binding is in the micromolar range. A heparin disaccharide analogue, sucrose octasulfate, binds with similar affinity to the N domain and to a naturally occurring HGF isoform, NK1, at nearly the same region as in heparin binding. (15)N relaxation data indicate structural flexibility on a microsecond-to-millisecond time scale around the primary binding site in the N domain. This flexibility appears to be dramatically reduced by ligand binding. On the basis of the NK1 crystal structure, we propose a model in which heparin binds to the two primary binding sites and the N-terminal regions of the N domains and stabilizes an NK1 dimer.
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Affiliation(s)
- H Zhou
- Macromolecular NMR Section, ABL-Basic Research Program, SAIC Frederick, NCI-Frederick Cancer Research and Development Center, Frederick, Maryland 21702-1201, USA
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48
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Weisz PB, Joullié MM, Hunter CM, Kumor KM, Zhang Z, Levine E, Macarak E, Weiner D, Barnathan ES. A basic compositional requirement of agents having heparin-like cell-modulating activities. Biochem Pharmacol 1997; 54:149-57. [PMID: 9296361 DOI: 10.1016/s0006-2952(97)00157-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Heparin has been recognized as possessing a large variety of cell-modulating activities. Using compositionally simple, structurally rigid, and low molecular weight saccharide molecules (cyclodextrins), we demonstrated that these activities depend primarily on a single, gross compositional parameter: a minimum intramolecular density of neighboring anionic (sulfate) groups. This same critical parameter is shown to be involved in achieving cell-modulating behavior as diverse as angiogenesis, endothelial proliferation, inhibition of smooth muscle cell growth, and cell protection against virus invasion. Physical chemical evidence is presented that associates this property with multi-ionic complex formation between the clusters of anionic and cationic sites on the complexing partners. These observations revive early suggestions of the decisive role of electrostatic complexation capabilities of glycosaminoglycans like heparin; taken together with numerous observations on heparinoids and other agents reported in diverse specialized fields of cell biology and medicine, they provide evidence that molecular agents of critical anionic (sulfate) density (MACADs) represent a broad class of molecules that, in contrast to proteins, do not rely on structural detail for their cell biological activities, but function by ionic complexation with proteinic agents (e.g. growth factors), thereby modifying their structure-specific activities.
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Affiliation(s)
- P B Weisz
- Department of Bioengineering, University of Pennsylvania, Philadelphia 19104, U.S.A
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49
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50
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Desai UR, Vlahov IR, Pervin A, Linhardt RJ. Conformational analysis of sucrose octasulfate by high resolution nuclear magnetic resonance spectroscopy. Carbohydr Res 1995; 275:391-401. [PMID: 8529231 DOI: 10.1016/0008-6215(95)00159-q] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- U R Desai
- Division of Medicinal and Natural Products Chemistry, College of Pharmacy, University of Iowa, Iowa City 52242, USA
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