Platelet-Derived Growth Factor B Is a Key Element in the Pathological Bone Formation of Ankylosing Spondylitis.

Enthesophyte formation plays a crucial role in the development of spinal ankylosis in ankylosing spondylitis (AS). We aimed to investigate the role of platelet-derived growth factor B (PDGFB) in enthesophyte formation of AS using in vitro and in vivo models and to determine the association between PDGFB and spinal progression in AS. Serum PDGFB levels were measured in AS patients and healthy controls (HC). Human entheseal tissues attached to facet joints or spinous processes were harvested at the time of surgery and investigated for bone-forming activity. The impact of a pharmacological agonist and antagonist of platelet-derived growth factor B receptor (PDGFRB) were investigated respectively in curdlan-treated SKG mice. PDGFB levels were elevated in AS sera and correlated with radiographic progression of AS in the spine. Mature osteoclasts secreting PDGFB proteins were increased in the AS group compared with HC and were observed in bony ankylosis tissues of AS. Expression of PDGFRB was significantly elevated in the spinous enthesis and facet joints of AS compared with controls. Moreover, recombinant PDGFB treatment accelerated bone mineralization of enthesis cells, which was pronounced in AS, whereas PDGFRB inhibition efficiently reduced the PDGFB-induced bone mineralization. Also, PDGFRB inhibition attenuated the severity of arthritis and enthesophyte formation at the joints of curdlan-treated SKG mice. This study suggests that regulating PDGFB/PDGFRB signaling could be a novel therapeutic strategy to block key pathophysiological processes of AS. © 2022 American Society for Bone and Mineral Research (ASBMR).

Relationship between spinal osteoarthritis and vertebral fractures in men older than 50 years: data from the Camargo Cohort Study.

Spinal osteoarthritis has been suggested as a risk factor for vertebral fractures. However, results are conflicting: most of the data are focused on the lumbar region, and referred to postmenopausal women, whereas data for men are scarce. The aim of this study is to assess the relationship between spinal osteoarthritis and vertebral fractures in men over 50 years of age. We conducted a cross-sectional study, nested in a prospective population-based cohort, including 507 community-dwelling men, 93 of them with at least one vertebral fracture. Vertebral fractures, osteophytosis, and disc space narrowing (DSN) were assessed by lateral thoracic and lumbar radiographs. Anthropometric, clinical, and densitometric variables were also analyzed. A multiple logistic regression model was performed. Eighty-five percent of vertebral fractures were located at the thoracic spine. Osteophytosis and DSN showed a bimodal distribution, with major frequency peaks at mid- and distal lumbar spine. The three distributions overlapped around the T9 vertebra. We did not find any relationship between lumbar osteoarthritis and vertebral fractures. Nevertheless, thoracic osteophytosis (OR, 1.84; 95 % CI, 1.05-3.17; p = 0.03) and DSN (OR, 2.52; 95 % CI, 1.43-4.46; p = 0.001) were found to be independently associated with prevalent vertebral fractures, after adjusting for confounders. Our results suggest a positive relationship between radiologic osteoarthritic changes at the thoracic spine and prevalent vertebral fractures in men more than 50 years of age. Osteoarthritis may act as a local risk factor, in addition to other mechanical factors, resulting in a greater propensity to fracture, especially at the mid-thoracic region.

Topography of the lumbar sympathetic trunk in normal lumbar spines and spines with spondylophytes.

BACKGROUND: Degenerative processes of the lumbar spine may change the position of the sympathetic trunk which might cause failure of sympathetic blocks owing to inadequate distribution of local anaesthetic. METHODS: The retroperitoneal spaces of 56 cadavers [24 males and 32 females; 79 (10) yr] embalmed with Thiel's method were investigated by dissection. The course of the lumbar sympathetic trunk (LST) was documented from the diaphragmatic level to the linea terminalis. Topography of the large vessels and the psoas muscle was documented. In the case of spondylophytes, the location or direction of displacement of the trunk was regarded with special interest. RESULTS: The LST entered the retroperitoneal space at the level of the vertebral body of L2 in 70 of the 112 sides and showed the most consistent relationship with the medial margin of the psoas muscle at intervertebral disc level L2/3. On 11 spines with spondylophytes, the sympathetic trunk was dislocated to the most ventrolateral point of the spondylophyte in 12 cases, in six cases dorsolaterally, and in one case ventromedially. The more the sympathetic chain departed at the vertebral body level, the more the body developed a concavity by loss of height. CONCLUSIONS: Spondylophytes influenced the location of the LST and the distribution of the local anaesthetic. The local anaesthetic should wash around the spondylophyte to reach all possible locations of the chain. The medial margin of the psoas muscle was confirmed to be a consistent reference point at intervertebral disc level L2/3.

