Objective This study aims to explore the clinical applicability and relevance of giycosaminoglycan Chemical Exchange Saturation Transfer (gagCEST) for intervertebral disc. Methods 25 subjects ranging in age from 24 ...Objective This study aims to explore the clinical applicability and relevance of giycosaminoglycan Chemical Exchange Saturation Transfer (gagCEST) for intervertebral disc. Methods 25 subjects ranging in age from 24 yrs to 74 yrs were enrolled, gagCEST was acquired using a single-slice TSE sequence on a 3T. Saturation used a continuous rectangular RF pulse with B1=0.8 I^T and a fixed duration time =1100 ms. Sagittal image was obtained firstly without saturation pulse, and then saturated images were acquired at 52 offsets ranging from +0.i25 to +_7 parts per million (ppm). MR T2 relaxivity map was acquired at the identical location. Six subjects were scanned twice to assess scan-rescan reproducibility. Results GagCEST intraclass correlation coefficient (ICC) of six subjects was 0.759 for nucleus pulposus (NP) and 0.508 for annulus fibrosus (AF). Bland-Altman plots showed NP had a mean difference of 0.10% (95% limits of agreement: -3.02% to 3.22%); while that of AF was 0.34% (95% limits of agreement: -2.28% to 2.95%). For the 25 subjects, gag CEST in NP decreased as disc degeneration increased, with a similar trend to T2 relaxivity. Gag CEST of AF showed a better correlation with disc degeneration than T2 relaxivity. Conclusion GagCEST in NP and AF decreased as disc degeneration increased, while gagCEST in AF showed a better correlation than T2 relaxivity.展开更多
Glycosaminoglycans(GAGs) play a significant role in various aspects of cell physiology.These are complex polymeric molecules characterized by disaccharides comprising of uronic acid and amino sugar.Compounded to the h...Glycosaminoglycans(GAGs) play a significant role in various aspects of cell physiology.These are complex polymeric molecules characterized by disaccharides comprising of uronic acid and amino sugar.Compounded to the heterogeneity,these are variously sulfated and epimerized depending on the class of GAG.Among the various classes of GAG,namely,chondroitin/dermatan sulfate,heparin/heparan sulfate,keratan sulfate and hyaluronic acid(HA),only HA is non-sulfated.GAGs are known to undergo remodeling in various tissues during various pathophysiological conditions,diabetes mellitus being one among them.These changes will likely affect their structure thereby impinging on their functionality.Till date,diabetes has been shown to affect GAGs in organs such as kidney,liver,aorta,skin,erythrocytes,etc.to name a few,with deleterious consequences.One of the mainstays in the treatment of diabetes is though dietary means.Various dietary factors are known to play a significant role in regulating glucose homeostasis.Furthermore,in recent years,there has been a keen interest to decipher the role of dietary factors on GAG metabolism.This review focuses on the remodeling of GAGs in various organs during diabetes and their modulation by dietary factors.While effect of diabetes on GAG metabolism has been worked out quite a bit,studies on the role of dietary factors in their modulation has been few and far between.We have tried our best to give the latest reports available on this subject.展开更多
Surgical brain injury may result in irreversible neurological deficits. Our previous report showed that partial regeneration of a traumatic brain lesion is achieved by implantation of collagen glycosaminoglycan(CGM)...Surgical brain injury may result in irreversible neurological deficits. Our previous report showed that partial regeneration of a traumatic brain lesion is achieved by implantation of collagen glycosaminoglycan(CGM). Matrix metalloproteinases(MMPs) may play an important role in neurogenesis but there is currently a lack of studies displaying the relationship between the stimulation of MMPs and neurogenesis after collagen glycosaminoglycan implantation following surgical brain trauma. The present study was carried out to further examine the expression of MMP2 and MMP9 after implantation of collagen glycosaminoglycan(CGM) following surgical brain trauma. Using the animal model of surgically induced brain lesion, we implanted CGM into the surgical trauma. Rats were thus divided into three groups:(1) sham operation group: craniotomy only;(2) lesion(L) group: craniotomy + surgical trauma lesion;(3) lesion + CGM(L + CGM) group: CGM implanted following craniotomy and surgical trauma lesion. Cells positive for SOX2(marker of proliferating neural progenitor cells) and matrix metalloproteinases(MMP2 and MMP9) in the lesion boundary zone were assayed and analyzed by immunofluorescence and ELISA commercial kits, respectively. Our results demonstrated that following implantation of CGM after surgical brain trauma, significant increases in MMP2^+/SOX2^+ cells and MMP9^+/SOX2^+ cells were seen within the lesion boundary zone in the L + CGM group. Tissue protein concentrations of MMP2 and MMP9 also increased after CGM scaffold implantation. These findings suggest that implantation of a CGM scaffold alone after surgical brain trauma can enhance the expression of MMP2 and MMP9 accompanied by neurogenesis.展开更多
