Coffee Drinking and the Odds of Osteopenia and Osteoporosis in Middle-Aged and Older Americans: A Cross-Sectional Study in NHANES 2005-2014.

The study investigates the association of coffee consumption and odds of osteoporosis/osteopenia among individuals older than 50 years in the United States. In NHANES 2005-2014, drinking ≤ 2 cups(16 oz) of coffee per day can reduce the risk of osteoporosis/osteopenia at the femoral neck and lumbar spine in US adults. Previous epidemiological studies revealed that daily coffee intake reduced the incidence of a cluster of metabolic diseases, however, the link between coffee consumption and prevalence of osteoporosis/osteopenia still remain inconclusive and awaits further confirmation. Based on data collection from 2005 to 2014 survey cycles, National Health and Nutrition Examination Survey (NHANES), a sample size of 8789 participants aged 50 and above completing two nonconsecutive 24-h dietary recalls were eventually enrolled for analysis. Associations between coffee intake and BMD were assessed. A lower odds of having femoral neck osteopenia/osteoporosis (FOO) was observed in participants with moderate intake of coffee (≤ 2 cups per day), rather than other beverages (OR 0.83; 95% CI, 0.72-0.95; p = 0.01). Moreover, significant associations existed between daily caffeine intake and both FOO and lumbar-spine osteopenia/osteoporosis (LOO). Even after adjusting for decaffeinated coffee, tea, sugar-sweetened beverages (SSBs), and coffee consumption, osteopenia and osteoporosis the odds remained lower at both femoral and neck levels. Our data suggest moderate habitual coffee intake (≤ 2 cups coffee/day) would have protective effects against osteoporosis/osteopenia of femoral neck and spine, among US adults over the age of 50.

Comparison of the bone mineral density status of patients with kidney stones stratified by stone composition.

PURPOSE: Bone loss has been found to occur frequently in patients with particular metabolic disorders that are likely associated with certain kidney stone composition. Thus, we compared the bone mineral density (BMD) of patients with different kidney stone compositions. PATIENTS AND METHODS: A total of 204 consecutive patients who exhibited stone formation with calcium oxalate (CaOx), calcium phosphate (CaP), uric acid (UA), and magnesium ammonium phosphate (MAP) underwent 24 h urine test and BMD measurement. BMD was measured by dual X-ray absorptiometry at the lumbar spine (LS) and femoral neck (FN). The Z-score was used to express BMD. A BMD Z-score ≤ - 2 was defined as a diagnostic threshold for bone loss. RESULTS: Amongst the patients, 38 had an LS BMD Z-score of ≤ - 2, but only 2 had FN BMD Z-score of ≤ - 2. The group with an LS BMD Z-score of ≤ - 2 exhibited significantly larger male - female ratio, higher frequency of hypercalciuria and CaP, and lower frequency of MAP than the group with an LS BMD Z-score of > - 2. Reduced LS BMD was most remarkable in the CaP group, followed by the CaOx, UA, and MAP groups. The LS BMD Z-score of hypercalciuric patients was significantly lower than that of normocalciuric patients only in the CaP group. CONCLUSION: Patients with different kidney stone compositions presented different BMD status. Using this information may facilitate medical decision-making in patients with kidney stone who should undergone BMD earlier.

Elevated circulating levels of IL-34 are strongly associated with osteoporosis.

In this cross-sectional study, we observed a strong, age-independent association of circulating interleukin-34 (IL-34) levels with osteoporosis. PURPOSE: The reported capacity of IL-34 to induce and enhance osteoclastogenesis suggests its potential involvement in the pathogenesis of osteoporosis. Our study aimed to evaluate whether there is an association between IL-34 expression and osteoporosis. METHODS: We enrolled 30 women with osteoporosis and 230 age-matched non-osteoporotic women as a control group. Osteoporosis diagnosis was based on dual-energy X-ray absorptiometry (DXA) of the lumbar spine and femoral neck. Body composition parameters were assessed by the bioimpedance method. Plasma IL-34 levels were measured by ELISA. RESULTS: In comparison with the control group, the mean plasma IL-34 levels were significantly higher in osteoporotic women (164.61 ± 36.40 pg/ml vs. 665.43 ± 253.67 pg/ml, p = 0.0002), whereas basal metabolic rate (BMR) was significantly lower (1422.03 ± 6.80 kcal vs. 1339.39 ± 17.52 kcal, p = 0.00007). Both variables remained statistically significant after adjustment for age (p < 0.001). We did not observe correlations between plasma IL-34 levels and body composition parameters in osteoporotic and control groups. Multiple logistic regression analysis with osteoporosis status as a dependent variable clearly showed that age, BMR and IL-34 levels were independently and significantly associated with osteoporosis. The calculated odds ratios (OR) were 1.66 (95% CI = 1.16-2.38) for IL-34 levels and 0.22 (95% CI = 0.07-0.65) for BMR. CONCLUSION: The significant (fourfold) elevation of IL-34 plasma levels in osteoporosis patients suggests that circulating IL-34 could be used as a biomarker for osteoporosis.

