Project description:The gut microbiota is closely associated with digestion, metabolism, immunity, and host health. The imbalance of the microbial community in livestock directly affects their well-being and, consequently, productivity. The composition and diversity of the gut microbiota are influenced not only by host genetics but also by environmental factors such as the microbial complexity of the rearing environment, feeds, and antibiotics. Here, we focus on the comparison of gut microbial communities in miniature pigs developed for xenotransplantation in specific pathogen-free (SPF) and conventional (non-SPF) facilities. To identify the disparities in gut microbial composition and functionality between these two environments, 16S RNA metagenome sequencing was conducted using fecal samples. The results revealed that the non-SPF pigs had higher gut microbiota diversity than the SPF pigs. The genera Streptococcus and Ruminococcus were more abundant in SPF pigs than in non-SPF pigs. Blautia, Bacteroides, and Roseburia were exclusively observed in SPF pigs, whereas Prevotella was exclusively found in non-SPF pigs. Carbohydrate and nucleotide metabolism, as well as environmental information processing, were predicted to be enriched in SPF pigs. In addition, energy and lipid metabolism, along with processes related to genetic information, cellular communication, and diseases, were predicted to be enriched in non-SPF pigs. This study makes an important contribution to elucidating the impact of environments harboring a variety of microorganisms, including pathogens, on the gut microbiota of miniature pigs. Furthermore, we sought to provide foundational data on the characteristics of the gut microbiota in genetically modified pigs, which serve as source animals for xenotransplantation.
Project description:The leukocyte NADPH oxidase 2 (NOX2) plays a key role in pathogen killing and immunoregulation. Genetic defects in NOX2 result in chronic granulomatous disease (CGD), associated with microbial infections and inflammatory disorders, often involving the lung. Alveolar macrophages (AM) are the predominant immune cell in the airways at steady state, and limiting their activation is important given constant exposure to inhaled materials, yet the importance of NOX2 in this process is not well-understood. Here, we show a previously undescribed role for NOX2 in maintaining lung homeostasis by suppressing AM activation, as studied using CGD mice or mice with selective loss of NOX2 primarily in macrophages. AM lacking NOX2 have increased cytokine responses to TLR2 and TLR4 stimulation ex vivo. Moreover, between 4 and 12 weeks of age, mice with global NOX2 deletion developed an activated CD11bhigh subset of AM with epigenetic and transcriptional profiles reflecting immune activation compared to WT AM. The presence of CD11bhigh AM in CGD mice correlated with increased numbers of alveolar neutrophils and proinflammatory cytokines at steady state as well as increased lung inflammation following insults. Moreover, deletion of NOX2 primarily in macrophages was sufficient for mice to develop an activated CD11bhigh AM subset and accompanying pro-inflammatory sequela. Additionally, we showed that the altered resident macrophage transcriptional profile in the absence of NOX2 is tissue-specific as these changes were not seen in resident peritoneal macrophages. Thus, these data demonstrate that absence of NOX2 in alveolar macrophages leads to their pro-inflammatory remodeling and dysregulates alveolar homeostasis.
Project description:Obesity is linked to an increased risk of atrial fibrillation (AF) via increased oxidative stress. While NADPH oxidase II (NOX2), a major source of oxidative stress and reactive oxygen species (ROS) in the heart predisposes to AF, the underlying mechanisms remain unclear. Here, we studied NOX2-mediated ROS production in obesity-mediated AF using Nox2-knock-out (KO) mice and mature human induced pluripotent stem cell-derived atrial cardiomyocytes (hiPSC-aCMs). Diet-induced obesity (DIO) mice and hiPSC-aCMs treated with palmitic acid (PA) were infused with a NOX blocker (apocynin) and a NOX2-specific inhibitor, respectively. We showed that NOX2 inhibition normalized atrial action potential duration and abrogated obesity-mediated ion channel remodeling with reduced AF burden. Unbiased transcriptomics analysis revealed that NOX2 mediates atrial remodeling in obesity-mediated AF in DIO mice, PA-treated hiPSC-aCMs, and human atrial tissue from obese individuals by upregulation of paired-like homeodomain transcription factor 2 (PITX2). Furthermore, hiPSC-aCMs treated with hydrogen peroxide, a NOX2 surrogate, displayed increased PITX2 expression, establishing a mechanistic link between increased NOX2-mediated ROS production and modulation of PITX2. Our findings offer insights into possible mechanisms through which obesity triggers AF and support NOX2 inhibition as a potential novel prophylactic or adjunctive therapy for patients with obesity-mediated AF.
Project description:To study the role of Nox2 in ethanol toxicity on the bone growth plate chondrocytes, we generated Nox2 conditional knockout mice (CKO), in which the catalytic subunit of Nox2, Cybb, is deleted in chondrocytes using a Cre-lox system, where Cre is expressed from the Col2a1 promoter. CKO mice and floxed control mice were fed an ethanol-containing Lieber De-Carli-based diet or pair-fed a control diet for 8 weeks starting at 5-6 weeks of age. As both the Nox2 genotype and ethanol diminished the number of chondrocytes in the growth plates, we conducted an RNA-Seq analysis of the growth-plate containing regions of the femurs.
Project description:Here we studied the NOX2 dependent redox-proteome in dorsal root ganglia in mice. The overall goal was to assess the degree of NOX2-dependent changes in oxidised proteins following exposure to enriched enviroment and sciatic nerve axotomy in dorsal root ganglia.
Project description:To investigate the function of NOX2 (CYBB) in leukemia stem cells, we created leukemia by tranforming primitive hematopoetic cells isolated from wild type and NOX2-KO mice with NUP98/HOXA9 and BCR/ABL oncogenes, isolated mRNA, and performed RNA-seq experiments to profile transcriptional changes upon NOX2 loss.