Transglutaminase 2 Contributes to Apoptosis Induction in Jurkat T Cells by Modulating Ca(2+) Homeostasis via Cross-Linking RAP1GDS1

BACKGROUND: Transglutaminase 2 (TG2) is a protein cross-linking enzyme known to be associated with the in vivo apoptosis program of T cells. However, its role in the T cell apoptosis program was not investigated yet. RESULTS: Here we report that timed overexpression of both the wild type (wt) and the cross-linking mutant of TG2 induced apoptosis in Jurkat T cells, the wt being more effective. Part of TG2 colocalised with mitochondria. WtTG2-induced apoptosis was characterized by enhanced mitochondrial Ca(2+) uptake. Ca(2+)-activated wtTG2 cross-linked RAP1, GTP-GDP dissociation stimulator 1, an unusual guanine exchange factor acting on various small GTPases, to induce a yet uncharacterized signaling pathway that was able to promote the Ca(2+) release from the endoplasmic reticulum via both Ins3P and ryanodine sensitive receptors leading to a consequently enhanced mitochondrial Ca(2+)uptake. CONCLUSIONS: Our data indicate that TG2 might act as a Ca(2+) sensor to amplify endoplasmic reticulum-derived Ca(2+) signals to enhance mitochondria Ca(2+) uptake. Since enhanced mitochondrial Ca(2+) levels were previously shown to sensitize mitochondria for various apoptotic signals, our data demonstrate a novel mechanism through which TG2 can contribute to the induction of apoptosis in certain cell types. Since, as compared to knock out cells, physiological levels of TG2 affected Ca(2+) signals in mouse embryonic fibroblasts similar to Jurkat cells, our data might indicate a more general role of TG2 in the regulation of mitochondrial Ca(2+) homeostasis

Role of IL-1β in experimental cystic fibrosis upon P. aeruginosa Infection

Cystic fibrosis is associated with increased inflammatory responses to pathogen challenge. Here we revisited the role of IL-1β in lung pathology using the experimental F508del-CFTR murine model on C57BL/6 genetic background (Cftrtm1eur or d/d), on double deficient for d/d and type 1 interleukin-1 receptor (d/d X IL-1R1-/-), and antibody neutralization. At steady state, young adult d/d mice did not show any signs of spontaneous lung inflammation. However, IL-1R1 deficiency conferred partial protection to repeated P. aeruginosa endotoxins/LPS lung instillation in d/d mice, as 50% of d/d mice succumbed to inflammation, whereas all d/d x IL-1R1-/- double mutants survived with lower initial weight loss and less pulmonary collagen and mucus production, suggesting that the absence of IL-1R1 signaling is protective in d/d mice in LPS-induced lung damage. Using P. aeruginosa acute lung infection we found heightened neutrophil recruitment in d/d mice with higher epithelial damage, increased bacterial load in BALF, and augmented IL-1β and TNF-α in parenchyma as compared to WT mice. Thus, F508del-CFTR mice show enhanced IL-1β signaling in response to P. aeruginosa. IL-1β antibody neutralization had no effect on lung homeostasis in either d/d or WT mice, however P. aeruginosa induced lung inflammation and bacterial load were diminished by IL-1β antibody neutralization. In conclusion, enhanced susceptibility to P. aeruginosa in d/d mice correlates with an excessive inflammation and with increased IL-1β production and reduced bacterial clearance. Further, we show that neutralization of IL-1β in d/d mice through the double mutation d/d x IL-1R1-/- and in WT via antibody neutralization attenuates inflammation. This supports the notion that intervention in the IL-1R1/IL-1β pathway may be detrimental in CF patients

No effect of autologous growth factors (AGF) around ungrafted loaded implants in dogs

Autologous growth factors (AGF) is a growth-factor-rich concentrate of platelets, white blood cells and fibrinogen. Application of AGF was presumed to improve implant fixation and gap healing of non-grafted, loaded implants. We inserted one loaded titanium implant intra-articularly in each medial femoral condyle of eight dogs. Each implant was surrounded by a 0.75 mm gap. One implant in each dog was coated with AGF prior to implantation whereas the contralateral implant served as a control. AGF was prepared by isolating the buffy-coat from blood and further concentrated using an Interpore Cross UltraConcentrator. Platelet counts were increased from a median baseline of 168×103/μl to 1003×103/μl in AGF. However, AGF had no significant effect on implant fixation or bone formation. Even though AGF increased ultimate shear strength and energy absorption by approximately 50%, these differences had a p-value less than 0.05. The sample size in this study was small and any negative conclusions should be taken with caution due to low statistical power. We have previously demonstrated that AGF significantly improves fixation and incorporation of grafted implants. AGF might require mixing with an osteoconductive grafting material in order to provide a scaffold on which to foster bone growth and to keep the growth factors on location for a prolonged period

Training Primary Care Physicians to Employ Self-Efficacy-Enhancing Interviewing Techniques: Randomized Controlled Trial of a Standardized Patient Intervention

BACKGROUND: Primary care providers (PCPs) have few tools for enhancing patient self-efficacy, a key mediator of myriad health-influencing behaviors. OBJECTIVE: To examine whether brief standardized patient instructor (SPI)-delivered training increases PCPs’ use of self-efficacy-enhancing interviewing techniques (SEE IT). DESIGN: Randomized controlled trial. PARTICIPANTS: Fifty-two family physicians and general internists from 12 primary care offices drawn from two health systems in Northern California. INTERVENTIONS: Experimental arm PCPs received training in the use of SEE IT training during three outpatient SPI visits scheduled over a 1-month period. Control arm PCPs received a single SPI visit, during which they viewed a diabetes treatment video. All intervention visits (experimental and control) were timed to last 20 min. SPIs portrayed patients struggling with self-care of depression and diabetes in the first 7 min, then delivered the appropriate intervention content during the remaining 13 min. MAIN MEASURES: The primary outcome was provider use of SEE IT (a count of ten behaviors), coded from three audio-recorded standardized patient visits at 1–3 months, again involving depression and diabetes self-care. Two five-point scales measured physician responses to training: Value (7 items: quality, helpfulness, understandability, relevance, feasibility, planned use, care impact), and Hassle (2 items: personal hassle, flow disruption). KEY RESULTS: Pre-intervention, study PCPs used a mean of 0.7 behaviors/visit, with no significant between-arm difference (P = 0.23). Post-intervention, experimental arm PCPs used more of the behaviors than controls (mean 2.7 vs. 1.0 per visit; adjusted difference 1.7, 95 % CI 1.1–2.2; P < 0.001). Experimental arm PCPs had higher training Value scores than controls (mean difference 1.05, 95 % CI 0.68–1.42; P < 0.001), and similarly low Hassle scores. CONCLUSIONS: Primary care physicians receiving brief SPI-delivered training increased their use of SEE IT and found the training to be of value. Whether patients visiting SEE IT-trained physicians experience improved health behaviors and outcomes warrants study. CLINICALTRIALS.GOV IDENTIFIER: NCT01618552 ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11606-016-3644-z) contains supplementary material, which is available to authorized users