Project description:It is commonly observed that patients with bone fracture concomitated with traumatic brain injury (TBI) had significantly increased fracture healing while the underlying mechanisms were not fully revealed. Long non-coding RNAs (lncRNAs) were known for paly complicated roles in bone homeostasis while its role in TBI accelerated fracture were rarely reported. The present study was designed to determine the role of lncRNAs in TBI accelerated fracture via transcriptome sequencing and further bioinformatical analysis. Blood samples from 3 fracture only patients, 3 fracture concomitated with TIB patients and 3 healthy controls were harvested and were subsequently subjected to transcriptome lncRNAs sequencing. Differentially expression genes were identified, and pathway enrichment were performed by Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyze. High high-dimensional data portraying by self-organizing map (SOM) machine learning was applied to further interpret the data. A xCell method were then used to predict cellular behavior in all samples based on gene expression profiles and a lncRNA-cell interaction network were generated. A total of 874 differentially expressed genes were identified, of which about 26% were lncRNAs. Those identified lncRNAs were mainly enriched on traumatic brain injury related- and damage repair related-pathways. SOM analyzes revealed that those differentially expressed lncRNAs could be divided into three major module implications and were mainly enriched on transcriptional regulation and immune related signal pathways, which promote us to further explore cellular behaviors based on differentially expressed lncRNAs. We have predicted that basophils, CD8+ T effector memory cells, B cells, and naïve B cells were significantly down-regulated while microvascular endothelia cells were predicated significantly up-regulated with TBI/Fr group was the lowest or highest, respectively. ENSG00000278905, ENSG00000240980, ENSG00000255670, and ENSG00000196634 were the most differentially expression lcnRNA that related to all changes of cellular behavior. The present study has revealed for the first time that several critical lncRNAs may participate in TBI accelerated fracture potentially via regulating cellular behaviors of basophils, cytotoxic T cells, B cells and endothelia cells.
Project description:Traumatic brain injury (TBI) accelerates fracture healing, but the underlying mechanism remains largely unknown. Accumulating evidence indicates that the central nervous system plays a pivotal role in regulating immune system and skeleton, however, the impact of TBI on hematopoiesis commitment was overlooked. Here, we found that the dramatically elevated sympathetic tone accompanied with TBI-accelerated fracture healing; chemical sympathectomy blocks TBI-induced fracture healing. Importantly, the adrenergic hypersensitivity swiftly skews bone marrow hematopoietic lineage cells toward anti-inflammation myeloid cells within 14 days, which favor fracture healing. Knockout of β3- or β2-adrenergic receptors (ARs) eliminate TBI mediated anti-inflammation macrophage expansion and TBI-accelerated fracture healing. Moreover, β3- and β2-ARs agonists synergistically promote M2 macrophages infiltration in callus and accelerate bone healing process. Our results suggest that TBI shapes the anti-inflammation environment during early stage of fracture healing, implicating the sympathetic nerve system as a potential target that can be exploited to treat fracture.
Project description:Genome-wide comparative gene expression analysis of callus tissue of osteoporotic mice (Col1a1-Krm2 and Lrp5-/-) and wild-type were performed to identify candidate genes that might be responsible for the impaired fracture healing observed in Col1a1-Krm2 and Lrp5-/- mice. To investigate bone healing in osteoporosis, we performed fracture healing studies in wild-type mice (C57BL/6 genetic background) and the low bone mass strains Col1a1-Krm2 and Lrp5-/- (Schulze et al., 2010; Kato et al., 2002). Osteotomy was set in femora of female mice and stabilized by a semi-rigid fixator to allow fast bone healing (RM-CM-6ntgen et al., 2010). 21 days post surgery we analyzed the fracture calli by biochemical/histological methods, as well as micro-computed tomography, and observed impaired fracture healing in Col1a1-Krm2 and Lrp5-/- mice in comparison to wild-type. To identify genes that may be responsible for the impaired healing in osteoporotic mice, we performed microarray analysis of three independent callus samples of each genotype. The callus tissue was taken 10 days after surgery, because extensive bone formation took place at this point.
