Evaluation of the Effect of Daptomycin, a Glycopeptide Agent, on Intact Intervertebral Disc Tissue.

AIM: To evaluate the effects of pre- and intra-operatively administered daptomycin (DAP) on the intact human primary intervertebral disc tissue cells. MATERIAL AND METHODS: Primary cell cultures were established using tissues obtained through decompressive laminectomy, traumatic intervertebral disc herniation excision, and posterior transpedicular stabilization. Non-drug-administered samples were used as a control group. The samples treated with DAP formed the study group. Molecular assays for proliferation and gene expression were performed. The obtained data were evaluated statistically, and results with a value of p < 0.05 were accepted as significant. RESULTS: While no reduction was observed in the proliferation, the gene expression of intact intervertebral disc tissue cells was time-dependently decreased compared to the control group, and these results were reported to be statistically significant. CONCLUSION: This study observed the effect that a pharmaceutical preparation, which was used on intervertebral disc tissue before and after the operation, had on normal, healthy, and intact tissue. It concludes that alterations in the expression of genes involved in the anabolic and/or catabolic process, even in adjacent healthy tissue, may slow down the healing process of the damaged tissue or cause undesired cell differentiation.

The Effect of Adenosine on Extracellular Matrix Production in Porcine Intervertebral Disc Cells.

Compressive loading promotes adenosine triphosphate (ATP) production and release by intervertebral disc (IVD) cells. Extracellular ATP can be rapidly hydrolyzed by ectonucleotidases. Adenosine, one of the adenine derivatives of ATP hydrolysis, can modulate diverse cellular actions via adenosine receptors. The objectives of this study were to investigate the effects of exogenous adenosine on the production of extracellular matrix (ECM; i.e., collagen type II and aggrecan) and ATP of IVD cells and explore the underlying mechanism of action. It was found that adenosine treatment significantly upregulated aggrecan and type II collagen gene expression and the ATP level in IVD cells. Dipyridamole, an adenosine transport blocker, completely suppressed the effects of adenosine on the ATP production and ECM gene expression of the IVD cells, whereas antagonists of adenosine receptors did not significantly affect adenosine-treated IVD cells. The findings suggested that elevated intracellular ATP and upregulation of ECM gene expression by adenosine treatment are mainly due to adenosine uptake rather than receptor activation. Since ECM biosynthesis is a high ATP demanding process, supplementing adenosine could be beneficial as IVD cells are able to utilize it to replenish intracellular ATP and sequentially promote ECM production, which is constantly suppressed by limited nutrition supply due to the avascular nature of the IVD.

Tanshinone IIA represses inflammatory response and reduces radiculopathic pain by inhibiting IRAK-1 and NF-κB/p38/JNK signaling.

Intervertebral disc (IVD) disease, a most common cause of disc failure and low back pain, is characterized by age-related changes in the adult disc. In this study we aimed to investigate the potential of Tanshinone IIA (TSA) for the treatment of IVD disease, through exploring its anti-inflammatory and anti-catabolic activities in both in vitro IVD cell culture and in vivo animal models. After the inflammatory response was induced in IVD cells by IL-1ß, the activity and expression of inflammatory mediators, and potentially involved pathways were investigated in the presence or absence of TSA. The p38-MAPK inhibitor, SB239063, was also used to investigate the involvement of the MAPK signaling pathway in the observed effects. Meanwhile, the analgesic properties of TSA were analyzed by the von Frey filament test in Sprague-Dawley rats. Our results indicated that TSA significantly inhibited the expression of pro-inflammatory mediators and matrix metalloproteinases in vitro, as well as radiculopathic pain in vivo, probably by modulation of the activity of interleukin-1 receptor-associated kinase 1 (IRAK-1) and its downstream effectors p38, JNK and NF-κB. Our current study strongly demonstrates the potential of TSA for the treatment of inflammation and followed pain in degenerative disc disease.

The effects of glucosamine sulfate on intervertebral disc annulus fibrosus cells in vitro.