ACSM5 inhibits ligamentum flavum hypertrophy by regulating lipid accumulation mediated by FABP4/PPAR signaling pathway.

BACKGROUND: Ligamentum flavum (LF) hypertrophy is the main cause of lumbar spinal canal stenosis (LSCS). Previous studies have shown that LF hypertrophy tissue exhibits abnormal lipid accumulation, but the regulatory mechanism remains unclear. The objective of this study was to explore the function and potential mechanism of ACSM5 in LF lipid accumulation. METHODS: To assess the ACSM5 expression levels, lipid accumulation and triglyceride (TG) level in LF hypertrophy and normal tissue, we utilized RT-qPCR, western blot, oil red O staining, and TG assay kit. The pearson correlation coefficient assay was used to analyze the correlation between ACSM5 levels and lipid accumulation or TG levels in LF hypertrophy tissue. The role of ACSM5 in free fatty acids (FFA)-induced lipid accumulation in LF cells was assessed in vitro, and the role of ACSM5 in LF hypertrophy in mice was verified in vivo. To investigate the underlying mechanisms of ACSM5 regulating lipid accumulation in LF, we conducted the mRNA sequencing, bioinformatics analysis, and rescue experiments. RESULTS: In this study, we found that ACSM5, which was significantly down-regulated in LF tissues, correlated with lipid accumulation. In vitro cell experiments demonstrated that overexpression of ACSM5 significantly inhibited FFA-induced lipid accumulation and fibrosis in LF cells. In vivo animal experiments further confirmed that overexpression of ACSM5 inhibited LF thickening, lipid accumulation, and fibrosis. Mechanistically, ACSM5 inhibited lipid accumulation of LF cells by inhibiting FABP4-mediated PPARγ signaling pathway, thereby improving hypertrophy and fibrosis of LF. CONCLUSIONS: our findings elucidated the important role of ACSM5 in the regulation of LF lipid accumulation and provide insight into potential therapeutic interventions for the treatment of LF hypertrophy. This study further suggested that therapeutic strategies targeting lipid deposition may be an effective potential approach to treat LF hypertrophy-induced LSCS.

Transthyretin amyloid deposition in ligamentum flavum (LF) is significantly correlated with LF and epidural fat hypertrophy in patients with lumbar spinal stenosis.

Lumbar spinal stenosis (LSS) is a degenerative disease characterized by intermittent claudication and numbness in the lower extremities. These symptoms are caused by the compression of nerve tissue in the lumbar spinal canal. Ligamentum flavum (LF) hypertrophy and spinal epidural lipomatosis in the spinal canal are known to contribute to stenosis of the spinal canal: however, detailed mechanisms underlying LSS are still not fully understood. Here, we show that surgically harvested LFs from LSS patients exhibited significantly increased thickness when transthyretin (TTR), the protein responsible for amyloidosis, was deposited in LFs, compared to those without TTR deposition. Multiple regression analysis, which considered age and BMI, revealed a significant association between LF hypertrophy and TTR deposition in LFs. Moreover, TTR deposition in LF was also significantly correlated with epidural fat (EF) thickness based on multiple regression analyses. Mesenchymal cell differentiation into adipocytes was significantly stimulated by TTR in vitro. These results suggest that TTR deposition in LFs is significantly associated with increased LF hypertrophy and EF thickness, and that TTR promotes adipogenesis of mesenchymal cells. Therapeutic agents to prevent TTR deposition in tissues are currently available or under development, and targeting TTR could be a potential therapeutic approach to inhibit LSS development and progression.

Associations of blood trace elements with bone mineral density: a population-based study in US adults.

