MicroRNA-29a Mitigates Laminectomy-Induced Spinal Epidural Fibrosis and Gait Dysregulation by Repressing TGF-ß1 and IL-6.

Spinal epidural fibrosis is one of the typical features attributable to failed back surgery syndrome, with excessive scar development in the dura and nerve roots. The microRNA-29 family (miR-29s) has been found to act as a fibrogenesis-inhibitory factor that reduces fibrotic matrix overproduction in various tissues. However, the mechanistic basis of miRNA-29a underlying the overabundant fibrotic matrix synthesis in spinal epidural scars post-laminectomy remained elusive. This study revealed that miR-29a attenuated lumbar laminectomy-induced fibrogenic activity, and epidural fibrotic matrix formation was significantly lessened in the transgenic mice (miR-29aTg) as compared with wild-type mice (WT). Moreover, miR-29aTg limits laminectomy-induced damage and has also been demonstrated to detect walking patterns, footprint distribution, and moving activity. Immunohistochemistry staining of epidural tissue showed that miR-29aTg was a remarkably weak signal of IL-6, TGF-ß1, and DNA methyltransferase marker, Dnmt3b, compared to the wild-type mice. Taken together, these results have further strengthened the evidence that miR-29a epigenetic regulation reduces fibrotic matrix formation and spinal epidural fibrotic activity in surgery scars to preserve the integrity of the spinal cord core. This study elucidates and highlights the molecular mechanisms that reduce the incidence of spinal epidural fibrosis, eliminating the risk of gait abnormalities and pain associated with laminectomy.

Umbilical cord-derived MSC and hyperbaric oxygen therapy effectively protected the brain in rat after acute intracerebral haemorrhage.

This study tested the hypothesis that combined therapy with human umbilical cord-derived mesenchymal stem cells (HUCDMSCs) and hyperbaric oxygen (HBO) was superior to either one on preserving neurological function and reducing brain haemorrhagic volume (BHV) in rat after acute intracerebral haemorrhage (ICH) induced by intracranial injection of collagenase. Adult male SD rats (n = 30) were equally divided into group 1 (sham-operated control), group 2 (ICH), group 3 (ICH +HUCDMSCs/1.2 × 106 cells/intravenous injection at 3h and days 1 and 2 after ICH), group 4 (ICH +HBO/at 3 hours and days 1 and 2 after ICH) and group 5 (ICH +HUCDMSCs-HBO), and killed by day 28 after ICH. By day 1, the neurological function was significantly impaired in groups 2-5 than in group 1 (P < .001), but it did not differ among groups 2 to 5. By days 7, 14 and 28, the integrity of neurological function was highest in group 1, lowest in group 2 and significantly progressively improved from groups 3 to 5 (all P < .001). By day 28, the BHV was lowest in group 1, highest in group 2 and significantly lower in group 5 than in groups 3/4 (all P < .0001). The protein expressions of inflammation (HMGB1/TLR-2/TLR-4/MyD88/TRAF6/p-NF-κB/IFN-γ/IL-1ß/TNF-α), oxidative stress/autophagy (NOX-1/NOX-2/oxidized protein/ratio of LC3B-II/LC3B-I) and apoptosis (cleaved-capspase3/PARP), and cellular expressions of inflammation (CD14+, F4/80+) in brain tissues exhibited an identical pattern, whereas cellular levels of angiogenesis (CD31+/vWF+/small-vessel number) and number of neurons (NeuN+) exhibited an opposite pattern of BHV among the groups (all P < .0001). These results indicate that combined HUCDMSC-HBO therapy offered better outcomes after rat ICH.

MicroRNA-29a in Osteoblasts Represses High-Fat Diet-Mediated Osteoporosis and Body Adiposis through Targeting Leptin.

Skeletal tissue involves systemic adipose tissue metabolism and energy expenditure. MicroRNA signaling controls high-fat diet (HFD)-induced bone and fat homeostasis dysregulation remains uncertain. This study revealed that transgenic overexpression of miR-29a under control of osteocalcin promoter in osteoblasts (miR-29aTg) attenuated HFD-mediated body overweight, hyperglycemia, and hypercholesterolemia. HFD-fed miR-29aTg mice showed less bone mass loss, fatty marrow, and visceral fat mass together with increased subscapular brown fat mass than HFD-fed wild-type mice. HFD-induced O2 underconsumption, respiratory quotient repression, and heat underproduction were attenuated in miR-29aTg mice. In vitro, miR-29a overexpression repressed transcriptomic landscapes of the adipocytokine signaling pathway, fatty acid metabolism, and lipid transport, etc., of bone marrow mesenchymal progenitor cells. Forced miR-29a expression promoted osteogenic differentiation but inhibited adipocyte formation. miR-29a signaling promoted brown/beige adipocyte markers Ucp-1, Pgc-1α, P2rx5, and Pat2 expression and inhibited white adipocyte markers Tcf21 and Hoxc9 expression. The microRNA also reduced peroxisome formation and leptin expression during adipocyte formation and downregulated HFD-induced leptin expression in bone tissue. Taken together, miR-29a controlled leptin signaling and brown/beige adipocyte formation of osteogenic progenitor cells to preserve bone anabolism, which reversed HFD-induced energy underutilization and visceral fat overproduction. This study sheds light on a new molecular mechanism by which bone integrity counteracts HFD-induced whole-body fat overproduction.