Single-nucleotide polymorphism in the hyaluronan and proteoglycan link protein 1 (HAPLN1) gene is associated with spinal osteophyte formation and disc degeneration in Japanese women.

Spinal osteoarthritis including disc degeneration is a very common condition in the axial skeletons of aged people. Recently, spinal osteoarthritis has been shown to be influenced by specific genetic risk factors. Vertebral osteophytes, endplate sclerosis, and intervertebral disc narrowing are recognized as radiographic features of spinal disc degeneration. HAPLN1 is a key component of the cartilage extracellular matrix; thus, variations in this gene may affect the pathogenesis of cartilage-related diseases such as spinal degeneration. Here, we examine the association between an HAPLN1 gene polymorphism and the radiographic features of spinal degeneration. We evaluated the degree of endplate sclerosis, osteophyte formation, and disc space narrowing in 622 Japanese postmenopausal women. Four SNPs in the HAPLN1 gene-in the 5' flanking region, intron 1, intron 2, and intron 4-were analyzed using the TaqMan polymerase chain reaction method. We found that compared to subjects with the CC or CT genotype, those with the TT genotype for an SNP at intron 2 (rs179851) were significantly overrepresented among the subjects with higher scores for osteophyte formation (P = 0.0001; odds ratio 2.12; 95% confidence interval 1.45-3.11, as determined by logistic regression analysis) and disc space narrowing (P = 0.0057; odds ratio 1.83; 95% confidence interval 1.19-2.83). Consistent with the involvement of the HAPLN1 gene in cartilage metabolism, a variation in a specific HAPLN1 gene locus may be associated with spinal degeneration.

Possible role of extracellular nucleotides in ectopic ossification of human spinal ligaments.

To reveal the involvement of extracellular nucleotides in the ossification process in ossification of the posterior longitudinal ligament of the spine (OPLL), the mRNA expression profiles of P2 purinoceptors, mechanical stress-induced ATP release, and ATP-stimulated expression of osteogenic genes were analyzed in ligament cells derived from the spinal ligament of OPLL patients (OPLL cells) and non-OPLL cells derived from the spinal ligaments of cervical spondylotic myelopathy patients as a control. The extracellular ATP concentrations of OPLL cells in static culture were significantly higher than those of non-OPLL cells, and this difference was diminished in the presence of ARL67156, an ecto-nuclease inhibitor. Cyclic stretch markedly increased the extracellular ATP concentrations of both cell types to almost the same level. P2Y1 purinoceptor subtypes were intensively expressed in OPLL cells, but only weakly expressed in non-OPLL cells. Not only ATP addition but also cyclic stretch raised the mRNA levels of alkaline phosphatase and osteopontin in OPLL cells, which were blocked by MRS2179, a selective P2Y1 antagonist. These increases in the expression of osteogenic genes were not observed in non-OPLL cells. These results suggest an important role of P2Y1 and extracellular ATP in the progression of OPLL stimulated by mechanical stress.

Calcium pyrophosphate crystal deposition in the ligamentum flavum of degenerated lumbar spine: histopathological and immunohistological findings.

We investigated the histological and immunohistochemical features of degenerative changes in the ligamentum flavum of the lumbar spine with calcium crystal deposition. We investigated degenerative changes in 270 ligamentum flavum specimens harvested from 198 patients who underwent decompressive surgeries for lumbar spinal canal stenosis. En bloc sections of the ligamentum flavum were examined histologically. We also examined immunoreactivity for transforming growth factor (TGF)-beta, vascular endothelial growth factor (VEGF), CD34, and CD68; immunoblot analysis for VEGF; and terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick end-labeling (TUNEL) method. The ligamentum flavum showed fragmented and disorganized elastic fiber bundles with increased collagen fibrils in the matrix. Calcium deposition, which was identified as calcium pyrophosphate dihydrate crystals, was evident in 72 of 198 patients and in 99 of 270 samples, and was associated with appearance of hypertrophic chondrocytes and new blood vessel formation. Areas of calcium deposits were surrounded by abundant hypertrophic chondrocytes (with marked immunoreactivity to TGF-beta and VEGF) and a significant number of TUNEL-positive chondrocytes. Calcium crystal deposition in the lumbar ligamentum flavum progresses with reduction in elastic fibers and accumulation of collagen fibrils in the matrix as well as expansion of chondrometaplastic areas.

