[Show abstract][Hide abstract] ABSTRACT: Transcriptional networks orchestrate complex developmental processes, and such networks are commonly instigated by master regulators for development. By now, considerable progress has been made in elucidating GATA factor-dependent genetic networks that control red blood cell development. Here we reported that GATA-1 and GATA-2 co-regulated the expression of two microRNA genes, microRNA-27a and microRNA-24, with critical roles in regulating erythroid differentiation. In general, GATA-2 occupied the miR-27a∼24 promoter and repressed their transcription in immature erythroid progenitor cells. As erythropoiesis proceeded, GATA-1 directly activated miR-27a∼24 transcription, and this involved a GATA-1-mediated displacement of GATA-2 from chromatin, a process termed 'GATA switch'. Furthermore, the mature miR-27a and miR-24 cooperatively inhibited GATA-2 translation and favoured the occupancy switch from GATA-2 to GATA-1, thus completing a positive feedback loop to promote erythroid maturation. In line with the essential role of GATA factors, ectopic expression of miR-27a or miR-24 promoted erythropoiesis in human primary CD34+ haematopoietic progenitor cells and mice, whereas attenuated miR-27 or miR-24 level led to impaired erythroid phenotypes in haematopoietic progenitor cells and zebrafish. Taken together, these data integrated micro RNA expression and function into GATA factor coordinated networks and provided mechanistic insight into a regulatory circuit that comprised GATA1/2 switch and miR-27a/24 in erythropoiesis.
Nucleic Acids Research 09/2013; 42(1). DOI:10.1093/nar/gkt848 · 9.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Degenerative scoliosis (DS) is an important degenerative lumbar disease causing spinal dysfunction. The true reason or pathogenesis of DS is still unknown. Bone marrow-derived mesenchymal stem cells (BM-MSCs) are the stem/progenitor cells of the osteoblasts. The diseases associated with osteogenesis could be caused by abnormality of the MSCs. The purpose of this study was to find the differential proteins expressed in MSCs of patients with DS.
We collected and cultured the MSCs from 12 DS patients and 12 age- and gender-matched patients with lumbar spinal stenosis. Then the MSC samples were analyzed with 2D-DIGE and MALDI-TOF-MS to find the differential proteins which were further validated by Western blot.
We found 115 spots that were differently expressed in the MSC of DS patients with 2D-DIGE, and 44 proteins were identified from samples of DS and control using MALDI-TOF-MS. Of these proteins, PIAS2, NDUFA2, and TRIM 68, which were up-regulated in DS more than 4 times were validated by Western blot.
The information obtained with this proteomics analysis will be useful in understanding the pathophysiology of DS. Further investigations on the functioning pathway, the specificity and the mechanism of these proteins will be carried out.
[Show abstract][Hide abstract] ABSTRACT: The developmental stage-specific expression of the human β-like globin genes has been studied for decades, and many transcriptional
factors as well as other important cis elements have been identified. However, little is known about the microRNAs that potentially regulate β-like globin gene
expression directly or indirectly during erythropoiesis. In this study, we show that microRNA 23a (miR-23a) and miR-27a promote
β-like globin gene expression in K562 cells and primary erythroid cells through targeting of the transcription factors KLF3
and SP1. Intriguingly, miR-23a and miR-27a further enhance the transcription of β-like globin genes through repression of
KLF3 and SP1 binding to the β-like globin gene locus during erythroid differentiation. Moreover, KLF3 can bind to the promoter
of the miR-23a∼27a∼24-2 cluster and suppress this microRNA cluster expression. Hence, a positive feedback loop comprised of
KLF3 and miR-23a promotes the expression of β-like globin genes and the miR-23a∼27a∼24-2 cluster during erythropoiesis.