Piezoelectric Microvibration Mitigates Estrogen Loss-Induced Osteoporosis and Promotes Piezo1, MicroRNA-29a, and Wnt3a Signaling in Osteoblasts.

Biophysical stimulation alters bone-forming cell activity, bone formation and remodeling. The effect of piezoelectric microvibration stimulation (PMVS) intervention on osteoporosis development remains uncertain. We investigated whether 60 Hz, 120 Hz, and 180 Hz PMVS (0.05 g, 20 min/stimulation, 3 stimulations/week for 4 consecutive weeks) intervention affected bone integrity in ovariectomized (OVX) mice or osteoblastic activity. PMVS (120 Hz)-treated OVX mice developed fewer osteoporosis conditions, including bone mineral density loss and trabecular microstructure deterioration together with decreased serum resorption marker CTX-1 levels, as compared to control OVX animals. The biomechanical strength of skeletal tissue was improved upon 120 Hz PMVS intervention. This intervention compromised OVX-induced sparse trabecular bone morphology, osteoblast loss, osteoclast overburden, and osteoclast-promoting cytokine RANKL immunostaining and reversed osteoclast inhibitor OPG immunoreactivity. Osteoblasts in OVX mice upon PMVS intervention showed strong Wnt3a immunoreaction and weak Wnt inhibitor Dkk1 immunostaining. In vitro, PMVS reversed OVX-induced loss in von Kossa-stained mineralized nodule formation, Runx2, and osteocalcin expression in primary bone-marrow stromal cells. PMVS also promoted mechanoreceptor Piezo1 expression together with increased microRNA-29a and Wnt3a expression, whereas Dkk1 rather than SOST expression was repressed in MC3T3-E1 osteoblasts. Taken together, PMVS intervention promoted Piezo1, miR-29a, and Wnt signaling to upregulate osteogenic activity and repressed osteoclastic bone resorption, delaying estrogen deficiency-induced loss in bone mass and microstructure. This study highlights a new biophysical remedy for osteoporosis.

Bone infarction of the hip after hand allotransplantation: A case report.

Vascularized composite allotransplantation represents as an emerging field in reconstructive surgery. However, some complications can be associated with the procedure. The authors describe a case of bone infarctions of the bilateral hip joints following the first hand allotransplantation in Taiwan. A 45-year-old man who experienced a traumatic amputation of the distal third of his forearm received a hand transplantation from a brain-dead donor. Immunosuppression included antithymocyte globulins, and bolus methylprednisolone (Solu-Medrol) was used for the induction. The maintenance therapy protocol included systemic tacrolimus, mycophenolate mofetil, and prednisone. The patient discontinued the systemic steroid 15 months after surgery. Two episodes of acute rejections were observed at 105 and 810 days after surgery. These signs disappeared after pulse therapy with Solu-Medrol, titration with tacrolimus, and topical immunosuppressive creams (tacrolimus and clobetasol). However, the patient felt pain in both hips after long periods of standing 30 months after the transplantation. A pelvic radiograph and magnetic resonance imaging revealed avascular necrosis (AVN) in both hip joints. Because of the progressive worsening of the pain, the patient underwent a decompression surgery on the left hip involving a fibula bone graft. The patient underwent a right hip hemi-arthroplasty with a bipolar prosthesis 3 months later. The patient remained in good health without major complications. These findings indicate that systemic steroids and tacrolimus might be the major predisposing factors for the induction of AVN after hand allotransplantation.

S100 Calcium Binding Protein A9 Represses Angiogenic Activity and Aggravates Osteonecrosis of the Femoral Head.

