Wnt1 inhibits vascular smooth muscle cell calcification by promoting ANKH expression.

AIMS: Wnt signaling plays a critical role in vascular calcification (VC). Wnt factors induce different physiological and pathological effects on cardiovascular functions. Wnt1, a ligand of Wnt/ß-catenin signaling, promotes pro-angiogenesis and reduces myocardial infarction. The role of Wnt1 on VC in chronic kidney disease (CKD) is not fully understood. METHODS AND RESULTS: We used human vascular smooth muscle cells (VSMCs) and a rat model of chronic renal failure (CRF), and observed a native protective mechanism by which VC is reduced via the activation of Wnt1 and its transcriptional target ANKH inorganic pyrophosphate transport regulator (ANKH) gene. ANKH is an essential calcification inhibitor that effluxes inorganic pyrophosphate (PPi) from VSMCs to play an inhibitory role in VC. Vascular ANKH and plasma PPi were significantly downregulated in the rat model of CRF. The knockdown or inhibition of ANKH reversed the effect of Wnt1 on VC in VSMCs. Clinical analysis revealed low plasma levels of Wnt1 and PPi were associated with CKD in patients. Applying a Wnt/ß-catenin signaling agonist can alleviate the progression of VC. CONCLUSION: This work reveals the ANKH regulation of Wnt1 in VSMCs is essential for blocking VC. Our findings may contribute to the development of medications that target Wnt signaling and/or ANKH to inhibit VC.

Utilizing muscle-derived stem cells to enhance long-term retention and aesthetic outcome of autologous fat grafting: pilot study in mice.

Autologous fat grafting has been regarded as the ideal soft tissue filler for more than a century. Low long-term retention rate and unpredictability limit it from widespread clinical practice. Many theories for this have been proposed: lack of sufficient blood supply and subsequent necrosis is the most accepted. In this pilot study, we showed both macroscopically and microscopically the viability of muscle-derived stem cells (MDSCs) cotransplanted with fat placed intramuscularly for 3 months. MRI scanning showed a stronger fat signal in the MDSC-treated group than that of the control group. Moreover, histological evaluation exhibited well-preserved and intact fat cells in the MDSC-treated group. In contrast, the control group showed extensive fibrosis and fat graft loss. Furthermore, the MDSC-treated group possessed almost threefold greater capillary density than the control group. We conclude that cotransplantation of muscle-derived stem cells and autologous fat tissue improves the long-term survival of intramuscular fat transplants by promoting neovascularization.

Profiling of the dynamically alteredgene expression in peripheral nerve injury using NGS RNA sequencing technique.

Functional recovery of peripheral nerve injuries is of major demand in clinical practice worldwide. Although, to some extent, peripheral nervous system can spontaneously regenerate, post-injury recovery is often associated with poor functional outcome. The molecular mechanism controlling the peripheral nerve repair process is still majorly unclear. In this study, by utilizing the Next Generation Sequencing (NGS) RNA sequencing technique, we aim to profile the gene expression spectrum of the peripheral nerve repair. In total, we detected 2847 were differentially expressed at day 7 post crush nerve injury. The GO, Panther, IPA and GSEA analysis was performed to decipher the biological processes involving the differentially expressed genes. Collectively, our results highlighted the inflammatory response and related signaling pathway (NFkB and TNFa signaling) play key role in peripheral nerve repair regulation. Furthermore, Network analysis illustrated that the IL10, IL18, IFN-γ and PDCD1 were four key regulators with multiple participations in peripheral nerve repair and potentially exert influence to the repair process. The expression changes of IL10, IL18, IFN-γ, PDCD1 and TNFSF14 (LIGHT) were further validated by western blot analysis. Hopefully, the present study may provide useful platform to further reveal the molecular mechanism of peripheral nerve repair and discover promising treatment target to enhance peripheral nerve regeneration.

GSK3ß inhibition accelerates axon debris clearance and new axon remyelination.

Glycogen synthase kinase 3ß (GSK3ß) inhibitors, especially the mood stabilizer lithium chloride, are also used as neuroprotective or anti-inflammatory agents. We studied the influence of LiCl on inducing early myelin clearance and on regulating the remyelination following peripheral nerves injury. We showed that the oral administration of adult mice with LiCl after sciatic nerve crush injury accelerated in vivo myelin debris clearance stimulated the expression of myelin proteins, restored the myelin structure, and accelerated the recovery of sciatic functions. LiCl treatment also promoted remyelination of the sciatic nerve after crush. Furthermore, we also demonstrated that LiCl exerts its action in Schwann cells by increasing the amount of ß-catenin and provoking its nuclear localization in vivo. We showed by ChIP experiments that LiCl treatment drives ß-catenin to bind to T-cell factor/lymphoid-enhancer factor response elements identified in myelin-related genes. Taken together, our results provide the first evidence that the GSK3ß could be considered as an important drug in inducing early myelin debris clearance and regulating the expression of myelin genes, which open new approaches in the clinical treatment of nerve injuries by utilizing GSK3ß inhibitors such as lithium.

