More Prevalent and Severe Low Bone-Mineral Density in Boys with Severe Adolescent Idiopathic Scoliosis Than Girls: A Retrospective Study of 798 Surgical Patients

INTRODUCTION

A total of 0.1-0.8% of AIS patients progress to severe stages without clear mechanisms, and AIS girls are more prone to curve progression than boys. Recent studies suggest that AIS girls have systemic and persistent low bone-mineral density (BMD), which has been shown to be a significant prognostic factor of curve progression in AIS. The present study aimed to (a) investigate the prevalence of low BMD in patients with severe AIS and (b) assess the sexual dimorphism and independent risk factors of low BMD in severe AIS patients.

MATERIALS AND METHODS

A total of 798 patients (140 boys vs. 658 girls) with AIS who reached surgical threshold (Cobb ≥ 40°) were recruited. BMD were assessed using BMD Z-scores from dual-energy X-ray absorptiometry (DXA). Demographic, clinical, and laboratory values of the subjects were collected from their medical records. Logistic regression analysis was performed to identify independent risk factors of low BMD.

RESULTS

The overall prevalence of BMD Z-score ≤ -2 and ≤ -1 were 8.1% and 37.5%, respectively. AIS boys had significantly lower BMD Z-scores (-1.2 ± 0.96 vs. -0.57 ± 0.92) and higher prevalence of low BMD (Z-score ≤ -2: 22.1% vs. 5.2%, p < 0.001; Z-score ≤ -1: 59.3% vs. 32.8%, p < 0.001) than girls. Sex, BMI, serum alkaline phosphatase, and potassium were independent factors of low BMD in the severe AIS patients.

CONCLUSIONS

The present large cohort of surgical AIS patients revealed that low BMD is more prevalent and severe in boys than in girls with severe curves. Low BMD may serve as a more valuable predictive factor for curve progression to the surgical threshold in boys than girls with AIS.

High-efficiency quantitative control of mitochondrial transfer based on droplet microfluidics and its application on muscle regeneration

Mitochondrial transfer is a spontaneous process to restore damaged cells in various pathological conditions. The transfer of mitochondria to cell therapy products before their administration can enhance therapeutic outcomes. However, the low efficiency of previously reported methods limits their clinical application. Here, we developed a droplet microfluidics-based mitochondrial transfer technique that can achieve high-efficiency and high-throughput quantitative mitochondrial transfer to single cells. Because mitochondria are essential for muscles, myoblast cells and a muscle injury model were used as a proof-of-concept model to evaluate the proposed technique. In vitro and in vivo experiments demonstrated that C2C12 cells with 31 transferred mitochondria had significant improvements in cellular functions compared to those with 0, 8, and 14 transferred mitochondria and also had better therapeutic effects on muscle regeneration. The proposed technique can considerably promote the clinical application of mitochondrial transfer, with optimized cell function improvements, for the cell therapy of mitochondria-related diseases.

Decreased cortical bone density and mechanical strength with associated elevated bone turnover markers at peri-pubertal peak height velocity: a cross-sectional and longitudinal cohort study of 396 girls with adolescent idiopathic scoliosis

Decreased cortical bone density and bone strength at peak height velocity (PHV) were noted in girls with adolescent idiopathic scoliosis (AIS). These findings could provide the link to the previously reported observation that low bone mineral density (BMD) could contribute as one of the prognostic factors for curve progression that mostly occurs during PHV in AIS.

INTRODUCTION

As part of the studies related to aetiopathogenesis of AIS, we assessed bone qualities, bone mechanical strength and bone turnover markers (BTMs) focusing at the peri-pubertal period and PHV in AIS girls.

METHODS

396 AIS girls in two separate cohorts were studied. Skeletal maturity was assessed using the validated thumb ossification composite index (TOCI). Bone qualities and strength were evaluated with high-resolution peripheral quantitative computed tomography (HR-pQCT) and finite element analysis (FEA).

RESULTS

Cohort-A included 179 girls (11.95 ± 0.95 years old). Girls at TOCI-4 had numerically the highest height velocity (0.71 ± 0.24 cm/month) corresponding to the PHV. Subjects at TOCI-4 had lower cortical volumetric BMD (672.36 ± 39.07 mg/mm³), cortical thickness (0.68 ± 0.08 mm) and apparent modulus (1601.54 ± 243.75 N/mm²) than: (a) those at TOCI-1-3 (724.99 ± 32.09 mg/mm³ (p < 0.001), 0.79 ± 0.11 mm (p < 0.001) and 1910.88 ± 374.75 N/mm² (p < 0.001), respectively) and (b) those at TOCI-8 (732.28 ± 53.75 mg/mm³ (p < 0.001), 0.84 ± 0.14 mm (p < 0.001), 1889.11 ± 419.37 N/mm² (p < 0.001), respectively). Cohort-B included 217 girls (12.22 ± 0.89 years old). Subjects at TOCI-4 had higher levels of C-terminal telopeptide of type 1 collagen (1524.70 ± 271.10 pg/L) and procollagen type 1 N-terminal propeptide (941.12 ± 161.39 µg/L) than those at TOCI-8 (845.71 ± 478.55 pg/L (p < 0.001) and 370.08 ± 197.04 µg/L (p < 0.001), respectively).