Ischemic damage aggravation of femoral head collapse is a prominent pathologic feature of osteonecrosis of the femoral head (ONFH). In this regard, S100 calcium binding protein A9 (S100A9) is known to deteriorate joint integrity, however, little is understood about which role S100A9 may play in ONFH. In this study, a proteomics analysis has revealed a decrease in the serum S100A9 level in patients with ONFH upon hyperbaric oxygen therapy. Serum S100A9 levels, along with serum vascular endothelial growth factor (VEGF), soluble vascular cell adhesion molecule-1 (sVCAM-1), interleukin-6 (IL-6), and tartrate-resistant acid phosphatase 5b levels were increased in patients with ONFH, whereas serum osteocalcin levels were decreased as compared to healthy controls. Serum S100A9 levels were increased with the Ficat and Arlet stages of ONFH and correlated with the patients with a history of being on glucocorticoid medication and alcohol consumption. Osteonecrotic tissue showed hypovasculature histopathology together with weak immunostaining for vessel marker CD31 and von Willrbrand factor (vWF) as compared to femoral head fracture specimens. Thrombosed vessels, fibrotic tissue, osteocytes, and inflammatory cells displayed strong S100A9 immunoreactivity in osteonecrotic lesion. In vitro, ONFH serum and S100A9 inhibited the tube formation of vessel endothelial cells and vessel outgrowth of rat aortic rings, whereas the antibody blockade of S100A9 improved angiogenic activities. Taken together, increased S100A9 levels are relevant to the development of ONFH. S100A9 appears to provoke avascular damage, ultimately accelerating femoral head deterioration through reducing angiogenesis. This study provides insight into the molecular mechanism underlying the development of ONFH. Here, analysis also highlights that serum S100A9 is a sensitive biochemical indicator of ONFH.

MicroRNA-29a Counteracts Glucocorticoid Induction of Bone Loss through Repressing TNFSF13b Modulation of Osteoclastogenesis.

Glucocorticoid excess escalates osteoclastic resorption, accelerating bone mass loss and microarchitecture damage, which ramps up osteoporosis development. MicroRNA-29a (miR-29a) regulates osteoblast and chondrocyte function; however, the action of miR-29a to osteoclastic activity in the glucocorticoid-induced osteoporotic bone remains elusive. In this study, we showed that transgenic mice overexpressing an miR-29a precursor driven by phosphoglycerate kinase exhibited a minor response to glucocorticoid-mediated bone mineral density loss, cortical bone porosity and overproduction of serum resorption markers C-teleopeptide of type I collagen and tartrate-resistant acid phosphatase 5b levels. miR-29a overexpression compromised trabecular bone erosion and excessive osteoclast number histopathology in glucocorticoid-treated skeletal tissue. Ex vivo, the glucocorticoid-provoked osteoblast formation and osteoclastogenic markers (NFATc1, MMP9, V-ATPase, carbonic anhydrase II and cathepsin K) along with F-actin ring development and pit formation of primary bone-marrow macrophages were downregulated in miR-29a transgenic mice. Mechanistically, tumor necrosis factor superfamily member 13b (TNFSF13b) participated in the glucocorticoid-induced osteoclast formation. miR-29a decreased the suppressor of cytokine signaling 2 (SOCS2) enrichment in the TNFSF13b promoter and downregulated the cytokine production. In vitro, forced miR-29a expression and SOCS2 knockdown attenuated the glucocorticoid-induced TNFSF13b expression in osteoblasts. miR-29a wards off glucocorticoid-mediated excessive bone resorption by repressing the TNFSF13b modulation of osteoclastic activity. This study sheds new light onto the immune-regulatory actions of miR-29a protection against glucocorticoid-mediated osteoporosis.

Increased circulating endothelial progenitor cells and improved short-term outcomes in acute non-cardioembolic stroke after hyperbaric oxygen therapy.

BACKGROUND: Acute ischemic stroke is a leading cause of mortality and long-term disability, and profiles of endothelial progenitor cells (EPCs) reflect the degree of endothelial impairment. This study tested the hypothesis that hyperbaric oxygen therapy (HBOT) both improves the clinical short-term outcomes and increases the number of circulating EPCs and antioxidant capacity. METHODS: The numbers of circulating EPCs [CD133+/CD34+ (%), KDR+/CD34+ (%)], biomarkers for oxidative stress (thiols and thiobarbituric acid-reactive substances), and clinical scores (National Institutes of Health Stroke Scale [NIHSS], Barthel index [BI], and modified Rankin Scale [MRS]) were prospectively evaluated in 25 patients with acute non-cardioembolic stroke under HBOT at two time points (pre- and post-HBOT). The biomarkers and clinical scores were compared with those of 25 age- and sex-matched disease controls. RESULTS: The numbers of KDR+/CD34+ (%) in the HBOT group following HBOT increased significantly, whereas the numbers of CD133+/CD34+ (%) also showed a tendency to increase without statistical significance. The mean high-sensitivity C-reactive protein levels showed significant decrease post-HBOT follow-up in the HBOT group. The changes in KDR+/CD34+EPC (%) numbers were positively correlated with changes in clinical outcomes scores (BI, NIHSS, and MRS) in the HBOT group. CONCLUSIONS: Based on the results of our study, HBOT can both improve short-term clinical outcomes and increase the number of circulating EPCs in patients with acute non-cardioembolic stroke.

