Yunzhen Chen

Shandong University, Chi-nan-shih, Shandong Sheng, China

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Publications (7)16.04 Total impact

  • Guangzong Zhao · Yao Liu · Jun Fang · Yunzhen Chen · Huazhuang Li · Kehai Gao
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    ABSTRACT: Osteocyte hypoxia has been induced by skeletal unloading and fracture. Hypoxia-dependent regulation of gene expression is mediated by hypoxia-sensitive transcription factors such as hypoxia-inducible factor-1α (HIF-1α). Dimethyl fumarate (DMF) is a recently approved first-line therapy for multiple sclerosis. However, the role of DMF in regulating HIF-1α expression and function has not been evaluated. In this study, we found that DMF inhibited hypoxia-induced expression of HIF-1α and its target genes such as interleukin 8 (IL-8) and vascular endothelial growth factor (VEGF) in MC3T3 E1 cells. Mechanistically, DMF promoted HIF-1α degradation in a proteasome-dependent but von Hippel–Lindau (VHL) protein-independent manner. Importantly, we found that DMF disrupted the interaction between HIF-1α and its chaperone heat shock protein 90 (Hsp90) but promoted the interaction between HIF-1α and the receptor of activated protein kinase C (RACK1). These data suggest that DMF might promote degradation of HIF-1α by affecting its folding and maturation. Based on these observations, we conclude that DMF is a novel inhibitor of HIF-1α.
    No preview · Article · Jun 2014 · Biochemical and Biophysical Research Communications
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    Yunzhen Chen · Haichun Liu · Wenliang Wu · Yi Li · Jianmin Li
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    ABSTRACT: Purpose: Osteopontin (OPN) plays important roles in the modulation of apoptosis, angiogenesis, immune response, and tumor invasion. Elevated osteopontin expression has been reported in the lung cancer tissues compared to counterpart normal tissues. This study examined whether genetic variations in the osteopontin gene are associated with survival of lung cancer patients and occurrence rate of bone metastasis.Experimental design: Three hundred and sixty patients with stages I to IV between 2003 and 2007 were recruited in this study and same number of healthy persons were used as control. Three promoter osteopontin polymorphisms, OPN-66 T/G, -156G/GG, and -443C/T variants were genotyped using DNA from blood lymphocytes. Chi-square test and a Fisher's exact test were used to analyze the genotype distribution among TNM stages and incidence of bone metastasis and lymph mode metastasis. Kaplan-Meier method and log-rank test were used to compare survival by different genotypes. For the variant at nt -443 (CC), there was a significant difference between the number of patients with stage IV and those with all other stages of lung cancer (p < 0.01). Patients with -443 (CC) variant had significant higher incidence of bone metastasis development compared to other genotypes. For the variant at nt -443 (CT), there was a significant difference between the number of lung cancer patients with stage III + IV and those with stage I + II (P < 0.01). The survival rates for patients with the C/C genotype were significantly lower than for patients with the other two genotypes (C/T, T/T). OSTEOPONTIN -443C/T polymorphism is a potential predictive marker of survival in lung cancer patients, it is correlated with bone metastasis significantly.
    Preview · Article · Jul 2013 · Journal of Experimental & Clinical Cancer Research
  • Haichun Liu · Wenliang Wu · Yi Li · Jinwei Liu · Kaiyun Yang · Yunzhen Chen
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    ABSTRACT: Object: During the past decades, lumbar fusion has increasingly become a standard treatment for degenerative spinal disorders. However, it has also been associated with an increased incidence of adjacent-segment degeneration (ASD). Previous studies have reported less ASD in anterior fusion surgeries; thus, the authors hypothesized that the integrity of the posterior complex plays an important role in ASD. This study was designed to investigate the effect of the posterior complex on adjacent instability after lumbar instrumentation and the development of ASD. Methods: To evaluate different surgical interventions, 120 patients were randomly allocated into 3 groups of 40 patients each who were statistically similar with respect to demographic and clinical data. Patients in Group A were allocated for facet joint resection and L4-5 fusion, Group B for semilaminectomy and fusion, and Group C for complete laminectomy and fusion. All of the patients were followed up for 5-7 years (mean 5.9 years). The disc height, intervertebral disc angle, dynamic intervertebral angular range of motion (ROM), L3-4 slip, and the total lordosis angle were each measured before the operation and at the final follow-up. The Japanese Orthopaedic Association (JOA) score was determined before surgery and at the final follow-up to evaluate the clinical results. Results: Among the 3 groups, no significant differences were detected in all clinical and demographic assessments before surgery. At 3 months after surgery, the JOA score of all groups improved significantly and showed no significant differences among the groups. At the final follow-up, Group C had a significantly (p < 0.05) lower JOA score than the other 2 groups. Moreover, the disc height and total lumbar lordosis in patients of Group C were significantly decreased compared with disc height and total lumbar lordosis in the other 2 groups. In contrast, disc angle, dynamic angular ROM, and listhesis were significantly higher in Group C than in the other 2 groups. Twenty-four patients showed signs of ASD after the operation (3 patients in Group A, 4 in B, and 17 in C). The number of patients in Group C showing ASD was significantly different from that in Groups A and B. Conclusions: During follow-up for 6 years, a significantly higher number of patients with ASD were noted in the complete-laminectomy group. The number of reoperations for treating ASD was much higher in this patient group than in the patients undergoing facet joint resection and L4-5 fusion or semilaminectomy and fusion. Therefore, preserving the posterior complex as much as possible during surgery plays an important role in preventing ASD and in reducing the reoperation rate.