Spinal cord tau pathology in cervical spondylotic myelopathy.

We conducted an immunohistochemical and ultrastructural examination of the spinal cords from 11 cases of cervical spondylotic myelopathy (CSM), together with those from 11 age- and sex-matched control subjects. Immunostaining with AT8 antibody revealed various numbers of tau-positive neuropil thread-like structures (NTSs), often demonstrating a conspicuous astrocytic foot-like perivascular or subpial arrangement, and glial cells with short and thick processes, so-called thorn-shaped astrocytes (TSAs), in the affected cervical cords in 8 of the 11 CSM cases (73%). A number of tau-positive neuronal cytoplasmic pretangles/tangles were also found in the gray matter in all the CSM cases (100%). No such astrocytic or neuronal tau lesions were found in the control subjects. The tau deposited in the NTSs and TSAs was predominantly 4-repeat tau, whereas the neuronal cytoplasmic pretangles/tangles contained both 3-repeat and 4-repeat tau. Ultrastructurally, paired helical filaments about 20 nm wide, together with glial filaments, were detected occasionally in the astrocytic processes. In conclusion, the present findings indicate that astrocytic and neuronal tau lesions appear in the affected cervical cord during the disease process of CSM.

Is there any relationship between proinflammatory mediator levels in disc material and myelopathy with cervical disc herniation and spondylosis? A non-randomized, prospective clinical study.

The proinflammatory mediator (PIM) levels were assessed in surgically removed samples of herniated cervical intervertebral discs. The objective of this study was to investigate if there is a correlation between the levels of PIMs in disc material and myelopathy associated with cervical intervertebral disc herniation and spondylosis. The role of proinflammatory mediators in the degeneration of intervertebral disc and the inflammatory effects of disc herniations on radicular pain has been previously published. However, the possible relationship between PIMs and myelopathy related to cervical disc herniation and spondylosis has not been investigated before. Thirty-two patients undergoing surgery for cervical disc herniation and spondylosis were investigated. Surgically obtained disc materials, stored at 70 degrees C, were classified into two groups: cervical disc herniation alone or with myelopathy. Biochemical preparation and solid phase enzyme amplified sensitivity immunoassay (ELISIA) analysis of the samples were performed to assess the concentration of mediators in the samples. Very similar values of interleukin-6 were found in both groups whereas the concentrations of mediators were significantly higher in myelopathy group. This study has demonstrated that PIMs are involved in cervical intervertebral disc degeneration with higher concentrations in the samples associated with myelopathy.

[A rabbit model of cervical spondylosis established by stimulation of wind, cold and dampness].

OBJECTIVE: To make an animal model of cervical spondylosis (arthralgia syndrome type) with stimulation of wind, cold, and dampness. METHODS: Twenty-four 8 months old male New Zealand white rabbits were randomly allocated into four groups: normal control group, light stimulation group, moderate stimulation group and severe stimulation group. The wind speed was 10.8-13.8 m/s, the temperature was (5+/-0.5)degrees centigrade, and the humidity was 100%. The rabbits of light, moderate, and severe stimulation groups were kept in the above-mentioned environments for 4 hours everyday, and for a total of 32, 64, and 128 hours, respectively. The intervertebral discs were stained with HE method, and observed with a light microscope. Prostaglandin E(2) (PGE(2)), 6-ketone-prostaglandin F1alpha (6-K-PGF(1alpha)) and thromboxane B(2) (TXB(2)) contents were measured by ELISA. Fas and Bcl-2 expressions were examined by immunohistochemical avidin-biotin peroxidose complex technique. Interleukin-1beta (IL-1beta), tumor necrosis factor alpha (TNF-alpha), and transforming growth factor beta (TGF-beta) mRNA expressions were examined by reverse transcription-polymerase chain reaction. RESULTS: The nucleus pulposus of rabbits in the light and moderate stimulation groups shrunken, and in the severe stimulation group, the anulus fibrosus loosed or ruptured, and the cartilage end-plate became proliferated. Compared with rabbits in the normal control group, the PGE(2) content rose in the light stimulation group, the contents of PGE(2), 6-K-PGF(1alpha), and TXB(2) increased, the expressions of IL-1beta and TNF-alpha mRNAs and Fas were up-regulated, and the expressions of TGF-beta mRNA and Bcl-2 were down-regulated in the moderate and severe stimulation groups. The expression of Fas was up-regulated mostly and Bcl-2 was down-regulated mostly in the severe group. CONCLUSION: Moderate and severe stimulations of wind, cold and dampness can lead to degeneration of cervical intervertebral discs of rabbits. The model corresponds to the theory of traditional Chinese medicine about arthralgia syndrome caused by wind, cold and dampness.