Adjunctive Hyperbaric Oxygen Therapy for Healing of Chronic Diabetic Foot Ulcers: A Randomized Controlled Trial.

PURPOSE: The purpose of this study was to compare the effect of standard wound care with adjunctive hyperbaric oxygen therapy (HBOT) to standard wound care alone on wound healing, markers of inflammation, glycemic control, amputation rate, survival rate of tissue, and health-related quality of life in patients with diabetic foot ulcers (DFUs). DESIGN: Prospective, randomized, open-label, controlled study. SUBJECTS AND SETTING: The sample comprised 38 patients with nonhealing DFUs who were deemed poor candidates for vascular surgery. Subjects were randomly allocated to an experimental group (standard care plus HBOT, n = 20) or a control group (standard care alone, n = 18). The study setting was a medical center in Kaohsiung City, Taiwan. METHODS: Hyperbaric oxygen therapy was administered in a hyperbaric chamber under 2.5 absolute atmospheric pressure for 120 minutes; subjects were treated 5 days a week for 4 consecutive weeks. Both groups received standard wound care including debridement of necrotic tissue, topical therapy for Wagner grade 2 DFUs, dietary control and pharmacotherapy to maintain optimal blood glucose levels. Wound physiological indices were measured and blood tests (eg, markers of inflammation) were undertaken. Health-related quality of life was measured using the Medical Outcomes Study 36-Item Short Form. RESULTS: Complete DFU closure was achieved in 5 patients (25%) in the HBOT group (n = 20) versus 1 participant (5.5%) in the routine care group (n = 18) (P = .001). The amputation rate was 5% for the HBOT group and 11% for the routine care group (χ = 15.204, P = .010). The HBOT group showed statistically significant improvements in inflammation index, blood flow, and health-related quality of life from pretreatment to 2 weeks after the last therapy ended (P < .05). Hemoglobin A1c was significantly lower in the HBOT group following treatment (P < .05) but not in the routine care group. CONCLUSIONS: Adjunctive HBOT improved wound healing in persons with DFU. Therapy also reduced the risk of amputation of the affected limb. We assert that at least 20 HBOT sessions are required to be effective.

The First Hand Allotransplantation in Taiwan: A Report at 9 Months.

PURPOSE: Hand transplantations have been initiated and have been encouraged by promising results for more than 1 decade. The aim of this study was to present the first case of hand transplantation performed in Taiwan. MATERIALS AND METHODS: On September 3, 2014, we transplanted the left distal forearm and hand of a brain-dead managed 37 years to a man aged 45 years who had traumatic amputation of the distal third of his right forearm 30 years ago. The total ischemic time during the transplantation was 6 hours and 45 minutes. Immunosuppression included anti-thymocyte globulins, and methylprednisolone (Solumedrol) was used for the induction. Maintenance therapy included systemic tacrolimus, mycophenolic acid [mycophenolate mofetil (MMF)], and prednisone. A combination of systemic (tacrolimus/MMF/prednisolone) and topical immunosuppressant cream (clobetasol and tacrolimus) was applied if acute rejection occurred. Follow-up included routine posttransplant laboratory tests, skin biopsies, intensive physiotherapy, and psychological support. RESULTS: The initial postoperative course was uneventful. No surgical complications were observed. Immunosuppression was well tolerated using tacrolimus, MMF, and prednisone, except for some immune-related complications. One episode of mild clinical and histological signs of cutaneous rejection was seen at 105 days after surgery. These signs disappeared after pulse therapy with Solumedrol and the topical application of immunosuppressive creams (tacrolimus and clobetasol). One infection episode occurred due to local cellulitis and axillary lymphadenopathy on day 140 and was successfully treated with antibiotics. The patient developed cytomegalovirus infection at 7 months that responded to medication. Intensive physiotherapy led to satisfactory progress in motor functioning. Sensory progress (Tinel sign) was good and reached the wrist by 3 months for the median and ulnar nerves, and could be felt in the finger tip by 9 months in response to deep pressure and light touch sensations. The patient has a lateral pinch that allows him to pick up and grip objects during daily living, although his muscle power is still insufficient. CONCLUSIONS: Hand allotransplantation is technically feasible. Currently available immunosuppression methods seem to control vascularized composite tissue allotransplantation rejection. A combination of topical and systemic immunosuppressants is a useful method to prevent acute hand allotransplant rejection.

