Project description:Articular and growth plate cartilage have comparable structures consisting of three distinct layers of chondrocytes, suggesting similar differentiation programs and therefore similar gene expression profiles. To address this hypothesis and to explore transcriptional changes that occur during the onset of articular and growth plate cartilage divergence, we used microdissection of 10-day-old rat proximal tibial epiphyses, microarray analysis, and bioinformatics to compare gene expression profiles in individual layers of articular and growth plate cartilage. We found that many genes that were spatially upregulated in intermediate/deep zone of articular cartilage were also spatially upregulated in resting zone of growth plate cartilage (overlap greater than expected by chance, P < 0.001). Interestingly, superficial zone of articular cartilage showed an expression profile with similarities to both proliferative and hypertrophic zones of growth plate cartilage (P < 0.001 each). Additionally, significant numbers of known proliferative zone markers (3 out of 6) and hypertrophic zone markers (27 out of 126) were spatially upregulated in superficial zone compared to intermediate/deep zone (more than expected by chance, P < 0.001 each). In conclusion, we provide evidence that intermediate/deep zone of articular cartilage has a gene expression profile more similar to resting zone of growth plate cartilage, whereas superficial zone has a gene expression profile more similar to proliferative and hypertrophic zones.
Project description:Articular and growth plate cartilage have comparable structures consisting of three distinct layers of chondrocytes, suggesting similar differentiation programs and therefore similar gene expression profiles. To address this hypothesis and to explore transcriptional changes that occur during the onset of articular and growth plate cartilage divergence, we used microdissection of 10-day-old rat proximal tibial epiphyses, microarray analysis, and bioinformatics to compare gene expression profiles in individual layers of articular and growth plate cartilage. We found that many genes that were spatially upregulated in intermediate/deep zone of articular cartilage were also spatially upregulated in resting zone of growth plate cartilage (overlap greater than expected by chance, P < 0.001). Interestingly, superficial zone of articular cartilage showed an expression profile with similarities to both proliferative and hypertrophic zones of growth plate cartilage (P < 0.001 each). Additionally, significant numbers of known proliferative zone markers (3 out of 6) and hypertrophic zone markers (27 out of 126) were spatially upregulated in superficial zone compared to intermediate/deep zone (more than expected by chance, P < 0.001 each). In conclusion, we provide evidence that intermediate/deep zone of articular cartilage has a gene expression profile more similar to resting zone of growth plate cartilage, whereas superficial zone has a gene expression profile more similar to proliferative and hypertrophic zones. 10-day-old rat proximal tibial epiphyses were manually microdissected into articular cartilage superficial (SZ) and intermediate/deep (IDZ) zones and growth plate cartilage resting zone (RZ) for total RNA extraction and hybridization on Affymetrix microarrays. We used 10-day-old animals because, at this age, the secondary ossification center has recently begun to form and divides the epiphysis into articular cartilage distally and growth plate cartilage more centrally. The 4 SZ samples were taken from animals 5-8, respectively, whereas the 4 IDZ and 4 RZ samples were each taken from animals 1-2, 3-4, 5-6, and 7-8, respectively.
Project description:We used laser capture microdissection to isolate different zones of the articular cartilage from proximal tibiae of 1-week old mice, and used microarray to analyze global gene expression. Bioinformatic analysis corroborated previously known signaling pathways, such as Wnt and Bmp signaling, and implicated novel pathways, such as ephrin and integrin signaling, for spatially associated articular chondrocyte differentiation and proliferation. In addition, comparison of the spatial regulation of articular and growth plate cartilage revealed unexpected similarities between the superficial zone of the articular cartilage and the hypertrophic zone of the growth plate. Collecte five biological replications in three superficial, mid zone and deep zones of Articular Cartilage Assessed by Laser Captured Microdissection and Microarray(Superficial Zone vs Mid Zone vs Deep Zone)
Project description:The characterization of knee articular cartilage changes with different zones -- articular surface, (AS), superficial zone (SZ), middle zone (MZ), and deep zone (DZ) -- based on the organization of the tissue and the alignment degree of collagen fibers. To comprehensively explore the spatial landscape of chondrocytes on human knee articular cartilage, we carried out the laser capture microdissection (LCM) coupled with full-length mRNA sequencing.