CONCLUSION

AIS girls had decreased cortical bone density and bone mechanical strength with elevated BTMs at PHV. Coupling of PHV with decreased cortical and FEA parameters could provide the link to the previously reported observation that low BMD could contribute as one of the prognostic factors for curve progression that mostly occurs during PHV in AIS.

A Functional SNP in the Promoter of LBX1 Is Associated With the Development of Adolescent Idiopathic Scoliosis Through Involvement in the Myogenesis of Paraspinal Muscles

Previous studies have shown that LBX1 is associated with adolescent idiopathic scoliosis (AIS) in multiple populations. For the first time, rs1322330 located in the putative promoter region of LBX1 was found significantly associated with AIS in the Chinese population [p = 6.08 × 10^–14, odds ratio (OR) = 1.42, 95% confidence interval of 1.03–1.55]. Moreover, the luciferase assay and electrophoretic mobility shift assay supported that the allele A of rs1322330 could down-regulate the expression of LBX1 in the paraspinal muscles of AIS. In addition, silencing LBX1 in the myosatellite cells resulted in significantly inhibited cell viability and myotube formation, which supported an essential role of LBX1 in muscle development of AIS. To summarize, rs1322330 may be a novel functional SNP regulating the expression of LBX1, which was involved in the etiology of AIS possibly via regulation of myogenesis in the paraspinal muscles.

Association of serum 25(OH)Vit-D levels with risk of pediatric fractures: a systematic review and meta-analysis

The association between the risk of fractures and suboptimal vitamin D (Vit-D) status remains controversial in children. This meta-analysis suggested that serum 25(OH)Vit-D levels were lower in pediatric cases with fractures. 25-hydroxyvitamin D (25(OH)Vit-D) levels less than 50 nmol/L were associated with increased fracture risk in children.

INTRODUCTION

This study aimed to assess the association between serum 25(OH)Vit-D and the risk of fractures in children, and to explore the sources of heterogeneity and investigate their impact on results.

METHODS

Systematic review and meta-analysis were conducted for observational studies comparing serum 25(OH)Vit-D levels between fracture and non-fracture pediatric cases. The quality of the included studies was assessed using the Newcastle-Ottawa Scale (NOS).

RESULTS

Analysis on 17 case-control and 6 cross-sectional studies (2929 fracture cases and 5000 controls) suggested that 25(OH)Vit-D was lower in fracture cases than in controls (pooled mean difference (MD) = - 3.51 nmol/L; 95% confidence interval (CI): - 5.60 to - 1.42) with a heterogeneity (I²) of 73.9%. The sensitivity analysis which merged the case-control studies that had a NOS score ≥ 4 showed a pooled MD of - 4.35 nmol/L (95% CI: - 6.64 to - 2.06) with a heterogeneity (I²) of 35.9%. Pooled odds ratio of fracture in subjects with 25(OH)Vit-D ≤ 50 nmol/L compared to subjects with 25(OH)Vit-D > 50 nmol/L was 1.29 (95% CI: 1.10 to 1.53; I² < 1%).

CONCLUSION

This study indicated that serum 25(OH)Vit-D levels were lower in pediatric patients with fractures. 25(OH)Vit-D ≤ 50 nmol/L was associated with increased fracture risk in children.

Association of higher bone turnover with risk of curve progression in adolescent idiopathic scoliosis

OBJECTIVE

Emerging evidence suggest abnormal bone metabolism and defective bone qualities are associated to etipathogenesis of Adolescent Idiopathic Scoliosis (AIS). Systemic low bone mass is important prognosticator to predict risk of curve progression in AIS. The underlying mechanism is still unclear. We hypothesize that aberrant bone turnover correlates with bone qualities in AIS and associates to risk of curve progression.

SUBJECTS AND METHODS

Two cohorts were included in this study. The case-control study recruited 161 AIS girls and 161 ethnic/age-matched healthy girls. The longitudinal cohort recruited 128 AIS girls with two-year follow-up. Areal bone mineral density (BMD) at femoral necks were measured with dual-energy x-ray absorptiometry (DXA), and bone qualities of distal radius by high-resolution peripheral quantitative computed tomography (HR-pQCT). Time-lapse analysis of registered HR-pQCT images estimated local bone remodeling quantitatively. Serum levels of CTX and P1NP were measured with ELISA kits.