Interplay between brain stem angiotensins and monocyte chemoattractant protein-1 as a novel mechanism for pressor response after ischemic stroke.

Pressor response after stroke commonly leads to early death or susceptibility to stroke recurrence, and detailed mechanisms are still lacking. We assessed the hypothesis that the renin-angiotensin system contributes to pressor response after stroke by differential modulation of the pro-inflammatory chemokine monocyte chemoattractant protein-1 (MCP-1) in the rostral ventrolateral medulla (RVLM), a key brain stem site that maintains blood pressure. We also investigated the beneficial effects of a novel renin inhibitor, aliskiren, against stroke-elicited pressor response. Experiments were performed in male adult Sprague-Dawley rats. Stroke induced by middle cerebral artery occlusion elicited significant pressor response, accompanied by activation of angiotensin II (Ang II)/type I receptor (AT1R) and AT2R signaling, depression of Ang-(1-7)/MasR and Ang IV/AT4R cascade, alongside augmentation of MCP-1/C-C chemokine receptor 2 (CCR2) signaling and neuroinflammation in the RVLM. Stroke-elicited pressor response was significantly blunted by antagonism of AT1R, AT2R or MCP-1/CCR2 signaling, and eliminated by applying Ang-(1-7) or Ang IV into the RVLM. Furthermore, stroke-activated MCP-1/CCR2 signaling was enhanced by AT1R and AT2R activation, and depressed by Ang-(1-7)/MasR and Ang IV/AT4R cascade. Aliskiren inhibited stroke-elicited pressor response via downregulating MCP-1/CCR2 activity and reduced neuroinflammation in the RVLM; these effects were potentiated by Ang-(1-7) or Ang IV. We conclude that whereas Ang II/AT1R or Ang II/AT2R signaling in the brain stem enhances, Ang-(1-7)/MasR or Ang IV/AT4R antagonizes pressor response after stroke by differential modulations of MCP-1 in the RVLM. Furthermore, combined administration of aliskiren and Ang-(1-7) or Ang IV into the brain stem provides more effective amelioration of stroked-induced pressor response.

Tricarboxylic Acid Cycle Regulation of Metabolic Program, Redox System, and Epigenetic Remodeling for Bone Health and Disease.

Imbalanced osteogenic cell-mediated bone gain and osteoclastic remodeling accelerates the development of osteoporosis, which is the leading risk factor of disability in the elderly. Harmonizing the metabolic actions of bone-making cells and bone resorbing cells to the mineralized matrix network is required to maintain bone mass homeostasis. The tricarboxylic acid (TCA) cycle in mitochondria is a crucial process for cellular energy production and redox homeostasis. The canonical actions of TCA cycle enzymes and intermediates are indispensable in oxidative phosphorylation and adenosine triphosphate (ATP) biosynthesis for osteogenic differentiation and osteoclast formation. Knockout mouse models identify these enzymes' roles in bone mass and microarchitecture. In the noncanonical processes, the metabolites as a co-factor or a substrate involve epigenetic modification, including histone acetyltransferases, DNA demethylases, RNA m6A demethylases, and histone demethylases, which affect genomic stability or chromatin accessibility for cell metabolism and bone formation and resorption. The genetic manipulation of these epigenetic regulators or TCA cycle intermediate supplementation compromises age, estrogen deficiency, or inflammation-induced bone mass loss and microstructure deterioration. This review sheds light on the metabolic functions of the TCA cycle in terms of bone integrity and highlights the crosstalk of the TCA cycle and redox and epigenetic pathways in skeletal tissue metabolism and the intermediates as treatment options for delaying osteoporosis.

Effects of Adding Extracorporeal Shockwave Therapy (ESWT) to Platelet-Rich Plasma (PRP) among Patients with Rotator Cuff Partial Tear: A Prospective Randomized Comparative Study.

A rotator cuff tear is a prevalent ailment affecting the shoulder joint. The clinical efficacy of combined therapy remains uncertain for partial rotator cuff tears. In this study, we integrated extracorporeal shockwave therapy (ESWT) with platelet-rich plasma (PRP) injection, juxtaposed with PRP in isolation. Both cohorts exhibited significant improvements in visual analogue scale (VAS), Constant-Murley score (CMS), degrees of forward flexion, abduction, internal rotation, and external rotation, and the sum of range of motion (SROM) over the six-month assessment period. The application of ESWT in conjunction with PRP exhibited notable additional enhancements in both forward flexion (p = 0.033) and abduction (p = 0.015) after one month. Furthermore, a substantial augmentation in the range of shoulder motion (SROM) (p < 0.001) was observed after six months. We employed isobaric tag for relative and absolute quantitation (iTRAQ) to analyze the differential plasma protein expression in serum samples procured from the two groups after one month. The concentrations of S100A8 (p = 0.042) and S100A9 (p = 0.034), known to modulate local inflammation, were both lower in the ESWT + PRP cohort. These findings not only underscore the advantages of combined therapy but also illuminate the associated molecular changes.