BACKGROUND CONTEXT: Glucosamine has gained widespread use among patients, despite inconclusive efficacy data. Inconsistency in the clinical literature may be related to lack of understanding of the effects of glucosamine on the intervertebral disc, and therefore, improper patient selection. PURPOSE: The goal of our study was to investigate the effects of glucosamine on intervertebral disc cells in vitro under the physiological conditions of inflammation and mechanical loading. STUDY DESIGN: Controlled in vitro laboratory setting. METHODS: Intervertebral disc cells isolated from the rabbit annulus fibrosus were exposed to glucosamine sulfate in the presence and absence of interleukin-1ß and tensile strain. Outcome measures included gene expression, measurement of total glycosaminoglycans, new proteoglycan synthesis, prostaglandin E2 production, and matrix metalloproteinase activity. The study was funded by NIH/NCCAM, and the authors have no conflicts of interest. RESULTS: Under conditions of inflammatory stimulation alone, glucosamine demonstrated a dose-dependent effect in decreasing inflammatory and catabolic mediators and increasing anabolic genes. However, under conditions of mechanical stimulation, although inflammatory gene expression was decreased, PGE2 was not. In addition, matrix metalloproteinase-3 gene expression was increased and aggrecan expression decreased, both of which would have a detrimental effect on matrix homeostasis. Consistent with this, measurement of total glycosaminoglycans and new proteoglycan synthesis demonstrated detrimental effects of glucosamine under all conditions tested. CONCLUSIONS: These results may in part help to explain the conflicting reports of efficacy, as there is biological plausibility for a therapeutic effect under conditions of predominate inflammation but not under conditions where mechanical loading is present or in which matrix synthesis is needed.

Differential response of encapsulated nucleus pulposus and bone marrow stem cells in isolation and coculture in alginate and chitosan hydrogels.

Cell-based therapies may hold significant promise for the treatment of early stage degeneration of the intervertebral disc (IVD). Given their propensity to proliferate and ability to form multiple tissue types, mesenchymal stem cells (MSCs) have been proposed as a potential cell source to promote repair of the nucleus pulposus (NP). However, for any successful cell-based therapy, a carrier biomaterial may be essential for targeted delivery providing key biophysical and biochemical cues to facilitate differentiation of MSCs. Two widely used biomaterials for NP regeneration are chitosan and alginate. The primary objective of this study was to assess the influence of alginate and chitosan hydrogels on bone marrow stem cells (BM) and NP cells in isolation or in coculture. A secondary objective of this study was to investigate coculture seeding density effects of BM and NP cells and simultaneously explore which cell type is responsible for matrix formation in a cocultured environment. Porcine NP and BM cells were encapsulated in alginate and chitosan hydrogels separately at two seeding densities (4×10(6) and 8×10(6) cells/mL) or in coculture (1:1, 8×10(6) cells/mL). Constructs (diameter=5 mm, height=3 mm) were maintained under IVD-like conditions [low-glucose, low (5%) oxygen] with or without transforming growth factor-ß3 (TGF-ß3) supplementation for 21 days. Results demonstrated differential viability depending on hydrogel type. NP cells remained viable in both biomaterial types whereas BM viability was diminished in chitosan. Further, hydrogel type was found to regulate sulfated glycosaminoglycan (sGAG) and collagen accumulation. Specifically, alginate better supports sGAG accumulation and collagen type II deposition for both NP and BM cell types compared with chitosan. Having identified that alginate more readily supports cell viability and matrix accumulation, we further explored additional effects of seeding density ratios (NP:BM--1:1, 1:2) for coculture studies. Interestingly, in coculture conditions, the BM cell population declined in number while NP cells increased, indicating that MSCs may in fact be signaling NP cells to proliferate rather than contributing to matrix formation. These findings provide exciting new insights on the potential of MSCs for NP tissue regeneration strategies.

Shape-memory porous alginate scaffolds for regeneration of the annulus fibrosus: effect of TGF-ß3 supplementation and oxygen culture conditions.

