Smooth muscle cell specific ablation of CXCL12 downregulates endothelial CXCR7 leading to defective coronary arteries and cardiac hypertrophy

Aims

The chemokine CXCL12 plays a fundamental role in cardiovascular development, cell trafficking, and myocardial repair. Human genome-wide association studies even have identified novel loci downstream of the CXCL12 gene locus associated with coronary artery disease and myocardial infarction. Nevertheless, cell and tissue specific effects of CXCL12 are barely understood. Since we detected high expression of CXCL12 in smooth muscle (SM) cells, we generated a SM22-alpha-Cre driven mouse model to ablate CXCL12 (SM-CXCL12−/−).

Methods and results

SM-CXCL12−/− mice revealed high embryonic lethality (50%) with developmental defects, including aberrant topology of coronary arteries. Postnatally, SM-CXCL12−/− mice developed severe cardiac hypertrophy associated with fibrosis, apoptotic cell death, impaired heart function, and severe coronary vascular defects characterized by thinned and dilated arteries. Transcriptome analyses showed specific upregulation of pathways associated with hypertrophic cardiomyopathy, collagen protein network, heart-related proteoglycans, and downregulation of the M2 macrophage modulators. CXCL12 mutants showed endothelial downregulation of the CXCL12 co-receptor CXCR7. Treatment of SM-CXCL12−/− mice with the CXCR7 agonist TC14012 attenuated cardiac hypertrophy associated with increased pERK signaling.

Conclusion

Our data suggest a critical role of smooth muscle-specific CXCL12 in arterial development, vessel maturation, and cardiac hypertrophy. Pharmacological stimulation of CXCR7 might be a promising target to attenuate adverse hypertrophic remodeling.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): FWF-Austria

Nursing home rehabilitation after acute rehabilitation: predictors and outcomes

OBJECTIVE

To determine the predictive factors and functional outcomes of patients who were discharged from an acute rehabilitation unit to a nursing home care unit (NHCU) at a Veterans Affairs (VA) hospital.

DESIGN

Cohort descriptive study.

SETTING

An academically affiliated urban VA Medical Center.

PATIENTS

All patients (n = 81, median age 68 years) admitted to a VA rehabilitation unit over a 1-year period.

OUTCOME MEASURES

Discharge locations, predictors for NHCU transfer, and functional status as determined by Functional Independence Measure (FIM) scores.

RESULTS

Patients discharged to the NHCU (17%) were compared with those discharged to the community (80%). Multiple logistic regression analysis showed that acute rehabilitation length of stay (LOS), admission, and discharge FIM scores were the only independent variables that predicted discharge to the VA NHCU. Although overall FIM gains in both groups during acute rehabilitation were similar, the NHCU group had significantly lower admission FIM scores and lower LOS efficiency because of longer acute rehabilitation LOS. Postacute NHCU rehabilitation resulted in significant gains in FIM scores at a slower rate. Sixty-four percent of these nursing home patients eventually returned to the community.

CONCLUSION

Nursing home rehabilitation can result in favorable functional and community outcomes for selected patients.

The thermoplastic Minerva body jacket: a clinical comparison with other cervical spine splinting techniques

A retrospective analysis of the efficacy of a variety of external stabilization techniques used in 155 cases of unstable cervical spine injuries is presented. The movement at each intervertebral level was evaluated during thermoplastic Minerva body jacket stabilization in 18 additional patients. Many currently available approaches to external stabilization of the cervical spine were, thus, assessed. Thermoplastic Minerva body jacket stabilization offered superior segmental immobilization compared with published data for the halo. It is concluded that some unstable injuries to the high cervical spine might best be treated with a halo device, whereas mid to low cervical injuries and the remaining upper cervical spine injuries appear to be optimally treated with a Minerva jacket. Lesser injuries may be treated with a variety of available orthoses. The thermoplastic Minerva body jacket offers a superior limitation of intervertebral movement compared with other commonly used braces, including the halo jacket, for most cervical spine injuries. The technique of application of the thermoplastic Minerva body jacket is reviewed.