A feasibility study on yoga's mechanism of action for chronic low back pain: psychological and neurophysiological changes, including global gene expression and DNA methylation, following a yoga intervention for chronic low back pain.

INTRODUCTION: Yoga has been shown to reduce pain and improve function in populations with chronic low back pain (cLBP), yet the underlying molecular mechanisms remain elusive. This study examined the feasibility and acceptability of a yoga research protocol, including recruitment, retention, and data collection, and investigated the preliminary effects of yoga on psychological and neurophysiological functions, including gene expression and DNA methylation profiles, in participants with cLBP. METHODS: A one-arm trial was conducted with 11 participants with cLBP who enrolled in a 12-week yoga intervention. Data on subjective pain characteristics, quantitative sensory testing, and blood for analysis of differentially expressed genes and CpG methylation was collected prior to the start of the intervention and at study completion. RESULTS: Based on pre-determined feasibility and acceptability criteria, the yoga intervention was found to be feasible and highly acceptable to participants. There was a reduction in pain severity, interference, and mechanical pain sensitivity post-yoga and an increase in emotion regulation and self-efficacy. No adverse reactions were reported. Differential expression analysis demonstrated that the yoga intervention induced increased expression of antisense genes, some of which serve as antisense to known pain genes. In addition, there were 33 differentially hypomethylated positions after yoga (log2 fold change ≥ 1), with enrichment of genes involved in NIK/NF-kB signaling, a major pathway that modulates immune function and inflammation. DISCUSSION/CONCLUSIONS: The study supports the feasibility and acceptability of the proposed protocol to test a specific mechanism of action for yoga in individuals with cLBP. These results also support the notion that yoga may operate through our identified psychological and neurophysiologic pathways to influence reduced pain severity and interference.

Computational Modeling of Macrophage Iron Sequestration during Host Defense against Aspergillus.

Iron is essential to the virulence of Aspergillus species, and restricting iron availability is a critical mechanism of antimicrobial host defense. Macrophages recruited to the site of infection are at the crux of this process, employing multiple intersecting mechanisms to orchestrate iron sequestration from pathogens. To gain an integrated understanding of how this is achieved in aspergillosis, we generated a transcriptomic time series of the response of human monocyte-derived macrophages to Aspergillus and used this and the available literature to construct a mechanistic computational model of iron handling of macrophages during this infection. We found an overwhelming macrophage response beginning 2 to 4 h after exposure to the fungus, which included upregulated transcription of iron import proteins transferrin receptor-1, divalent metal transporter-1, and ZIP family transporters, and downregulated transcription of the iron exporter ferroportin. The computational model, based on a discrete dynamical systems framework, consisted of 21 3-state nodes, and was validated with additional experimental data that were not used in model generation. The model accurately captures the steady state and the trajectories of most of the quantitatively measured nodes. In the experimental data, we surprisingly found that transferrin receptor-1 upregulation preceded the induction of inflammatory cytokines, a feature that deviated from model predictions. Model simulations suggested that direct induction of transferrin receptor-1 (TfR1) after fungal recognition, independent of the iron regulatory protein-labile iron pool (IRP-LIP) system, explains this finding. We anticipate that this model will contribute to a quantitative understanding of iron regulation as a fundamental host defense mechanism during aspergillosis. IMPORTANCE Invasive pulmonary aspergillosis is a major cause of death among immunosuppressed individuals despite the best available therapy. Depriving the pathogen of iron is an essential component of host defense in this infection, but the mechanisms by which the host achieves this are complex. To understand how recruited macrophages mediate iron deprivation during the infection, we developed and validated a mechanistic computational model that integrates the available information in the field. The insights provided by this approach can help in designing iron modulation therapies as anti-fungal treatments.

Multi-scale mechanistic modelling of the host defence in invasive aspergillosis reveals leucocyte activation and iron acquisition as drivers of infection outcome.

