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A minimally invasive rabbit model of progressive and reproducible disc degeneration confirmed by radiology, gene expression, and histology.

Kwon YJ - J Korean Neurosurg Soc (2013)

Bottom Line: Significant disc space narrowing compared to preoperative disc height was observed during the time period (p<0.001).The MRI grade, aggrecan, and matrix metalloprotease-13 mRNA expression and hematoxylin and eosin/safranin O/anti-collagen II staining were consistently indicative of degeneration, supporting the results of the X-ray data.This in vivo model can be used to study and evaluate the safety and efficacy of biologic treatments for degenerative disc disease.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurosurgery, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Seoul, Korea.

ABSTRACT

Objective: To develop a simple, reproducible model of disc degeneration in rabbits through percutaneous annular puncture and to confirm the degree of degeneration over time.

Methods: Fifteen New Zealand white rabbits (4 to 5 months old and weighing approximately 3 to 3.5 kg each) underwent annular puncture of the L2-L3, L3-L4, and L4-L5 discs. Rabbits were sacrificed at 4, 8, or 20 weeks after puncture. For a longitudinal study to assess changes in disc height over time, serial X-rays were performed at 0, 2, 4, 8, and 20 weeks for rabbits in the 20-week group. Upon sacrifice, the whole spinal column and discs were extracted and analyzed with magnetic resonance imaging (MRI), real time reverse transcriptase-polymerase chain reaction, and histological staining.

Results: The X-rays showed a slow, progressive decrease in disc height over time. Significant disc space narrowing compared to preoperative disc height was observed during the time period (p<0.001). The MRI grade, aggrecan, and matrix metalloprotease-13 mRNA expression and hematoxylin and eosin/safranin O/anti-collagen II staining were consistently indicative of degeneration, supporting the results of the X-ray data.

Conclusion: Percutaneous annular puncture resulted in slow, reproducible disc degeneration that was confirmed by radiology, biochemistry, and histology. This in vivo model can be used to study and evaluate the safety and efficacy of biologic treatments for degenerative disc disease.

No MeSH data available.


Related in: MedlinePlus

Histologic analyses of the rabbit discs. 40× and 200× (inner rectangle) power images. A : Normal non-punctured disc shows a clear boundary between the NP and AP with a normal pattern of fibrocartilage lamellas in AF. The NP cells are numerous large, vacuolated notochordal cells (left). In moderate degenerated disc, the border between the NP and AF is less distinct than in the normal disc. The notochordal cells are decreased in number and replaced with chondrocyte-like cells (middle). In a severely degenerated disc, the NP tissue is lost and replaced with fibrocartilage lamellas of the AF with abundant associated fibroblasts (right). B : Serial sections of the discs stained with Safranin O. C : Significantly higher grades are noted in the degenerated discs when compared with the controls (*p<0.01). NP : nucleus pulposus, AF : annulus fibrosus.
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Figure 6: Histologic analyses of the rabbit discs. 40× and 200× (inner rectangle) power images. A : Normal non-punctured disc shows a clear boundary between the NP and AP with a normal pattern of fibrocartilage lamellas in AF. The NP cells are numerous large, vacuolated notochordal cells (left). In moderate degenerated disc, the border between the NP and AF is less distinct than in the normal disc. The notochordal cells are decreased in number and replaced with chondrocyte-like cells (middle). In a severely degenerated disc, the NP tissue is lost and replaced with fibrocartilage lamellas of the AF with abundant associated fibroblasts (right). B : Serial sections of the discs stained with Safranin O. C : Significantly higher grades are noted in the degenerated discs when compared with the controls (*p<0.01). NP : nucleus pulposus, AF : annulus fibrosus.

Mentions: Representative H&E staining and safranin O staining of histologic sections from the rabbit discs showed various stages of degeneration (Fig. 6A, B). Each healthy, non-punctured disc displayed an AF with a normal pattern of fibrocartilage lamellas and a normal border between the AF and NP. The NP was round and bloated in appearance and consisted of numerous large, notochordal cells (Fig. 6A, B; left column). The middle column of Fig. 6A, B depicts a disc with intermediate degeneration from a rabbit sacrificed at 4 weeks. In this disc, the annulus had a more wavy appearance, and the NP was reduced in the extracellular matrix and the large vacuolated cells. The border between the annulus and nucleus was less distinct than in the normal disc. The right column of Fig. 6A, B represents a severely degenerated disc at the 20-week time point; in this disc, most of the contents of the NP had been lost, and the disc showed wavy fibrocartilage lamellas of the AF with abundant associated fibroblasts. The immunohistochemical expression of type II collagen in degenerated discs was decreased in the ECM and pericellular area of the NP, compared with that of a normal control disc (Fig. 7). The histologic score of the degenerated discs was significantly higher than that of control discs at each time point (p<0.01) (Fig. 6C).


