Dataset Information

Comparative Effectiveness of Structural versus Regulatory Protein Gene Transfer on Articular Chondrocyte Matrix Gene Expression.

ABSTRACT: OBJECTIVE:The production of extracellular matrix is a necessary component of articular cartilage repair. Gene transfer is a promising method to improve matrix biosynthesis by articular chondrocytes. Gene transfer may employ transgenes encoding regulatory factors that stimulate the production of matrix proteins, or may employ transgenes that encode the proteins themselves. The objective of this study was to determine which of these 2 approaches would be the better choice for further development. We compared these 2 approaches using the transgenes encoding the structural matrix proteins, aggrecan or type II collagen, and the transgene encoding the anabolic factor, insulin-like growth factor I (IGF-I). METHODS:We transfected adult bovine articular chondrocytes with constructs encoding type II collagen, aggrecan, or IGF-I, and measured the expression of type II collagen ( COL2A1) and aggrecan ( ACAN) from their native genes and from their transgenes. RESULTS:IGF-I gene ( IGF1) transfer increased the expression of the native chondrocyte COL2A1 and ACAN genes 2.4 and 2.9 times control, respectively. COL2A1 gene transfer did not significantly increase COL2A1 transcripts, even when the transgene included the genomic COL2A1 regulatory sequences stimulated by chondrogenic growth factors. In contrast, ACAN gene transfer increased ACAN transcripts up to 3.4 times control levels. IGF1, but not ACAN, gene transfer increased aggrecan protein production. CONCLUSION:Taken together, these results suggest that the type II collagen and aggrecan production required for articular cartilage repair will be more effectively achieved by genes that encode anabolic regulatory factors than by genes that encode the matrix molecules themselves.

SUBMITTER: Shi S

PROVIDER: S-EPMC6376561 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Comparative Effectiveness of Structural versus Regulatory Protein Gene Transfer on Articular Chondrocyte Matrix Gene Expression.

Shi Shuiliang S Wang Congrong C Chan Albert A Kirmani Kashif K Eckert George J GJ Trippel Stephen B SB

Cartilage 20170713 1

<h4>Objective</h4>The production of extracellular matrix is a necessary component of articular cartilage repair. Gene transfer is a promising method to improve matrix biosynthesis by articular chondrocytes. Gene transfer may employ transgenes encoding regulatory factors that stimulate the production of matrix proteins, or may employ transgenes that encode the proteins themselves. The objective of this study was to determine which of these 2 approaches would be the better choice for further devel ...[more]

PMID: 28703018

Similar Datasets

Project description:BackgroundLong-term acute care hospital (LTACH) use varies considerably across the U.S., which may reflect uncertainty about the effectiveness of LTACHs vs. skilled nursing facilities (SNF), the principal post-acute care alternative. Given that LTACHs provide more intensive care and thus receive over triple the reimbursement of SNFs for comparable diagnoses, we sought to compare outcomes and spending between LTACH versus SNF transfer.MethodsUsing Medicare claims linked to electronic health record (EHR) data from six Texas Hospitals between 2009 and 2010, we conducted a retrospective cohort study of patients hospitalized on a medicine service in a high-LTACH use region and discharged to either an LTACH or SNF and followed for one year. The primary outcomes included mortality, 60-day recovery without inpatient care, days at home, and healthcare spending RESULTS: Of 3503 patients, 18% were transferred to an LTACH. Patients transferred to LTACHs were younger (median 71 vs. 82 years), less likely to be female (50.5 vs 66.6%) and white (69.0 vs. 84.1%), but were sicker (24.3 vs. 14.2% for prolonged intensive care unit stay; median diagnosis resource intensity weight of 2.03 vs. 1.38). In unadjusted analyses, patients transferred to an LTACH vs. SNF were less likely to survive (59.1 vs. 65.0%) or recover (62.5 vs 66.0%), and spent fewer days at home (186 vs. 200). Adjusting for demographic and clinical confounders available in Medicare claims and EHR data, LTACH transfer was not significantly associated with differences in mortality (HR, 1.12, 95% CI, 0.94-1.33), recovery (SHR, 1.07, 0.93-1.23), and days spent at home (IRR, 0.96, 0.83-1.10), but was associated with greater Medicare spending ($16,689 for one year, 95% CI, $12,216-$21,162).ConclusionLTACH transfer for Medicare beneficiaries is associated with similar clinical outcomes but with higher healthcare spending compared to SNF transfer. LTACH use should be reserved for patients who require complex inpatient care and cannot be cared for in SNFs.