Objective: To assess glycosaminoglycan (GAG) content of lumbar intervertebral discs (IVDs) in patients with radiculopathy compared with healthy volunteers with glycosaminoglycan chemical exchange saturation transfer (...Objective: To assess glycosaminoglycan (GAG) content of lumbar intervertebral discs (IVDs) in patients with radiculopathy compared with healthy volunteers with glycosaminoglycan chemical exchange saturation transfer (gagCEST). Methods: The lumbar spines of 15 patients with radiculopathy (9 women, 6 men;mean age 45 years;range: 19 - 80 years) and 13 healthy controls (10 women, 3 men;mean age 29 years;range: 19 - 38 years) without lumbar back pain or previous spine surgery were examined at a 3 Tesla (T) magnetic resonance imaging (MRI) scanner in this prospective study. The MRI protocol included standard morphological, sagittal, and transverse T2-weighted (T2w) images of the five lumbar IVDs (L1-S1) to assess Pfirrmann score and to detect disc disorders according to the Combined Task Force classification. To analyze biochemically the lumbar IVDs, a gagCEST sequence was applied to measure the GAG content of the nucleus pulposus (NP) and annulus fibrosus (AF). Results: Patients with radiculopathy indicated significantly lower gagCEST values in NP than healthy volunteers (2.82% ±3.12% vs. 4.09% ±2.25%, P = 0.017). The GAG content of AF showed no significant difference between volunteers and patients (2.66% ±2.01% vs. 1.92% ±2.56%;P = 0.175). Conclusions. Patients with radiculopathy presented with lower GAG values than healthy volunteers in NP, indicating an association between pain and IVD degeneration. gagCEST of lumbar IVDs is a powerful, non-invasive tool to investigate early disc degeneration, which we could demonstrate in the NP in our study collective.展开更多
Objective To establish a method for quantitative detection of the sulfate glycosaminoglycans ( GAG) content in extracellular matrix of in vitro cultured chondrocytes so as to evaluate the biological characteristics of...Objective To establish a method for quantitative detection of the sulfate glycosaminoglycans ( GAG) content in extracellular matrix of in vitro cultured chondrocytes so as to evaluate the biological characteristics of epiphyseal, articular and rib chondrocytes. Methods Sulfate GAG content in extracellular matrix of three chondrocytes was measured by the modified dimethylmethylene blue (DMB) method. The changes of the toluidine blue (TB) stain of chondrocytes were observed by light microscope. Results Primary chondrocytes had the highest content of sulfate GAG in the extracellular matrix, ie, epiphyseal chondrocytes reached ( 70. 12 ± 7. 72 )μg/cm2, articular chondrocytes (92.00 ± 10.15) μg/cm2 and rib chondrocytes (80.61 ± 11. 40) μg/cm2, respectively. On the third pasage chondrocytes, epiphyceal chondrocytes decreased to (53.27 ± 9. 50 ) μg/cm2, articular chondrocytes to (63.88 ± 11.92) μg/cm2 and rib chondrocytes to (58.94 ±8.21) μg/cm2, respectively. The change of TB in every passage展开更多
This paper aims to prepare a PVA-GAG-COL composite with polyvinyl alcohol (PVA), glycosaminoglycan (GAG) and collagen (COL) by the method of freeze drying and to investigate the feasibility as a tissue engineering sca...This paper aims to prepare a PVA-GAG-COL composite with polyvinyl alcohol (PVA), glycosaminoglycan (GAG) and collagen (COL) by the method of freeze drying and to investigate the feasibility as a tissue engineering scaffold for tissue or organ repairing. In this study, SEM was used to observe the morphology. Biocompatibility was tested by cell culture with the extracted fluid of composite materials. Different proportional scaffolds could be obtained with different concentrations and alcoholysis degree of PVA. Different proportional scaffolds also had different porous structures. SEM proved that large amount of porous structure could be formed. Biocompatibility test showed that the extracted fluid of composite materials was nontoxic, which could promote the adhesion and proliferation of the fibroblast. Fibroblast could grow on the scaffold normally.A porous scaffold for tissue engineering with high water content can be fabricated by PVA, GAG and COL, which has excellent cell biocompatibility. The porous structure shows potential in tissue engineering and cell culture.展开更多
A PVA- GAG- COL composite scaffold is fabricated by polyvinyl alcohol (PVA), glycosaminoglycan (GAG) and collagen (COL). Laser surface modification technology is used to make holes on the surface of the scaffolds. Ins...A PVA- GAG- COL composite scaffold is fabricated by polyvinyl alcohol (PVA), glycosaminoglycan (GAG) and collagen (COL). Laser surface modification technology is used to make holes on the surface of the scaffolds. Inside and outside interconnection microporous structure is obtained. Biocompatibility test of the scaffolds shows that PVA- GAG- COL scaffold can promote the adhesion and proliferation of the fibroblast. Also, fibroblast can grow normally on the scaffolds with pore diameter from 115 um to 255 um and pore distance from 500 um to 2000 um. PVA- GAG- COL scaffolds possess excellent cell biocompatibility. The porous structure is suitable for cell culture in tissue engineering.展开更多