Project description:The association between DM and impaired fracture healing including delayed union and nonunion has been documented in clinical and experimental settings. We examine miRNA expression specific for impaired fracture healing in diabetic rat.
Project description:The association between DM and impaired fracture healing including delayed union and nonunion has been documented in clinical and experimental settings. We examine mRNA expression specific for impaired fracture healing in diabetic rat.
Project description:Skeletal tissue is known to respond to mechanical stress. Ultrasound stimulation is one of mechanical stress and low intensity pulsed ultrasound (LIPUS) devices have been clinically utilized to promote the fracture healing. However, it is still not clear which skeletal cells, especially osteocytes or osteoblasts, mainly respond to LIPUS stimulation and how they contribute to fracture healing. To examine that, we utilized medaka known to have bones without embedded osteocytes and zebrafish known to have bones with embedded osteocytes as an in vivo model. Interestingly, fracture healing was accelerated by ultrasound stimulation in zebrafish but not in medaka. To examine the molecular events induced by LIPUS stimulation in osteocyte, we performed RNA-sequencing with the murine long bone osteocyte Y4 (MLO-Y4) cell line exposed to LIPUS. 179 genes reacted to LIPUS stimulation and functional cluster analysis defined that several molecular signatures related in immunity, secretion and transcription. Especially, most of isolated transcription related genes were modulated by LIPUS also in vivo experiments using zebrafish. Target genes analysis showed that inflammatory response and bone formation in fracture healing could be transcriptionally regulated in osteocytes by LIPUS stimulation. Among these transcription genes, early growth response (Egr) 1,2, JunB, Forkhead box Q1 (FoxQ1) and nuclear factor of activated T cells (NFAT) c1 were not altered by LIPUS in medaka unlike zebrafish suggesting that these genes would be key transcriptional regulator of LIPUS-dependent fracture healing through osteocytes. In this study, we revealed bone-equipped osteocytes is necessary for LIPUS-induced promotion of fracture healing through the transcriptional control of target genes presumably to activate neighboring cells involved in fracture healing event.
Project description:Phosphate is essential for healthy bone growth and plays an essential role in fracture repair. Although phosphate deficiency has been shown to impair fracture healing, the mechanisms involved in impaired healing are unknown. More recently, studies have shown that the effect of phosphate deficiency on the repair process varied based on the genetic strain of mice, which is not characterized. We used data from microarrays to (1) determine the effects of phosphate restriction on the biologic functions identified from the gene expression in fracture calluses; and (2) examine whether there are genetic differences within the primary biologic functions.
Project description:Sprague-Dawley rats were placed on an ethanol-containing or pair-fed Lieber and DeCarli diets for 4 wks prior to surgical fracture. Following insertion of a medullary pin, a closed mid-diaphyseal fracture was induced using a Bonnarens and Einhorn fracture device. At 3 days post-fracture, the region of the fracture calluses were harvested from the right hind-limb. RNA was extracted and microarray analysis was conducted against the entire rat genome to study the effects of alcohol-consumption on the fracture healing. The experiments were on four rat subjects, i.e., pair-fed rats with subsequent surgical fracture or no surgical fracture, and alcohol-fed rats with subsequent surgical fracture or no surgical fracture. Each rat subject described above has three replicates so 6 kinds of pairing can be made and each pairing has a dye-swap replicate (thus, a total 12 array experiments). The focus of this study is on the pair-fed fracture subject vs. alcohol-fed fracture subject.
Project description:Time-point expression analysis of fractures calluses at 1, 3, and 5 days post-fracture in young and old BALB/c mice. Femur fractures were generated on female c57BI6 mice in triplicate: 8 month old retired breeders (old mice) and 6 week old mice (young mice) were used. 1, 3, and 5 days post-fracture, fracture calluses were dissected and total RNA isolated. Expression profiling was performed using Affymetrix's Mouse Genome 430 2.0 array.