[Show abstract][Hide abstract] ABSTRACT: miRNAs play important roles in many biological processes, including erythropoiesis. Although several miRNAs regulate erythroid differentiation, how the key erythroid regulator, GATA-1, directly orchestrates differentiation through miRNA pathways remains unclear. In this study, we identified miR-23a as a key regulator of erythropoiesis, which was upregulated both during erythroid differentiation and in GATA-1 gain-of-function experiments, as determined by miRNA expression profile analysis. In primary human CD34+ hematopoietic progenitor cells, miR-23a increased in a GATA-1-dependent manner during erythroid differentiation. Gain- or loss-of-function analysis of miR-23a in mice or zebrafish demonstrated that it was essential for normal morphology in terminally differentiated erythroid cells. Furthermore, a protein tyrosine phosphatase, SHP2, was identified as a downstream target of miR-23a that mediated its regulation of erythropoiesis. Taken together, our data identify a key GATA-1-miRNA axis in erythroid differentiation.
Nucleic Acids Research 02/2013; 41(7). DOI:10.1093/nar/gkt093 · 9.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Degenerative scoliosis (DS) is an important degenerative lumbar disease causing spinal dysfunction and affecting the quality of life of the elderly, and is associated not only with severe back or leg pain but also with complicated surgical outcomes. The pathogenesis of DS is still unknown. Therefore, it is very important to ascertain the etiology of degenerative scoliosis and establish related molecular markers predicting and controlling the scoliosis. For the first time, we used two-dimensional fluorescence DIGE to compare the serum proteome profiles of 12 DS patients and controls. Proteins found to be differentially expressed were identified by MALDI-TOF mass spectrometric analysis, coupled with database interrogation. Eleven spots that were differentially expressed in the sera of DS patients were found, and eight gene products were identified among these spots. Clusterin, CLU cDNA FLJ57622, ALB cDNA FLJ50830, Hypothetical short protein, HLA-A MHC class 1 antigen. (Fragment), ALB 23 kDa protein, Isoform 1 of G protein-regulated inducer of neurite outgrowth 1 (GPRIN I)and Ficolin-3 were down-regulated in the sera of DS patients. The decreased levels of Clusterin and Ficolin-3 were confirmed by Western blot. The information obtained with this proteomic analysis will be very useful in understanding the pathophysiology of DS as well as in finding candidates as drug targets of DS. These results may provide a novel approach for the pathogenesis study of DS.
Journal of Orthopaedic Research 12/2011; 29(12):1896-903. DOI:10.1002/jor.21466 · 2.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Leptin affects a number of cell signaling pathways, at present, the mechanism(s) by which leptin affects the cartilage cells in OA patient is not well understood. The current study seeks to elucidate whether leptin induces cytoskeletal remodeling in chondrocytes and the possible involvement of the RhoA/ROCK pathway and its downstream mediators in this process. Fluorescent resonance energy transfer (FRET) and western analysis were used to determine the activations of the key proteins in the RhoA/LIMK1/Cofilin pathway. Accompanying cytoskeletal remodeling was elucidated. Upon leptin stimulation, a substantial increase of RhoA activity localized at one end of the cell was observed from 2 to 30 min post-stimulation. The results of Western blot showed leptin significantly increased LIMK1 and cofilin-2 phosphorylation in a time-dependent manner with maximal stimulation attained 60 min and 24 h post-stimulation, respectively. Chondrocytes stimulated with leptin exhibited an epithelioid morphology with increased cellular spreading. F-actin in leptin-stimulated chondrocytes also showed more intense cytoplasmic staining with occasional localization along filamentous structures. The results indicate that leptin activates the RhoA/ROCK/LIMK/cofilin pathway, which results in cytoskeletal reorganization in chondrocytes. These findings provide novel evidence supporting the possible involvement of leptin and the RhoA pathway in the pathogenesis of OA.
Journal of Orthopaedic Research 03/2011; 29(3):369-74. DOI:10.1002/jor.21257 · 2.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Kaposiform hemangioendothelioma (KHE) is a rare locally aggressive vascular tumor that usually presents as a superficial or deep soft tissue mass with associated cutaneous lesions. We report a unique spinal KHE with painless thoracic scoliosis in a 14-year-old girl. She underwent simultaneous tumor biopsy, spinal deformity correction and fusion. At 3 years follow-up, the patient's MRI showed no significant deterioration of process without any therapy. KHE presenting as scoliosis is rare and to our knowledge this is the first recognized case in the reported world literature.
[Show abstract][Hide abstract] ABSTRACT: To analyze the clinical outcomes and losses of correction for posterolateral fusion on low-grade lumbar spondylolisthesis.
From October 2001 to July 2008, 37 patients with a mean age of 60.1 years (range, 27 - 88 years) with low-grade lumbar spondylolisthesis treated with posterolateral fusion, including 9 males and 28 females, were reviewed retrospectively. The clinical outcomes were evaluated using the visual analogue scale (VAS) and Oswestry disability index (ODI). The fusion status and loss of correction were assessed using plain radiographs and CT.
All the 37 patients had got complete follow-up for 14 - 96 months (average 36.4 months); post-operative reduction rate was 76.4%, and 34 patients (91.9%) showed loss of correction with a mean loss rate 5.8% (range, -3.0% - 25.8%). The percentage of slip of pre-operative, post-operative and final follow-up indicated significant difference (P < 0.05)compared with each other; post-operative intervertebral disc height indicated significant difference in comparison with that of pre-operatively and at final follow-up (P < 0.05); lumbar lordosis angle at final follow-up showed significant difference when compared with that of pre-operatively and postoperatively (P < 0.05); VAS and ODI at final follow-up indicated significant difference in contrast to that of pre-operative (P < 0.05). Upon final follow-up, the complications were found in 2 cases who presented degenerative scoliosis at 15 and 17 months after the surgery, in 1 case with cranial adjacent segment retrolisthesis at the 14 months after the surgery, in 1 case with cut-out and breakage of screws at the 24 months after the surgery, and in 1 case with postoperative infection which were cured after debridement.
For mid-term follow-up of low-grade lumbar spondylolisthesis, posterolateral fusion shows loss of correction in most cases, but presents good clinical outcome and fusion rate.
Zhonghua wai ke za zhi [Chinese journal of surgery] 02/2011; 49(2):119-24.
[Show abstract][Hide abstract] ABSTRACT: To investigate the effect of microRNA-205 reduction by antagomirs on adhesion ability of normal human corneal epithelial keratinocytes (NHCEKs).
Antagomir-205, complementary and inhibitory to microRNA-205, was used to suppress endogenous microRNA-205 in NHCEKs. The adhesion ability of treated NHCEKs was then assessed by cell adhesion assay. Immunoblot and immunohistochemistry were conducted to determine the level of two focal adhesion-related proteins, focal adhesion kinase (FAK) and paxillin (Pax). Phalloidin staining was performed to measure the level of filamentous actin in antagomir-treated NHCEKs.
Antagomir-205 markedly reduced the level of microRNA-205 in NHCEKs and significantly enhanced adhesion ability of NHCEKs (P<0.01). Further protein analysis validated that inhibition of microRNA-205 increased the number of phosphorylated FAK and phosphorylated Pax, and decreased filamentous actin.
Our findings suggest that microRNA-205 has down-regulating effect on cell motility in NHCEKs.
Chinese Medical Sciences Journal 06/2010; 25(2):65-70. DOI:10.1016/S1001-9294(10)60024-7
[Show abstract][Hide abstract] ABSTRACT: To explore the feasibility and clinical results of circumferential decompression and three-column reconstruction through single-stage posterior transpedicular approach for spinal tumor treatment.
Totally, 24 patients with spinal tumor underwent tumor resection and spinal reconstruction through single-stage posterior transpedicular approach. Preoperatively, according to the Frankel classification, 12 patients were grade E, 9 grade D, and 3 grade C. Anterior column was reconstructed with non-expandable titanium cages. Posterior segmental instrumentation was used to maintain the stability of spine in all cases. Anterior and posterolateral fusion was performed with autograft and allogenic bone. The following data were followed up in these patients: deformity angle, local recurrence, neurological function, and spinal bony fusion.
The average operating time and blood loss was 5.6 hours and 3,400 ml respectively. No intraoperative and postoperative complications were observed in this group. Postoperatively, 21 patients were Frankel grade E, 2 grade D, and 1 grade C. Four patients reported significant functional restoration and twenty patients reported complete resolution of pain. At follow-up (range, 6-42 months), implant failure or recurrent neurological symptoms was not found.
The tumor resection and spinal reconstruction through single-stage posterior transpedicular approach is a safe and effective technique for the treatment of spinal tumor. It can fully decompress the neurological structures, correct the kyphosis, and achieve early weight-bearing. This technique can improve life quality for the patients with spinal tumor.
Chinese Medical Sciences Journal 09/2009; 24(3):172-7. DOI:10.1016/S1001-9294(09)60084-5
[Show abstract][Hide abstract] ABSTRACT: To investigate the feasibility and clinical significance of single-stage posterior vertebrectomy with reconstruction for the treatment of spinal tumor.
Twenty-six consecutive patients with spinal tumor, 5 with giant cell tumor, 6 with metastatic tumor of breast cancer, 8 with metastatic tumor of lung cancer, 2 with plasmacytoma, 3 with metastatic tumor of renal carcinoma, and 2 with lymphoma, 12 males and 14 females, aged 49 (20-74), underwent single-stage posterior vertebrectomy through bilateral transpedicular route via posterior midline approach. Anterior column reconstruction was performed with non-expandable cages. Anterior and posterolateral arthrodeses were achieved using autograft. Posterior segmental instrumentation was used in all cases. Follow-up was conducted for 10-48 months.
The mean operative time was 4.5 hours and the mean blood loss was 1600 ml. Sagittal deformity correction was performed for the four patients with preoperative kyphosis. 15 patients were neurologically intact preoperatively (at Frankel grade E) and remained intact postoperatively. 11 patients with functional disorders of spinal cord or nerves (Frankel grade D) preoperatively showed improvement to Frankel grade E postoperatively. Local pain disappeared in 19 patients and reduced in 7 patients.
A safe and effective technique for the treatment of spinal tumor, single-stage posterior vertebrectomy with reconstruction fully decompresses the neurological structures, corrects kyphosis, and achieves early weight-bearing, thus significantly improving the quality of life of the patients with spinal tumor.
[Show abstract][Hide abstract] ABSTRACT: To assess the value of computer navigation technique in spinal pedicle screw insertion.
95 patients undergoing spinal pedicle screw internal fixation were randomly divided in 2 groups:navigation group (n=36) undergoing pedicle screw insertion with computer-assisted navigation technique, and conventional group (n=50) undergoing pedicle screw insertion using conventional anatomic landmark combined. The 2 groups were compared in respect to screw canal preparation time, accuracy of screw position, and incidence of postoperative complication.
206 screws were inserted in the navigation group, 169 being with excellent outcome (82.0%), 29 with good outcome (14.1%), and 8 with bad outcome (3.9%). Nine patients in the navigation group failed to adopt the computer-assisted navigation technique because of different reasons. 285 screws were inserted in the conventional group, 257 being were excellent outcome (90.2%), 28 with good outcome (9.8%), and none with bad outcome. The general fitness rate of the navigation group was 96.1%, not significantly different from that of the conventional group (100%, P>0.05). The screw canal preparation time of the navigation group was (360+/-22) sec, significantly longer than that of the conventional group [(56+/-8) sec, P<0.001)]. No postoperative complication was found in both groups.
The accuracy of pedicle screw insertion using preoperative CT-based navigation technique is not different from that using conventional anatomic landmark, but the operation time is significantly prolonged. Preoperative CT-based navigation technique has limited value in spinal pedicle screw insertion.