G1P3/IFI6, an interferon stimulated protein, promotes the association of RAB5+ endosomes with mitochondria in breast cancer cells.

G1P3/IFI6 is an interferon stimulated gene with antiapoptotic, prometastatic, and antiviral functions. Despite its pleiotropic functions, subcellular localization of G1P3 remains unclear. Using biochemical- and confocal microscopic approaches, this study identified the localization of G1P3 in organelles of the endomembrane system and in the mitochondria of breast cancer cells. In cell fractionation studies, both interferon-induced endogenous- and stably expressed G1P3 cofractionated with affinity-isolated mitochondria. Results of the protease protection assay have suggested that ~24% of mitochondrial G1P3 resides within the mitochondria. Conforming to this, confocal microscopy studies of cells stably expressing epitope-tagged G1P3 (MCF-7/G1P3-FLAG), identified its localization in mitochondria (~38%) as well as in ER, trans-Golgi network (TGN), lysosomes, and in RAB5 positive (RAB5+ ) endosomes. These results suggested the trafficking of G1P3 from TGN into endolysosomes. Both G1P3 and RAB5 were known to confer apoptosis resistance through mitochondrial stabilization. Therefore, the effects of G1P3 on the localization of RAB5 in mitochondria were tested. Compared to vector control, the co-occurrence of RAB5 with the mitochondria was increased by 1.5-fold in MCF-7/G1P3-FLAG expressing cells (p ≤ .005). Taken together, our results demonstrate a role for G1P3 to promote the association of RAB5+ endosomes with mitochondria and provide insight into yet another mechanism of G1P3-induced cancer cell survival.

Relationship of Age And Mobility Levels During Physical Rehabilitation With Clinical Outcomes in Critical Illness.

Objective: To determine whether age, mobility level, and change in mobility level across the first 3 physical rehabilitation sessions associate with clinical outcomes of patients who are critically ill. Design: Retrospective, observational cohort study. Setting: Medical Intensive Care Unit (MICU). Participants: Hospitalized adults (n = 132) who received 3 or more, consecutive rehabilitation sessions in the MICU. Interventions: Not applicable. Measurements and Main Results: Sample included 132 patients with 60 (45%) classified as younger (18-59 years) and 72 (55%) as older (60+ years). The most common diagnosis was sepsis/septicemia (32.6%). Older relative to younger patients had a significantly slower rate of improvement in ICU Mobility Scale (IMS) scores across rehabilitation sessions (mean slope coefficient 0.3 vs 0.6 points, P<.001), were less likely to be discharged to home (30.6% vs 55.0%, P=.005), and were more likely to die within 12 months (41.7% vs 25.0%, P=.046). Covariate-adjusted models indicated greater early improvement in IMS scores were associated with discharge home (P=.005). Longer time to first rehabilitation session, lower initial IMS scores, and slower improvement in IMS scores were associated with increased ICU days (all P<.03). Conclusion: Older age and not achieving the mobility milestone of sitting at edge of bed or limited progression of mobility across sessions is associated with poor patient outcomes. Our findings suggest that age and mobility level contribute to outcome prognostication, and can aide in clinical phenotyping and rehabilitative service allocation.

G1P3 (IFI6), a mitochondrial localised antiapoptotic protein, promotes metastatic potential of breast cancer cells through mtROS.

BACKGROUND: Redox deregulations are ubiquitous in cancer cells. However, the role of mitochondrial redox deregulation in metastasis remains unclear. In breast cancer, upregulation of mitochondrial antiapoptotic protein G1P3 (IFI6) was associated with poor distance metastasis-free survival (DMFS). Therefore, we tested the hypothesis that G1P3-induced mitochondrial redox deregulation confers metastatic potentials in breast cancer cells. METHODS: Cell migration and invasion assays; confocal and immunofluorescence microscopy; and Illumina HumanHT-12 BeadChip to assess gene expression. RESULTS: Consequent to its localisation on inner-mitochondrial membrane, mtROS were higher in G1P3-expressing cells (MCF-7G1P3). G1P3-overexpressing cells migrated and invaded faster than the vector controls with increased number of filopodia and F-actin bundles (p ≤ 0.05). mtROS suppression with H2O2 scavengers and mitochondrial-specific antioxidants significantly decreased migratory structures and reversed G1P3-induced migration and invasion (p ≤ 0.05). Knocking down G1P3 decreased both migration and migratory structures in MCF-7G1P3 cells. Moreover, gene networks involved in redox regulation, metastasis and actin remodelling were upregulated in MCF-7G1P3 cells. CONCLUSIONS: G1P3-induced mtROS have a direct role in migratory structure formation and nuclear gene expression to promote breast cancer cell metastasis. Therefore, interrupting mitochondrial functions of G1P3 may improve clinical outcomes in breast cancer patients.

Loss of Maspardin Attenuates the Growth and Maturation of Mouse Cortical Neurons.

BACKGROUND: Mast syndrome, an autosomal recessive, progressive form of hereditary spastic paraplegia, is associated with mutations in SPG21 loci that encode maspardin protein. Although SPG21-/- mice exhibit lower limb dysfunction, the role of maspardin loss in mast syndrome is unclear. OBJECTIVE: To test the hypothesis that loss of maspardin attenuates the growth and maturation of cortical neurons in SPG21-/- mice. METHODS AND RESULTS: In a randomized experimental design SPG21-/- mice demonstrated significantly less agility and coordination compared to wild-type mice in beam walk, ledge, and hind limb clasp tests for assessing neuronal dysfunction (p ≤ 0.05). The SPG21-/- mice exhibited symptoms of mast syndrome at 6 months which worsened in 12-month-old cohort, suggesting progressive dysfunction of motor neurons. Ex vivo, wild-type cortical neurons formed synapses, ganglia and aggregates at 96 h, whereas SPG21-/- neurons exhibited attenuated growth with markedly less axonal branches. Additionally, epidermal growth factor markedly promoted the growth and maturation of SPG21+/+ cortical neurons but not SPG21-/- neurons. Consequently, quantitative RT-PCR identified a significant reduction in the expression of a subset of EGF-EGFR signaling targets. CONCLUSIONS: Our current study uncovered a direct role for maspardin in normal and EGF-induced growth and maturation of primary cortical neurons. The loss of maspardin resulted in attenuated growth, axonal branching, and attenuation of EGF signaling. Reinstating the functions of maspardin may reverse hind limb impairment associated with neuronal dysfunction in mast syndrome patients.

Libera me, Domine: Christian Roots of Palliative Care.

This article reviews key aspects of the history of the emergence of palliative care to point out that the language and expressions that are routinely used in communicating with palliative care patients are often infused with an unrecognized religious coloration.