Cervical intervertebral disc degeneration induced by unbalanced dynamic and static forces: a novel in vivo rat model.

STUDY DESIGN: Establishment of a novel in vivo animal model of cervical spondylosis. OBJECTIVE: To investigate apoptotic, degenerative, and inflammatory changes occurring in the cervical intervertebral discs of rats. SUMMARY OF BACKGROUND DATA: Cervical degeneration occurs as the result of imbalance of both static and dynamic spinal stabilizers. The disc degeneration that occurs is characterized by increased local inflammation and increased apoptosis of intervertebral disc cells. METHODS: By excising the paraspinal musculature and posterior cervical spinal ligaments of rats, both static and dynamic cervical stabilizers were disrupted. The resultant biomechanical imbalance resulted in biochemical and histologic changes, which were characterized by light microscopy, electron microscopy, immunostaining, enzyme-linked immunosorbent assay, polymerase chain reaction, and in situ hybridization. RESULTS: Histologic analysis showed characteristic degenerative changes of the intervertebral discs and vertebral endplates following surgery. Ultrastructural examination revealed apoptotic changes, which were verified by immunostaining. Instability also resulted in significant up-regulation of inflammatory factors, as shown by enzyme-linked immunosorbent assay, polymerase chain reaction, and in situ hybridization. CONCLUSIONS: By creating static and dynamic posterior instability of the cervical spine, this novel model of cervical spondylosis results in rapid intervertebral disc degeneration characterized by increased apoptosis and local inflammation, such as that seen clinically.

Prescripción del ejercicio en pacientes con artrosis. Recomendaciones actuales / Exercise prescription for patients with osteoarthritis. Current recommendations

La artrosis alcanza una alta incidencia y prevalencia en todo el mundo, por lo que esta enfermedad representa un problema sanitario de primer orden. Actualmente el tratamiento no farmacológico se considera de primera elección en el manejo de los pacientes con artrosis. Jugando un papel esencial la practica del ejercicio físico. En el presente trabajo realizamos una revisión a los artículos más relevantes publicados en los últimos años que relacionan ejercicio físico y artrosis. Elaboramos unas tablas de prescripción de ejercicio en dichos pacientes, recomendando aquellos deportes que supongan una menor sobrecarga articular como son la marcha, la carrera, el ciclismo y la natación (AU

Osteoarthritis has a high incidence and prevalence in the world, therefore this illness is an important health problem. Nowadays the non-pharmacological treatment is considered the first choice for patients suffering from arthrosis. Physical exercise plays a key role. In this work we review the most important papers published in the last years related to physical exercise and osteoarthritis. We have prepared some tables for the exercise prescription for these patients, recommending those sports that imply a less joint overload such as walking, running, cycling and swimming (AU)

[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.

Expression of c-fos in gastric myenteric plexus and spinal cord of rats with cervical spondylosis.

AIM: To determine the expression of c-fos in gastric myenteric plexus and spinal cord of rats with cervical spondylosis and its clinical significance. METHODS: A cervical spondylosis model was established in rats by destroying the stability of cervical posterior column, and the cord segments C(4-6) and gastric antrum were collected 3, 4 and 5 mo after the operation. Rats with sham operation were used as controls. c-fos neuronal counter-staining was performed with an immunohistochemistry method. Every third sections from C(4-6) segments were drawn. The 10 most labeled c-fos-immunoreactive (Fos-IR) neurons were counted, and the average number was used for statistical analysis. The mean of Fos-IR neurons in myenteric plexus was calculated after counting Fos-IR neurons in 25 ganglia from each antral preparation, and expressed as a mean count per myenteric ganglion. RESULTS: There were a few c-fos-positive neurons in the cervical cord and antrum in the control group. There was an increased c-fos expression in model group 3, 4 and 5 mo after operation, whereas there was no significant increase in c-fos expression in the control group at 3, 4 and 5 mo. More importantly, there was a significant difference in c-fos expression between rats followed up for 3 mo and those for 5 mo in the model group (11.20+/-2.26 vs 27.68+/-4.36, P<0.05, for the cervical cord; and 11.3+/-2.3 vs 29.3+/-4.6, P<0.05, for the gastric antrum). There was no significant difference between rats followed up for 3 mo and those for 4 mo and between rats followed up for 4 mo and those for 5 mo in the model group. CONCLUSION: c-fos expression in gastric myenteric plexus was dramatically associated with that in the spinal cord in rats with cervical spondylosis, suggesting that the gastrointestinal function may be affected by cervical spondylosis. If this hypothesis is confirmed by further studies, functional gastrointestinal diseases such as functional dyspepsia and irritable bowel syndrome could be explained by neurogastroenterology.