Disc herniation as a result of degenerative or traumatic injury is believed to be the primary instigator of low back pain. At present there is a lack of viable treatment options to repair damaged annulus fibrosus (AF) tissue. Developing alternative strategies to fill and repair ruptured AF tissue is a key challenge. In this work we developed a porous alginate scaffold with shape-memory properties which can be delivered using minimally invasive approaches and recover its original geometry once hydrated. Covalently cross-linked alginate hydrogels were created using carbodiimide chemistry, followed by a freeze-drying step to impart porosity and create porous scaffolds. Results showed that porous alginate scaffolds exhibited shape-memory recovery and mechanical behaviour that could be modulated depending on the cross-linker concentrations. The scaffold can be repeatedly compressed and expanded, which provides the potential to deliver the biomaterial directly to the damaged area of the AF tissue. In vitro experiments demonstrated that scaffolds were cytocompatible and supported cell seeding, penetration and proliferation under intervertebral-disc-like microenvironmental conditions (low glucose media and low oxygen concentration). Extracellular matrix (ECM) was secreted by AF cells with TGF-ß3 stimulation and after 21days had filled the porous scaffold network. This biological matrix was rich in sulfated glycosaminoglycan and collagen type I, which are the main compounds of native AF tissue. Successful ECM deposition was also confirmed by the increase in the peak stress of the scaffold. However, the immaturity of the matrix network after only 21days of in vitro culture was not sufficient to attain native AF tissue mechanical properties. The ability to deliver porous scaffolds using minimal invasive approaches that can potentially promote the regeneration of AF defects provides an exciting new avenue for disc repair.

Chondroprotective supplementation promotes the mechanical properties of injectable scaffold for human nucleus pulposus tissue engineering.

A result of intervertebral disc (IVD) degeneration, the nucleus pulposus (NP) is no longer able to withstand applied load leading to pain and disability. The objective of this study is to fabricate a tissue-engineered injectable scaffold with chondroprotective supplementation in vitro to improve the mechanical properties of a degenerative NP. Tissue-engineered scaffolds were fabricated using different concentrations of alginate and calcium chloride and mechanically evaluated. Fabrication conditions were based on structural and mechanical resemblance to the native NP. Chondroprotective supplementation, glucosamine (GCSN) and chondroitin sulfate (CS), were added to scaffolds at concentrations of 0:0µg/mL (0:0-S), 125:100µg/mL (125:100-S), 250:200µg/mL (250:200-S), and 500:400µg/mL (500:400-S), GCSN and CS, respectively. Scaffolds were used to fabricate tissue-engineered constructs through encapsulation of human nucleus pulposus cells (HNPCs). The tissue-engineered constructs were collected at days 1, 14, and 28 for biochemical and biomechanical evaluations. Confocal microscopy showed HNPC viability and rounded morphology over the 28 day period. MTT analysis resulted in significant increases in cell proliferation for each group. Collagen type II ELISA quantification and compressive aggregate moduli (HA) showed increasing trends for both 250:200-S and the 500:400-S groups on Day 28 with significantly greater HA compared to 0:0-S group. Glycosaminoglycan and water content decreased for all groups. Results indicate the increased mechanical properties of the 250:200-S and the 500:400-S was due to production of a functional matrix. This study demonstrated potential for a chondroprotective supplemented injectable scaffold to restore biomechanical function of a degenerative disc through the production of a mechanically functional matrix.

Effects of pulsed electromagnetic field on intervertebral disc cell apoptosis in rats.

Despite numerous studies on pulsed electromagnetic field (PEMF) application, its effects of PEMF on intervertebral disc (IVD) have not yet been investigated in vivo. Accordingly, the effects of PEMF upon IVD in rats were evaluated through molecular surveys. Rats were divided into six groups: Group I and II were exposed to low and high frequency of PEMF (LF and HF, respectively). Group III and IV underwent induced disc degeneration and were exposed to low and high frequency of PEMF (LF/IDD and HF/IDD, respectively). Group V underwent induced disc degeneration (IDD), and group VI was control. The values of caspase 3, Bax, Bcl-2 and ß-actin band density, as cell apoptotic markers, were obtained from band densitometry. Our results showed that the value of cleaved caspase-3 of cells and Bax/Bcl-2 ratio in IDD group increased significantly compared to the control group (p < 0.001). The value of cleaved caspase-3 and Bax/Bcl-2 ratio decreased significantly in LF/IDD and HF/IDD groups compared to IDD group (p < 0.05). No significant increase was seen in the cell apoptotic markers in the groups just exposed to PEMF compared to the control group. There was also no significant decrease in the Bax/Bcl-2 ratio in HF/IDD and LF/IDD groups compared to the control group. These data suggest that PEMF attenuates degenerative processes in rat's intervertebral discs and has no effect on normal discs. Regulations of the expression of apoptotic proteins may be one of the mechanisms by which PEMF is effective in reduce disc degeneration.