Local administration of IKK small molecule inhibitor may enhance fracture healing in osteoporosis patient.

Osteoporosis is an inflammatory bone disease affecting millions of population worldwide, which often cause increased fracture risks and prolonged fracture healing. Growing evidence suggests that IKK-NF-κB signaling exert inhibitory influence on MSCs osteogenic differentiation and bone formation. Moreover, enhance the fracture healing process in osteoporosis patient. In the current work, IKK-NF- κB differentiated osteoblasts. Thus, manipulating local inflammatory IKK-NF-κB signaling was also found to suppress the anabolic effect of signaling in osteoporotic related fracture emerge as a promising therapy to we hypothesized to use locally delivered IKK small molecule inhibitor to augment the impaired fracture healing ability in osteoporosis patient via enhancing both MSCs osteogenic differentiation and osteoblast function.

A novel specialized staging system for cancellous fracture healing, distinct from traditional healing pattern of diaphysis corticalfracture?

Metaphysis cancellous bone fracture is one of the most common fracture types in clinical orthopedic practice. The specialized healing process of cancellous bone fracture has long been ignored by the academic society. Comparing with diaphyseal cortical bone healing, cancellous bone healing showed less bone tissue necrosis, barely any hematoma formation, limited inflammation events and no external callus formation. Based on our clinical practice and preliminary study, we hypothesize that the healing process of metaphysis cancellous fracture is a distinct process which could be concluded into five overlapping stages with distinguished histological features of each other. Different from the traditional theory defining diaphyseal cortical fracture, our novel staging theory is specialized in cancellous bone tissue fully considering its unique histological features. This novel staging system may help clinical orthopedists gain specialized understanding concerning cancellous healing process and aid in their clinical evaluation and treatment to metaphysis cancellous bone fracture.

Local transplantation of osteogenic pre-differentiated autologous adipose-derived mesenchymal stem cells may accelerate non-union fracture healing with limited pro-metastatic potency.

Fracture non-union is a serious complication in orthopedic clinical practice. Mesenchymal stem cells are believed to play a vital role in fracture healing process. Among various origins of mesenchymal stem cell, adipose derived stem cells hold great promise especially in clinical milieu. However, the wide spread application of mesenchymal stem cell based therapy is impeded by the pro-metastasis nature of the mesenchymal stem cell itself. Based on the findings from previous studies, we hypothesize that local transplanted osteogenic pre-differentiatiated adipose stem cell may promote the non-union fracture healing. Moreover, the pre-differnetiation stem cells by down-regulating the expression of CCL5 and CCL2. This novel osteogenic pre-differnetiation technique may help clinical orthopedists to resolve the refractory non-union cases and shed new light on other stem cell based therapies to counteract to avoid the pro-metastasis nature of the mesenchymal stem cells.

Healing of cancellous fracture in a novel mouse model.

Fractures are one of the most prevalent clinical conditions worldwide. Among them, cancellous fracture is a major cause of extremities fractures. Unfortunately, it is largely unknown about how is the healing of cancellous fracture. In the current study, we present a novel cancellous fracture mice model, which successfully mimic clinical cancellous fracture scenario. Next, we showed that the newly repaired trabeculae in fracture healing zone were thicker than normal bone tissue with more sufficient local blood supply. There are more osteoclasts reside in the fracture healing zone than normal bone tissue and these osteoclasts distributed more closely and densely. Moreover, the early repairing bone mass in fracture healing zone was not fully collagen loaded as normal bone tissue. Comparing to similar cell proliferation activity, upregulated local cell function play more important role in the cancellous fracture repair.

Muscle derived stem cell contains the potential to enhance long term retention as well as an aesthetic outcome of autologous fat grafting.

Autologous fat graft has been mentioned as a prospective source of soft-tissue filler for decades. It gives a natural consistency, is easy and safe to harvest, exhibits no hypersensitivity or foreign body reactions, and is readily available. However, the traditional fat grafting has its limitations in long term process, such as partial necrosis, loss of volume, and internal calcification. They all compromise the functional and aesthetic outcome of this procedure. In recent studies, the best results were obtained by transplanting fat tissue inside muscle, thus benefiting from its better blood supply. Muscle-derived stem cells have recently emerged as a promising source of multipotent cells which give rise to muscle fibers within muscular environment. Previous studies have also proved that muscle-derived stem cells are capable of releasing various kinds of angiogenesis agents, such as VEGF, HGF, and FGF. These cytokines are known to promote revascularization. Based on the foregoing facts, we postulate that co-transplant of autologous fat and muscle derived stem cells may enhance the long term retention and aesthetic outcome of fat grafting.