RESULTS

AIS presented significantly higher serum level of P1NP. In both AIS and control, the negative correlations were consistently observed between serum CTX/P1NP levels and most cortical bone quality parameters after adjustment to age. Significant correlation between serum bone turnover markers and trabecular bone parameters have been observed only in control. Progressive AIS has significant increase of serum P1NP level at first clinic visit. Time lapse register analysis showed high bone resorption and low net bone gain was associated with risk of progression in AIS.

CONCLUSIONS

Our study characterized AIS with higher serum bone turnover markers, which may contribute to defective bone qualities in AIS. For the first time, we showed that progressive AIS had higher systemic bone turnover markers level and local bone remodeling. This fresh evidence indicated association between disrupted bone turnover and risk of progression of AIS, which set the foundation of new prognostic method and of novel treatment target to curve progression. This study demonstrated the importance of bone metabolism in developing disease management of AIS to achieve goal of early prediction and non-surgical modulation.

Abnormal lacuno-canalicular network and negative correlation between serum osteocalcin and Cobb angle indicate abnormal osteocyte function in adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) is a prevalent spinal deformity occurring during peripubertal growth period that affects 1-4% of adolescents globally without clear etiopathogenetic mechanism. Low bone mineral density is an independent and significant prognostic factor for curve progression. Currently, the cause underlying low bone mass in AIS remains elusive. Osteocytes play an important role in bone metabolism and mineral homeostasis, but its role in AIS has not been studied. In the present study, iliac bone tissues were harvested from 21 patients with AIS (mean age of 14.3 ± 2.20 yr old) with a mean Cobb angle of 55.6 ± 10.61° and 13 non-AIS controls (mean age of 16.5 ± 4.79 yr old) intraoperatively. Acid-etched scanning electron microscopy (SEM) images of AIS demonstrated abnormal osteocytes that were more rounded and cobblestone-like in shape and were aligned in irregular clusters with shorter and disorganized canaliculi. Further quantitative analysis with FITC-Imaris technique showed a significant reduction in the canalicular number and length as well as an increase in lacunar volume and area in AIS. SEM with energy-dispersive X-ray spectroscopy analysis demonstrated a lower calcium-to-phosphorus ratio at the perilacunar/canalicular region. Moreover, microindentaion results revealed lower values of Vickers hardness and elastic modulus in AIS when compared with controls. In addition, in the parallel study of 99 AIS (27 with severe Cobb angle of 65.8 ± 14.1° and 72 with mild Cobb angle of 26.6 ± 9.1°) with different curve severity, the serum osteocalcin level was found to be significantly and negatively associated with the Cobb angle. In summary, the findings in this series of studies demonstrated the potential link of abnormal osteocyte lacuno-canalicular network structure and function to the observed abnormal bone mineralization in AIS, which may shed light on etiopathogenesis of AIS.-Chen, H., Zhang, J., Wang, Y., Cheuk, K.-Y., Hung, A. L. H., Lam, T.-P., Qiu, Y., Feng, J. Q., Lee, W. Y. W., Cheng, J. C. Y. Abnormal lacuno-canalicular network and negative correlation between serum osteocalcin and Cobb angle indicate abnormal osteocyte function in adolescent idiopathic scoliosis.

Characterisation of multipotent stem cells from human peripheral blood using an improved protocol

Background

A promising approach of bone repair is to use stem cells, such as mesenchymal stem cells (MSCs). Seeking available source of MSCs still remains a great challenge in tissue engineering and cell therapy. Peripheral blood (PB) emerges as an alternative source of MSCs which can be easily acquired with minimal invasiveness. This study was undertaken to evaluate the multipotency of PB-MSCs and effects of human PB-MSCs transplantation on ectopic bone regeneration in nude mice.

Methods

Human venous blood collected was mixed with heparin and then red blood cells were removed using red blood cell lysis buffer. Cell suspension was cultured in normoxia-culture and hypoxia-culture conditions, respectively. The non-adherent cells were removed by half changing culture media every three days. Cells were selected due to plastic adherence. The adherent cells were then passaged and subjected to multi-differentiation induction assays in vitro and in vivo ectopic bone formation assay.

Results

Characterization assays indicated that cells cultured under hypoxia possessed potent multi-lineage differentiation capacity and expressed Nanog and Lgr5, as well as a series of MSC surface antigens (including CD29, CD90, CD105, and CD73). Additionally, regenerated bone tissues by transplantation of human PB-MSCs in vivo were confirmed by histological examinations of ectopic osteogenesis assay. A purified population of MSCs can be obtained within a short period of time using this protocol with a successful rate of 60%.

Conclusion

We reported an effective and reliable method to harvest highly purified MSCs with potent multi-differentiation potential from human peripheral blood. Lgr5 may be a potential biomarker for identification of a subpopulation of PB-MSCs.

The translational potential of this article

PB-MSCs is an alternative cell source for cell therapy, which may be harvested, culture expanded and PB-MSCs loaded with β-tricalcium phosphate (β-TCP) may be used to promote bone repair.