Evoked thalamic neuronal activity following DRG application of two nucleus pulposus derived cell populations: an experimental study in rats.

PURPOSE: To investigate the effects on evoked thalamic neuronal activity of application of notochordal cells and chondrocyte-like cells derived from nucleus pulposus (NP) onto a dorsal root ganglion (DRG) and to compare these effects with a previously reported increased thalamic activity induced by NP. METHODS: Nucleus pulposus was harvested from tail discs of adult rats and the disc cells were separated into two cell populations, notochordal cells and chondrocyte-like cells. The two cell populations were applied separately, or in combination, to the L4 DRG of anaesthetised female Sprague-Dawley rats during acute electrophysiological experiments. In control experiments, cell suspension medium was applied on the DRG. Recordings from the contralateral thalamus were sampled for 40 min while electrically stimulating the ipsilateral sciatic nerve at above Aδ-fibre thresholds. RESULTS: Application of notochordal cells resulted in a decrease in evoked thalamic activity within 10 min while chondrocyte-like cells did not induce any changes during the 40 min of recording. The difference in evoked thalamic activity 40 min after notochordal and chondrocyte-like cell application, respectively, was statistically significant. Neither an increased concentration of chondrocyte-like cells alone nor a combination of the two cell populations induced any changes in thalamic activity. CONCLUSIONS: Separate exposure of the DRG to the two NP-derived cell populations induced different effects on evoked thalamic activity, but none of the tested cell samples induced an increase in neuronal activity similar to that previously observed with NP. This indicates a high complexity of the interaction between NP and nervous tissue.

Triptolide exhibits anti-inflammatory, anti-catabolic as well as anabolic effects and suppresses TLR expression and MAPK activity in IL-1ß treated human intervertebral disc cells.

INTRODUCTION: Increased levels of proinflammatory cytokines seem to play a pivotal role in the development of back pain in a subpopulation of patients with degenerative intervertebral disc (IVD) disease. As current treatment options are mostly limited to surgical interventions or conservative treatment, anti-inflammatory substances might offer a novel, more target-orientated therapeutic approach. Triptolide (TPL), a natural substance found in the Chinese medicinal herb Tripterygium wilfordii Hook, has been demonstrated to possess anti-inflammatory effects in various cells, but no studies exist so far for the IVD. Therefore, the aim of this study was to determine the effects of TPL on human IVD cells by analyzing changes in gene expression and underlying molecular mechanisms. MATERIALS AND METHODS: In order to investigate the anti-inflammatory, anabolic and anti-catabolic effect of TPL, dose-dependency experiments (n = 5) and time course experiments (n = 5) were performed on IL-1ß prestimulated human IVD cells and changes in gene expression of IL-6/-8, TNF-α, PGE2S, MMP1/2/3/13, aggrecan and collagen-I/-II were analyzed by real-time RT-PCR. The molecular mechanisms underlying the effects observed upon TPL treatment were investigated by analyzing involvement of Toll-like receptors TLR2/4 (real-time RT-PCR, n = 5), NF-κB, MAP kinases p38, ERK and JNK (immunoblotting and immunocytochemistry, n = 4) as well as RNA polymerase II (immunoblotting, n = 3). RESULTS: Results showed that 50 nM TPL exhibited an anti-inflammatory, anti-catabolic and anabolic effect on the mRNA level for IL-6/-8, PGE2S, MMP1/2/3/13, aggrecan, collagen-II and TLR2/4, with most pronounced changes after 18 h for proinflammatory cytokines and MMPs or 30 h for TLRs and matrix proteins. However, we also observed an up-regulation of TNF-α at higher concentrations. The effects of TPL did not seem to be mediated via an inhibition of NF-κB or a decrease of RNA polymerase II levels, but TPL influenced activity of MAP kinases p38 and ERK (but not JNK) and expression of TLR2/4. CONCLUSIONS: In conclusion, TPL may possess promising potential for the treatment of inflammation-related discogenic back pain in vitro, but its analgetic effect will need to be confirmed in an appropriate in vivo animal model.