The aim of this study is to prepare a PVA-GAG-COL composite material by polyvinyl alcohol (PVA),glycosaminoglycan (GAG) and collagen (COL),and to investigate the feasibility of serving as a scaffold for tissue enginee...The aim of this study is to prepare a PVA-GAG-COL composite material by polyvinyl alcohol (PVA),glycosaminoglycan (GAG) and collagen (COL),and to investigate the feasibility of serving as a scaffold for tissue engineering. PVA was blended with various amounts of GAG and COL. Different proportional scaffolds could be obtained with different molecular weight and alcoholysis degree of PVA and different amounts of GAG,which exhibited high water content (60%-95%) and showed different inner configuration with swelling ratio (120%-620%). SEM proved that different composite materials had different porous structures.展开更多
Capsular polysaccharides(CPS)of Colwellia psychrerythraea 34H consist of linear tetrasaccharides repeating units in a glycosaminoglycan-like fashion.Their biological function is likely involved in the cold adaptation ...Capsular polysaccharides(CPS)of Colwellia psychrerythraea 34H consist of linear tetrasaccharides repeating units in a glycosaminoglycan-like fashion.Their biological function is likely involved in the cold adaptation of microbial organisms.The low availability of these glycosaminoglycan structures greatly limits the study of their functions and biological activities.Here,an efficient semisynthetic strategy for CPS tetrasaccharide derivatives is achieved by using disaccharide units degraded from hyaluronic acids.This new synthetic process is suitable for largescale preparation,and several rare tetrasaccharide derivatives containing GalA-GalNAc were readily obtained in high yields.Biological evaluation of their anti-inflammatory effects demonstrated that these CPS tetrasaccharides effectively attenuated the lipopolysaccharide-induced sepsis and acute lung injury by decreasing macrophage infiltration and secretion of microphage-related cytokines in mice.All these results suggest that this new type of CPS tetrasaccharide can be developed as an anti-inflammation agent.展开更多
Objective:To extract,characterize and quantify glycosaminoglycans(GAGs)from the body of cuttlefish,tennis-ball sea cucumber,shrimp,seabass and fresh water fish Nile tilapia.Methods:The extracted crude powder was evalu...Objective:To extract,characterize and quantify glycosaminoglycans(GAGs)from the body of cuttlefish,tennis-ball sea cucumber,shrimp,seabass and fresh water fish Nile tilapia.Methods:The extracted crude powder was evaluated for the content of GAGs.The qualitative analysis of sulfated pattern and other important functional groups related with GAGs were explained in the form of Fourier transform infra-red spectroscopy data.Proteins and nucleic acid in the crude extract were determined by the ultraviolet spectrophotometer,while the quantification of total sulfated GAGs and estimation of N-sulfated and O-sulfated GAGs in the crude mixture were performed by using Blyscan kit.Results:The sulfated pattern and other important functional groups related with GAGs were intercepted in Fourier transform infrared analysis.Blyscan quantification method reported that a rare variety of sea cucumber(tennis-ball sea cucumber)emerged as a rich source of GAGs with high values of both N-sulfated and O-sulfated GAGs in comparison to its other counterparts.Conclusions:Findings in this study point out the potential of tennis-ball sea cucumber,a rare variety of sea cucumber to act as an alternative source for GAG extraction for commercial purpose.展开更多
The effects of AAV-TGFβ1 and AAV-TGFβ3 on promoting synthesis of glycosaminoglycan and collagen type II of dedifferentiated rabbit lumbar disc NP cells were studied in this work. The rabbit lumbar disc NP cells were...The effects of AAV-TGFβ1 and AAV-TGFβ3 on promoting synthesis of glycosaminoglycan and collagen type II of dedifferentiated rabbit lumbar disc NP cells were studied in this work. The rabbit lumbar disc NP cells were isolated and cultured. The earlier and later dedifferentiated NP cells were established by subculture. The AAV transfection efficiency to dedifferentiated NP cells was analyzed with AAV-EGFP in vitro. After dedifferentiated NP cells were transfected by AAV-TGFβ1 or AAV-TGFβ3, their biological effects on promoting synthesis of glycosaminoglycan or collagen type II were detected and compared by the methods of 35S incorporation or immunoblotting. The experimental results showed that AAV could transfect efficiently the earlier dedifferentiated NP cells, but its transfection rate was shown to be at a low level to the later dedifferentiated NP cells. Both AAV-TGFβ1 and AAV-TGFβ3 could promote the earlier dedifferentiated NP cells to synthesize glycosaminoglycan and collagen type II, and the effect of AAV-TGFβ1 was better than that of AAV-TGFβ3. For the later dedifferentiated NP cells, the AAV-TGFβ3 could promote their synthesis, but AAV-TGFβ1 could slightly inhibit their synthesis. Therefore, AAV-TGFβ1 and AAV-TGFβ3 could be used for the earlier dedifferentiated NP cells, and the TGFβ3 could be used as the objective gene for the later dedifferentiated NP cells.展开更多