BACKGROUND: This study aimed to investigate the association between blood trace elements and bone mineral density (BMD) and to determine the association between blood trace elements and the risk of low BMD/osteoporosis among US adults. METHODS: We performed a cross-sectional study using data from National Health and Nutrition Examination Survey (NHANES, 2011-2016). Multivariable linear regression models were employed to assess the associations of BMD in lumbar spine (LS-BMD), pelvic (PV-BMD) and total femur (TF-BMD) with blood trace elements, including Fe, Zn, Cu, Se, Mn, Cd, Pb, Hg. Additionally, the associations of low BMD/osteoporosis with blood trace elements were also evaluated using multivariable logistic regression. RESULTS: Higher blood Pb levels were found associated with decreased LS-BMD (p for trend < 0.001), PV-BMD (p for trend = 0.007), and TF-BMD (p for trend = 0.003) in female, while higher blood Se levels were associated with increased PV-BMD in female (p for trend = 0.042); no linear association between BMD and other blood trace element was observed. Also, significant associations were found between Pb levels and the prevalence of low BMD (p for trend = 0.030) and the prevalence of osteoporosis (p for trend = 0.036), while association between other blood trace elements and low BMD/osteoporosis was not observed. CONCLUSION: This study provides comprehensive insight into the association between blood trace elements and BMD and supports a detrimental effect of blood Pb levels on bone mass in women. Considering our analysis from a representative US general population, further study is warranted for the extreme levels of blood trace elements on bone metabolism.

Magnetic resonance spectroscopy (MRS) of multifidus muscle metabolites in chronic low back pain (CLBP).

PURPOSE: The purpose of the study was to investigate several potential imaging biomarkers of CLBP that may be useful for diagnosis and treatment efficacy evaluation. Proton magnetic resonance spectroscopy (1H-MRS) was used to detect the content and ratio of creatine (Cr), choline (Cho), and lipid (Lip) in the multifidus muscle (Mm) in patients with CLBP and to test for relationships between these metabolites and pain severity and duration. METHODS: Sixty patients with CLBP (experimental group) and sixty-nine asymptomatic volunteers (control group) underwent routine diagnostic magnetic resonance imaging of the lumbar spine. 1H-MRS was acquired with single-voxel MR spectroscopy. The MRS region of interest for measuring Cho, Cr, and Lip concentrations was determined at the L4/5 multifidus muscle (Mm), bilaterally. The contents and ratios of Cr, Cho, and Lip in bilateral and ipsilateral-to-pain (or matched control side) Mm were obtained, and the integral ratios of different metabolites obtained by using Cr as an internal reference were statistically analyzed. RESULTS: There were no significant within-group differences in the contents and ratios of Lip, Cr, Cho, Lip/Cr, and Cho/Cr between the left and right Mm of the healthy control group (p > 0.05) or the CLBP group (p > 0.05). The CLBP group showed a much higher Lip and Lip/Cr ratio in the bilateral Mm compared to the healthy control group (p < 0.05) but there were no between-group differences in Cr, Cho, or the Cho/Cr ratio (p > 0.05). The severity of CLBP was correlated with Lip (p < 0.05). CONCLUSION: Using 1H-MRS, we demonstrated higher Lip and Lip/Cr ratios in the Mm of patients with CLBP, compared to asymptomatic controls. Mm Lip was correlated with CLBP intensity. An increase in Lip in the Mm may be a characteristic finding in CLBP and may offer a useful prognostic marker for guiding rehabilitation strategies.

Associations of Hormonal and Metabolic Parameters with Bone Mineralization in Young Adult Females.

Osteoporosis is characterized by impaired bone mineralization and microarchitecture. An important protective factor is a high peak bone mass (PBM), attained in the second and third decade of life. The aim of the study was to evaluate the effect of hormonal and metabolic parameters on bone mineralization in young adult female patients. A total of 111 participants qualified for the study. Bone mineral density of the lumbar spine (L1-L4) and whole skeleton was measured using dual-energy X-ray absorptiometry (DXA). Hormonal parameters were determined: the concentrations of androstendione, dihydroepiandrosterone sulphate, testosterone, sex hormone binding protein, 17-OH-progesterone, folliculotropic hormone, estradiol, thyrotropic hormone, free thyroxine and cortisol. Metabolic parameters were also examined. The study showed a statistically significant correlation between bone mineral density and estradiol concentration and a negative relationship between cortisol concentration and the bone mineral density (BMD) Z-score of the lumbar spine. Sclerostin measurements taken during this study were not related to bone mineral density. It has been shown that the concentration of the hormones tested, even within the reference range, may affect bone mineralization. We suggest observing the follow-up of the menstrual cycles, as well as analyzing the results of test patients in an annual examination system. However, each clinical case should be considered individually. The sclerostin test is currently not useful in the clinical evaluation of bone mineralization in young adult women.