[Effects of Chinese herbal medicine Yiqi Huayu Bushen Recipe on expressions of aggrecan and type X collagen mRNAs in cells from degenerated human intervertebral discs].

OBJECTIVE: To investigate the effects of serum containing Yiqi Huayu Bushen Recipe, a compound Chinese herbal medicine, on expressions of aggrecan and type X collagen mRNAs of the degenerated intervertebral disc cells in patients with cervical spondylotic myelopathy. METHODS: Six inpatients diagnosed as cervical spondylotic myelopathy and undergoing cervical decompression and fusion surgery to remove the degenerated disc tissue were enrolled in this study. Primary intervertebral disc cells were isolated using small tissue mass method. Serum containing Yiqi Huayu Bushen recipe were obtained after SD rats were fed with Yiqi Huayu Bushen recipe for 3 days. MTT method was used to detect proliferation of the first-passage cells isolated from degenerated intervertebral discs and growth curve was drawn. In the following tests, the first-passage cells were cultured with the sera containing drugs and sodium chloride (NaCl), respectively. Proliferation of intervertebral disc cells was detected by MTT method and expressions of aggrecan and type X collagen mRNAs were detected by real-time polymerase chain reaction. RESULTS: The growth curve of the first-passage cells of the degenerated intervertebral discs showed that the time of cell proliferation peak was the sixth day. Compared with the same concentrations of NaCl solution, serum containing Yiqi Huayu Bushen Recipe at 5%, 10% and 20% promoted cell proliferation and expression of aggrecan mRNA and decreased expression of type X collagen mRNA (P<0.01). 10% serum containing Yiqi Huayu Bushen recipe was more effective than 5% and 20%. CONCLUSION: Yiqi Huayu Bushen Recipe inhibits degeneration of the intervertebral disc cells by regulating collagen and proteoglycan expressions.

[Effect of guizhi plus gegen decoction on ultrastructural changes of intervertebral disc annulus fibrosus cells].

OBJECTIVE: To observe the effect of Guizhi plus Gegen Decoction (GGD) on ultrastructural changes of intervertebral disc annulus fibrosus cells. METHODS: Rats' intervertebral disc annulus fibrosus cells were isolated and cultured using adherence wall screening method. After annulus fibrosus cells were intervened by GGD, the microstructure and ultrastructural features of untreated annulus fibrosus cells and annulus fibrosus cells treated by GGD containing serum at different concentrations were observed under optical microscope and electron microscope. RESULTS: Under optical microscope, most annulus fibrosus cells showed irregular polygons and few in star shape with rich superficial ecphyma. The nuclei were oval, large and complete. Under electron microscope, most cells in the blank group were oval after intervened by GGD containing serum at different concentrations. The nucleus was large, deviated, and irregular, the heterochromatin scattered diffusely, partial mitochondria vacuolized, and rough endoplasmic reticulum dilated. In the low dose GGD group, increased mitochondria and condensed density could be seen. The rough endoplasmic reticulum were expanded, lipid drops or glycogen could be occasionally seen. In the middle dose GGD group, increased endoplasmic reticulum expansion and condensed density could be seen. More medium density protein sediment could be seen. Increased mitochondria with condensed density could be seen, showing irregular cystic form with various sizes nucleus. In the high dose GGD group, increased rough endoplasmic reticulum with obvious expansion could be seen. More high density protein sediment could be seen. The nuclei were deviated. More mitochondria could be seen with secretory granules in them. CONCLUSIONS: After intervened by GGD containing serum at different concentrations, the ultrastructure of annulus fibrosus cells were manifested as follows: (1) The endoplasmic reticulum increased more in the middle and high dose GGD groups than in the blank group and the low dose GGD group. Greater density protein sediment occurred, especially in the high dose GGD group. (2) GGD played an important role in preventing ultrastructural changes induced by the degeneration of annulus fibrosus cells.