Background: The quality of the lateral compartment cartilage is important to preoperative evaluation and prognostic prediction of unicompartmental knee arthroplasty (UKA). Delayed gadolinium-enhanced magnetic reson...Background: The quality of the lateral compartment cartilage is important to preoperative evaluation and prognostic prediction of unicompartmental knee arthroplasty (UKA). Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) enables noninvasive assessment of glycosaminoglycan (GAG) content in cartilage. This study aimed to determine the GAG content of the lateral compartment cartilage in knees scheduled to undergo Oxford medial UKA. Methods: From December 2016 to May 2017, twenty patients (20 osteoarthritic knees) conforming to the indications fbr Oxford medial UKA were included as the osteoarthritis (OA) group, and 20 healthy volunteers (20 knees) paired by sex, knee side, age (±3 years), and body mass index (BMI) (i3 kg/m2) were included as the control group. The GAG contents of the weight-bearing femoral cartilage (wbFC), the posterior non-weight-bearing femoral cartilage (pFC), the lateral femoral cartilage (FC), and tibial cartilage (TC) were detected using dGEMRIC. The dGEMRIC indices (T1Gd) were calculated in the middle three consecutive slices of the lateral compartment. Paired t-tests were used to compare the T1Gd in each region of interest between the OA group and control group. Results: The average age and BMI in the two groups were similar. In the OA group, TIGd of FC and TC was 386.7 ± 50.7 ms and 429.6 ± 59.9 ins, respectively. In the control group, T1Gd of FC and TC was 397.5 ± 52.3 ms and 448.6 ±62.5 ms, respectively. The respective T 1Gd ofwbFC and pFC was 380.0 ± 47.8 ms and 391.0 ± 66.3 ms in the OA group and 400.3 ± 51.5 ms and 393.6 ± 57.9 ms in the control group. Although the T 1Gd ofwbFC and TC tended to be lower in the OA group than the control group, there was no significant difference between groups in the TIGd in any of the analyzed cartilage regions (P value ofwbFC, pFC, FC, and TC was 0.236, 0.857, 0.465, and 0.324, respectively). Conclusions: The GAG content of the lateral compartment cartilage in knees confonning to indications for Oxford medial UKA is similar with those of age- and BMl-matched participants without OA.展开更多
Glycosaminoglycans(GAGs)are a class of linear polysaccharides,consisting of alternating disaccharide sequences of uronic acid and hexosamines(or galactose)with and without sulfation.They can interact with various prot...Glycosaminoglycans(GAGs)are a class of linear polysaccharides,consisting of alternating disaccharide sequences of uronic acid and hexosamines(or galactose)with and without sulfation.They can interact with various proteins,such as growth factors,receptors and cell adhesion molecules,endowing these with various biological and pharmacological activi-ties.Such activities make GAGs useful in health care products and medicines.Currently,all GAGs,with the exception of hyaluronan,are produced by extraction from animal tissues.However,limited availability,poor control of animal tissues,impurities,viruses,prions,endotoxins,contamination and other problems have increased the interest in new approaches for GAG production.These new approaches include GAGs production by chemical synthesis,chemoenzymatic synthesis and metabolic engineering.One chemically synthesized heparin pentasaccharide,fondaparinux sodium,is in clinical use.Mostly,hyaluronan today is prepared by microbial fermentation,largely replacing hyaluronan from rooster comb.The recent gram scale chemoenzymatic synthesis of a heparin dodecasaccharide suggests its potential to replace currently used animal-sourced low molecular weight heparin(LMWH).Despite these considerable successes,such high-tech approaches still cannot meet worldwide demands for GAGs.This review gives a brief introduction on the manufacturing of unfractionated and low molecular weight heparins,the chemical synthesis and chemoenzymatic synthesis of GAGs and focuses on the progress in the bioengineered preparation of GAGs,particularly heparin.展开更多
The objective of this paper is to design a porous polyvinyl alcohol(PVA)based on composite membrane with certain mechanical strength and biocompatibilities serving as tissue regenerative scaffolds.PVA-glycosaminoglyca...The objective of this paper is to design a porous polyvinyl alcohol(PVA)based on composite membrane with certain mechanical strength and biocompatibilities serving as tissue regenerative scaffolds.PVA-glycosaminoglycan(GAG)-type I collagen(COL) composite membrane was fabricated by PVA with different molecular weight(Mw)and alcoholysis degree(AD) being blended with certain amounts of GAG and COL and dried at 38℃ for 24 h.The water content of the composite membranes were from 61.9%to 95.1% and swelling ratio ranged from 123.6% to 621.7%.Scanning electron microscope(SEM) analysis proved that PVA-GAG-COL composite membrane has porous and homogenous structure.Biocompatibility test results showed that the composite membrane was nontoxic,which could promote adhesion and proliferation of fibroblasts on the composite membrane.In conclusion,PVA-GAG-COL composite membrane with high water content and swelling ratio,suitable mechanical strength and good biocompatibility,has potential in tissue engineering and regenerative medicine.展开更多