Smurf1 Facilitates Oxidative Stress and Fibrosis of Ligamentum Flavum by Promoting Nrf2 Ubiquitination and Degradation.

Lumbar spinal stenosis (LSS), which can lead to irreversible neurologic damage and functional disability, is characterized by hypertrophy and fibrosis in the ligamentum flavum (LF). However, the underlying mechanism is still unclear. In the current study, the effect of Smurf1, a kind of E3 ubiquitin ligase, in promoting the fibrosis and oxidative stress of LF was investigated, and its underlying mechanism was explored. The expression of oxidative stress and fibrosis-related markers was assessed in the tissue of lumbar spinal stenosis (LSS) and lumbar disc herniation (LDH). Next, the expression of the top 10 E3 ubiquitin ligases, obtained from Gene Expression Omnibus (GEO) dataset GSE113212, was assessed in LDH and LSS, and confirmed that Smurf1 expression was markedly upregulated in the LSS group. Furthermore, Smurf1 overexpression promotes the fibrosis and oxidative stress of LF cells. Subsequently, NRF2, an important transcription factor for oxidative stress and fibrosis, was predicted to be a target of Smurf1. Mechanistically, Smurf1 directly interacts with Nrf2 and accelerates Nrf2 ubiquitination and degradation. In conclusion, the current study suggests that Smurf1 facilitated the fibrosis and oxidative stress of LF and induced the development of LSS by promoting Nrf2 ubiquitination and degradation.

ISSLS PRIZE in basic science 2023: Lactate in lumbar discs-metabolic waste or energy biofuel? Insights from in vivo MRS and T2r analysis following exercise and nimodipine in healthy volunteers.

PURPOSE: To quantitatively assess the dynamic changes of Lactate in lumbar discs under different physiological conditions using MRS and T2r. METHODS: In step1, MRS and T2r sequences were standardized in 10 volunteers. Step2, analysed effects of high cellular demand. 66 discs of 20 volunteers with no back pain were evaluated pre-exercise (EX-0), immediately after targeted short-time low back exercises (EX-1) and 60 min after (EX-2). In Step 3, to study effects of high glucose and oxygen concentration, 50 lumbar discs in 10 volunteers were analysed before (D0) and after 10 days intake of the calcium channel blocker, nimodipine (D1). RESULTS: Lactate showed a distinctly different response to exercise in that Grade 1 discs with a significant decrease in EX-1 and a trend for normalization in Ex-2. In contrast, Pfirrmann grade 2 and 3 and discs above 40 years showed a higher lactate relative to proteoglycan in EX-0, an increase in lactate EX-1 and mild dip in Ex-2. Similarly, following nimodipine, grade 1 discs showed an increase in lactate which was absent in grade 2 and 3 discs. In contrast, exercise and Nimodipine had no significant change in T2r values and MRS spectrum of proteoglycan, N-acetyl aspartate, carbohydrate, choline, creatine, and glutathione across age groups and Pfirrmann grades. CONCLUSION: MRS documented changes in lactate response to cellular demand which suggested a 'Lactate Symbiotic metabolic Pathway'. The differences in lactate response preceded changes in Proteoglycan/hydration and thus could be a dynamic radiological biomarker of early degeneration.

Correlations of IL-6 and TGF-ß Gene Polymorphisms and Expressions With Osteoporotic, Thoracolumbar, Vertebral Compression Fracture.