Chondrogenic differentiation of neonatal human dermal fibroblasts encapsulated in alginate beads with hydrostatic compression under hypoxic conditions in the presence of bone morphogenetic protein-2.

In the present work, neonatal human dermal fibroblasts (nHDFs) were evaluated as a potential cell source for intervertebral disc repair. Chondrogenic differentiation of nHDFs was studied in the presence or absence of hydrostatic compression under normal and hypoxic conditions. In addition, the potentially synergistic effects of mechanical stimulation and bone morphogenetic protein (BMP)-2 on the chondrogenic differentiation of nHDFs were assessed. Mechanical stimulation was applied to the cells encapsulated in alginate beads using a custom-built bioreactor system for either a 1- or 3-week period at a frequency of 1 Hz for 4 h/day. In general, after 21 days of culture, high cell viability was observed for all the groups, with the exception of the groups exposed to intermittent mechanical stimulation for 3 weeks. Long-term intermittent application of mechanical stimulation under low O(2) conditions resulted in elevated collagen biosynthesis rate from day 0. Inclusion of BMP-2 for this group improved the chondrogenic differentiation of nHDFs, as indicated by elevated aggrecan gene expression and an increased collagen production rate compared to the day 0 group. Thus, the combination of hypoxia, BMP-2 supplementation, and long-term intermittent application of dynamic hydrostatic pressure was found to be a potent promoter of the chondrogenic differentiation of nHDFs.

Evaluation of biocompatibility of a pectin/polyvinyl alcohol composite hydrogel as a new nucleus material.

OBJECTIVE: To evaluate the biocompatibility of a new kind of prosthetic nucleus: a pectin/polyvinyl alcohol composite (CoPP) hydrogel. METHODS: According to Chinese national standard GB/-T16886 documents, the toxicity of the CoPP prosthetic nucleus material was examined by cytotoxicity, sensitization, Ames, mice marrow micronucleus, chromosome aberration test of mammalian cell and implantation tests. RESULTS: Cell growth was similar in the CoPP culture and control groups. No significant difference was found between the CoPP culture and control groups at each time point (P > 0.05). The cell proliferation rate was greater than 100%. In accordance with the relationship between cytotoxicity to proliferation rate, it was confirmed that the cytotoxicity of CoPP was 0 grade. Mice had no allergic reaction when injected with an extract of CoPP. A reverse mutation test with Salmonella typhimurium showed that no significant effect on the number of histidine revertants of TA97, TA98, TA100 and TA102 strains after CoPP was added. The micronucleus rate in bone marrow cells was less than 5%; there was no significant difference compared with the negative control group (P > 0.05). The rate of chromosome aberration was less than 5%; no significant difference was found between the CoPP culture and the control groups. All experimental animal wounds achieved primary healing without exudation, infection or sinus formation. On macroscopic observation, no abscess or hematoma formed at the implantation site. CONCLUSION: The CoPP prosthetic nucleus has good biocompatibility and can potentially be used as an implant material.

The potential of chitosan-based gels containing intervertebral disc cells for nucleus pulposus supplementation.

The suitability of chitosan-based hydrogels as scaffolds for the encapsulation of intervertebral disc (IVD) cells and the accumulation of a functional extracellular matrix mimicking that of the nucleus pulposus (NP) was investigated. The specific hypothesis under study was that the cationic chitosan would form an ideal environment in which large quantities of newly synthesized anionic proteoglycan could be entrapped. Indeed, all the formulations of cell-seeded chitosan hydrogels, studied under in vitro culture conditions, showed that the majority of proteoglycan produced by encapsulated NP cells was retained within the gel rather than released into the culture medium. This was not always the case when annulus fibrosus cells were encapsulated, as unlike the nucleus cells the annulus cells often did not survive when cultured in chitosan. The results support the concept that chitosan may be a suitable scaffold for cell-based supplementation to help restore the function of the NP during the early stages of IVD degeneration.

[Effects of yiqi huayu recipe and its decomposed formulas on apoptosis-related factors of anulus fibrosus cells in rats].

