Project description:Environmental enteric dysfunction (EED), a chronic diffuse inflammation of the small intestine, is associated with stunting in children in the developing world. The pathobiology of EED is poorly understood because of the lack of a method to elucidate the host response. This study utilized a novel microarray method to interrogate the host transcriptome in feces in Malawian children with EED. Our data showed that the children studied had a range of %L values, consistent a spectrum of EED from normal to severe. We identified 12 transcripts associated with the severity of EED, including chemokines that stimulate T-cell proliferation, Fc fragments of multiple immunoglobulin families, interferon-induced proteins, activators of neutrophils and B-cells, and mediators that dampen cellular responses to hormones. EED associated transcripts mapped to pathways related to cell adhesion, and responses to a broad spectrum of viral, bacterial and parasitic microbes and enhanced phagocytosis. Several mucins, regulatory factors and protein kinases associated with the maintenance of the mucous layer were expressed less in children with EED than normal children. In conclusion, EED represents the focused activation of elements of the immune system and is associated with widespread intestinal barrier disruption. The differentially expressed transcripts may be explored as potential biomarkers. In 259 children, EED was measured by lactulose permeability (%L) in the small intestine. After isolating low copy numbers of mRNA, the transcriptome was reliably and reproducibly profiled. mRNA copy number was correlated with %L using analyses of covariance. The transcripts identified were mapped to biological pathways and processes.
Project description:Circadian clock is a highly conserved regulatory system which could coordinate many physiological processes with external stimuli, displaying oscillation with a periodicity of ~24 hour. Dysfunction of circadian clock has been involved in the pathogenesis of a broad spectrum of diseases such as metabolic diseases and chronic kidney disease. However the role of circadian clock in diabetic nephropathy remains largely unknown.
Project description:Abstract Isorhynchophylline, a tetracyclic indole alkaloid, has anti-inflammatory and antioxidant activities against cardiovascular diseases and central nervous system disorders. Acute lung injury (ALI) is a manifestation of inflammation concentrated in the lungs and has a high incidence rate and mortality. Here, we established a mouse model of ALI and observed the effects of isorhynchophylline. Proteomic results showed that 5727 proteins were detected in mouse lung tissues, and 16 proteins were screened out. Isorhynchophylline could reverse the trend of these differential proteins. In addition, isorhynchophylline can act on integrin alpha M to reduce neutrophil recruitment and thereby produce anti-inflammatory effects and may suppress neutrophil migration through the leukocyte transendothelial migration pathway. TUNEL and RT-PCR experiments revealed that LPS-induced ALI in mice increases the apoptosis of lung tissues, damage to alveolar epithelial cells and levels of inflammatory factors. Treatment with isorhynchophylline can repair tissues, improve lung tissue pathology and reduce lung inflammation.
Project description:Although modern clinical practices such as cesarean sections and perinatal antibiotics have improved infant survival, treatment with broad-spectrum antibiotics alters intestinal microbiota and causes dysbiosis. Infants exposed to perinatal antibiotics have an increased likelihood of life-threatening infections, including pneumonia. Here, we investigated how the gut microbiota sculpt pulmonary immune responses, promoting recovery and resolution of infection in newborn rhesus macaques. Early-life antibiotic exposure interrupted the maturation of intestinal commensal bacteria and disrupted the developmental trajectory of the pulmonary immune system, as assessed by single-cell proteomic and transcriptomic analyses. Early-life antibiotic exposure rendered newborn macaques more susceptible to bacterial pneumonia, concurrent with increases in neutrophil senescence and hyperinflammation, broad inflammatory cytokine signaling, and macrophage dysfunction. This pathogenic reprogramming of pulmonary immunity was further reflected by a hyperinflammatory signature in all pulmonary immune cell subsets coupled with a global loss of tissue-protective, homeostatic pathways in the lungs of dysbiotic newborns. Fecal microbiota transfer was associated with partial correction of the broad immune maladaptations and protection against severe pneumonia. These data demonstrate the importance of intestinal microbiota in programming pulmonary immunity and support the idea that gut microbiota promote the balance between pathways driving tissue repair and inflammatory responses associated with clinical recovery from infection in infants. Our results highlight a potential role for microbial transfer for immune support in these at-risk infants.