Context: Associations between genes and diseases manifest as the influence of gene expression on disease development as well as the impact of variations in the disease-related genes themselves. It's important to determine the genetic variations that can lead to compressed fractures of osteoporotic, thoracic lumbar vertebrae to develop personalized clinical methods to prevent or delay the disease's development. Objective: The study intended to explore the correlations between the gene polymorphisms and gene expressions of the interleukin-6 (IL-6) gene and the transforming growth factor-beta (TGF-ß) gene and osteoporotic, thoracolumbar, vertebral compression fracture. Design: The research team performed an observational study using data from medical records. Setting: The study took place at Xuzhou Medical University in Xuzhou, China. Participants: Participants were 200 patients with an osteoporotic, thoracolumbar, vertebral compression fracture who had been admitted to the hospital at the university between 2019 and 2021 prior to the study and 200 healthy people The research team divided the participants into two groups. The patients became participants in the disease group, and the healthy individuals became participants in the control group. Outcome Measures: The research team: (1) collected peripheral blood from the two groups, (2) extracted genomic deoxyribonucleic acids (DNAs) from karyocytes, (3) examined the IL-6 and TGF-ß gene polymorphisms, and (4) analyzed and correlated participants' clinical data with the gene polymorphisms and expressions. The team used a quantitative polymerase chain reaction (qPCR) to examine the expression levels of IL-6 and TGF-ß. Results: Compared to the control group, the disease group: (1) had allele distributions that were significantly different at the rs2069829 locus of the IL-6 gene (P < .001) and at the rs3087453 of the TGF-ß gene (P = .004); (2) had significantly higher frequencies of allele T at the rs2069829 locus of the IL-6 gene and of allele G at the rs3087453 locus of the TGF-ß gene; (3) had genotype distributions that were significantly different at the rs2069829 locus (P < .001) and the rs2069857 locus (P = .048) of the IL-6 gene and at the rs3087453 locus (P < .001) of the TGF-ß gene; (4) had frequencies that were significantly higher of the TT genotype at the rs2069829 locus, the CC genotype at the rs2069857 locus, and the GC genotype at the rs3087453 locus of the IL-6 gene and the TGF-ß gene; (5) had dominant models that were significantly different at the rs2069829 locus of the IL-6 gene (P = .009) and at rs3087453 locus of the TGF-ß gene (P = .026) and had a recessive model that was significantly different at the rs2069857 locus of the IL-6 gene (P = .040); (6) had significantly different haplotypes CC (P < .001) and TC (P < .001) at the rs2069829 locus and the rs2069857 locus of the IL-6 gene and a significantly different haplotype AC (P = .011) at the rs1800469 locus and the rs3087453 locus of the TGF-ß gene; (7) had an IL-6 gene polymorphism at the rs2069857 locus that was related to the expression of the IL-6 gene (P < .05) and an expression of the IL-6 gene for participants with the AA genotype that was significantly lower than for other genotypes; (8) had a TGF-ß gene polymorphism at the rs1800469 locus that was associated with the expression of the TGF-ß gene (P < .05), and an expression for participants with the GG genotype that was significantly higher than for other genotypes; (9) had an IL-6 gene polymorphism at the rs2069857 locus with an overt correlation with the genotype of osteoporotic, thoracolumbar, vertebral compression fracture (P < .001). Also, participants in the disease group with the genotype CC mainly had type 2 and 3 fractures, while those with genotype AA primarily had type 0 and 1 fractures. Conclusions: IL-6 and TGF-ß gene polymorphisms and expressions are significantly related to osteoporotic, thoracolumbar, vertebral compression fracture.

Transient receptor potential (TRP) channels mRNA transcripts in the lumbar intervertebral discs: biomarkers for inflammation, pain, disability, and clinical outcome.

Transient receptor potential (TRP) channels are widely expressed cation channels that play an essential role in mediating Ca2+ homeostasis and are considered potential regulators of inflammatory pain. This study investigates the expression of the TRP channel subtypes TRPV1, TRPV4, TRPC6, TRPM2, TRPM8 in lumbar intervertebral disc (IVD) biopsies from patients with chronic low back pain (LBP). We determined the expression of these TRP channel subtypes in the annulus fibrosus (AF) and the nucleus pulposus (NP) from 46 patients with LBP undergoing 1-2 level lumbar fusion surgery for degenerative disc disease. The mRNA transcripts were analyzed using quantitative real-time polymerase chain reaction (RT-qPCR), and the expression levels were compared against visual analog scale (VAS) and oswestry disability index (ODI) scores (0-100) for pain and disability. A significant positive correlation was demonstrated between VAS score and the mRNA expression of TRPV1, TRPC6, TRPM2, TRPM8 in the AF. We also found a significant positive correlation between ODI scores and expression of TRPV1 and TRPM8. Further, there is a significant positive correlation between TNF-α and TRPV1, TRPM2 and TRPM8 expression in the AF, and IL-6 to TRPV1 in the NP. Interestingly, when investigating treatment response via a 12-month postoperative follow-up ODI, we found a significant correlation between only TRPV1 expression at baseline and the follow-up ODI scores, which indicates this marker could predict the effectiveness of surgery. These results strongly suggest an association between pain, inflammatory mediators, and TRP channel expression in lumbar disc biopsies of patients with chronic LBP.

Greater bone marrow fat and myosteatosis are associated with lower vBMD but not asymptomatic vertebral fracture.

