Sonic hedgehog therapy in a mouse model of age-associated impairment of skeletal muscle regeneration.

Sonic hedgehog (Shh) is a morphogen regulating muscle development during embryogenesis. We have shown that the Shh pathway is postnatally recapitulated after injury and during regeneration of the adult skeletal muscle and regulates angiogenesis and myogenesis after muscle injury. Here, we demonstrate that in 18-month-old mice, there is a significant impairment of the upregulation of the Shh pathway that physiologically occurs in the young skeletal muscle after injury. Such impairment is even more pronounced in 24-month-old mice. In old animals, intramuscular therapy with a plasmid encoding the human Shh gene increases the regenerative capacities of the injured muscle, in terms of Myf5-positive cells, regenerating myofibers, and fibrosis. At the molecular level, Shh treatment increases the upregulation of the prototypical growth factors, insulin-like growth factor-1 and vascular endothelial growth factor. These data demonstrate that Shh increases regeneration after injury in the muscle of 24-month-old mice and suggest that the manipulation of the Shh pathway may be useful for the treatment of muscular diseases associated with aging.

Is posterior percutaneous screw-rod instrumentation a safe and effective alternative approach to TLSO rigid bracing for single-level pyogenic spondylodiscitis? Results of a retrospective cohort analysis.

BACKGROUND CONTEXT: Currently, treatment for patients diagnosed with noncomplicated (ie, known infectious agent, no neurologic compromise, and preserved spinal stability) pyogenic spondylodiscitis (PS) is based on intravenous antibiotics and rigid brace immobilization. Since January 2010, we started offering our patients percutaneous posterior screw-rod instrumentation as an alternative approach to rigid bracing. Supposed benefits of posterior percutaneous instrumentation over rigid bracing are earlier free mobilization, increased comfort, and faster recovery. PURPOSE: To evaluate safety and effectiveness of posterior percutaneous spinal instrumentation for single-level PS and compare clinical and quality-of-life outcomes with standard thoracolumbosacral orthosis (TLSO) rigid bracing. STUDY DESIGN/SETTING: Retrospective observational cohort study. PATIENT SAMPLE: Twenty-seven patients consecutively diagnosed with single-level noncomplicated lower thoracic or lumbar PS from January 2010 to December 2011. OUTCOME MEASURES: Healing rate, healing time, and changes in segmental kyphosis Cobb angle were compared in the two treatment groups. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and complete blood count at regular time points until complete healing were also obtained. Self-report measures included Visual Analog Scale (VAS), Short-Form 12 (SF-12), and EuroQol five-dimension (EQ-5D) questionnaires. METHODS: At enrollment, patients were offered to choose between 24/7 TLSO rigid bracing for 3 to 4 months and bridging posterior percutaneous screw-rod instrumentation followed by soft bracing for 4 weeks after surgery. All patients underwent antibiotic therapy accordingly to isolated infectious agents. Patients were seen in the clinic at 1, 3, 6, and 9 months, and ESR, CRP, complete blood count, VAS, SF-12, and EQ-5D questionnaires were obtained. Segmental kyphosis was measured at diagnosis and at 9 months follow-up. Two-way repeated-measures analysis of variance was used to assess group and time differences across time points. RESULTS: Fifteen patients chose conservative treatment, whereas 12 patients chose surgical treatment. Complete infection healing was achieved in all patients with no significant differences in healing time (p<.366). C-reactive protein and ESR levels decreased in both groups accordingly with positive response to therapy with no significant differences. Surgically treated patients had significantly lower VAS scores at 1 month (2.76±0.80 vs. 5.20±1.21, p<.001) and 3 months (2.31±0.54 vs. 2.85±0.54, p<.016) post-diagnosis over TLSO patients. Moreover, surgery patients also showed steeper and statistically significant improvements in SF-12 scores over TLSO patients at 1, 3, and 6 months post-diagnosis (p<.012); no significant differences were detected at the other time points. EuroQol five-dimension index was significantly higher in surgery patients at 1 month (0.764±0.043 vs. 0.458±0.197, p<.001) and 3 months (0.890±0.116 vs. 0.688±0.142, p<.001); no significant changes were observed in segmental pre- and posttreatment kyphosis between the two groups. No instrumentation-related complications were observed in any patient. CONCLUSIONS: Posterior percutaneous spinal instrumentation is a safe, feasible, and effective procedure in relieving pain, preventing deformity, and neurologic compromise in patients affected by noncomplicated lower thoracic (T9-T12) or lumbar PS. Posterior instrumentation did not offer any advantage in healing time over TLSO rigid bracing because infection clearance is strongly dependent on proper antibiotic therapy. Nevertheless, surgical stabilization was associated with faster recovery, lower pain scores, and improved quality of life compared with TLSO conservative treatment at 1, 3, and 6 months after treatment.

Angiogenic impairment of the vascular endothelium: a novel mechanism and potential therapeutic target in muscular dystrophy.