A minimally invasive rabbit model of progressive and reproducible disc degeneration confirmed by radiology, gene expression, and histology.

Kwon YJ - J Korean Neurosurg Soc (2013)

Histologic analyses of the rabbit discs. 40× and 200× (inner rectangle) power images. A : Normal non-punctured disc shows a clear boundary between the NP and AP with a normal pattern of fibrocartilage lamellas in AF. The NP cells are numerous large, vacuolated notochordal cells (left). In moderate degenerated disc, the border between the NP and AF is less distinct than in the normal disc. The notochordal cells are decreased in number and replaced with chondrocyte-like cells (middle). In a severely degenerated disc, the NP tissue is lost and replaced with fibrocartilage lamellas of the AF with abundant associated fibroblasts (right). B : Serial sections of the discs stained with Safranin O. C : Significantly higher grades are noted in the degenerated discs when compared with the controls (*p<0.01). NP : nucleus pulposus, AF : annulus fibrosus.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3756123&req=5

Figure 6: Histologic analyses of the rabbit discs. 40× and 200× (inner rectangle) power images. A : Normal non-punctured disc shows a clear boundary between the NP and AP with a normal pattern of fibrocartilage lamellas in AF. The NP cells are numerous large, vacuolated notochordal cells (left). In moderate degenerated disc, the border between the NP and AF is less distinct than in the normal disc. The notochordal cells are decreased in number and replaced with chondrocyte-like cells (middle). In a severely degenerated disc, the NP tissue is lost and replaced with fibrocartilage lamellas of the AF with abundant associated fibroblasts (right). B : Serial sections of the discs stained with Safranin O. C : Significantly higher grades are noted in the degenerated discs when compared with the controls (*p<0.01). NP : nucleus pulposus, AF : annulus fibrosus.
Mentions: Representative H&E staining and safranin O staining of histologic sections from the rabbit discs showed various stages of degeneration (Fig. 6A, B). Each healthy, non-punctured disc displayed an AF with a normal pattern of fibrocartilage lamellas and a normal border between the AF and NP. The NP was round and bloated in appearance and consisted of numerous large, notochordal cells (Fig. 6A, B; left column). The middle column of Fig. 6A, B depicts a disc with intermediate degeneration from a rabbit sacrificed at 4 weeks. In this disc, the annulus had a more wavy appearance, and the NP was reduced in the extracellular matrix and the large vacuolated cells. The border between the annulus and nucleus was less distinct than in the normal disc. The right column of Fig. 6A, B represents a severely degenerated disc at the 20-week time point; in this disc, most of the contents of the NP had been lost, and the disc showed wavy fibrocartilage lamellas of the AF with abundant associated fibroblasts. The immunohistochemical expression of type II collagen in degenerated discs was decreased in the ECM and pericellular area of the NP, compared with that of a normal control disc (Fig. 7). The histologic score of the degenerated discs was significantly higher than that of control discs at each time point (p<0.01) (Fig. 6C).

Bottom Line: Significant disc space narrowing compared to preoperative disc height was observed during the time period (p<0.001).The MRI grade, aggrecan, and matrix metalloprotease-13 mRNA expression and hematoxylin and eosin/safranin O/anti-collagen II staining were consistently indicative of degeneration, supporting the results of the X-ray data.This in vivo model can be used to study and evaluate the safety and efficacy of biologic treatments for degenerative disc disease.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurosurgery, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Seoul, Korea.

ABSTRACT

Objective: To develop a simple, reproducible model of disc degeneration in rabbits through percutaneous annular puncture and to confirm the degree of degeneration over time.

Methods: Fifteen New Zealand white rabbits (4 to 5 months old and weighing approximately 3 to 3.5 kg each) underwent annular puncture of the L2-L3, L3-L4, and L4-L5 discs. Rabbits were sacrificed at 4, 8, or 20 weeks after puncture. For a longitudinal study to assess changes in disc height over time, serial X-rays were performed at 0, 2, 4, 8, and 20 weeks for rabbits in the 20-week group. Upon sacrifice, the whole spinal column and discs were extracted and analyzed with magnetic resonance imaging (MRI), real time reverse transcriptase-polymerase chain reaction, and histological staining.

Results: The X-rays showed a slow, progressive decrease in disc height over time. Significant disc space narrowing compared to preoperative disc height was observed during the time period (p<0.001). The MRI grade, aggrecan, and matrix metalloprotease-13 mRNA expression and hematoxylin and eosin/safranin O/anti-collagen II staining were consistently indicative of degeneration, supporting the results of the X-ray data.

Conclusion: Percutaneous annular puncture resulted in slow, reproducible disc degeneration that was confirmed by radiology, biochemistry, and histology. This in vivo model can be used to study and evaluate the safety and efficacy of biologic treatments for degenerative disc disease.

No MeSH data available.


Related in: MedlinePlus