OBJECTIVES: Organ fat may affect bone metabolism and be associated with vertebral fracture (VF). This study aimed to explore relationships between VF, adiposity indexes measured by MRI, and volumetric BMD (vBMD) measured by quantitative CT (QCT). METHODS: Four hundred volunteers, ranging in age from 22 to 83 years, were recruited and underwent same-day abdominal QCT and chemical shift-encoded (CSE) MRI. We used MRI to quantify the fat content of bone marrow (BMF), psoas major and paraspinal muscles, and the liver. Abdominal fat, VF, and vBMD of the lumbar spine were measured by QCT. For VF discrimination analysis, we examined both the whole cohort (60 VF cases in 30 men and 30 women) and a restricted subgroup of those aged over 50 years (50 VF cases in 23 men and 27 women). RESULTS: Amongst the men, a 1 SD increase in BMF was associated with a 27.67 (95% CI, -32.71 to -22.62) mg/cm3 decrease in vBMD after adjusting for age and BMI. Amongst women, all adiposity indexes except for liver fat were significantly associated with vBMD, with BMF having the strongest association (ß, -24.00; 95% CI, -28.54 to -19.46 mg/cm3). Similar findings were also observed in participants aged over 50 years. The associations of adiposity indexes with vertebral fracture were not significant after adjusting for age in both sexes aged over 50 years. CONCLUSIONS: In both sexes, higher bone marrow fat was associated with lower vBMD at the spine. However, marrow fat and other adipose tissues were not associated with radiographic-based prevalent vertebral fractures. KEY POINTS: • In both sexes, higher bone marrow fat was associated with lower vBMD at the spine. • Among women, all adiposity indexes except for liver fat content were significantly associated with vBMD, with bone marrow fat having the strongest association. • Marrow fat and other adipose tissues were not associated with radiographic-based asymptomatic vertebral fractures.

Body composition, trabecular bone score and vertebral fractures in subjects with Klinefelter syndrome.

BACKGROUND: Klinefelter syndrome (KS) frequently causes skeletal fragility characterized by profound alterations in bone microstructure with increased risk of fractures. Increased body fat mass associated with decreased body lean mass are frequent features of KS with possible detrimental effects on skeletal health. In this cross-sectional study, we evaluated the associations between body composition parameters, vertebral fractures (VFs) and trabecular bone score (TBS) in adult subjects with KS. METHODS: Seventy-one adult males (median age 41 years, range 18-64) with 47, XXY KS were consecutively enrolled by two Endocrinology and Andrology Units (IRCCS Humanitas Research Hospital in Milan and ASST Spedali Civili in Brescia). Dual-energy X-ray absorptiometry (DXA) was performed to assess bone mineral density (BMD) at lumbar spine, femoral neck and total hip, TBS and body composition. Prevalence of VFs was assessed by quantitative morphometry on lateral spine X-rays. RESULTS: VFs were detected in 14 patients (19.7%), without significant association with low BMD (p = 0.912). In univariate logistic regression analysis, VFs were significantly associated with truncal/leg fat ratio (OR 2.32 per tertile; 95% CI 1.05-5.15; p = 0.038), whereas impaired TBS (detected in 23.4% of subjects) was associated with older age at study entry (p = 0.001) and at diagnosis of disease (p = 0.015), body mass index (BMI; p = 0.001), waist circumference (p = 0.007), fat mass index (FMI; p < 0.001), FMI/lean mass index (LMI) ratio (p = 0.001). Prevalence of VFs was not significantly different between subjects with impaired TBS as compared to those with normal TBS (26.7 vs. 18.4%; p = 0.485). Skeletal end-points were not significantly associated with duration of testosterone replacement therapy and serum testosterone and 25hydroxyvitamin D values. CONCLUSION: Body composition might influence bone quality and risk of VFs in subjects with KS.

Correlation between Adrenoceptor Expression and Clinical Parameters in Degenerated Lumbar Intervertebral Discs.

