Effect of treadmill exercise combined with bone marrow stromal cell transplantation on atrophy-related signaling pathway in the denervated soleus muscle

The purpose of this study was to investigate whether combination of low-intensity exercise with bone marrow stromal cell (BMSC) transplantation could regulate protein kinas B (Akt)- mammalian target of rapamycin (mTOR) and Wnt3a-β-catenin signaling pathways for prevention of soleus muscle atrophy after sciatic nerve injury (SNI). The experimental rats divided into 5 groups (n= 10): normal control group, SNI+sedentary group (SED), SNI+low-intensity treadmill exercise group (TEX), SNI+BMSC transplantation group (BMSC), SNI+TEX+BMSC transplantation group (TEX+BMSC). Sciatic nerve crush injury was applied into the middle of thigh twice for 1 min and 30 sec at interval. Low-intensity treadmill exercise was comprised of walking at a speed of 4 to 8 m/min for 30 min once a day. cultured BMSC at a density of 5× 106 in 50-μL phosphate-buffered saline was injected into the distal portion of the injured sciatic nerves. TEX+BMSC group dramatically upregulated expression levels of growth-associated protein-43 in the injured sciatic nerve at 2 weeks postinjury. Also, although Akt and mTOR signaling pathway significantly increased in TEX and BMSC groups than SED group, TEX+BMSC group showed more potent increment on this signaling in soleus muscle after SNI. Lastly, Wnt3a and the nuclear translocation of β-catenin and nuclear factor-kappa B in soleus were increased by SNI, but TEX+BMSC group significantly downregulated activity of this signaling pathway in the nuclear cell lysate of soleus muscle. Present findings provide new information that combination of low-intensity treadmill exercise might be effective therapeutic approach on restriction of soleus muscle atrophy after peripheral nerve injury.

Effect of treadmill exercise and bone marrow stromal cell engraftment on activation of BDNF-ERK-CREB signaling pathway in the crushed sciatic nerve

The effect of combined approach of exercise training and bone marrow stromal cell (BMSC) engraftment on activation of brain-derived neurotrophic factor (BDNF)-extracellular signal-regulated kinase 1 and 2 (ERK1/2)-cyclic adenosine monophosphate response element-binding protein (CREB) signaling pathway after sciatic nerve injury (SNI) was investigated. Sixty male Sprague-Dawley rats divided into the normal control, nonexercise (NEX), exercise training (EX), BMSC transplantation (TP), and exercise training+BMSC transplantation (EX+TP) groups 4 weeks after SCI. Exercise training was carried out on the treadmill device at 5–10 m/min for 20 min for 4 weeks. Single dose of 5× 106 harvested BMSC was injected into the injury area of the injured sciatic nerve. In order to evaluate induction levels of BDNF-ERK1/2-CREB signaling molecules in the whole cell and nuclear cell lysates of the injured sciatic nerve, we applied Western blot analysis. BDNF was significantly increased only in EX+TP compared to NEX, EX, and TP groups. Phosphoinositide-dependent kinase-1 was more increased in EX, TP, and EX+TP groups than NEX group, but EX+TP group showed the most upregulation of phosphorylated protein kinase B compared to other groups. In addition, in the whole cell lysate, phosphorylated ERK1/2, but not activating transcription factor-3 (ATF-3) and phosphorylated CREB, was significantly increased in TP and EX+TP groups. In the nuclear cell lysate, ATF-3 and phosphorylated CREB were strongly activated in EX+TP group compared to EX group. Regular exercise training combined with BMSC engraftment would seem to be more effective in controlling activation of regeneration-related signaling pathway after SNI.