Hyaluronate lyases were obtained from two types of naturally isolated bacterial strains Paenibacillus yunnanensis and Paennarthrobacter nicotinovorans.PyHL(form P.yunnanensis)in the culture supernatant of the bacteria...Hyaluronate lyases were obtained from two types of naturally isolated bacterial strains Paenibacillus yunnanensis and Paennarthrobacter nicotinovorans.PyHL(form P.yunnanensis)in the culture supernatant of the bacteria was purified by two steps of column chromatography.The enzyme showed the molecular mass of 74 kDa by SDS-PAGE and the maximal activity at pH 5.0,35℃.PyHL maximally degraded hyaluronate by an endo-type manner,and showed low degradation activity toward chondroitin sulfates.Dermatan sulfate was not the substrate.PnHL(from P.nicotinovorans)in the culture supernatant of the bacteria was purified by two steps of column chromatography.The enzyme showed the molecular mass of 70 kDa by SDS-PAGE and the maximal activity at pH 6.0,30℃.Genomic analysis of P.nicotinovorans on the bases of the internal amino acid sequences of PnHL.展开更多
基金partially by grants from the Research Grants Council of the Hong Kong SAR,China(Project No.SEG_CUHK02)
文摘Objective This study aims to explore the clinical applicability and relevance of giycosaminoglycan Chemical Exchange Saturation Transfer (gagCEST) for intervertebral disc. Methods 25 subjects ranging in age from 24 yrs to 74 yrs were enrolled, gagCEST was acquired using a single-slice TSE sequence on a 3T. Saturation used a continuous rectangular RF pulse with B1=0.8 I^T and a fixed duration time =1100 ms. Sagittal image was obtained firstly without saturation pulse, and then saturated images were acquired at 52 offsets ranging from +0.i25 to +_7 parts per million (ppm). MR T2 relaxivity map was acquired at the identical location. Six subjects were scanned twice to assess scan-rescan reproducibility. Results GagCEST intraclass correlation coefficient (ICC) of six subjects was 0.759 for nucleus pulposus (NP) and 0.508 for annulus fibrosus (AF). Bland-Altman plots showed NP had a mean difference of 0.10% (95% limits of agreement: -3.02% to 3.22%); while that of AF was 0.34% (95% limits of agreement: -2.28% to 2.95%). For the 25 subjects, gag CEST in NP decreased as disc degeneration increased, with a similar trend to T2 relaxivity. Gag CEST of AF showed a better correlation with disc degeneration than T2 relaxivity. Conclusion GagCEST in NP and AF decreased as disc degeneration increased, while gagCEST in AF showed a better correlation than T2 relaxivity.
文摘Glycosaminoglycans(GAGs) play a significant role in various aspects of cell physiology.These are complex polymeric molecules characterized by disaccharides comprising of uronic acid and amino sugar.Compounded to the heterogeneity,these are variously sulfated and epimerized depending on the class of GAG.Among the various classes of GAG,namely,chondroitin/dermatan sulfate,heparin/heparan sulfate,keratan sulfate and hyaluronic acid(HA),only HA is non-sulfated.GAGs are known to undergo remodeling in various tissues during various pathophysiological conditions,diabetes mellitus being one among them.These changes will likely affect their structure thereby impinging on their functionality.Till date,diabetes has been shown to affect GAGs in organs such as kidney,liver,aorta,skin,erythrocytes,etc.to name a few,with deleterious consequences.One of the mainstays in the treatment of diabetes is though dietary means.Various dietary factors are known to play a significant role in regulating glucose homeostasis.Furthermore,in recent years,there has been a keen interest to decipher the role of dietary factors on GAG metabolism.This review focuses on the remodeling of GAGs in various organs during diabetes and their modulation by dietary factors.While effect of diabetes on GAG metabolism has been worked out quite a bit,studies on the role of dietary factors in their modulation has been few and far between.We have tried our best to give the latest reports available on this subject.
基金supported by grants from the National Science Council of China(NSC 102-2314-B-303-004)the Tzu Chi Medical Mission Project 105-06,Buddhist Tzu Chi Medical Foundation
文摘Surgical brain injury may result in irreversible neurological deficits. Our previous report showed that partial regeneration of a traumatic brain lesion is achieved by implantation of collagen glycosaminoglycan(CGM). Matrix metalloproteinases(MMPs) may play an important role in neurogenesis but there is currently a lack of studies displaying the relationship between the stimulation of MMPs and neurogenesis after collagen glycosaminoglycan implantation following surgical brain trauma. The present study was carried out to further examine the expression of MMP2 and MMP9 after implantation of collagen glycosaminoglycan(CGM) following surgical brain trauma. Using the animal model of surgically induced brain lesion, we implanted CGM into the surgical trauma. Rats were thus divided into three groups:(1) sham operation group: craniotomy only;(2) lesion(L) group: craniotomy + surgical trauma lesion;(3) lesion + CGM(L + CGM) group: CGM implanted following craniotomy and surgical trauma lesion. Cells positive for SOX2(marker of proliferating neural progenitor cells) and matrix metalloproteinases(MMP2 and MMP9) in the lesion boundary zone were assayed and analyzed by immunofluorescence and ELISA commercial kits, respectively. Our results demonstrated that following implantation of CGM after surgical brain trauma, significant increases in MMP2^+/SOX2^+ cells and MMP9^+/SOX2^+ cells were seen within the lesion boundary zone in the L + CGM group. Tissue protein concentrations of MMP2 and MMP9 also increased after CGM scaffold implantation. These findings suggest that implantation of a CGM scaffold alone after surgical brain trauma can enhance the expression of MMP2 and MMP9 accompanied by neurogenesis.
