Endochondral ossification is a physiological process involving a sequential formation of cartilage and bone tissues.Classically,cartilage and bone formation have been considered independent processes at cellular level...Endochondral ossification is a physiological process involving a sequential formation of cartilage and bone tissues.Classically,cartilage and bone formation have been considered independent processes at cellular level.However,the recently described multiple cell differentiation dynamics suggest that some bone cells are indeed the progeny of cartilage cells,or chondrocyte-derived osteoblasts.We hypothesized that the cartilage-to-bone phenotype transition is triggered by specific molecular events.First,the process was assessed in mouse bone tissue,and then,it was mimicked using in vivo cell implantation and in vitro serial differentiation protocols.Data indicates that cartilage cells transition to bone cell phenotype during postnatal physiological bone formation.This process can be reproduced using cartilage precursor cells coupled to specific implantation procedures or differentiation protocols.Gene expression profiling reveals that NOTCH,BMP and MAPK signaling pathways are relevant at the phenotype-switch,while the transcription factors Mesp1,Alx1,Grhl3 and Hmx3 are the feasible driver genes for chondrocyte-derived osteoblasts formation.Altogether,this report shows that endochondral ossification can be modeled using primary cell cultures and data indicate that this process is regulated by specific molecular events,previously described at skeleton morphogenesis during embryo development,and from now on also linkable to postnatal bone development and regeneration processes.展开更多
A systematic approach was developed to investigate the stability of gentamicin sulfate(GS) and GS/poly(lacticco-glycolic acid)(PLGA) coatings on hydroxyapatite surfaces.The influence of environmental factors(light,hum...A systematic approach was developed to investigate the stability of gentamicin sulfate(GS) and GS/poly(lacticco-glycolic acid)(PLGA) coatings on hydroxyapatite surfaces.The influence of environmental factors(light,humidity,oxidation and heat) upon degradation of the drug in the coatings was investigated using liquid chromatography with evaporative light scattering detection and mass spectrometry.GS coated rods were found to be stable across the range of environments assessed,with only an oxidizing atmosphere resulting in significant changes to the gentamicin composition.In contrast,rods coated with GS/PLGA were more sensitive to storage conditions with compositional changes being detected after storage at 60 °C,75% relative humidity or exposure to light.The effect of γ-irradiation on the coated rods was also investigated and found to have no significant effect.Finally,liquid chromatography–mass spectrometry analysis revealed that known gentamines C_1,C_1 aand C_2were the major degradants formed.Forced degradation of gentamicin coatings did not produce any unexpected degradants or impurities.展开更多
Pathological cardiac damage during heart failure is associated with cell death and damage associated molecular patterns (DAMPs) release which triggers a viscous cycle of sterile inflammation to mediate maladaptive car...Pathological cardiac damage during heart failure is associated with cell death and damage associated molecular patterns (DAMPs) release which triggers a viscous cycle of sterile inflammation to mediate maladaptive cardiac tissue remodelling during the progression to heart failure. DAMPs like cytokines, chemokines, and nuclear or mitochondrial genomic fragments are released in the pathological myocardium. Interestingly, circulating or cytosolic DNA fragments can play a role in the disease by interaction with nucleic acid sensors expressed in cardiomyocyte and non-myocyte neighbouring cells. The circulating cell free DNA (cfDNA) fragments have been clinically reported as markers for various diseases including cardiovascular pathophysiology. Such cfDNA within the DAMP pool can mediate intra- and inter-cellular signalling cascade to upregulate transcriptional expression of inflammatory mediators and trigger oxidative stress within cells. The cellular role of such genomic equivalents varying with chronic or acute stress might be correlated with the cell death forms encountered in myocardium during disease progression. Thus, cfDNA can be phenotypically correlated as a critical player towards upregulation of pathological processes like interstitial fibrosis, cardiomyocyte contractile dysfunction and cell death. Herein, we review the association of cfDNA with heart failure and analyse their potential usage as novel and effective therapeutic targets towards augmentation of cardiac function.展开更多
While there have been significant advances in the development of peptide oral dosage forms in recent years,highlighted by the clinical and commercial success of approved peptides such as Rybelsus®,there remain se...While there have been significant advances in the development of peptide oral dosage forms in recent years,highlighted by the clinical and commercial success of approved peptides such as Rybelsus®,there remain several barriers in the way of broad range applicability of this approach to peptide delivery.One such barrier includes the poor physical and chemical stability inherent to their structures,which persists in the solid state although degradation typically occurs at different rates and via different pathways in comparison to the solution state.Using insulin as a model peptide,this work sought to contribute to the development of analytical techniques for investigating common insulin degradation pathways.Chemically denatured,deamidated and aggregated samples were prepared and used to benchmark circular dichroism spectroscopy,reverse phase HPLC and size exclusion chromatography methods for the investigation of unfolding,chemical modifications and covalent aggregation of the insulin molecule respectively.Solid state degraded samples were prepared by heating insulin powder at 60°C and 75%relative humidity for 1,3,5 and 7 d,and the degradation profiles of the samples were evaluated and compared with those observed in solution.While no unfolding was observed to occur,significant deamidation and covalent aggregation were detected.Reductive disulfide bond cleavage using dithiothreitol allowed for separation of the insulin A-and B-chains,offering a facile yet novel means of assessing the mechanisms of deamidation and covalent aggregation occurring in the solid state.展开更多
基金funded by Grants PID2021-127191OB-I00,RTI2018-101708-A-I00,PRE2018-084542 and PRE2022-102680 funded by MCIN/AEI/10.13039/501100011033 and by“ERDF A way of making Europe”Grant RYC2018-025502-I is funded by MCIN/AEI/10.13039/501100011033 and by“ESF Investing in your future”+1 种基金Grant MDM-20170720 Maria de Maeztu Units of Excellence Program funded by the Spanish State Research Agencysupported by Instituto de Salud CarlosⅢ,Infrastructure of Precision Medicine associated with Science and Technology(IMPaCT)of the Strategic Action in Health(iDATA-MP)。
文摘Endochondral ossification is a physiological process involving a sequential formation of cartilage and bone tissues.Classically,cartilage and bone formation have been considered independent processes at cellular level.However,the recently described multiple cell differentiation dynamics suggest that some bone cells are indeed the progeny of cartilage cells,or chondrocyte-derived osteoblasts.We hypothesized that the cartilage-to-bone phenotype transition is triggered by specific molecular events.First,the process was assessed in mouse bone tissue,and then,it was mimicked using in vivo cell implantation and in vitro serial differentiation protocols.Data indicates that cartilage cells transition to bone cell phenotype during postnatal physiological bone formation.This process can be reproduced using cartilage precursor cells coupled to specific implantation procedures or differentiation protocols.Gene expression profiling reveals that NOTCH,BMP and MAPK signaling pathways are relevant at the phenotype-switch,while the transcription factors Mesp1,Alx1,Grhl3 and Hmx3 are the feasible driver genes for chondrocyte-derived osteoblasts formation.Altogether,this report shows that endochondral ossification can be modeled using primary cell cultures and data indicate that this process is regulated by specific molecular events,previously described at skeleton morphogenesis during embryo development,and from now on also linkable to postnatal bone development and regeneration processes.