OBJECTIVE: To study the effects of Yiqi Huayu Recipe and its decomposed formulas-medicated sera on expressions of bcl-2, Bax and caspase-8 of apoptotic anulus fibrosus cells in rats. METHODS: Immunohistochemical and integral optical density analytic methods were used to observe the effects of Yiqi Huayu Recipe-, Yiqi Recipe-, Huayu Recipe-medicated sera and insulin-like growth factor 1 (IGF-1) on the expressions of bcl-2, Bax and caspase-8 of apoptotic anulus fibrosus cells in rats induced by anti-Fas antibody. RESULTS: As compared with apoptosis group, bcl-2 expression was higher, Bax and caspase-8 expressions were lower in Yiqi Huayu-treated, Yiqi-treated, Huayu-treated and IGF-1 groups (P<0.01). As compared with Yiqi-treated group and Huayu-treated group, Bax expression was lower in Yiqi Huayu-treated group (P<0.05). CONCLUSION: Yiqi Huayu Recipe and its decomposed formulas can delay degeneration of the cervical intervertebral disc, which may be due to its action in regulating the expressions of bcl-2, Bax and caspase-8.

An in-vitro study on regeneration of human nucleus pulposus by using gelatin/chondroitin-6-sulfate/hyaluronan tri-copolymer scaffold.

Tissue engineering approaches for treating degenerative intervertebral discs aim to promote tissue regeneration then retard or even reverse the degenerative process. A gelatin/chondroitin-6-sulfate/hyaluronan tri-copolymer was developed to serve as a bioactive scaffold that could help human nucleus pulposus (NP) cells to preserve their cell viability/proliferation and promote matrix synthesis. Each scaffold was seeded with 1 x 10(6) monolayer-expanded human NP cells and then cultured in vitro. Over a 4-week cultivation period, cell-scaffold hybrids demonstrated active cell viability/proliferation and a progressive increase in net production of glycosaminoglycans. In comparison to monolayer cells, scaffold-cultured cells showed significantly higher mRNA expression in collagen II, aggrecan, Sox9, TGFbeta1, and TIMP1. Expression of mRNA was significantly suppressed in collagen I, collagen X, IL1, and Fas-associating death domain protein. Histological studies showed newly synthesized glycosaminoglycans deposits and collagen II in scaffolds. These results indicate that the tri-copolymer scaffold could be considered as a promising bioactive scaffold for regenerating human NP.

[Effects of Yiqi Huayu Recipe on gene expression pattern of normal and apoptotic chondrocytes in cervical intervertebral disc in rats].

OBJECTIVE: To study the effects of Yiqi Huayu Recipe on the gene expression pattern in normal and apoptotic chondrocytes in the cervical intervertebral disc of rats. METHODS: The intervertebral disc endplates of rats were digested enzymatically. The apoptosis of the chondrocytes was induced by anti-Fas antibody. BiostarR-40s microarray chips were used to investigate the gene expression pattern in chondrocytes in the normal control, apoptosis and Yiqi Huayu Recipe groups. The results were scanned with Scan Array 4000 and analyzed with GenePix Pro 3.0, and then subjected to standardization and ratio analysis. RESULTS: In the apoptosis group, 30 kinds of genes expressed in cervical intervertebral disc chondrocytes were screened out, in which 10 were up-regulated (ratio>2) and 20 down-regulated (ratio<0.5) as compared with the normal control group. On the other hand, in the Yiqi Huayu Recipe group, 97 kinds of genes expressed in cervical intervertebral disc chondrocytes were screened out, in which 44 were up-regulated (ratio>2) and 53 down-regulated (ratio<0.5) as compared with the apoptosis group. CONCLUSION: There are some signal transduction pathways that control the apoptosis of the intervertebral disc chondrocytes. Yiqi Huayu Recipe regulates the gene express of the apoptotic chondrocytes in intervertebral disc. The study gives a further understanding to the mechanism of the cervical spondylosis and enriches the theories of qi and blood of traditional Chinese medicine.

Biological evaluation of chitosan salts cross-linked to genipin as a cell scaffold for disk tissue engineering.