Hypothalamic digoxin and hemispheric chemical dominance--relation to the pathogenesis of senile osteoporosis, degenerative osteoarthritis, and spondylosis.

The isoprenoid pathway produces three key metabolites: i) digoxin (a membrane sodium-potassium ATPase inhibitor which can regulate intracellular calcium/magnesium ratios), ii) dolichol (which regulates N-glycosylation of proteins), and iii) ubiquinone (a free radical scavenger), all of which are important in bone and joint metabolism. The pathway was assessed in senile osteoporosis, spondylosis, and osteoarthritis. Digoxin could possibly play a role in the genesis of cerebral dominance because it can regulate multiple neurotransmitter systems. The pathway was also assessed in individuals of differing hemispheric dominance for comparison and to find out the role of cerebral dominance in the pathogenesis of these diseases. The plasma/serum-activity of HMG CoA reductase, magnesium, digoxin, dolichol, ubiquinone, and tryptophan/tyrosine catabolic patterns, as well as RBC Na(+)-K+ ATPase activity, were measured in the above mentioned groups. The glycoconjugate metabolism, free radical metabolism, and membrane composition were also studied. The pathway was upregulated with increased digoxin synthesis in patients with spondylosis and osteoarthritis. In this group of patients, the glycoconjugate levels and dolichol levels were increased and lysosomal stability reduced. The ubiquinone levels were low and free radicals increased in spondylosis and osteoarthritis. On the other hand, in senile osteoporosis, the isoprenoid pathway was downregulated and digoxin synthesis reduced. The glycoconjugate and dolichol levels were low and lysosomal stability increased. The ubiquinone levels were increased and free radical production increased in senile osteoporosis. The significance of these changes in the pathogenesis of osteoarthritis, spondylosis, and osteoporosis is discussed. The hyperdigoxinemic state is seen in osteoarthritis and spondylosis and in right hemispheric dominance. The hypodigoxinemic state is seen in left hemispheric dominance and senile osteoporosis. Hemispheric dominance plays a crucial role in deciding the predisposition to bone and joint diseases. Right hemispheric chemical dominance predisposes to spondylosis and osteoarthritis. Left hemispheric chemical dominance predisposes to osteoporosis.

Distribution of genes for parathyroid hormone (PTH)-related peptide, Indian hedgehog, PTH receptor and patched in the process of experimental spondylosis in mice.

OBJECT: Little is known about the molecular mechanisms underlying the process of spondylosis. The authors determined the extent of genetic localization of major regulators of chondrogenesis such as Indian hedgehog (Ihh) and parathyroid hormone (PTH)-related peptide (PTHrP) and their receptors during the development of spondylosis in their previously established experimental mouse model. METHODS: Experimental spondylosis was induced in 5-week-old ICR mice. The cervical spines were chronologically harvested, and histological sections were prepared. Messenger (m) RNA for PTHrP, Ihh, PTH receptor (PTHR; a receptor for PTHrP), patched (Ptc; a receptor for Ihh), bone morphogenetic protein (BMP)-6, and collagen type X (COL10; a marker for mature chondrocyte) was localized in the tissue sections by performing in situ hybridization. In the early stage, mRNA for COL10, Ihh, and BMP-6 was absent; however, mRNA for PTHrP, PTHR, and Ptc was detected in the anterior margin of the cervical discs. In the late stage, evidence of COL10 mRNA began to be detected, and transcripts for Ihh, PTHrP, and BMP-6 were localized in hypertrophic chondrocytes adjacent to the bone-forming area in osteophyte. Messenger RNA for Ptc and PTHR continued to localize at this stage. In control mice, expression of these genes was absent. CONCLUSIONS: The localization of PTHrP, Ihh, BMP-6, and the receptors PTHR and Ptc demonstrated in the present experimental model indicates the possible involvement of molecular signaling by PTHrP (through the PTHR), Ihh (through the Ptc), and BMP-6 in the regulation of chondrocyte maturation leading to endochondral ossification in spondylosis.