Aberrant miR-145-5p/β-catenin signal impairs osteocyte function in adolescent idiopathic scoliosis

Recently, noncoding RNAs have been thought to play important roles in the sporadic occurrence of spinal deformity of adolescent idiopathic scoliosis (AIS). As a prognostic factor for curve progression, low bone mass has been hypothesized to crosstalk with AIS pathogenesis. Abnormal osteoblasts activities are reported in AIS without a clear mechanism. In this study, bone biopsies from patients with AIS and control subjects and the primary osteoblasts derived from those samples were used to identify the potential microRNA (miRNA) candidates that interfere with osteoblasts and osteocytes function. Microarray analysis identified miRNA-145-5p (miR-145) as a potential upstream regulator. miR-145 and β-catenin mRNA ( CTNNB1) were overexpressed in AIS bone tissues and primary osteoblasts, and their expression correlated positively in AIS. Knockdown of miR-145 restored impaired osteocyte activity through the down-regulation of active β-catenin expression and its transcriptional activity. Significant negative correlations between circulating miR-145 and serum sclerostin, osteopontin, and osteoprotegerin were noted in patients with AIS, which was in line with our cellular findings. This is the first study to demonstrate the effect of aberrant miRNA expression and its effect on osteocyte function in AIS, which may contribute to the low bone mass. Our findings also provide insight into the development of circulating microRNAs as a bone quality biomarker or even a prognostic biomarker for AIS.-Zhang, J., Chen, H., Leung, R. K. K., Choy, K. W., Lam, T. P., Ng, B. K. W., Qiu,Y., Feng, J. Q., Cheng, J. C. Y., Lee, W. Y. W. Aberrant miR-145-5p/β-catenin signal impairs osteocyte function in adolescent idiopathic scoliosis.

Stepwise preconditioning enhances mesenchymal stem cell-based cartilage regeneration through epigenetic modification

OBJECTIVE

This study is to investigate the functions and underlying mechanisms of mesenchymal stem cells (MSCs) underwent stepwise preconditioning in chondrogenic medium before expansion, then further explore their therapeutic effects in a surgically induced osteoarthritis (OA) model.

METHODS

MSCs isolated from the adult rats expressing Green Fluorescence Protein (GFP) were incubated in basal medium or primed in chondrogenic medium before expansion. The multipotency including cell proliferation, differentiation, and survivability was compared between chondrogenic manipulated MSCs (M-MSCs) and untreated MSCs. Methylation modification of Nanog and Oct4 were detected by bisulfite genomic sequencing. Loss-of-function phenotype in M-MSCs induced by shNanog was also observed. Then the therapeutic effect of the cells was evaluated in a surgically induced OA rat model by single intraarticular injection. The injected GFP-labeled cells in the joints were monitored in vivo. These rats were sacrificed and subjected to histological examinations and microstructural analysis after 4 weeks.

RESULTS

We found that cell clonogenicity, proliferation, survivability, and chondrogenic property were enhanced after stepwise preconditioning. We then further found that the expression level of Nanog and Oct4 was temporarily increased in the M-MSCs. Results of epigenetic analysis revealed that demethylation happened in Nanog and Oct4 after the stepwise preconditioning. Results of in vivo imaging showed more GFP-labeled cells in the M-MSCs-injected group. And results of histology and micro-CT analysis also indicated a superior therapeutic effect of M-MSCs on the surgically induced-OA.

CONCLUSION

These findings indicated a feasible method to obtain a cell population with high survivability and chondrogenic commitment for the treatment of OA.

Aspirin prevents bone loss with little mechanical improvement in high-fat-fed ovariectomized rats

Obesity and osteoporosis are often concurrently happened in the menopausal women. Obesity in menopausal women is not only related to a high risk of cardiovascular disease, but also results in a detrimental effect on bone health. This study aimed to investigate the effects of aspirin, a popular anti-thrombosis drug, on bone quantity and quality in the high-fat-fed animal model. Adult female rats were subjected to either sham operations or ovariectomized operations. The ovariectomized rats were orally administered with deionized water or standardized high fat emulsion with or without aspirin. All rats were injected with calcein before killed for the purpose of double in vivo labeling. Biochemistry, histomorphometry, micro-computed tomography analysis, mechanical test, and component analysis were performed after 12 weeks. In vitro cell culture was also performed to observe the effect of aspirin in osteogenesis. We found that high fat remarkably impaired bone formation and bone biomechanics. Aspirin treatment significantly prevented bone loss by increasing bone formation. In vitro studies also validated the enhancement of osteogenic differentiation. However, aspirin presented no significant improvement in bone mechanical properties. Component analysis shown aspirin could significantly increase the content of mineral, but had limited effect on the content of collagen. In conclusion, aspirin is beneficial for the prevention of bone loss; meanwhile, it may cause an imbalance in the components of bone which may weaken the mechanical properties. The current study provided further evidence that aspirin might not be powerful for the prevention of fracture in osteoporotic patients.