Project description:Objective. Identify novel genes and pathways specific to superficial (SZ), middle (MZ) and deep zones (DZ) of normal articular cartilage. Methods. Articular cartilage was obtained from knees of 4 normal human donors. The cartilage zones were dissected on a microtome. RNA was analyzed on human genome arrays. Data obtained with human tissue were compared to bovine cartilage zone specific DNA arrays. Genes differentially expressed between zones were evaluated using direct annotation for structural or functional features, and by enrichment analysis for integrated pathways or functions. Results. The greatest differences were observed between SZ and DZ in both human and bovine cartilage. The MZ was transitional between the SZ and DZ and thereby shared some of the same pathways as well as structural/functional features of the adjacent zones. Cellular functions and biological processes enriched in the SZ relative to the DZ, include most prominently ECM receptor interactions, cell adhesion molecules, regulation of actin cytoskeleton, ribosome-related functions and signaling aspects such as Interferon gamma, IL4, CDC42Rac and Jak-Stat. Two pathways were enriched in the DZ relative to the SZ, including PPARG and EGFR_SMRTE. Conclusion. These differences in cartilage zonal gene expression identify new markers and pathways that govern the unique differentiation status of chondrocyte subpopulations.
Project description:Objective. Identify novel genes and pathways specific to superficial (SZ), middle (MZ) and deep zones (DZ) of normal articular cartilage. Methods. Articular cartilage was obtained from knees of 4 normal human donors. The cartilage zones were dissected on a microtome. RNA was analyzed on human genome arrays. Data obtained with human tissue were compared to bovine cartilage zone specific DNA arrays. Genes differentially expressed between zones were evaluated using direct annotation for structural or functional features, and by enrichment analysis for integrated pathways or functions. Results. The greatest differences were observed between SZ and DZ in both human and bovine cartilage. The MZ was transitional between the SZ and DZ and thereby shared some of the same pathways as well as structural/functional features of the adjacent zones. Cellular functions and biological processes enriched in the SZ relative to the DZ, include most prominently ECM receptor interactions, cell adhesion molecules, regulation of actin cytoskeleton, ribosome-related functions and signaling aspects such as Interferon gamma, IL4, CDC42Rac and Jak-Stat. Two pathways were enriched in the DZ relative to the SZ, including PPARG and EGFR_SMRTE. Conclusion. These differences in cartilage zonal gene expression identify new markers and pathways that govern the unique differentiation status of chondrocyte subpopulations.
Project description:We used laser capture microdissection to isolate different zones of the articular cartilage from proximal tibiae of 1-week old mice, and used microarray to analyze global gene expression. Bioinformatic analysis corroborated previously known signaling pathways, such as Wnt and Bmp signaling, and implicated novel pathways, such as ephrin and integrin signaling, for spatially associated articular chondrocyte differentiation and proliferation. In addition, comparison of the spatial regulation of articular and growth plate cartilage revealed unexpected similarities between the superficial zone of the articular cartilage and the hypertrophic zone of the growth plate.
Project description:Objective. Identify novel genes and pathways specific to superficial (SZ), middle (MZ) and deep zones (DZ) of normal articular cartilage. Methods. Articular cartilage was obtained from knees of 4 normal human donors. The cartilage zones were dissected on a microtome. RNA was analyzed on human genome arrays. Data obtained with human tissue were compared to bovine cartilage zone specific DNA arrays. Genes differentially expressed between zones were evaluated using direct annotation for structural or functional features, and by enrichment analysis for integrated pathways or functions. Results. The greatest differences were observed between SZ and DZ in both human and bovine cartilage. The MZ was transitional between the SZ and DZ and thereby shared some of the same pathways as well as structural/functional features of the adjacent zones. Cellular functions and biological processes enriched in the SZ relative to the DZ, include most prominently ECM receptor interactions, cell adhesion molecules, regulation of actin cytoskeleton, ribosome-related functions and signaling aspects such as Interferon gamma, IL4, CDC42Rac and Jak-Stat. Two pathways were enriched in the DZ relative to the SZ, including PPARG and EGFR_SMRTE. Conclusion. These differences in cartilage zonal gene expression identify new markers and pathways that govern the unique differentiation status of chondrocyte subpopulations. 12 samples, 4 donors, 3 conditions each donor (SZ, MZ and DZ), 0 donor replicates, comparisons made between SZ, MZ and DZ to identify differentially expressed genes.