👤 Daniel Gillis

Altering inflammation can impact the recovering heart's structure and function following myocardial infarction (MI). MAP kinase-activated protein kinase 2 (MK2) regulates the stability of several pro-inflammatory cytokines. Hence, this study was to determine if MK2 deficiency impaired the inflammatory phase of post-MI wound repair. Myocardial infarctions were induced by permanent ligation of the left anterior descending coronary artery in 12-week-old male MK2 Show less

Various adverse mental health outcomes (e.g., burnout) have been reported and shown to impact the longevity of veterinarians' careers, especially during the early career. Both compassion fatigue (CF) and compassion satisfaction (CS) are significant predictors of burnout. Increasing attention is being paid to positive psychology, including psychological wellbeing (PWB) and resilience, as they have the potential to enhance wellbeing in the profession. The objectives of this research were to measure various psychological outcomes of newly graduated veterinarians in Canada and identify underlying profiles based on empirical data. An online questionnaire with validated psychometric scales was distributed to graduates of all five Canadian veterinary schools in 2022 and 2023. Latent profile analysis (LPA) (n = 189) revealed two profiles, interpreted as follows: thriving (n = 116; high PWB, CS and resilience, and low burnout and CF) and surviving (n = 73; low PWB, CS and resilience, and high burnout and CF). The sample size was smaller than typically recommended for LPA. Our findings revealed that 61% (116/191) of newly graduated veterinarians were considered to have good mental wellbeing or were 'thriving'. Our study amplifies the need for more research on positive wellbeing outcomes and interventions to strengthen veterinary students' and veterinarians' wellbeing. Show less

Polymorphisms in the adenylate cyclase 9 (ADCY9) gene influence the benefits of the cholesteryl ester transfer protein (CETP) modulator dalcetrapib on cardiovascular events after acute coronary syndrome. We hypothesized that Adcy9 inactivation could improve cardiac function and remodelling following myocardial infarction (MI) in absence of CETP activity. Wild-type (WT) and Adcy9-inactivated (Adcy9 All mice developed LV hypertrophy, dilation, and systolic dysfunction, but Adcy9 Adcy9 inactivation reduced infarct size, pathologic remodelling, and cardiac dysfunction. These changes were accompanied by preserved myocardial capillary density and increased adaptive immune response. Most of the benefits of Adcy9 inactivation were only observed in the absence of CETP. Show less

Pharmacogenomic studies have shown that ADCY9 genotype determines the effects of the CETP (cholesteryl ester transfer protein) inhibitor dalcetrapib on cardiovascular events and atherosclerosis imaging. The underlying mechanisms responsible for the interactions between ADCY9 and CETP activity have not yet been determined. Adcy9-inactivated ( Adcy9 Adcy9 Adcy9 inactivation protects against atherosclerosis, but only in the absence of CETP activity. This atheroprotection may be explained by decreased macrophage accumulation and proliferation in the arterial wall, and improved endothelial function and autonomic tone. Show less

Canonical Wnt signals, transduced by stabilized β-catenin, play similar roles across animals in maintaining stem cell pluripotency, regulating cell differentiation, and instructing normal embryonic development. Dysregulated Wnt/β-catenin signaling causes diseases and birth defects, and a variety of regulatory processes control this pathway to ensure its proper function and integration with other signaling systems. We previously identified GTP-binding protein 2 (Gtpbp2) as a novel regulator of BMP signaling, however further exploration revealed that Gtpbp2 can also affect Wnt signaling, which is a novel finding reported here. Knockdown of Gtpbp2 in Xenopus embryos causes severe axial defects and reduces expression of Spemann-Mangold organizer genes. Gtpbp2 knockdown blocks responses to ectopic Wnt8 ligand, such as organizer gene induction in ectodermal tissue explants and induction of secondary axes in whole embryos. However, organizer gene induction by ectopic Nodal2 is unaffected by Gtpbp2 knockdown. Epistasis tests, conducted by activating Wnt signal transduction at sequential points in the canonical pathway, demonstrate that Gtpbp2 is required downstream of Dishevelled and Gsk3β but upstream of β-catenin, which is similar to the previously reported effects of Axin1 overexpression in Xenopus embryos. Focusing on Axin in Xenopus embryos, we find that knockdown of Gtpbp2 elevates endogenous or exogenous Axin protein levels. Furthermore, Gtpbp2 fusion proteins co-localize with Dishevelled and co-immunoprecipitate with Axin and Gsk3b. We conclude that Gtpbp2 is required for canonical Wnt/β-catenin signaling in Xenopus embryos. Our data suggest a model in which Gtpbp2 suppresses the accumulation of Axin protein, a rate-limiting component of the β-catenin destruction complex, such that Axin protein levels negatively correlate with Gtpbp2 levels. This model is supported by the similarity of our Gtpbp2-Wnt epistasis results and previously reported effects of Axin overexpression, the physical interactions of Gtpbp2 with Axin, and the correlation between elevated Axin protein levels and lost Wnt responsiveness upon Gtpbp2 knockdown. A wide variety of cancer-causing Wnt pathway mutations require low Axin levels, so development of Gtpbp2 inhibitors may provide a new therapeutic strategy to elevate Axin and suppress aberrant β-catenin signaling in cancer and other Wnt-related diseases. Show less

Castleman disease is a rare hematologic disorder, closely linked to the HHV-8, and most commonly observed in immunocompromised individuals. Thirteen months following a liver transplant for CPS-1 defect, a 15-month-old boy presented with fevers, anemia, and growth retardation. Abdominal CT scan showed splenomegaly and generalized lymphadenopathy. Histology of chest wall lymph nodes revealed a mixed CD3+ T-cell and CD20+ B-cell population with atretic germinal centers consistent with multicentric Castleman disease. Qualitative DNA PCR detected HHV-8 in the resected lymph node and in the blood, supporting the diagnosis. Immunosuppression was tapered, and he was transitioned from tacrolimus to sirolimus. His graft function remained stable, and repeat imaging showed regression of the lymphadenopathy. The child is living one yr after Castleman disease diagnosis with a well-functioning graft. Castleman disease is a potential complication of solid organ transplant and HHV-8 infection. Reduction in immunosuppression and switch to sirolimus may be an effective strategy to treat this condition. Show less