Pulmonary veno-occlusive disease (PVOD) is a rare form of pulmonary hypertension arising from EIF2AK4 gene mutations or mitomycin C (MMC) administration. The lack of effective PVOD therapies is compounded by a limited understanding of the mechanisms driving vascular remodeling in PVOD. Here we show that administration of MMC in rats mediates activation of protein kinase R (PKR) and the integrated stress response (ISR), which leads to the release of the endothelial adhesion molecule vascular endothelial (VE) cadherin (VE-Cad) in complex with RAD51 to the circulation, disruption of endothelial barrier and vascular remodeling.
View Article and Find Full Text PDFIntroduction: Group A streptococcus (GAS) infections, such as pharyngitis and impetigo, can lead to rheumatic fever and rheumatic heart disease (RHD). Australian Aboriginal and Torres Strait Islander populations experience high rates of RHD and GAS skin infection, yet rates of GAS pharyngitis are unclear. Anecdotally, clinical presentations of pharyngitis, including tonsillar hypertrophy and sore throat, are uncommon.
View Article and Find Full Text PDFAccumulating evidence has implicated impaired extracellular matrix (ECM) clearance as a key factor in fibrotic disease. Despite decades of research elucidating the effectors of ECM clearance, relatively little is understood regarding the upstream regulation of this process. Collagen is the most abundant constituent of normal and fibrotic ECM in mammalian tissues.
View Article and Find Full Text PDFIntegrins are cell adhesion receptors that dimerize to mediate cell-cell interactions and regulate processes, including proliferation, inflammation, and tissue repair. The role of integrins in regulating insulin signaling is incompletely understood. We have previously shown that binding of the integrin ligand milk fat globule epidermal growth factor like 8 (MFGE8) to the αvβ5 integrin promotes termination of insulin receptor signaling in mice.
View Article and Find Full Text PDFPulmonary veno-occlusive disease (PVOD) is a rare form of pulmonary hypertension arising from EIF2AK4 gene mutations or mitomycin C (MMC) administration. The lack of effective PVOD therapies is compounded by a limited understanding of the mechanisms driving the vascular remodeling in PVOD. We show that the administration of MMC in rats mediates the activation of protein kinase R (PKR) and the integrated stress response (ISR), which lead to the release of the endothelial adhesion molecule VE-Cadherin in the complex with Rad51 to the circulation, disruption of endothelial barrier, and vascular remodeling.
View Article and Find Full Text PDFMicroglia diversity emerges from interactions between intrinsic genetic programs and environment-derived signals, but how these processes unfold and interact in the developing brain remains unclear. Here, we show that radial glia-expressed integrin beta 8 (ITGB8) expressed in radial glia progenitors activates microglia-expressed TGFβ1, permitting microglial development. Domain-restricted deletion of in these progenitors establishes complementary regions with developmentally arrested "dysmature" microglia that persist into adulthood.
View Article and Find Full Text PDFThe role of integrins in regulating insulin signaling is incompletely understood. We have previously shown that binding of the integrin ligand milk fat globule epidermal growth factor like 8 (MFGE8) to the αvβ5 integrin promotes termination of insulin receptor signaling in mice. Upon ligation of MFGE8, β5 complexes with the insulin receptor beta (IRβ) in skeletal muscle resulting in dephosphorylation of IRβ and reduction of insulin-stimulated glucose uptake.
View Article and Find Full Text PDFGroup 2 innate lymphoid cells (ILC2s) cooperate with adaptive Th2 cells as key organizers of tissue type 2 immune responses, while a spectrum of innate and adaptive lymphocytes coordinate early type 3/17 immunity. Both type 2 and type 3/17 lymphocyte associated cytokines are linked to tissue fibrosis, but how their dynamic and spatial topographies may direct beneficial or pathologic organ remodelling is unclear. Here we used volumetric imaging in models of liver fibrosis, finding accumulation of periportal and fibrotic tract IL-5 lymphocytes, predominantly ILC2s, in close proximity to expanded type 3/17 lymphocytes and IL-33 niche fibroblasts.
View Article and Find Full Text PDFEnterocytes modulate the extent of postprandial lipemia by storing dietary fats in cytoplasmic lipid droplets (cLDs). We have previously shown that the integrin ligand MFGE8 links absorption of dietary fats with activation of triglyceride (TG) hydrolases that catabolize cLDs for chylomicron production. Here, we identify CES1D as the key hydrolase downstream of the MFGE8-αvβ5 integrin pathway that regulates catabolism of diet-derived cLDs.
View Article and Find Full Text PDFAberrant tissue-immune interactions are the hallmark of diverse chronic lung diseases. Here, we sought to define these interactions in emphysema, a progressive disease characterized by infectious exacerbations and loss of alveolar epithelium. Single-cell analysis of human emphysema lungs revealed the expansion of tissue-resident lymphocytes (TRLs).
View Article and Find Full Text PDFEndothelial and erythropoietic lineages arise from a common developmental progenitor. Etv2 is a master transcriptional regulator required for the development of both lineages. However, the mechanisms through which Etv2 initiates the gene-regulatory networks (GRNs) for endothelial and erythropoietic specification and how the two GRNs diverge downstream of Etv2 remain incompletely understood.