Despite advanced knowledge of the cellular and biomechanical processes of intervertebral disc degeneration (IVDD), the trigger and underlying mechanisms remain unclear. Since the sympathetic nervous system (SNS) has been shown to exhibit catabolic effects in osteoarthritis pathogenesis, it is attractive to speculate that it also influences IVDD. Therefore, we explored the adrenoceptor (AR) expression profile in human IVDs and correlated it with clinical parameters of patients. IVD samples were collected from n = 43 patients undergoing lumbar spinal fusion surgery. AR gene expression was analyzed by semi-quantitative polymerase chain reaction. Clinical parameters as well as radiological Pfirrmann and Modic classification were collected and correlated with AR expression levels. In total human IVD homogenates α1A-, α1B-, α2A-, α2B-, α2C-, ß1- and ß2-AR genes were expressed. Expression of α1A- (r = 0.439), α2A- (r = 0.346) and ß2-AR (r = 0.409) showed a positive and significant correlation with Pfirrmann grade. α1A-AR expression was significantly decreased in IVD tissue of patients with adjacent segment disease (p = 0.041). The results of this study indicate that a relationship between IVDD and AR expression exists. Thus, the SNS and its neurotransmitters might play a role in IVDD pathogenesis. The knowledge of differential AR expression in different etiologies could contribute to the development of new therapeutic approaches for IVDD.

Elucidating the effect of mechanical stretch stress on the mechanism of ligamentum flavum hypertrophy: Development of a novel in vitro multi-torsional stretch loading device.

OBJECTIVE: We developed a novel multi-torsional mechanical stretch stress loading device for ligamentum flavum cells and evaluated its influence on the development of ligamentum flavum hypertrophy, a common cause of lumbar spinal canal stenosis. MATERIALS AND METHODS: Stretch strength of the device was optimized by applying 5% and 15% MSS loads for 24, 48, and 72 h. A cytotoxicity assay of human ligamentum flavum cells was performed and the results were compared to control (0% stress). Inflammatory markers (interleukin [IL]-6, IL-8), vascular endothelial growth factor [VEGF], and extracellular matrix (ECM)-regulating cytokines (matrix metalloproteinase [MMP]-1, MMP-3 and MMP-9, and tissue inhibitor of metalloproteinase [TIMP]-1 and TIMP-2) were quantified via enzyme-linked immunosorbent assay. RESULTS: Using our multi-torsional mechanical stretch stress loading device, 5% stress for 24 hour was optimal for ligamentum flavum cells. Under this condition, the IL-6 and IL-8 levels, VEGF level, and MMP-1, MMP-3, and TIMP-2 were significantly increased, compared to the control. CONCLUSION: Using the novel multi-torsional mechanical stretch stress loading device we confirmed that, mechanical stress enhances the production of inflammatory cytokines and angiogenic factors, and altered the expression of ECM-regulating enzymes, possibly triggering ligamentum flavum hypertrophy.

Maternal alloxan exposure induces damage in rat offspring lumbar vertebrae and protective role of arachidonic acid.

BACKGROUND: Vertebral abnormalities in offspring of diabetic mothers make major challenges worldwide and were not sufficiently studied before. AIM: To investigate the effects of alloxan-induced diabetes on rats' lumbar vertebrae, and to assess the potential beneficial impact of arachidonic acid. MATERIALS AND METHODS: Pregnant rats were randomly equally divided into four groups: control, alloxan-induced diabetes received alloxan injection 150 mg∕kg, alloxan + arachidonic acid group received arachidonic acid 10 µg∕animal then given alloxan injection, and arachidonic acid group received it, until offspring age of three weeks. Six male offspring from each group were included in this study at ages of newborn, three-week-old, two-month-old, and their body measurements were recorded. Lumbar vertebrae and pancreas specimens were examined by light microscopy, morphometry, transmission electron microscopy (TEM), and immunohistochemistry for insulin expression. RESULTS: In alloxan-induced diabetes newborn, three-week-old, and two-month-old rats, body measurements were significantly declined, histomorphometry of 6th lumbar vertebrae revealed disorganized chondrocytes, with vacuolated cytoplasm, empty lacunae, diminished matrix staining, with areas devoid of cells. TEM showed shrunken reserve and proliferative cells, with irregular nuclei, and damaged mitochondria. In contrast, alloxan + arachidonic acid group had cytoarchitecture of lumbar vertebrae that were like control group. Histomorphometry of pancreas in alloxan-induced diabetes group showed significant reduction in pancreatic islets number and surface area, damaged pancreatic islet cells appeared atrophied with apoptotic nuclei, and very weak insulin immunostaining. Whereas alloxan + arachidonic acid group displayed healthy features of pancreatic islets, which resembled control group, with strong insulin immunostaining. CONCLUSIONS: Arachidonic acid mitigated alloxan-induced diabetes by its antidiabetic activity.

Macrophage migration inhibitory factor takes part in the lumbar ligamentum flavum hypertrophy.