文摘Objective: To assess glycosaminoglycan (GAG) content of lumbar intervertebral discs (IVDs) in patients with radiculopathy compared with healthy volunteers with glycosaminoglycan chemical exchange saturation transfer (gagCEST). Methods: The lumbar spines of 15 patients with radiculopathy (9 women, 6 men;mean age 45 years;range: 19 - 80 years) and 13 healthy controls (10 women, 3 men;mean age 29 years;range: 19 - 38 years) without lumbar back pain or previous spine surgery were examined at a 3 Tesla (T) magnetic resonance imaging (MRI) scanner in this prospective study. The MRI protocol included standard morphological, sagittal, and transverse T2-weighted (T2w) images of the five lumbar IVDs (L1-S1) to assess Pfirrmann score and to detect disc disorders according to the Combined Task Force classification. To analyze biochemically the lumbar IVDs, a gagCEST sequence was applied to measure the GAG content of the nucleus pulposus (NP) and annulus fibrosus (AF). Results: Patients with radiculopathy indicated significantly lower gagCEST values in NP than healthy volunteers (2.82% ±3.12% vs. 4.09% ±2.25%, P = 0.017). The GAG content of AF showed no significant difference between volunteers and patients (2.66% ±2.01% vs. 1.92% ±2.56%;P = 0.175). Conclusions. Patients with radiculopathy presented with lower GAG values than healthy volunteers in NP, indicating an association between pain and IVD degeneration. gagCEST of lumbar IVDs is a powerful, non-invasive tool to investigate early disc degeneration, which we could demonstrate in the NP in our study collective.
文摘Objective To establish a method for quantitative detection of the sulfate glycosaminoglycans ( GAG) content in extracellular matrix of in vitro cultured chondrocytes so as to evaluate the biological characteristics of epiphyseal, articular and rib chondrocytes. Methods Sulfate GAG content in extracellular matrix of three chondrocytes was measured by the modified dimethylmethylene blue (DMB) method. The changes of the toluidine blue (TB) stain of chondrocytes were observed by light microscope. Results Primary chondrocytes had the highest content of sulfate GAG in the extracellular matrix, ie, epiphyseal chondrocytes reached ( 70. 12 ± 7. 72 )μg/cm2, articular chondrocytes (92.00 ± 10.15) μg/cm2 and rib chondrocytes (80.61 ± 11. 40) μg/cm2, respectively. On the third pasage chondrocytes, epiphyceal chondrocytes decreased to (53.27 ± 9. 50 ) μg/cm2, articular chondrocytes to (63.88 ± 11.92) μg/cm2 and rib chondrocytes to (58.94 ±8.21) μg/cm2, respectively. The change of TB in every passage
基金National High-tech Reasearch and Development Program of China(863 Program)grant number:2077AA09Z436+1 种基金Guangdong Project '211'grant number:50621030
文摘This paper aims to prepare a PVA-GAG-COL composite with polyvinyl alcohol (PVA), glycosaminoglycan (GAG) and collagen (COL) by the method of freeze drying and to investigate the feasibility as a tissue engineering scaffold for tissue or organ repairing. In this study, SEM was used to observe the morphology. Biocompatibility was tested by cell culture with the extracted fluid of composite materials. Different proportional scaffolds could be obtained with different concentrations and alcoholysis degree of PVA. Different proportional scaffolds also had different porous structures. SEM proved that large amount of porous structure could be formed. Biocompatibility test showed that the extracted fluid of composite materials was nontoxic, which could promote the adhesion and proliferation of the fibroblast. Fibroblast could grow on the scaffold normally.A porous scaffold for tissue engineering with high water content can be fabricated by PVA, GAG and COL, which has excellent cell biocompatibility. The porous structure shows potential in tissue engineering and cell culture.
基金863 Program grant number: 2077AA09Z436+1 种基金Guangdong Province '211' Fund for Biomaterials and Tissue Engineering grantnumber: 50621030
文摘A PVA- GAG- COL composite scaffold is fabricated by polyvinyl alcohol (PVA), glycosaminoglycan (GAG) and collagen (COL). Laser surface modification technology is used to make holes on the surface of the scaffolds. Inside and outside interconnection microporous structure is obtained. Biocompatibility test of the scaffolds shows that PVA- GAG- COL scaffold can promote the adhesion and proliferation of the fibroblast. Also, fibroblast can grow normally on the scaffolds with pore diameter from 115 um to 255 um and pore distance from 500 um to 2000 um. PVA- GAG- COL scaffolds possess excellent cell biocompatibility. The porous structure is suitable for cell culture in tissue engineering.