    No preview · Article · Jun 2013 · Journal of neurosurgery. Spine
  • Haichun Liu · Yi Li · Yunzhen Chen · Wenliang Wu · Debo Zou
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    ABSTRACT: Objective Factors impacting surgical options and outcomes in patients with cervical ossification of the posterior longitudinal ligament (OPLL) were explored. Methods A retrospective analysis was conducted of 127 eligible cervical OPLL patients (61 males, 66 females) aged 41–70 years (mean 55.2 years) selected from 152 total OPLL patients treated from 2002 to 2006, with 5–10-year (mean 6.8 years) follow-up. Patients underwent anterior subtotal corpectomy with ossification ligament resection (anterior surgery, n = 68) or posterior cervical double-door laminoplasty (posterior surgery, n = 59). Radiographic assessments of cervical curvature, T2-weighted MRI (MRIT2) signal, and OPLL occupying ratio were correlated with surgical strategy before surgery and at 1, 5 weeks, and 5 years. Results Lordosis increased following anterior surgery, though kyphosis improved by 10.3 %. The canal stenosis occupying ratio was >50 %, and short-term improvement following anterior surgery was significantly higher than posterior surgery (P > 0.0001). Superior neurological function was observed in patients with unchanged versus high spinal MRIT2 signals (P = 0.0434). No significant differences were observed in short-term outcomes between anterior and posterior surgeries in high spinal MRIT2 signal patients, but anterior surgery produced significantly better long-term outcomes at 1 week (P = 0.7564) and 1 year (P = 0.0071). Complications occurred in five anterior and three posterior surgeries. Conclusion Preoperative assessment of cervical curvature, MRIT2 signal, and occupying ratio can be used to guide clinical surgical approach selection to potentially produce better long-term outcomes in patients with OPLL.
    No preview · Article · Feb 2013 · European Spine Journal
  • Haichun Liu · Kaiyun Yang · Tao Xin · Wenliang Wu · Yunzhen Chen
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    ABSTRACT: Abstract Spinal cord injury (SCI) is one of the most serious disorders in clinics, and the high disability rate and functional deficits are common issues in patients. Transplantation of bone-marrow-derived mesenchymal stromal cells (BMSCs) into the injured spinal cord is emerging as a novel method in the therapeutics of SCI; however, its application is limited by the poor survival rate of the transplanted cells and low differentiation rate into neurons. Our laboratory recently reported that electrical stimulation (ES) dramatically improves the survival rate of transplanted BMSCs and increases spinal cord functions in animals with spinal cord injury. In this paper, we asked whether implanted electro-acupuncture (iEA) can advance the beneficial effects from the ES treatment in animals with spinal cord injury. We showed that BMSCs transplantation alone resulted in significant functional recovery in animals. Interestingly, iEA with BMSCs treatment induced a significantly higher functional improvement in locomotor functions and SSEP compared to the BMSCs treatment alone. Additionally, we used molecular biology techniques and showed that BMSCs transplantation with iEA treatment significantly increased the number of surviving BMSCs compared to the BMSCs alone group. In conclusion, our experiment showed that the approach of coupling iEA electric stimulation and BMSCs transplantation remarkably promotes functional improvements in animals with spinal cord injury and holds promising potential to treat spinal cord injury in humans.
    No preview · Article · Mar 2012 · Artificial Cells Blood Substitutes and Biotechnology (formerly known as Artificial Cells Blood Substitutes and Immobilization Bi
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    ABSTRACT: Genetic factors are thought to be crucial in the pathogenesis of ankylosing spondylitis (AS). Recent studies have reported that ERAP1, TGBβ1 and TLRs genes are likely to have association with AS in different populations. We carried out this study to determine whether single-nucleotide polymorphisms covering the three genes are associated with AS in a Chinese Han population. Genomic DNA was isolated from the peripheral blood of 328 patients with AS and 627 healthy blood donors from Jinan region as a case-control study. The diagnosis of AS was made according to the modified New York criteria. The ERAP1 rs27044, TGBβ1 rs1800470 and TLR9 rs55704465 were genotyped by a polymerase chain reaction--restriction fragment length polymorphism method. Strong association with AS was observed for marker rs27044, but no significant differences were observed between AS patients and controls in the frequencies of the carriership of the alleles rs55704465 and rs1800470. Our data thus indicate that ERAP1 likely constitutes one of AS-associated loci of susceptibility after HLA in Chinese Han population. On the contrary, TGFB1 and TLR9 variations show no association with the susceptibility of AS.
    No preview · Article · Jul 2011 · Rheumatology International
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    ABSTRACT: Transplantation of bone marrow-derived mesenchymal stromal cells (BMSCs) into the injured spinal cord may provide therapeutic benefit, but its application is limited by their poor survival and low differentiation rate into neurons. Electrical stimulation (ES) has been reported to promote survival and differentiation of the BMSCs. Therefore we investigated whether implanted spike wave ES could improve survival of BMSCs after transplantation and result in functional improvement in animals with spinal cord injury. Our results showed that the number and ratio of survived BMSCs near the lesion site were significantly increased in the BMSCs+ES-treated group as compared to BMSCs transplantation or ES treatment alone group. Furthermore, results from BBB scales, SSEP and DTI demonstrated a significant improved functional recovery in the BMSCs+ES group. This indicated that implanted spike wave ES could promote the bioactivity of BMSCs and their survival. This represents a new therapeutic potential of the combination of BMSCs transplantation with implanted spike wave ES to treat spinal cord injury.
    No preview · Article · Mar 2011 · Neuroscience Letters