Structural and cognitive deficits in chronic carbon monoxide intoxication: a voxel-based morphometry study.

BACKGROUND: Patients with carbon monoxide (CO) intoxication may develop ongoing neurological and psychiatric symptoms that ebb and flow, a condition often called delayed encephalopathy (DE). The association between morphologic changes in the brain and neuropsychological deficits in DE is poorly understood. METHODS: Magnetic resonance imaging and neuropsychological tests were conducted on 11 CO patients with DE, 11 patients without DE, and 15 age-, sex-, and education-matched healthy subjects. Differences in gray matter volume (GMV) between the subgroups were assessed and further correlated with diminished cognitive functioning. RESULTS: As a group, the patients had lower regional GMV compared to controls in the following regions: basal ganglia, left claustrum, right amygdala, left hippocampus, parietal lobes, and left frontal lobe. The reduced GMV in the bilateral basal ganglia, left post-central gyrus, and left hippocampus correlated with decreased perceptual organization and processing speed function. Those CO patients characterized by DE patients had a lower GMV in the left anterior cingulate and right amygdala, as well as lower levels of cognitive function, than the non-DE patients. CONCLUSIONS: Patients with CO intoxication in the chronic stage showed a worse cognitive and morphologic outcome, especially those with DE. This study provides additional evidence of gray matter structural abnormalities in the pathophysiology of DE in chronic CO intoxicated patients.

Cannabinoid receptor 1 mediates glucocorticoid-induced bone loss in rats by perturbing bone mineral acquisition and marrow adipogenesis.

OBJECTIVE: Prolonged glucocorticoid treatment increases the risk of osteopenic disorders. Bone loss and marrow fat accumulation are prominent features of glucocorticoid-induced skeletal destruction. Cannabinoid receptor 1 (CB(1) ) has been found to regulate energy expenditure and adipose tissue lipogenesis. We undertook this study to investigate whether CB(1) signaling regulates glucocorticoid-induced bone loss. METHODS: Rats were administered glucocorticoid, CB(1) antisense oligonucleotide, CB(1) sense oligonucleotide, or the CB(1) antagonist AM251. Bone mineral density, microstructure, biomechanical strength, and signaling transduction were assessed by dual x-ray absorptiometry, micro-computed tomography, material testing, and immunoblotting, respectively. Primary bone marrow stromal cells were isolated for assessment of ex vivo osteoblast and adipocyte differentiation. RESULTS: Glucocorticoid administration accelerated bone deterioration and fatty marrow formation in association with up-regulation of CB(1) expression. Genetic and pharmacologic blockade of CB(1) by CB(1) antisense oligonucleotide and AM251 attenuated the deleterious effects of glucocorticoid treatment on bone mineral density, trabecular microarchitecture, and mechanical properties. CB(1) antagonism improved osteoblast survival, osteoblast surface, and bone mineral acquisition, but abrogated marrow adiposity. Knockdown of CB(1) restored osteogenic differentiation capacity and attenuated the promoting effects of glucocorticoid on adipogenic differentiation in primary bone marrow mesenchymal cells. CB(1) signaling modulated ERK, JNK, and Akt activation as well as runt-related transcription factor 2 and peroxisome proliferator-activated receptor γ2 signaling. Adiponectin signaling was activated by CB(1) regulation of bone formation and fatty marrow. CONCLUSION: CB(1) mediates glucocorticoid-induced suppression of bone formation and marrow fat homeostasis. CB(1) antagonism reduces adipogenic and apoptotic reactions in bone microenvironments, thereby abrogating the deleterious effects of glucocorticoid treatment on bone integrity. Modulation of CB(1) signaling has therapeutic potential for preventing glucocorticoid-induced osteopenic disorders.

Interplay between fat, muscle, bone mass, and oteophytes and risk for tophaceous gout.