In vitro characteristics of cultured posterior longitudinal ligament tissue.

STUDY DESIGN: To determine the osteogenicity of posterior longitudinal ligament ossification, the posterior longitudinal ligament obtained during anterior cervical surgery from patients with the disorder was analyzed with in vitro cultures. OBJECTIVES: To determine the osteogenicity of the posterior longitudinal ligament. SUMMARY OF BACKGROUND DATA: The osteogenicity of posterior longitudinal ligament ossification in North America requires better documentation. METHODS: The posterior longitudinal ligament obtained during anterior cervical corpectomy with fusion from seven patients, three with ossification of the posterior longitudinal ligament documented by magnetic resonance imaging and computed tomography and four with spondylosis, was blindly submitted for in vitro culture. Explants of the posterior longitudinal ligament were placed in Dulbecco modified Eagle medium with 10% fetal calf serum, antibiotics, 4 mmol/L x L-proline, and 50 mg/L ascorbic acid. After reaching confluency, cells were trypsinized, and first-passage cells were used for all osteocalcin measurements to establish their osteoblastic phenotype. Periosteal cells, previously shown to synthesize osteocalcin, were used as a positive control. The cells were incubated with 1,25(OH)2 vitamin D3 at 10E-8 M for 72 hours in serum-free medium. The supernatants were collected and frozen, after which the quantity of osteocalcin induced by exposure to 1,25(OH)2 vitamin D3 was determined using enzyme-linked immunoassay. Control replicate cultures were measured without incubation using vitamin D3. RESULTS: Ossification of the posterior longitudinal ligament cell lines responded positively with osteocalcin synthesis in the 0.1 to 0.4 ng/M range. The cell line of the patient with spondylosis alone did not respond to vitamin D3 priming. CONCLUSIONS: Posterior longitudinal ligament cells from the three North American white patients with ossification of the posterior longitudinal ligament, when cultured in vitro, synthesized osteocalcin on vitamin D3 priming, confirming their osteoblastic phenotype, whereas posterior longitudinal ligament cells from four white patients with isolated spondylosis did not.

The relative roles of intragenic polymorphisms of the vitamin d receptor gene in lumbar spine degeneration and bone density.

STUDY DESIGN: A retrospective cohort study. OBJECTIVES: To compare the magnitudes of the associations of TaqI polymorphisms of the vitamin D receptor gene with bone density and lumbar spine degeneration in the same sample. SUMMARY OF BACKGROUND DATA: Vitamin D receptor gene variations are associated with osteoporosis, osteoarthritis, and disc degeneration. Their role in these conditions remains poorly understood. METHODS: Bone density of the spine and femur were determined through DEXA, and lumbar disc degeneration was determined from magnetic resonance imaging assessments of signal intensity, disc narrowing, bulging, anular tears, herniations, and osteophytes. Associations between these measures and TaqI polymorphisms of the coding region of the Vitamin D receptor locus were examined in a population-based sample of 142 men. RESULTS: The strongest associations were with signal intensity and anular tears, which were worse for the subjects with tt genotypes than for those with TT genotypes in the L4-S1 spine discs. Conversely, the prevalences of disc bulges and osteophytes were lowest for the tt genotype. Bone density, disc height, and herniations did not differ significantly by genotype. CONCLUSIONS: The strongest association of Vitamin D receptor TaqI polymorphisms with degeneration in nonmineralized connective tissues suggests that the underlying mechanism of TaqI polymorphisms is not specific to bone. This study demonstrated for the first time that those with the tt genotype had more anular tears than those with the TT genotype, a finding that should stimulate further analyses of this gene in conditions that result in back pain. The apparent discrepancies of the associations of the tt genotype with lower signal intensity and more anular tears, but less bulges and osteophytes, could be explained if bulging and osteophytes primarily represented remodeling related to lifetime physical loading.

Distribution of genes for bone morphogenetic protein-4, -6, growth differentiation factor-5, and bone morphogenetic protein receptors in the process of experimental spondylosis in mice.