OBJECTIVE: Dystrophin, the missing or defective protein in Duchenne muscular dystrophy, is expressed not only in muscle cells but also in vascular endothelial cells (ECs). In this study, we assessed the effects of dystrophin deficiency on the angiogenic capacities of ECs. APPROACH AND RESULTS: We isolated vascular ECs from mdx mice, the murine equivalent of Duchenne muscular dystrophy in humans, and wild-type controls, and we found that mdx-derived ECs have impaired angiogenic properties, in terms of migration, proliferation, and tube formation. They also undergo increased apoptosis in vitro compared with wild-type cells and have increased senescence-associated ß-galactosidase activity. Mdx-derived ECs also display reduced ability to support myoblast proliferation when cocultured with satellite cell-derived primary myoblasts. These endothelial defects are mirrored by systemic impairment of angiogenesis in vivo, both on induction of ischemia, stimulation with growth factors in the corneal model and matrigel plug assays, and tumor growth. We also found that dystrophin forms a complex with endothelial NO synthase and caveolin-1 in ECs, and that NO production and cGMP formation are compromised in ECs isolated from mdx mice. Interestingly, treatment with aspirin enhances production of both cGMP and NO in dystrophic ECs, whereas low-dose aspirin improves the dystrophic phenotype of mdx mice in vivo, in terms of resistance to physical exercise, muscle fiber permeability, and capillary density. CONCLUSIONS: These findings demonstrate that impaired angiogenesis is a novel player and potential therapeutic target in Duchenne muscular dystrophy.

HAART simplification with lopinavir/ritonavir monotherapy in HIV/HCV co-infected patients starting anti-HCV treatment: a randomised pilot study (KaMon study).

The aim of this randomised, prospective, open-label, multicentre pilot clinical trial was to compare the 48-week toxicity profile of lopinavir/ritonavir (LPV/r) monotherapy with LPV/r-based HAART (KaMon = Kaletra monotherapy) in HIV/HCV patients undergoing HCV treatment. The study involved 30 HIV/HCV co-infected patients naive to anti- HCV therapy. One patient in each arm (6.7%) discontinued anti-HCV therapy because of adverse events. There were no significant between-group differences in terms of the proportion of patients experiencing AEs (p=0.999) or the number of grade 3-4 AEs (p=0.146). No HIV failure was observed. The safety profile of LPV/r monotherapy was similar to that of LPV/r-based HAART, thus encouraging HAART simplification in patients receiving anti-HCV treatment.

Combined therapy with sonic hedgehog gene transfer and bone marrow-derived endothelial progenitor cells enhances angiogenesis and myogenesis in the ischemic skeletal muscle.

We have previously demonstrated that sonic hedgehog (Shh) gene transfer improves angiogenesis in the setting of ischemia by upregulating the expression of multiple growth factors and enhancing the incorporation of endogenous bone marrow (BM)-derived endothelial progenitor cells (EPCs). In this study, we hypothesized that combined therapy with Shh gene transfer and BM-derived EPCs is more effective than Shh gene therapy alone in an experimental model of peripheral limb ischemia. We used old mice, which have a significantly reduced angiogenic response to ischemia, and compared the ability of Shh gene transfer, exogenous EPCs, or both to improve regeneration after ischemia. We found a significantly higher capillary density in the Shh + EPC-treated muscles compared to the other experimental groups. We also found that Shh gene transfer increases the incorporation and survival of transplanted EPCs. Finally, we found a significantly higher number of regenerating myofibers in the ischemic muscles of mice receiving combined treatment with Shh and BM-derived EPCs. In summary, the combination of Shh gene transfer and BM-derived EPCs more effectively promotes angiogenesis and muscle regeneration than each treatment individually and merits further investigation for its potential beneficial effects in ischemic diseases.

Pleiotropic beneficial effects of sonic hedgehog gene therapy in an experimental model of peripheral limb ischemia.

We have previously shown that the signaling pathway of the embryonic morphogen Sonic hedgehog (Shh) is recapitulated in the postnatal skeletal muscle in response to ischemia. We have also demonstrated that Shh is an indirect angiogenic agent upregulating various families of angiogenic growth factors and that Shh gene therapy improves angiogenesis and heart function in experimental models of myocardial ischemia. Based on these findings, we hypothesized that Shh gene therapy is beneficial in an experimental model of peripheral ischemia. We found that intramuscular (i.m.) treatment with a plasmid encoding the Shh human gene (phShh) increased blood flow, capillary density, and arteriole density in mice in which peripheral circulation of the hindlimb was disrupted by removal of the common femoral artery. Shh gene therapy also enhanced vasculogenesis, by increasing the number of circulating bone marrow (BM)-derived endothelial precursors and improving the contribution of these cells to the process of neovascularization. Finally, phShh treatment induced upregulation of prototypical angiogenic, arteriogenic, and vasculogenic factors, such as vascular endothelial growth factor (VEGF), angiopoietin 1 (Ang-1), and stromal cell-derived factor-1 (SDF-1α). These data suggest that Shh gene therapy merits further investigation for its ability to trigger the expression of potent trophic factors and stimulate pleiotropic aspects of neovascularization in the setting of ischemia.