Miltirone Is a Dual Inhibitor of P-Glycoprotein and Cell Growth in Doxorubicin-Resistant HepG2 Cells

Miltirone (1), an abietane-type diterpene quinone isolated from Salvia miltiorrhiza, possesses anticancer activity in p-glycoprotein (P-gp)-overexpressing human cancer cells. Results of the current study suggest a dual effect of miltirone on P-gp inhibition and apoptotic induction in a human hepatoma HepG2 cell line and its P-gp-overexpressing doxorubicin-resistant counterpart (R-HepG2). Miltirone (1) elicited a concentration-dependent cytotoxicity, with a similar potency (EC50 ≈ 7-12 μM), in HepG2 and R-HepG2 cells. Miltirone (1) (1.56-6.25 μM) produced synergistic effects on doxorubicin (DOX)-induced growth inhibition of R-HepG2 (synergism: 0.3 < combination index < 0.5). Molecular docking studies illustrated that miltirone (1) interacted with the active site of P-gp with a higher binding affinity than DOX, suggesting that it was a P-gp inhibitor. Flow cytometric analysis confirmed miltirone (1) as a competitive inhibitor of P-gp. At non-necrotic concentrations (1.56-25 μM), miltirone (1) activated caspase-dependent apoptotic pathways and triggered the generation of reactive oxygen species (ROS) and ROS-mediated mitogen-activated protein kinase (MAPK) signaling pathways (e.g., p38 MAPK, stress-activated protein kinase/c-Jun N-terminal kinase, and extracellular regulated kinase 1/2) in both HepG2 and R-HepG2 cells. Thus, we conclude that miltirone (1) is a dual inhibitor of P-gp and cell growth in human drug-resistant hepatoma cells.

The effects of atorvastatin on the prevention of osteoporosis and dyslipidemia in the high-fat-fed ovariectomized rats

Previous studies reported that statins showed positive effects on bone in both human and animal models. This study aimed to investigate the effects of atorvastatin on the prevention of osteoporosis and dyslipidemia in ovariectomized rats fed with high-fat emulsion. The 3-month-old female rats were subjected to either sham operations (n = 8) or ovariectomized operations (OVX, n = 24). The OVX rats were orally administered deionized water (n = 8) or standardized high-fat emulsion without (n = 8) or with atorvastatin (n = 8). All rats were injected twice with calcein before sacrificed for the purpose of double in vivo labeling. After 12 weeks, all rats were sacrificed under anesthesia. Biochemistry, histomorphometry, mechanical test, micro-computed tomography analysis, mechanical test, histology, and component analysis were performed. We found that high-fat emulsion significantly decreased body weight, bone formation, collagen content of bone, and bone biomechanics, while increased blood, liver, and bone marrow lipids. Atorvastatin treatment prevented dyslipidemia, reversed hepatic steatosis, optimized composition of bone, and improved bone mechanical properties. The current study provided further evidence that atorvastatin might be useful for the treatment of osteoporotic patients with dyslipidemia.

Danshen (Salvia miltiorrhiza) water extract inhibits paracetamol-induced toxicity in primary rat hepatocytes via reducing CYP2E1 activity and oxidative stress

OBJECTIVES

This study aimed to investigate the protective effects of Danshen (Salvia miltiorrhiza) water extract (DSE) and its major phenolic acid components against CYP2E1-mediated paracetamol (APAP)-induced hepatic toxicity.

METHODS

The protection and underlying mechanisms were detected in CYP2E1 overexpression primary rat hepatocytes by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, alamar blue assay, CYP2E1 inhibition assay and glutathione assay.

KEY FINDINGS

After APAP treatment, DSE (0.06-1 mg/ml) significantly increased cell viability in MTT assay. Two major components danshensu (8.2-130.5 μm) and salvianolic acid B (Sal B; 3.3-53.5 μm) mainly contributed to this protection, but rosmarinic acid, protocatechuic aldehyde and Sal A did not. Alamar blue assay showed that DSE, danshensu and Sal B maintained mitochondrial metabolic activity. DSE inhibited CYP2E1 (Ki = 1.46 mg/ml) in a mixed mode in rat liver microsomes in vitro; DSE decreased APAP-induced total glutathione depletion and preserved redox status (GSH/GSSG ratio) in hepatocytes. Danshensu and Sal B did not inhibit CYP2E1 or decrease total glutathione depletion, but preserved redox status.

CONCLUSIONS

DSE protected hepatocytes against APAP-induced injury via maintenance of mitochondrial metabolic activity, CYP2E1 inhibition, reduction of total glutathione depletion and preservation of redox status. Danshensu and Sal B were mainly responsible for this protection.