文摘The aim of this study is to prepare a PVA-GAG-COL composite material by polyvinyl alcohol (PVA),glycosaminoglycan (GAG) and collagen (COL),and to investigate the feasibility of serving as a scaffold for tissue engineering. PVA was blended with various amounts of GAG and COL. Different proportional scaffolds could be obtained with different molecular weight and alcoholysis degree of PVA and different amounts of GAG,which exhibited high water content (60%-95%) and showed different inner configuration with swelling ratio (120%-620%). SEM proved that different composite materials had different porous structures.
基金financially supported by the National Natural Science Foundation of China (grant nos.82151223,81930097,and 21977005)the National Key R&D Program of China (grant nos.2022YFF1203005 and 2022YFC2303700).
文摘Capsular polysaccharides(CPS)of Colwellia psychrerythraea 34H consist of linear tetrasaccharides repeating units in a glycosaminoglycan-like fashion.Their biological function is likely involved in the cold adaptation of microbial organisms.The low availability of these glycosaminoglycan structures greatly limits the study of their functions and biological activities.Here,an efficient semisynthetic strategy for CPS tetrasaccharide derivatives is achieved by using disaccharide units degraded from hyaluronic acids.This new synthetic process is suitable for largescale preparation,and several rare tetrasaccharide derivatives containing GalA-GalNAc were readily obtained in high yields.Biological evaluation of their anti-inflammatory effects demonstrated that these CPS tetrasaccharides effectively attenuated the lipopolysaccharide-induced sepsis and acute lung injury by decreasing macrophage infiltration and secretion of microphage-related cytokines in mice.All these results suggest that this new type of CPS tetrasaccharide can be developed as an anti-inflammation agent.
文摘Objective:To extract,characterize and quantify glycosaminoglycans(GAGs)from the body of cuttlefish,tennis-ball sea cucumber,shrimp,seabass and fresh water fish Nile tilapia.Methods:The extracted crude powder was evaluated for the content of GAGs.The qualitative analysis of sulfated pattern and other important functional groups related with GAGs were explained in the form of Fourier transform infra-red spectroscopy data.Proteins and nucleic acid in the crude extract were determined by the ultraviolet spectrophotometer,while the quantification of total sulfated GAGs and estimation of N-sulfated and O-sulfated GAGs in the crude mixture were performed by using Blyscan kit.Results:The sulfated pattern and other important functional groups related with GAGs were intercepted in Fourier transform infrared analysis.Blyscan quantification method reported that a rare variety of sea cucumber(tennis-ball sea cucumber)emerged as a rich source of GAGs with high values of both N-sulfated and O-sulfated GAGs in comparison to its other counterparts.Conclusions:Findings in this study point out the potential of tennis-ball sea cucumber,a rare variety of sea cucumber to act as an alternative source for GAG extraction for commercial purpose.
基金Supported by the National Natural Science Foundation of China (Grant No. 30271318)
文摘The effects of AAV-TGFβ1 and AAV-TGFβ3 on promoting synthesis of glycosaminoglycan and collagen type II of dedifferentiated rabbit lumbar disc NP cells were studied in this work. The rabbit lumbar disc NP cells were isolated and cultured. The earlier and later dedifferentiated NP cells were established by subculture. The AAV transfection efficiency to dedifferentiated NP cells was analyzed with AAV-EGFP in vitro. After dedifferentiated NP cells were transfected by AAV-TGFβ1 or AAV-TGFβ3, their biological effects on promoting synthesis of glycosaminoglycan or collagen type II were detected and compared by the methods of 35S incorporation or immunoblotting. The experimental results showed that AAV could transfect efficiently the earlier dedifferentiated NP cells, but its transfection rate was shown to be at a low level to the later dedifferentiated NP cells. Both AAV-TGFβ1 and AAV-TGFβ3 could promote the earlier dedifferentiated NP cells to synthesize glycosaminoglycan and collagen type II, and the effect of AAV-TGFβ1 was better than that of AAV-TGFβ3. For the later dedifferentiated NP cells, the AAV-TGFβ3 could promote their synthesis, but AAV-TGFβ1 could slightly inhibit their synthesis. Therefore, AAV-TGFβ1 and AAV-TGFβ3 could be used for the earlier dedifferentiated NP cells, and the TGFβ3 could be used as the objective gene for the later dedifferentiated NP cells.