Degenerative disc disease has been implicated as a major component of spine pathology. However, although biological repair of the degenerate disk would be the ideal treatment, there is no universally accepted scaffold for tissue engineering of the intervertebral disk. To help remedy this, we investigated the gelation kinetics of various concentrations (2.5 to 10%) of two water-soluble chitosan chlorides (low molecular weight Protasan UP CL113 and high molecular weight Protasan UP CL213) and two chitosan glutamates (low molecular weight Protasan UP G113 and high molecular weight Protasan UP G213). Various concentrations (5 to 20%) of genipin, a naturally occurring cross-linking reagent used in herbal medicine and in the fabrication of food dyes, were used to prepare cross-linked chitosan hydrogels. The results show that 2.5% Protasan UP G213 cross-linked to 5% genipin was the best candidate. This formulation gelled fastest at 37 degrees C, and maintained 95% viability of encapsulated cultured disk cells. The gel did not produce an inflammatory reaction when injected subcutaneously into C57BL/6 mice and is therefore biocompatible. Most importantly, when injected into the degenerated nucleus pulposus of human cadaveric intervertebral disk, the gel flowed into the clefts without leakage. This study demonstrates that 2.5% Protasan UP G213 cross-linked to 5% genipin might be a promising scaffold for disk tissue engineering.

Mechanisms of age-related decline in insulin-like growth factor-I dependent proteoglycan synthesis in rat intervertebral disc cells.

STUDY DESIGN: Age-related fluctuations in insulin-like growth factor-I dependent proteoglycan synthesis in rat intervertebral disc cells were investigated. OBJECTIVES: The purpose of this study was to determine whether synthetic responses to insulin-like growth factor-I decline with age and to explore the possibility that an age-related increase in the expression of insulin-like growth factor binding proteins suppresses matrix synthesis in intervertebral disc cells. SUMMARY AND BACKGROUND DATA: Several studies have reported that the responsiveness of chondrocytes to insulin-like growth factor-I decreases with age and furthermore that this phenomenon may be related to increased expression of insulin-like growth factor binding proteins by chondrocytes. MATERIALS AND METHODS: Nucleus pulposus tissue and cells were obtained from the coccygeal vertebrae of 8-week-old, 40-week-old, and 120-week-old rats. Age-related changes in the expression of insulin-like growth factor-I and its receptor were assessed together with insulin-like growth factor-I dependent proteoglycan synthesis by the cultured nucleus pulposus cells. Also, western blot analysis of insulin-like growth factor binding protein-1 was carried out, and further examination was performed of insulin-like growth factor-I signal transduction through tyrosine phosphorylation of insulin receptor substrate-1, which is a signal transducer of insulin-like growth factor-I. RESULTS: Semiquantitative reverse transcription polymerase chain reaction analysis indicated that the expression of insulin-like growth factor-I receptor in 120-week cells decreased clearly in comparison with the cells of younger animals. By contrast, insulin-like growth factor-I dependent proteoglycan synthesis decreased with age, and the sharpest decline of synthesis was found between 8-week and 40-week cells, although the level of insulin-like growth factor-I/insulin-like growth factor-I receptor gene expression was maintained in 40-week-old animals. Consistent with the results of proteoglycan synthesis, the expression of phosphorylated insulin receptor substrate-1 decreased with age. Thus, the expression of insulin-like growth factor binding protein-1 and proteoglycan synthesis was investigated by use of Long R3 insulin-like growth factor-I, which was not influenced by insulin-like growth factor binding proteins. Insulin-like growth factor binding protein-1 was strongly expressed in 40-week cells in comparison with the expression in 8-week cells. Furthermore, proteoglycan synthesis in 40-week cells supplemented with Long R3 insulin-like growth factor-I was upregulated in comparison with that in 40-week cells supplemented with insulin-like growth factor-I. CONCLUSION: The present findings indicate that the age-related decline in insulin-like growth factor-I dependent proteoglycan synthesis in nucleus pulposus is caused, at least in part, by the increase in insulin-like growth factor binding proteins at the early stages of aging, and further suggest that a loss of proteoglycan synthesis during the late stages of aging is caused by the downregulation of insulin-like growth factor-I receptor in addition to an increase in insulin-like growth factor binding proteins.