Immortalized human fetal bone marrow-derived mesenchymal stromal cell expressing suicide gene for anti-tumor therapy in vitro and in vivo

BACKGROUND AIMS

Cancer is one of the greatest health challenges facing the world today with >10 million new cases of cancer every year. The self-renewal, tumor-homing ability and low immunogenicity of mesenchymal stromal cells (MSCs) make them potential delivery candidates for suicide genes for anti-tumor therapy. However, unstable supply and short life span of adult MSCs in vitro have limited this therapeutic potential. In this study, we aimed to evaluate if immortalization of human fetal bone marrow-derived mesenchymal stromal cells by simian virus 40 (SV40-hfBMSCs) could be a stable source of MSCs for clinical application of suicide gene therapy.

METHODS AND RESULTS

Transduction of SV40 and herpes simplex virus thymidine kinase-IRES-green fluorescent protein (TK-GFP) did not cause significant change in the stem cell properties of hfBMSCs. The anti-tumor effect of SV40-TK-hfBMSCs in the presence of the prodrug ganciclovir was demonstrated in vitro and in nude mice bearing human prostate cancer cells, DU145 and PC3, which had been transduced with luciferase and GFP for imaging evaluation by an in vivo live imaging system (IVIS 200 imaging system; Caliper Life Sciences). Repeated injection of low doses (1 × 10(6) cells/kg) of SV40-TK-hfBMSCs was as effective as previously reported and did not cause observable harmful side effects in multiple organs. Mixed lymphocyte reaction showed that SV40-TK-hfBMSCs did not induce significant proliferation of lymphocytes isolated from healthy adults.

CONCLUSIONS

Taken together, immortalized hfBMSCs represent a reliable and safe source of MSCs for further clinical translational study.

Tanshinone I increases CYP1A2 protein expression and enzyme activity in primary rat hepatocytes

This study investigated the effects of Danshen and its active ingredients on the protein expression and enzymatic activity of CYP1A2 in primary rat hepatocytes. The ethanolic extract of Danshen roots (containing mainly tanshinones) inhibited CYP1A2-catalyzed phenacetin O-deethylation (IC(50)=24.6 μg/ml) in primary rat hepatocytes while the water extract containing mainly salvianolic acid B and danshenshu had no effect. Individual tanshinones such as cryptotanshinone, dihydrotanshinone, tanshinone IIA inhibited the CYP1A2-mediated metabolism with IC(50) values at 12.9, 17.4 and 31.9 μM, respectively. After 4-day treatment of the rat hepatocytes, the ethanolic extract of Danshen and tanshinone I increased rat CYP1A2 activity by 6.8- and 5.2-fold, respectively, with a concomitant up-regulation of CYP1A2 protein level by 13.5- and 6.5-fold, respectively. CYP1A2 induction correlated with the up-regulation of mRNA level of aryl hydrocarbon receptor (AhR), which suggested a positive feedback mechanism of tanshinone I-mediated CYP1A2 induction. A formulated Danshen pill (containing mainly danshensu and salvianolic acid B and the tanshinones) up-regulated CYP1A2 protein expression and enzyme activity, but danshensu and salvianolic acid B, when used individually, did not affect CYP1A2 activity. This study was the first report on the Janus action of the tanshinones on rat CYP1A2 activity.

A pharmacodynamic-pharmacokinetic (PD-PK) study on the effects of Danshen (Salvia miltiorrhiza) on midazolam, a model CYP3A probe substrate, in the rat

This study investigated the effect of Danshen on the pharmacodynamic-pharmacokinetic (PD-PK) effects of midazolam, a model CYP3A probe substrate. The effects of acute and 3-day Danshen treatment on the pharmacokinetics of a low dose midazolam (10 mg/kg, i.p.) were determined in vivo in the rat. Danshen (200 mg/kg, i.p.) treatment decreased midazolam clearance by 16%, with increases in the AUC by 22% and the half-life by 14%. 3-Day Danshen treatment (200 mg/kg/day, i.p.) for 3 days decreased the clearance, with increases in the T(1/2) and AUC. The effects of acute and 3-day Danshen on midazolam-induced hypnosis, serum 1'-hydroxy-midazolam to midazolam ratio and hepatic CYP3A protein expression were determined in the rat. Danshen treatments (100-200 mg/kg, i.p. and 200-500 mg/kg, p.o.) increased the sleeping time (p<0.001) produced by a hypnotic dose of midazolam (50 mg/kg, i.p.) without affecting the sleep latency. Serum 1'-hydroxy-midazolam to midazolam ratio after the hypnotic dose of midazolam was decreased after intraperitoneal Danshen treatment (200 mg/kg) but not after oral treatment at up to 500 mg/kg. All the treatment groups with Danshen, after intraperitoneal and oral administration, decreased hepatic CYP3A protein expression (p<0.05) by about 25%. The results confirmed that Danshen had no enzyme inducing effects on rat CYP3A.