The present study aimed to observe the content difference of macrophage migration inhibitory factor [MIF; novoprotein recombinant human MIF (n­6his) (ch33)], TGFß1 and MMP13 in patients with and without ligamentum flavum (LF) hypertrophy and investigate the roles of MIF in LF hypertrophy. The concentration of MIF, TGFß1 and MMP13 in LF were detected by ELISA in a lumbar spinal stenosis (LSS) group and a lumbar disc herniation (LDH) group. Culture of primary LFs and identification were performed for the subsequent study. Cell treatments and cell proliferation assay by CCK­8 was performed. Western blot and quantitative PCR analysis were used to detect the expression of TGFß1, MMP13, type I collagen (COL­1) and type III collagen (COL­3) and Src which were promoted by MIF. The concentration of MIF, TGFß1 and MMP13 were higher in the LSS group compared with the LDH group. Culture of primary LFs and identification were performed. Significant difference in LFs proliferation occurred with treatment by MIF at a concentration of 40 nM for 48 h (P<0.05). The gene and protein expression of TGFß1, MMP13, COL­1, COL­3 and Src were promoted by MIF (P<0.05). Proliferation of LFs was induced by MIF and MIF­induced proliferation of LFs was inhibited by PP1 (a Src inhibitor). MIF may promote the proliferation of LFs through the Src kinase signaling pathway and can promote extracellular matrix changes by its pro­inflammatory effect. MIF and its mediated inflammatory reaction are driving factors of LF hypertrophy.

Mechanical-Stress-Related Epigenetic Regulation of ZIC1 Transcription Factor in the Etiology of Postmenopausal Osteoporosis.

Mechanical loading exerts a profound influence on bone density and architecture, but the exact mechanism is unknown. Our study shows that expression of the neurological transcriptional factor zinc finger of the cerebellum 1 (ZIC1) is markedly increased in trabecular bone biopsies in the lumbar spine compared with the iliac crest, skeletal sites of high and low mechanical stress, respectively. Human trabecular bone transcriptome analyses revealed a strong association between ZIC1 mRNA levels and gene transcripts characteristically associated with osteoblasts, osteocytes and osteoclasts. This supposition is supported by higher ZIC1 expression in iliac bone biopsies from postmenopausal women with osteoporosis compared with age-matched control subjects, as well as strongly significant inverse correlation between ZIC1 mRNA levels and BMI-adjusted bone mineral density (BMD) (Z-score). ZIC1 promoter methylation was decreased in mechanically loaded vertebral bone compared to unloaded normal iliac bone, and its mRNA levels correlated inversely with ZIC1 promoter methylation, thus linking mechanical stress to epigenetic control of gene expression. The findings were corroborated in cultures of rat osteoblast progenitors and osteoblast-like cells. This study demonstrates for the first time how skeletal epigenetic changes that are affected by mechanical forces give rise to marked alteration in bone cell transcriptional activity and translate to human bone pathophysiology.

Localization of Nerve Growth Factor Expression to Structurally Damaged Cartilaginous Tissues in Human Lumbar Facet Joint Osteoarthritis.

Purpose: Nerve Growth Factor (NGF) is a pivotal mediator of chronic pain and plays a role in bone remodelling. Through its high affinity receptor TrkA, NGF induces substance P (SP) as key downstream mediator of pain and local inflammation. Here we analysed NGF, TrkA and SP tissue distribution in facet joint osteoarthritis (FJOA), a major cause of chronic low back pain. Methods: FJOA specimens (n=19) were harvested from patients undergoing intervertebral fusion surgery. Radiologic grading of FJOA and spinal stenosis, followed by immunohistochemistry for NGF, TrkA and SP on consecutive tissue sections, was performed in ten specimens. Explant cultures (n=9) were used to assess secretion of NGF, IL-6, and SP by FJOA osteochondral tissues under basal and inflammatory conditions. Results: NGF was predominantly expressed in damaged cartilaginous tissues (80%), occasionally in bone marrow (20%), but not in osteochondral vascular channels. NGF area fraction in cartilage was not associated with the extent of proteoglycan loss or radiologic FJOA severity. Consecutive sections showed that NGF and SP expression was localized at structurally damaged cartilage, in absence of TrkA expression. SP and TrkA were expressed in subchondral bone marrow in both presence and absence of NGF. Low level NGF, but not SP secretion, was detected in four out of eighteen FJOA explants under both basal or inflammatory conditions (n=2 each). Conclusion: NGF is associated with SP expression and structural cartilage damage in osteoarthritic facet joints, but not with radiologic disease severity. NGF tissue distribution in FJOA differs from predominant subchondral bone expression reported for knee OA.