Tofacitinib Blocks Entheseal Lymphocyte Activation and Modulates MSC Adipogenesis, but Does Not Directly Affect Chondro- and Osteogenesis

Entheseal spinal inflammation and new bone formation with progressive ankylosis may occur in ankylosing spondylitis (AS) and psoriatic arthritis (PsA). This study evaluated whether JAK inhibition with tofacitinib modulated the key disease associated cytokines, TNF and IL-17A, and whether tofacitinib also modulated bone marrow stromal cell-derived mesenchymal stem cell (MSCs) function, including osteogenesis, since post inflammation new bone formation occurs under these conditions. Methods: Conventional entheseal derived αβ CD4+ and CD8+ T-cells were investigated following anti-CD3/CD28 bead stimulation to determine IL-17A and TNF levels in tofacitinib treated (1000 nM) peri-entheseal bone (PEB) and peripheral blood mononuclear cells (PBMC) using ELISA. Bone marrow stromal cell-derived mesenchymal stem cell (MSC) colony forming units (CFU-F) and multi-lineage potential were evaluated using tofacitinib (dosages ranging between 100, 500, 1000 and 10,000 nM). Results: Induced IL-17A and TNF cytokine production from both entheseal CD4+ T-cells and CD8+ T-cells was effectively inhibited by tofacitinib. Tofacitinib treatment did not impact on CFU-F potential or in vitro chondro- and osteogenesis. However, tofacitinib stimulation increased MSC adipogenic potential with greater Oil Red O stained areas. Conclusion: Inducible IL-17A and TNF production by healthy human entheseal CD4+ and CD8+ T-cells was robustly inhibited in vitro by tofacitinib. However, tofacitinib did not impact MSC osteogenesis, but stimulated in vitro MSC adipogenesis, the relevance of which needs further evaluation given that the adipocytes are associated with new bone formation in SpA.

BST1 regulates nicotinamide riboside metabolism via its glycohydrolase and base-exchange activities

Nicotinamide riboside (NR) is one of the orally bioavailable NAD+ precursors and has been demonstrated to exhibit beneficial effects against aging and aging-associated diseases. However, the metabolic pathway of NR in vivo is not yet fully understood. Here, we demonstrate that orally administered NR increases NAD+ level via two different pathways. In the early phase, NR was directly absorbed and contributed to NAD+ generation through the NR salvage pathway, while in the late phase, NR was hydrolyzed to nicotinamide (NAM) by bone marrow stromal cell antigen 1 (BST1), and was further metabolized by the gut microbiota to nicotinic acid, contributing to generate NAD+ through the Preiss–Handler pathway. Furthermore, we report BST1 has a base-exchange activity against both NR and nicotinic acid riboside (NAR) to generate NAR and NR, respectively, connecting amidated and deamidated pathways. Thus, we conclude that BST1 plays a dual role as glycohydrolase and base-exchange enzyme during oral NR supplementation.

MicroRNA-204 Attenuates Oxidative Damage in Cardiac Stem Cell Through Regulation of Bone Marrow Stromal Cell (BMSC) Adipogenic and Osteogenic Differentiation

Exosomes (exo) derived from bone marrow mesenchymal stem cells (BMSCs) are known to promote cell growth through delivering multiple kinds of bioactive molecule including microRNAs (miR-NAs). This study aimed to explore the mechanism underlying miR-204 secreted by exo interacting oxidative damage of cardiac stem cell (CSCs). Exosomes were extracted from BMSCs (BMSC-exo) and characterized by immunofluorescence and electron microscope, while BMSC-exo were internalized by CSCs. ARS and ALP staining confirmed the mineralization of BMSCs and osteogenic and adipogenic differentiation of BMSCs. Then BMSCs were cultured in ordinary culture medium (OM) and normal medium. RT-qPCR identified miR-204 level in BMSCs disposed by OM was about five times as that of controls. miR-204 was up-regulated in the osteogenic differentiation of CSCs. Functional experiment revealed up-regulation of miR-204 inhibited the BMSC adipogenic differentiation with decreased ROS and MDA expression and elevated SOD level in the CSCs. Treatment with BMSC-exos or miR-204 up-regulation alleviated oxidative damage of CSCs. Collectively, miR-204 attenuates the oxidative damage of CSCs through regulating BMSC adipogenic and osteogenic differentiation.