Major tanshinones of Danshen (Salvia miltiorrhiza) exhibit different modes of inhibition on human CYP1A2, CYP2C9, CYP2E1 and CYP3A4 activities in vitro

This study investigated the effects of tanshinones on human CYP1A2 (phenacetin O-deethylase), CYP2C9 (tolbutamide 4-hydroxylase), CYP2E1 (chlorzoxazone 6-hydroxylase) and CYP3A4 (testosterone 6beta-hydroxylase) activities in vitro using pooled human liver microsomes and specific human CYP isoforms. Tanshinone I, tanshinone IIA, and cryptotanshinone were potent competitive CYP1A2 inhibitors (K(i)=1.5-2.5 microM); medium competitive inhibitors of CYP2C9 (K(i)=22-62 microM); medium competitive inhibitors of CYP2E1 (K(i)=3.67 microM) for tanshinone I and 10.8 microM for crytotanshinone; but weak competitive inhibitors of CYP3A4 (K(i)=86-220 microM). Dihydrotanshinone was a competitive inhibitor of human CYP1A2 (K(i)=0.53 microM) and CYP2C9 (K(i)=1.92 microM), a noncompetitive inhibitor of CYP3A4 (K(i)=2.11 microM) but an uncompetitive CYP2E1 inhibitor. In conclusion, these results showed that tanshinones inhibited the metabolism of various CYP probe substrates in human liver microsomes and specific human CYP isoforms in vitro. Given that CYP1A2, 2C9, 2E1 and 3A4 are responsible for the metabolism and disposition of a large number of drugs currently used, the potential herb-drug interactions of Danshen preparations containing the major tanshinones with drugs which are substrates of these CYPs may be important.

Cytotoxic effects of tanshinones from Salvia miltiorrhiza on doxorubicin-resistant human liver cancer cells

P-Glycoprotein (Pgp) overexpression and alterations in p53 oncogene expression are known to affect chemotherapeutic efficacy in the treatment of human hepatocellular carcinoma (HCC). The present study has demonstrated the anti-HCC potential of cryptotanshinone (1), dihydrotanshinone (2), tanshinone I (3), and tanshinone IIA (4), the active lipophilic constituents of Salvia miltiorrhiza, using MTT and caspase-3 activity assays and poly(ADP-ribose) polymerase cleavage in HepG2, Hep3B, and PLC/PRF/5 cells. THLE-3, a normal human immortalized liver cell line, was used to demonstrate the selective growth inhibitory effect of 3 for a HCC cell line. Compound 1 suppressed doxorubicin efflux, a process mediated by P-glycoprotein, in a Pgp-overexpressed HepG2 subclone (R-HepG2 cells). Despite its moderate cytostatic and pro-apoptotic effects and minimal influence on doxorubicin efflux, 4 provided the best synergism with doxorubicin as determined by the Combination Index, the Loewe additivity model, and the Bliss independence criterion.

Pharmacokinetic interaction studies of tanshinones with tolbutamide, a model CYP2C11 probe substrate, using liver microsomes, primary hepatocytes and in vivo in the rat

The effects of Danshen and its active components (tanshinone I, tanshinone IIA, dihydrotanshinone and cryptotanshinone) on tolbutamide 4-hydroxylation was investigated in the rat. Danshen (0.125-2mg/ml) decreased 4-hydroxy-tolbutamide formation in vitro and in vivo. Enzyme kinetics studies showed that inhibition of tolbutamide 4-hydroxylase activity was competitive and concentration-dependent. The K(i) values of the tanshinones were: dihydrotanshinone (8.92microM), cryptotanshinone (24.5microM), tanshinone I (80.3microM) and tanshinone IIA (242.9microM). In freshly prepared primary rat hepatocytes, tanshinones inhibited tolbutamide 4-hydroxylation in a concentration-dependent manner, with EC(40) values in the order: cryptotanshinone (15.8microM), tanshinone IIA (16.2microM), dihydrotanshinone (20.1microM) and tanshinone I (48.2microM). In whole animal studies, single dose Danshen treatment (50 or 200mg/kg, i.p.) increased tolbutamide clearance (17-26.9%), decreased AUC (14.4-20.9%) and increased the Vd (7.26%). Three-day Danshen treatment (200mg/kg/day, i.p.) decreased the C(initial), increased T(1/2) and Vd but did not affect tolbutamide clearance and AUC. Tolbutamide-4-hydroxylation in vivo was decreased by Danshen after acute and after 3-day treatment, with decreases in the AUC of 4-hydroxy-tolbutamide (15-28%) over the time period studied. Despite competitive inhibition of rat CYP2C11 in vitro and in vivo, as shown by the decrease in tolbutamide 4-hydroxylation, only minor changes in tolbutamide pharmacokinetics was observed. This study illustrated that the herb-drug interaction potential should be monitored by both in vitro and in vivo biotransformation/ pharmacokinetic parameters.