Aspergillus species are ubiquitous environmental moulds, with spores inhaled daily by most humans. Immunocompromised hosts can develop an invasive infection resulting in high mortality. There is, therefore, a pressing need for host-centric therapeutics for this infection. To address it, we created a multi-scale computational model of the infection, focused on its interaction with the innate immune system and iron, a critical nutrient for the pathogen. The model, parameterized using published data, was found to recapitulate a wide range of biological features and was experimentally validated in vivo. Conidial swelling was identified as critical in fungal strains with high growth, whereas the siderophore secretion rate seems to be an essential prerequisite for the establishment of the infection in low-growth strains. In immunocompetent hosts, high growth, high swelling probability and impaired leucocyte activation lead to a high conidial germination rate. Similarly, in neutropenic hosts, high fungal growth was achieved through synergy between high growth rate, high swelling probability, slow leucocyte activation and high siderophore secretion. In summary, the model reveals a small set of parameters related to fungal growth, iron acquisition and leucocyte activation as critical determinants of the fate of the infection.

The use of TMZ embedded hydrogels for the treatment of orthotopic human glioma xenografts.

The current treatment of glioblastoma multiforme (GBM) is limited by the restricted arsenal of agents which effectively cross the blood brain barrier (BBB). For example, only a fraction of temozolomide (TMZ) administered systemically is available for therapeutic effect because of the BBB and the instability of TMZ under physiologic conditions. A novel approach to overcome this obstacle is to bypass the BBB and locally deliver chemotherapeutic agents directly to the tumor mass. We have explored the loading of TMZ into a novel hydrogel matrix, which can be delivered in liquid form and then solidifies in situ and releases chemotherapy as the matrix dissolves. Here, we tested the effect of amphiphilic diblock copolypeptide hydrogels (DCHs) of 180-poly-lysine and 20-poly-leucine (K180L20) on TMZ using Glioblastoma models. In both the in vitro model, which involved treatment of a human glioblastoma GSC line suspended as neurospheres, and in vivo using an orthotopic glioma xenograft mouse model, we found that K180L20 could safely enhance the efficacy of TMZ. This technique may offer the opportunity to 'coat' the inner lining of the cavity following glioma resection with a slow-release TMZ and potentially decrease recurrence. Future studies in larger animals are needed to delineate this effect.

Epigenetic suppression of EGFR signaling in G-CIMP+ glioblastomas.

The intrinsic signaling cascades and cell states associated with the Glioma CpG Island Methylator Phenotype (G-CIMP) remain poorly understood. Using published mRNA signatures associated with EGFR activation, we demonstrate that G-CIMP+ tumors harbor decreased EGFR signaling using three independent datasets, including the Chinese Glioma Genome Atlas(CGGA; n=155), the REMBRANDT dataset (n=288), and The Cancer Genome Atlas (TCGA; n=406). Additionally, an independent collection of 25 fresh-frozen glioblastomas confirmed lowered pERK levels in G-CIMP+ specimens (p<0.001), indicating suppressed EGFR signaling. Analysis of TCGA glioblastomas revealed that G-CIMP+ glioblastomas harbored lowered mRNA levels for EGFR and H-Ras. Induction of G-CIMP+ state by exogenous expression of a mutated isocitrate dehydrogenase 1, IDH1-R132H, suppressed EGFR and H-Ras protein expression as well as pERK accumulation in independent glioblastoma models. These suppressions were associated with increased deposition of the repressive histone markers, H3K9me3 and H3K27me3, in the EGFR and H-Ras promoter regions. The IDH1-R132H expression-induced pERK suppression can be reversed by exogenous expression of H-RasG12V. Finally, the G-CIMP+ Ink4a-Arf-/- EGFRvIII glioblastoma line was more resistant to the EGFR inhibitor, Gefitinib, relative to its isogenic G-CIMP- counterpart. These results suggest that G-CIMP epigenetically regulates EGFR signaling and serves as a predictive biomarker for EGFR inhibitors in glioblastoma patients.