Tofacitinib Blocks Entheseal Lymphocyte Activation and Modulates MSC Adipogenesis but Does not Directly Affect Chondro- and Osteogenesis

Entheseal spinal inflammation and new bone formation with progressive ankylosis may occur in ankylosing spondylitis (AS) and psoriatic arthritis (PsA). This study evaluated whether JAK inhibition with tofacitinib modulated the key disease associated cytokines, TNF and IL-17A and whether tofacitinib also modulated bone marrow stromal cell-derived mesenchymal stem cells (MSCs) function including osteogenesis, since post inflammation new bone formation occurs in these conditions. Methods: Conventional entheseal derived αβ CD4+ and CD8+ T-cells were in-vestigated following anti-CD3/CD28 bead stimulation to determine IL-17A and TNF levels in Tofacitinib treated (1000nM) peri-entheseal bone (PEB) and peripheral blood mononuclear cells (PBMC) following ELISA. Bone marrow stromal cell-derived mesenchymal stem cells (MSCs) colony forming unit (CFU-F) and multilineage potential was evaluated using tofacitinib (dosag-es ranging between 100, 500, 1000 and 10000nM). Results: Induced IL-17A and TNF cytokine production from both entheseal CD4+ T-cells and CD8+ T-cells were effectively inhibited by to-facitinib. Tofacitinib treatment did not impact on CFU-F potential or in vitro chondro- and oste-ogenesis. However, tofacitinib stimulation increased MSC adipogenic potential with greater Oil Red O stained area. Conclusion: Inducible IL-17A and TNF production by healthy human enthe-seal CD4+ and CD8+ T-cells was robustly inhibited in vitro by tofacitinib. However, tofacitinib did not impact on MSC osteogenesis but stimulated in vitro MSC adipogenesis, the rele-vance of which needs further evaluation given the adipocytes are associated with new bone formation in SpA.

Tofacitinib Blocks Entheseal Lymphocyte Activation and modulates MSC adipogenesis but does not directly affect chondro- and osteogenesis

Entheseal spinal inflammation and new bone formation with progressive ankylosis may occur in ankylosing spondylitis (AS) and psoriatic arthritis (PsA). This study evaluated whether JAK inhibition with tofacitinib modulated the key disease associated cytokines, TNF and IL-17A and whether tofacitinib also modulated bone marrow stromal cell-derived mesenchymal stem cells (MSCs) function including osteogenesis, since post inflammation new bone formation occurs in these conditions. Methods: Conventional entheseal derived αβ CD4+ and CD8+ T-cells were in-vestigated following anti-CD3/CD28 bead stimulation to determine IL-17A and TNF levels in Tofacitinib treated (1000nM) peri-entheseal bone (PEB) and peripheral blood mononuclear cells (PBMC) following ELISA. Bone marrow stromal cell-derived mesenchymal stem cells (MSCs) colony forming unit (CFU-F) and multilineage potential was evaluated using tofacitinib (dosag-es ranging between 100, 500, 1000 and 10000nM). Results: Induced IL-17A and TNF cytokine production from both entheseal CD4+ T-cells and CD8+ T-cells were effectively inhibited by to-facitinib. Tofacitinib treatment did not impact on CFU-F potential or in vitro chondro- and oste-ogenesis. However, tofacitinib stimulation increased MSC adipogenic potential with greater Oil Red O stained area. Conclusion: Inducible IL-17A and TNF production by healthy human enthe-seal CD4+ and CD8+ T-cells was robustly inhibited in vitro by tofacitinib. However, tofacitinib did not impact on MSC osteogenesis but stimulated in vitro MSC adipogenesis, the rele-vance of which needs further evaluation given the adipocytes are associated with new bone formation in SpA.

Publisher Correction: Bone marrow stromal cell therapy improves survival after radiation injury but does not restore endogenous hematopoiesis

An amendment to this paper has been published and can be accessed via a link at the top of the paper.