Project description:BackgroundThe non-canonical NF-?B activating kinase IKK?, encoded by CHUK (conserved-helix-loop-helix-ubiquitous-kinase), has been reported to modulate pro- or anti- inflammatory responses, cellular survival and cellular differentiation. Here, we have investigated the mechanism of action of IKK? as a novel effector of human and murine chondrocyte extracellular matrix (ECM) homeostasis and differentiation towards hypertrophy.Methodology/principal findingsIKK? expression was ablated in primary human osteoarthritic (OA) chondrocytes and in immature murine articular chondrocytes (iMACs) derived from IKK?(f/f):CreERT2 mice by retroviral-mediated stable shRNA transduction and Cre recombinase-dependent Lox P site recombination, respectively. MMP-10 was identified as a major target of IKK? in chondrocytes by mRNA profiling, quantitative RT-PCR analysis, immunohistochemistry and immunoblotting. ECM integrity, as assessed by type II collagen (COL2) deposition and the lack of MMP-dependent COL2 degradation products, was enhanced by IKK? ablation in mice. MMP-13 and total collagenase activities were significantly reduced, while TIMP-3 (tissue inhibitor of metalloproteinase-3) protein levels were enhanced in IKK?-deficient chondrocytes. IKK? deficiency suppressed chondrocyte differentiation, as shown by the quantitative inhibition of.Alizarin red staining and the reduced expression of multiple chondrocyte differentiation effectors, including Runx2, Col10a1 and Vegfa,. Importantly, the differentiation of IKK?-deficient chondrocytes was rescued by a kinase-dead IKK? protein mutant.Conclusions/significanceIKK? acts independent of its kinase activity to help drive chondrocyte differentiation towards a hypertrophic-like state. IKK? positively modulates ECM remodeling via multiple downstream targets (including MMP-10 and TIMP-3 at the mRNA and post-transcriptional levels, respectively) to maintain maximal MMP-13 activity, which is required for ECM remodeling leading to chondrocyte differentiation. Chondrocytes are the unique cell component in articular cartilage, which are quiescent and maintain ECM integrity during tissue homeostasis. In OA, chondrocytes reacquire the capacity to proliferate and differentiate and their activation results in pronounced cartilage degeneration. ????, our findings are also of potential relevance for defining the onset and/or progression of OA disease.

Project description:During the development of the appendicular skeleton, the cartilaginous templates undergo hypertrophic differentiation and remodels into bone, except for the cartilage most adjacent to joint cavities where hypertrophic differentiation and endochondral bone formation are prevented, and chondrocytes instead form articular cartilage. The mechanisms that prevent hypertrophic differentiation and endochondral bone formation of the articular cartilage have not been elucidated. To explore the role of the synovial microenvironment in chondrocyte differentiation, osteochondral allografts consisting of articular cartilage, epiphyseal bone, and growth plate cartilage from distal femoral epiphyses of inbred Lewis rats expressing enhanced green fluorescent protein from a ubiquitous promoter were transplanted either in inverted or original (control) orientation to matching sites in wildtype littermates, thereby allowing for tracing of transplanted cells and their progenies. We found that no hypertrophic differentiation occurred in the growth plate cartilage ectopically placed at the joint surface. Instead, the transplanted growth plate cartilage, with time, remodeled into articular cartilage. This finding suggests that the microenvironment at the articular surface inhibits hypertrophic differentiation and supports articular cartilage formation. To explore this hypothesis, rat chondrocyte pellets were cultured with and without synoviocyte-conditioned media. Consistent with the hypothesis, hypertrophic differentiation was inhibited and expression of the articular surface marker lubricin (Prg4) was dramatically induced when chondrocyte pellets were exposed to synovium- or synoviocyte-conditioned media, but not to chondrocyte- or osteoblast-conditioned media. Taken together, we present evidence for a novel mechanism by which synoviocytes, through the secretion of a factor or factors, act directly on chondrocytes to inhibit hypertrophic differentiation and endochondral bone formation and promote articular cartilage formation. This mechanism may have important implications for articular cartilage development, maintenance, and regeneration.

Dataset Information

Comparative Effectiveness of Structural versus Regulatory Protein Gene Transfer on Articular Chondrocyte Matrix Gene Expression.

Publications

Comparative Effectiveness of Structural versus Regulatory Protein Gene Transfer on Articular Chondrocyte Matrix Gene Expression.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets