Attempt to treat congenital pseudarthrosis of the tibia with mesenchymal stromal cell transplantation

Differential expression and effect analysis of lncRNA-mRNA in congenital pseudarthrosis of the tibia

Background: To analyze the lncRNA-mRNA differential expression and co-expression network of periosteal stem cells (PSCs) from congenital pseudarthrosis of the tibia (CPT) and normal patients, and to explore the role of key lncRNAs. Methods: Differentially expressed lncRNAs and mRNAs in PSCs were obtained by sequencing, and biological functions of differentially expressed mRNAs were detected by gene ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG) pathway and protein -protein interaction (PPI) analysis. The co-expression network of lncRNA-mRNA was constructed by correlation analysis of differentially expressed lncRNAs and mRNAs, and the key lncRNAs were screened according to the connectivity degree. After that, the cis-regulated target genes of differential expressed lncRNAs and mRNAs were predicted. Results: A total of 194 differentially expressed lncRNAs were identified, including 73 upregulated and 121 downregulated genes. A total of 822 differentially expressed mRNAs were identified, including 311 upregulated and 511 downregulated genes. GO, KEGG and PPI enrichment analysis showed that the regulatory function of differentially expressed mRNAs were mainly gathered in skeletal system development and tissue morphogenesis. The co-expression network with 226 nodes and 3,390 edges was constructed based on correlation analysis. A total of 10 key lncRNAs, including FAM227B, POM121L9P, AF165147 and AC103702, were screened according to connectivity degree. Prediction of target genes indicated that FAM227B-FGF7 and AC103702-HOXB4/5/6 may play an important role in the pathogenesis of CPT. Conclusion: A total of 10 key lncRNAs, including FAM227B, POM121L9P, AF165147, and AC103702, occupy the core position in the co-expression network, suggesting that these lncRNAs and their target genes may play an important role in the pathogenesis of CPT.

Evaluation of bone marrow-derived mesenchymal stem cell quality from patients with congenital pseudoarthrosis of the tibia

Background

The treatment of congenital pseudoarthrosis of the tibia (CPT) remains challenging in pediatric orthopedics due to the difficulties in bone union, continuous angulation, joint stiffness, and severe limb length discrepancy. Mesenchymal stem cells (MSCs) therapy offers a complementary approach to improve the conventional surgical treatments. Although the autologous MSC treatment shows a promising strategy to promote bone healing in CPT patients, the quality of MSCs from CPT patients has not been well studied. The purpose of this study is to investigate the quality of MSCs isolated from patients with CPT.

Methods

The bone marrow-derived MSCs from the fracture site and iliac crest of six CPT patients were isolated and compared. The cumulative population doubling level (cPDL), phenotype characteristics, and trilineage differentiation potency were observed to assess the quality of both MSCs.

Results

There were no significant differences of the MSCs derived from the fracture site and the MSCs from the iliac crest of the subjects, in terms of cPDL, phenotype characteristics, and trilineage differentiation potency (all p > 0.05). However, MSCs from the fracture site had a higher senescence tendency than those from the iliac crest.

Conclusion

MSC quality is not the main reason for delayed bone regeneration in those with CPT. Thus, autologous MSC is a promising source for treating CPT patients

Osteogenic differentiation of mesenchymal stromal cells in two-dimensional and three-dimensional cultures without animal serum

INTRODUCTION

Bone marrow-derived mesenchymal stromal cells (MSCs) have been intensely studied for the purpose of developing solutions for clinical tissue engineering. Autologous MSCs can potentially be used to replace tissue defects, but the procedure also carries risks such as immunization and xenogeneic infection. Replacement of the commonly used fetal calf serum (FCS) with human platelet lysate and plasma (PLP) to support cell growth may reduce some of these risks. Altered media could, however, influence stem cell differentiation and we address this experimentally.

METHODS

We examined human MSC differentiation into the osteoblast lineage using in vitro two- and three-dimensional cultures with PLP or FCS as cell culture medium supplements. Differentiation was followed by quantitative polymerase chain reaction, and alkaline phosphatase activity, matrix formation and matrix calcium content were quantified.

RESULTS

Three-dimensional culture, where human MSCs were grown on collagen sponges, markedly stimulated osteoblast differentiation; a fourfold increase in calcium deposition could be observed in both PLP and FCS groups. PLP-grown cells showed robust osteogenic differentiation both in two- and three-dimensional MSC cultures. The calcium content of the matrix in the two-dimensional PLP group at day 14 was 2.2-fold higher in comparison to the FCS group (p < 0.0001), and at day 21 it was still 1.3-fold higher (p < 0.001), suggesting earlier calcium accumulation to the matrix in the PLP group. This was supported by stronger Alizarin Red staining in the PLP group at day 14. In two-dimesional PLP cultures, cellular proliferation appeared to decrease during later stages of differentiation, while in the FCS group the number of cells increased throughout the experiment. In three-dimensional experiments, the PLP and FCS groups behaved more congruently, except for the alkaline phosphatase activity and mRNA levels which were markedly increased by PLP.

CONCLUSIONS

Human PLP was at least equal to FCS in supporting osteogenic differentiation of human MSCs in two- and three-dimensional conditions; however, proliferation was inferior. As PLP is free of animal components, and thus represents reduced risk for xenogeneic infection, its use for human MSC-induced bone repair in the clinic by the three-dimensional live implants presented here appears a promising therapy option.

Orthopaedic aspects of neurofibromatosis: update

PURPOSE OF REVIEW

Neurofibromatosis type I (NF-1), affecting 1: 3000 people, is one of the most common disorders of the nervous system, and most pediatricians will care for a patient with this condition. It is imperative that careful attention be paid to screening for scoliosis and tibial dysplasia. Prompt referral to an orthopaedist at the time of diagnosis, as well as neurologist, ophthalmologist, and dermatologist, will provide a global spectrum of care for the individual. Patient care between surgical procedures will be inevitable, with 70% of patients with NF-1 undergoing hospitalization or surgery.

RECENT FINDINGS

This review provides a description of diagnosis, presurgical evaluation, and advances in understanding tibial dysplasia, scoliosis and malignant peripheral nerve sheath tumors. New pharmaceutical treatments such as lovastatin have improved bone healing in vivo and induced apoptosis in vitro. Multiple pharmaceuticals have shown neurofibroma arrest in vitro and are in phase II clinical trials.

SUMMARY

As animal models improve and clinical trials proceed, there is momentum toward eliminating the musculoskeletal morbidity associated with NF-1.