Tophaceous gout is a common arthritis caused by the deposition of urate crystals and is related to limited joint function. Although there are reports that uric acid (UA) is associated with bone mineral density (BMD), little is known about the relationship between UA, osteophytes, and muscle. This cross-sectional case-control study was performed in patients with tophaceous gout. The control group included patients without gout. All subjects underwent BMD and body composition analyses. Age, sex, alcohol consumption, smoking, and radiography of both knees were recorded. Adjusted ORs for tophaceous gout were calculated using the logistical regression models. A total of 150 male patients were enrolled, including 65 individuals with tophaceous gout and 85 without gout. The mean age of the patients with tophaceous gout was 59.94±12.40 years, while that of individuals without gout was 61.29±11.57 years (p=0.492). Patients with tophaceous gout have a higher mean body mass index, fat mass, appendicular lean mass, BMD, and osteophytes. Multiple logistic regression analysis revealed that fat mass (OR 2.01, 95% CI 1.27 to 3.18), appendicular lean mass (OR 4.27, 95% CI 1.86 to 9.83), and osteophytes (OR 5.88, 95% CI 1.72 to 20.13) were significantly associated with tophaceous gout. In the current study, higher fat mass, high muscle mass, and osteophyte formation were found to increase the risk of tophaceous gout, as the association is the most than can be inferred from a cross-sectional study. Therefore, reducing body fat and weight management may prevent tophaceous gout.

Association of a femoral neck T score with knee joint osteophyte formation but not with skeletal muscle mass.

BACKGROUND: Osteophyte formation is an important radiographic sign of osteoarthritis (OA) and limited joint motion in knee osteoarthritis patients. Some studies revealed relationships of osteophyte formation with a high bone mineral density and a high muscle mass, while others showed no correlations. The aim of this study was to identify relationships of osteophyte formation with bone mineral density and muscle mass. METHODS: A cross sectional study of knee osteoarthritis was conducted. Cases were classified as patients with osteophyte formation, while controls were those without osteophytes. All subjects underwent a knee x-ray and bone mineral density and body composition evaluation. General patient characteristics, covariates, and the results of biochemical analyses were also recorded. Statistical analysis was conducted using SPSS Version 22.0. Logistic regression and the chi-square test were utilized to analyze the relationships between the presence of knee osteophytes and the study variables. RESULTS: A total of 228 patients were enrolled, including 78 with osteophytes in the knee joint and 150 without. A total of 162/228 are females; knee OA is commonly explained among females. (p = 0.001). The mean age was 73.23 ± 11.10 years in the osteophyte group and 71.86 ± 12.23 in the no osteophyte group (p = 0.409). The mean body mass index was 24.15 ± 3.27 kg/m2 in the osteophyte group and 23.37 ± 3.48 kg/m2 in the no osteophyte group (p = 0.433). More patients in the osteophyte group had hypertension (p = 0.002), so the age group 73 years expected to have OA and hypertension along other metabolic diseases, and the femoral neck T score was higher in the osteophyte group (p = 0.044). Logistic regression analysis showed that the male gender was associated with less osteophyte formation (p = 0.001, odds ratio (OR) 0.11 (0.03-0.37)), and hypertension was associated with increased muscle loss (p = 0.005). Femoral neck T score was associated with the presence of osteophyte formation (p = 0.011, OR 1.98 (1.17-3.36)). CONCLUSIONS: The results demonstrated an association of knee osteophyte formation with the femoral neck T score and hypertension, but no association with muscle mass. We speculated that in patients with osteophytosis and increased bone mass, metabolic factors such as hypertension should be considered. Further study of the molecular mechanisms regulating these processes is needed in the future. Key Points • Associations of knee osteophyte formation with the femoral neck T score, but not with muscle mass. • Those with osteophytosis and an increased bone mass and metabolic factors such as hypertension need to be assessed.

Inhibition of histone lysine demethylase 6A promotes chondrocytic activity and attenuates osteoarthritis development through repressing H3K27me3 enhancement of Wnt10a.