View Article and Find Full Text PDFObjectives: To establish the priorities of primary care providers to improve assessment and treatment of skin sores and sore throats among Aboriginal and Torres Strait Islander people at risk of acute rheumatic fever (ARF) and rheumatic heart disease (RHD).
Design: Modified eDelphi survey, informed by an expert focus group and literature review.
Setting: Primary care services in any one of the five Australian states or territories with a high burden of ARF.
Allergic immunity is orchestrated by group 2 innate lymphoid cells (ILC2s) and type 2 helper T (Th2) cells prominently arrayed at epithelial- and microbial-rich barriers. However, ILC2s and Th2 cells are also present in fibroblast-rich niches within the adventitial layer of larger vessels and similar boundary structures in sterile deep tissues, and it remains unclear whether they undergo dynamic repositioning during immune perturbations. Here, we used thick-section quantitative imaging to show that allergic inflammation drives invasion of lung and liver non-adventitial parenchyma by ILC2s and Th2 cells.
View Article and Find Full Text PDFHaloarchaea are extreme halophilic microorganisms belonging to the domain Archaea, phylum Euryarchaeota, and are producers of interesting antioxidant carotenoid compounds. In this study, four new strains of sp., isolated from saline lakes of the Atacama Desert, are reported and studied by high-resolution mass spectrometry (UHPLC-Q-Orbitrap-MS/MS) for the first time.
View Article and Find Full Text PDFIssue Addressed: Aboriginal and Torres Strait Islander peoples in Australia have an inequitable burden of acute rheumatic fever (ARF) and rheumatic heart disease (RHD), concentrated among young people and necessitating ongoing medical care during adolescence. There is an unmet need for improved well-being and support for these young people to complement current biomedical management.
Methods: This pilot program initiative aimed to determine the suitability and appropriate format of an ongoing peer support program to address the needs of young people living with RHD in urban Darwin.
The role of integrins, in particular αv integrins, in regulating insulin resistance is incompletely understood. We have previously shown that the αvβ5 integrin ligand milk fat globule epidermal growth factor like 8 (MFGE8) regulates cellular uptake of fatty acids. In this work, we evaluated the impact of MFGE8 on glucose homeostasis.
View Article and Find Full Text PDFFibrosis is a common pathological response to inflammation in many peripheral tissues and can prevent tissue regeneration and repair. Here, we identified persistent fibrotic scarring in the CNS following immune cell infiltration in the experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis. Using lineage tracing and single-cell sequencing in EAE, we determined that the majority of the fibrotic scar is derived from proliferative CNS fibroblasts, not pericytes or infiltrating bone marrow-derived cells.
View Article and Find Full Text PDFWe give representations for solutions of time-fractional differential equations that involve operators on Lebesgue spaces of sequences defined by discrete convolutions involving kernels through the discrete Fourier transform. We consider finite difference operators of first and second orders, which are generators of uniformly continuous semigroups and cosine functions. We present the linear and algebraic structures (in particular, factorization properties) and their norms and spectra in the Lebesgue space of summable sequences.
View Article and Find Full Text PDFWe characterize for the first time the chaotic behavior of nonlocal operators that come from a broad class of time-stepping schemes of approximation for fractional differential operators. For that purpose, we use criteria for chaos of Toeplitz operators in Lebesgue spaces of sequences. Surprisingly, this characterization is proved to be-in some cases-dependent of the fractional order of the operator and the step size of the scheme.
View Article and Find Full Text PDFAs the resident macrophages of the brain and spinal cord, microglia are crucial for the phagocytosis of infectious agents, apoptotic cells and synapses. During brain injury or infection, bone-marrow derived macrophages invade neural tissue, making it difficult to distinguish between invading macrophages and resident microglia. In addition to circulation-derived monocytes, other non-microglial central nervous system (CNS) macrophage subtypes include border-associated meningeal, perivascular and choroid plexus macrophages.
View Article and Find Full Text PDFFowler syndrome is a rare autosomal recessive brain vascular disorder caused by mutation in FLVCR2 in humans. The disease occurs during a critical period of brain vascular development, is characterized by glomeruloid vasculopathy and hydrocephalus, and is almost invariably prenatally fatal. Here, we sought to gain insights into the process of brain vascularization and the pathogenesis of Fowler syndrome by inactivating Flvcr2 in mice.
View Article and Find Full Text PDFMicroglia play a pivotal role in the coordination of brain development and have emerged as a critical determinant in the progression of neurodegenerative diseases; however, the role of microglia in the onset and progression of neurodevelopmental disorders is less clear. Here we show that conditional deletion of αVβ8 from the central nervous system ( mice) blocks microglia in their normal stepwise development from immature precursors to mature microglia. These "dysmature" microglia appear to result from reduced TGFβ signaling during a critical perinatal window, are distinct from microglia with induced reduction in TGFβ signaling during adulthood, and directly cause a unique neurodevelopmental syndrome characterized by oligodendrocyte maturational arrest, interneuron loss, and spastic neuromotor dysfunction.
View Article and Find Full Text PDFIn nature, there are >200 species of fungi with hallucinogenic properties. These fungi are classified as Psilocybe, Gymnopilus, and Panaeolus which contain active principles with hallucinogenic properties such as ibotenic acid, psilocybin, psilocin, or baeocystin. In Chile, fungi seizures are mainly of mature specimens or spores.
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