OBJECT: Because little is known about the molecular mechanisms underlying the process of spondylosis, the authors examined the extent of genetic localization of several members of bone morphogenetic protein (BMP) and BMP receptors in chondrogenesis during the process of inducing spondylosis in their previously established experimental mice model. METHODS: Experimental spondylosis was induced in 5-week-old ICR mice. The cervical spine was harvested chronologically, and histological sections were prepared. Messenger RNA for BMP-4, growth and differentiation (GDF)-5, BMP-6, and BMP receptors (ALK-3, -6, and BMP-RII) was localized in the tissue sections by in situ hybridization. In the early stage, BMP-4-derived mRNA was localized mainly in cells in the anterior margin of the cervical discs, together with ALK-6 and BMP-RII mRNA. No GDF-5 and BMP-6 mRNA was detected at this stage. In the late stage, cells positive for BMP-4 decreased, whereas GDF-5 and BMP-6 mRNA were localized in cells undergoing chondrogenesis. The ALK-3 mRNA began to appear in this stage, as did ALK-6 and BMP-RII. CONCLUSIONS: The localization of transcripts for BMP-4, -6, and GDF-5 as well as BMP receptors shown during the present experimental model indicate the possible involvement of molecular signaling by these BMPs in the chondrogenic progress in spondylosis.

Lumbar osteoarthritis, bone mineral density, and quantitative ultrasound.

Low bone mass is a major risk factor for osteoporotic fractures. Thus, bone density evaluation, performed by Dual Energy X-ray Absorptiometry (DXA) is important for diagnosis and monitoring treatment of osteoporosis. The accuracy of DXA, particularly at the lumbar spine, can be affected by several factors such as degenerative diseases. To evaluate the effects of vertebral osteophytosis on densitometric measurements, we examined 198 women, aged 32-81 years, who had undergone lateral X-ray of the lumbar spine. We classified patients according to different grades of osteophytosis, and evaluated bone density at the lumbar spine and the proximal femur by DXA. We also performed quantitative ultrasound at the heel (QUS). Patients with severe osteophytosis were significantly older (p < 0.0005), and values were adjusted for this parameter. We observed a significant increase in lumbar bone density with worsening osteophytosis (p < 0.02). On the contrary, no significant differences were found at the femur and QUS. According to bone density at the femoral neck, we subdivided patients into two groups: osteoporotic (group A) and non-osteoporotic (group B). Both groups showed increasingly high bone density at the spine with worsening osteophytosis (A: p < 0.01; B: p < 0.02). No differences were found in all the other evaluations. In conclusion, lumbar spine measurement is dramatically influenced by osteophytosis, particularly in the elderly. Consequently, other strategies should be performed such as evaluation of the hip and also measurement of the heel by ultrasound, which could be an interesting approach in these cases.

[Separate measurement of radial trabecular and cortical bone mineral density by peripheral quantitative computed tomography (pQCT) in degenerative joint disease].

Degenerative joint disease and osteoporosis, both of which tend to increase with advance in age, were thought to be essentially different mainly because of the artifactually high lumbar spine bone mineral density (BMD) in the former unlike osteoporosis characterized by persistent decrease of BMD. To clarify the relationship between these two diseases, three-dimensional BMD of the trabecular and cortical bone was measured separately in an area of the radius relatively free of degenerative changes by peripheral computed tomography (pQCT). In addition to radiological assessment of spondylosis deformans, quantification of vertebral deformity was attempted by calculation of standard deviation, coefficient of variation, difference between maximum and minimum density divided by the mean of L1-L4. With advance in age and progress of spondylosis deformans, the standard deviation, coefficient of variation difference between the maximum and minimum density and this difference divided by the mean of L1-L4 increased, but radial trabecular bone density, cortcal density and relative cortical volume decreased, suggesting parallel advance of degenerative joint disease and osteoporosis. Sodium etidronate, an antiresorber commonly used in the treatment of osteoporosis, increased mean lumbar spine BMD and markedly decreased the standard deviation, coefficient of variation, difference between the maximum and minimum density and this difference divided by the mean of L1 and L2 but maintained maximum BMD constant, decreasing vertebral deformity due to spondylosis deformans. It is conceivable that calcium release from bone on increased resorption leads to osteoporosis, and calcium entrance into cartilage, causing its hardening, disappearance and degeneration, direct contact between bones, osteoarthritis and subsequent deformity in a single sequence of events.