Effects of major tanshinones isolated from Danshen (Salvia miltiorrhiza) on rat CYP1A2 expression and metabolism of model CYP1A2 probe substrates

This study explored the effects of Danshen on metabolism/pharmacokinetics of model CYP1A2 substrates and hepatic CYP1A2 expression in rats. The effects of Danshen and tanshinones on CYP1A2 activity was determined by metabolism of model substrates in vitro (phenacetin) and in vivo (caffeine). HPLC was used to determine model substrates/metabolites. The effect of Danshen on CYP1A2 expression was determined by Western blot. Tanshinones (1.25-50 microM) competitively inhibited phenacetin O-deethylation in vitro. Inhibition kinetics studies showed the K(i) values were in the order: dihydrotanshinone (3.64 microM), cryptotanshinone (4.07 microM), tanshinone I (22.6 microM) and tanshinone IIA (23.8 microM), furafylline (35.8 microM), a CYP1A2 inhibitor. The Ki of Danshen extract (mainly tanshinones) was 72 microg/ml. Acute Danshen extract treatment (50-200mg/kg, i.p.) decreased metabolism of caffeine to paraxanthine, with overall decrease in caffeine clearance (14-22%); increase in AUC (11-25%) and plasma T(1/2) (12-16%). Danshen treatment with (100mg/kg/day, i.p. or 200mg/kg/day, p.o.) for three or fourteen days showed similar pharmacokinetic changes of the CYP1A2 probe substrate without affecting CYP1A2 expression. This study demonstrated that major tanshinones competitively inhibited the metabolism of model CYP1A2 probe substrates but had no effect on rat CYP1A2 expression.

Reactive oxygen species-mediated kinase activation by dihydrotanshinone in tanshinones-induced apoptosis in HepG2 cells

The role of reactive oxygen species (ROS) and p38 mitogen-activated protein kinases (MAPK) in tanshinones-induced apoptosis was investigated in HepG2 cells in this study. The major tanshinones (cryptotanshinone, dihydrotanshinone, tanshinone I, tanshinone IIA), isolated from Salvia miltiorrhiza, inhibit cell growth and induce caspase-dependent apoptosis concentration-dependently, with dihydrotanshinone being the most potent. All four tanshinones were found to induce ROS generation, but only dihydrotanshinone can induce activation of p38 MAPK. The p38 MAPK activation by dihydrotanshinone was inhibited by N-acetyl cysteine pretreatment. It is thus concluded that ROS-mediated p38 MAPK activation plays a vital role in dihydrotanshinone-induced apoptosis in HepG2 cells.

Cytotoxicity of major tanshinones isolated from Danshen (Salvia miltiorrhiza) on HepG2 cells in relation to glutathione perturbation

Tanshinones are abietane type-diterpene quinones isolated from the roots of Radix Salvia miltiorrhiza (Danshen), a well-known traditional Chinese medicine in the treatment of cardiovascular diseases. Among the major diterpenes isolated, including cryptotanshinone, tanshinone I, tanshinone IIA and dihydrotanshinone, tanshinone IIA had been shown to posses various pharmacological activities including antioxidant, protection/prevention from angina pectoris and myocardial infarction, and anticancer properties. Tanshinone IIA, usually the most abundant tanshinone present in the herb, has been the focus of studies in its clinical potential, among which its ability to inhibit the proliferation of cancer cell lines. The aim of this study was to study the cytotoxicity of the tanshinones on human HepG2 cells in vitro in relation to intracellular glutathione perturbation (reduced glutathione, GSH and oxidized glutathione, GSSG). Studies using MTT assay showed that all tanshinones decreased cell viability of HepG2 cells in a concentration-dependent manner, with the cell viability decreased to 60% and 35% after 24 h and 48 h treatment, respectively. Assessment of apoptotic cells with fragmented DNA by flow cytometry indicated that only tanshinone IIA (12.5 and 25 microM) induced apoptosis in the cancer cells. Tanshinone IIA and cryptotanshinone caused significant decreases in G(1) cells by 23% and 13%, respectively, after 24 h treatment. The declines in G(1) cells were compensated by increases in G(2)/M (15% for tanshinone IIA) and S cells (8% and 13% for tanshinone IIA and cryptotanshinone, respectively). All the tanshinones studied, except tanshinone IIA, elevated GSH/GSSG ratio at low concentrations (1.56 and 3.13 microM), but the ratio decreased, indicating oxidative stress at high concentrations (6.25-25 microM). Taken together, tanshinone IIA caused HepG2 cytotoxicity through apoptosis without influencing oxidative stress, while the other tanshinones showed lower efficacy in inducing apoptosis in the HepG2 cells.