基金jointly funded by De Puy Synthes and Enterprise Ireland IP 2010-0068
文摘A systematic approach was developed to investigate the stability of gentamicin sulfate(GS) and GS/poly(lacticco-glycolic acid)(PLGA) coatings on hydroxyapatite surfaces.The influence of environmental factors(light,humidity,oxidation and heat) upon degradation of the drug in the coatings was investigated using liquid chromatography with evaporative light scattering detection and mass spectrometry.GS coated rods were found to be stable across the range of environments assessed,with only an oxidizing atmosphere resulting in significant changes to the gentamicin composition.In contrast,rods coated with GS/PLGA were more sensitive to storage conditions with compositional changes being detected after storage at 60 °C,75% relative humidity or exposure to light.The effect of γ-irradiation on the coated rods was also investigated and found to have no significant effect.Finally,liquid chromatography–mass spectrometry analysis revealed that known gentamines C_1,C_1 aand C_2were the major degradants formed.Forced degradation of gentamicin coatings did not produce any unexpected degradants or impurities.
基金funded by the SCIENCE&ENGINEERING RESEARCH BOARD(SERB)(No.-ECR/2018/001901 Dated 19.09.2019)Department of Science and Technology,Government of IndiaWe also gratefully acknowledge the BOOST funding(No.-1086/BT(Estt)/1P-03/2018 Dated 24.10.2019)by Department of Science&Technology and Biotechnology,Government of West Bengal,India.
文摘Pathological cardiac damage during heart failure is associated with cell death and damage associated molecular patterns (DAMPs) release which triggers a viscous cycle of sterile inflammation to mediate maladaptive cardiac tissue remodelling during the progression to heart failure. DAMPs like cytokines, chemokines, and nuclear or mitochondrial genomic fragments are released in the pathological myocardium. Interestingly, circulating or cytosolic DNA fragments can play a role in the disease by interaction with nucleic acid sensors expressed in cardiomyocyte and non-myocyte neighbouring cells. The circulating cell free DNA (cfDNA) fragments have been clinically reported as markers for various diseases including cardiovascular pathophysiology. Such cfDNA within the DAMP pool can mediate intra- and inter-cellular signalling cascade to upregulate transcriptional expression of inflammatory mediators and trigger oxidative stress within cells. The cellular role of such genomic equivalents varying with chronic or acute stress might be correlated with the cell death forms encountered in myocardium during disease progression. Thus, cfDNA can be phenotypically correlated as a critical player towards upregulation of pathological processes like interstitial fibrosis, cardiomyocyte contractile dysfunction and cell death. Herein, we review the association of cfDNA with heart failure and analyse their potential usage as novel and effective therapeutic targets towards augmentation of cardiac function.
基金supported in part by a research grant from Science Foundation Ireland(SFI)and is co-funded under the European Regional Development Fund(grant numbers 12/RC/2275(P2)and 18/EPSRC-CDT/3587)the Engineering and Physical Sciences Research Council UK(grant number EP/S023054/1).
文摘While there have been significant advances in the development of peptide oral dosage forms in recent years,highlighted by the clinical and commercial success of approved peptides such as Rybelsus®,there remain several barriers in the way of broad range applicability of this approach to peptide delivery.One such barrier includes the poor physical and chemical stability inherent to their structures,which persists in the solid state although degradation typically occurs at different rates and via different pathways in comparison to the solution state.Using insulin as a model peptide,this work sought to contribute to the development of analytical techniques for investigating common insulin degradation pathways.Chemically denatured,deamidated and aggregated samples were prepared and used to benchmark circular dichroism spectroscopy,reverse phase HPLC and size exclusion chromatography methods for the investigation of unfolding,chemical modifications and covalent aggregation of the insulin molecule respectively.Solid state degraded samples were prepared by heating insulin powder at 60°C and 75%relative humidity for 1,3,5 and 7 d,and the degradation profiles of the samples were evaluated and compared with those observed in solution.While no unfolding was observed to occur,significant deamidation and covalent aggregation were detected.Reductive disulfide bond cleavage using dithiothreitol allowed for separation of the insulin A-and B-chains,offering a facile yet novel means of assessing the mechanisms of deamidation and covalent aggregation occurring in the solid state.