Histone hypermethylation represses gene transcription, which affects cartilage homeostasis or joint remodeling. Trimethylation of lysine 27 of histone 3 (H3K27me3) changes epigenome signatures, regulating tissue metabolism. This study aimed to investigate whether loss of H3K27me3 demethylase Kdm6a function affected osteoarthritis development. We revealed that chondrocyte-specific Kdm6a knockout mice developed relatively long femurs and tibiae as compared to wild-type mice. Kdm6a deletion mitigated osteoarthritis symptoms, including articular cartilage loss, osteophyte formation, subchondral trabecular bone loss, and irregular walking patterns of destabilized medial meniscus-injured knees. In vitro, loss of Kdm6a function compromised the loss in expression of key chondrocyte markers Sox9, collagen II, and aggrecan and improved glycosaminoglycan production in inflamed chondrocytes. RNA sequencing showed that Kdm6a loss changed transcriptomic profiles, which contributed to histone signaling, NADPH oxidase, Wnt signaling, extracellular matrix, and cartilage development in articular cartilage. Chromatin immunoprecipitation sequencing uncovered that Kdm6a knockout affected H3K27me3 binding epigenome, repressing Wnt10a and Fzd10 transcription. Wnt10a was, among others, functional molecules regulated by Kdm6a. Forced Wnt10a expression attenuated Kdm6a deletion-induced glycosaminoglycan overproduction. Intra-articular administration with Kdm6a inhibitor GSK-J4 attenuated articular cartilage erosion, synovitis, and osteophyte formation, improving gait profiles of injured joints. In conclusion, Kdm6a loss promoted transcriptomic landscapes contributing to extracellular matrix synthesis and compromised epigenetic H3K27me3-mediated promotion of Wnt10a signaling, preserving chondrocytic activity to attenuate osteoarthritic degeneration. We highlighted the chondroprotective effects of Kdm6a inhibitor for mitigating the development of osteoarthritic disorders.

Histone H3K27 demethylase UTX compromises articular chondrocyte anabolism and aggravates osteoarthritic degeneration.

Epigenome alteration in chondrocytes correlates with osteoarthritis (OA) development. H3K27me3 demethylase UTX regulates tissue homeostasis and deterioration, while its role was not yet studied in articulating joint tissue in situ. We now uncovered that increased UTX and H3K27me3 expression in articular chondrocytes positively correlated with human knee OA. Forced UTX expression upregulated the H3K27me3 enrichment at transcription factor Sox9 promoter, inhibiting key extracellular matrix molecules collagen II, aggrecan, and glycosaminoglycan in articular chondrocytes. Utx overexpression in knee joints aggravated the signs of OA, including articular cartilage damage, synovitis, osteophyte formation, and subchondral bone loss in mice. Chondrocyte-specific Utx knockout mice developed thicker articular cartilage than wild-type mice and showed few gonarthrotic symptoms during destabilized medial meniscus- and collagenase-induced joint injury. In vitro, Utx loss changed H3K27me3-binding epigenomic landscapes, which contributed to mitochondrial activity, cellular senescence, and cartilage development. Insulin-like growth factor 2 (Igf2) and polycomb repressive complex 2 (PRC2) core components Eed and Suz12 were, among others, functional target genes of Utx. Specifically, Utx deletion promoted Tfam transcription, mitochondrial respiration, ATP production and Igf2 transcription but inhibited Eed and Suz12 expression. Igf2 blockade or forced Eed or Suz12 expression increased H3K27 trimethylation and H3K27me3 enrichment at Sox9 promoter, compromising Utx loss-induced extracellular matrix overproduction. Taken together, UTX repressed articular chondrocytic activity, accelerating cartilage loss during OA. Utx loss promoted cartilage integrity through epigenetic stimulation of mitochondrial biogenesis and Igf2 transcription. This study highlighted a novel noncanonical role of Utx, in concert with PRC2 core components, in controlling H3K27 trimethylation and articular chondrocyte anabolism and OA development.

Gut Microbiota Ecosystem Governance of Host Inflammation, Mitochondrial Respiration and Skeletal Homeostasis.

Osteoporosis and osteoarthritis account for the leading causes of musculoskeletal dysfunction in older adults. Senescent chondrocyte overburden, inflammation, oxidative stress, subcellular organelle dysfunction, and genomic instability are prominent features of these age-mediated skeletal diseases. Age-related intestinal disorders and gut dysbiosis contribute to host tissue inflammation and oxidative stress by affecting host immune responses and cell metabolism. Dysregulation of gut microflora correlates with development of osteoarthritis and osteoporosis in humans and rodents. Intestinal microorganisms produce metabolites, including short-chain fatty acids, bile acids, trimethylamine N-oxide, and liposaccharides, affecting mitochondrial function, metabolism, biogenesis, autophagy, and redox reactions in chondrocytes and bone cells to regulate joint and bone tissue homeostasis. Modulating the abundance of Lactobacillus and Bifidobacterium, or the ratio of Firmicutes and Bacteroidetes, in the gut microenvironment by probiotics or fecal microbiota transplantation is advantageous to suppress age-induced chronic inflammation and oxidative damage in musculoskeletal tissue. Supplementation with gut microbiota-derived metabolites potentially slows down development of osteoarthritis and osteoporosis. This review provides latest molecular and cellular insights into the biological significance of gut microorganisms and primary and secondary metabolites important to cartilage and bone integrity. It further highlights treatment options with probiotics or metabolites for modulating the progression of these two common skeletal disorders.