文摘Background: The quality of the lateral compartment cartilage is important to preoperative evaluation and prognostic prediction of unicompartmental knee arthroplasty (UKA). Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) enables noninvasive assessment of glycosaminoglycan (GAG) content in cartilage. This study aimed to determine the GAG content of the lateral compartment cartilage in knees scheduled to undergo Oxford medial UKA. Methods: From December 2016 to May 2017, twenty patients (20 osteoarthritic knees) conforming to the indications fbr Oxford medial UKA were included as the osteoarthritis (OA) group, and 20 healthy volunteers (20 knees) paired by sex, knee side, age (±3 years), and body mass index (BMI) (i3 kg/m2) were included as the control group. The GAG contents of the weight-bearing femoral cartilage (wbFC), the posterior non-weight-bearing femoral cartilage (pFC), the lateral femoral cartilage (FC), and tibial cartilage (TC) were detected using dGEMRIC. The dGEMRIC indices (T1Gd) were calculated in the middle three consecutive slices of the lateral compartment. Paired t-tests were used to compare the T1Gd in each region of interest between the OA group and control group. Results: The average age and BMI in the two groups were similar. In the OA group, TIGd of FC and TC was 386.7 ± 50.7 ms and 429.6 ± 59.9 ins, respectively. In the control group, T1Gd of FC and TC was 397.5 ± 52.3 ms and 448.6 ±62.5 ms, respectively. The respective T 1Gd ofwbFC and pFC was 380.0 ± 47.8 ms and 391.0 ± 66.3 ms in the OA group and 400.3 ± 51.5 ms and 393.6 ± 57.9 ms in the control group. Although the T 1Gd ofwbFC and TC tended to be lower in the OA group than the control group, there was no significant difference between groups in the TIGd in any of the analyzed cartilage regions (P value ofwbFC, pFC, FC, and TC was 0.236, 0.857, 0.465, and 0.324, respectively). Conclusions: The GAG content of the lateral compartment cartilage in knees confonning to indications for Oxford medial UKA is similar with those of age- and BMl-matched participants without OA.
基金This study was supported by China Scholarship Council(W.J.)the National Institutes of Health(DK111958 and CA231074)(F.Z.and R.J.L.).
文摘Glycosaminoglycans(GAGs)are a class of linear polysaccharides,consisting of alternating disaccharide sequences of uronic acid and hexosamines(or galactose)with and without sulfation.They can interact with various proteins,such as growth factors,receptors and cell adhesion molecules,endowing these with various biological and pharmacological activi-ties.Such activities make GAGs useful in health care products and medicines.Currently,all GAGs,with the exception of hyaluronan,are produced by extraction from animal tissues.However,limited availability,poor control of animal tissues,impurities,viruses,prions,endotoxins,contamination and other problems have increased the interest in new approaches for GAG production.These new approaches include GAGs production by chemical synthesis,chemoenzymatic synthesis and metabolic engineering.One chemically synthesized heparin pentasaccharide,fondaparinux sodium,is in clinical use.Mostly,hyaluronan today is prepared by microbial fermentation,largely replacing hyaluronan from rooster comb.The recent gram scale chemoenzymatic synthesis of a heparin dodecasaccharide suggests its potential to replace currently used animal-sourced low molecular weight heparin(LMWH).Despite these considerable successes,such high-tech approaches still cannot meet worldwide demands for GAGs.This review gives a brief introduction on the manufacturing of unfractionated and low molecular weight heparins,the chemical synthesis and chemoenzymatic synthesis of GAGs and focuses on the progress in the bioengineered preparation of GAGs,particularly heparin.
基金National Natural Science Foundation of China,grant number:51070853Guangzhou Technology Plans,grant number:2010B103315 and 2010J-E041
文摘The objective of this paper is to design a porous polyvinyl alcohol(PVA)based on composite membrane with certain mechanical strength and biocompatibilities serving as tissue regenerative scaffolds.PVA-glycosaminoglycan(GAG)-type I collagen(COL) composite membrane was fabricated by PVA with different molecular weight(Mw)and alcoholysis degree(AD) being blended with certain amounts of GAG and COL and dried at 38℃ for 24 h.The water content of the composite membranes were from 61.9%to 95.1% and swelling ratio ranged from 123.6% to 621.7%.Scanning electron microscope(SEM) analysis proved that PVA-GAG-COL composite membrane has porous and homogenous structure.Biocompatibility test results showed that the composite membrane was nontoxic,which could promote adhesion and proliferation of fibroblasts on the composite membrane.In conclusion,PVA-GAG-COL composite membrane with high water content and swelling ratio,suitable mechanical strength and good biocompatibility,has potential in tissue engineering and regenerative medicine.
文摘Hyaluronate lyases were obtained from two types of naturally isolated bacterial strains Paenibacillus yunnanensis and Paennarthrobacter nicotinovorans.PyHL(form P.yunnanensis)in the culture supernatant of the bacteria was purified by two steps of column chromatography.The enzyme showed the molecular mass of 74 kDa by SDS-PAGE and the maximal activity at pH 5.0,35℃.PyHL maximally degraded hyaluronate by an endo-type manner,and showed low degradation activity toward chondroitin sulfates.Dermatan sulfate was not the substrate.PnHL(from P.nicotinovorans)in the culture supernatant of the bacteria was purified by two steps of column chromatography.The enzyme showed the molecular mass of 70 kDa by SDS-PAGE and the maximal activity at pH 6.0,30℃.Genomic analysis of P.nicotinovorans on the bases of the internal amino acid sequences of PnHL.