Project description:Tissue maintenance and repair depend on the integrated activity of multiple cell types. Whereas the contributions of epithelial, immune and stromal cells in intestinal tissue integrity are well understood, the role of intrinsic neuroglia networks remains largely unknown. Here, we uncover pivotal roles of enteric glial cells (EGCs) in intestinal homeostasis, immunity and tissue repair. We demonstrate that infection of mice with Heligmosomoides polygyrus (H. poly) leads to enteric gliosis and upregulation of the interferon gamma (IFN-γ) gene signature. Single-cell transcriptomics of tunica muscularis (TM) showed that glia-specific abrogation of IFN-γ signaling leads to tissue-wide activation of pro-inflammatory transcriptional programs. In addition, disruption of the IFN-γ-EGC signaling axis enhanced the inflammatory and granulomatous response of TM to helminths. Mechanistically, we show that upregulation of Cxcl10 is an early immediate response of EGCs to IFN-γ signaling and provide evidence that this chemokine and the downstream amplification of IFN-γ signaling in the TM are required for a measured inflammatory response to helminths and resolution of granulomatous pathology. Our study demonstrates that IFN-γ signaling in enteric glia is central to intestinal homeostasis and reveals critical roles of the IFN-γ-EGC-Cxcl10 axis in immune response and tissue repair following infectious challenge. To characterize the response of enteric glia to helminth infection, we performed bulk RNAseq of tdT+ cells (=EGCs) and tdT- cells (=non-glia cells) from the TM of naïve and H. poly-infected Sox10CreERT2;Rosa26tdTomato mice.
Project description:Tissue maintenance and repair depend on the integrated activity of multiple cell types. Whereas the contributions of epithelial, immune and stromal cells in intestinal tissue integrity are well understood, the role of intrinsic neuroglia networks remains largely unknown. Here, we uncover pivotal roles of enteric glial cells (EGCs) in intestinal homeostasis, immunity and tissue repair. We demonstrate that infection of mice with Heligmosomoides polygyrus (H. poly) leads to enteric gliosis and upregulation of the interferon gamma (IFN-γ) gene signature. Single-cell transcriptomics of tunica muscularis (TM) showed that glia-specific abrogation of IFN-γ signaling leads to tissue-wide activation of pro-inflammatory transcriptional programs. In addition, disruption of the IFN-γ-EGC signaling axis enhanced the inflammatory and granulomatous response of TM to helminths. Mechanistically, we show that upregulation of Cxcl10 is an early immediate response of EGCs to IFN-γ signaling and provide evidence that this chemokine and the downstream amplification of IFN-γ signaling in the TM are required for a measured inflammatory response to helminths and resolution of granulomatous pathology. Our study demonstrates that IFN-γ signaling in enteric glia is central to intestinal homeostasis and reveals critical roles of the IFN-γ-EGC-Cxcl10 axis in immune response and tissue repair following infectious challenge. To characterize the response of enteric glia to helminth infection at single cell resolution, we next performed scRNAseq (C1 Fluidigm platform) of tdT+ cells from the TM of naïve and H. poly-infected mice.
Project description:The p53 transcription factor is a regulator of key cellular processes including DNA repair, cell cycle arrest, and apoptosis. In this theoretical study, we investigate how the complex circuitry of the p53 network allows for stochastic yet unambiguous cell fate decision-making. The proposed Markov chain model consists of the regulatory core and two subordinated bistable modules responsible for cell cycle arrest and apoptosis. The regulatory core is controlled by two negative feedback loops (regulated by Mdm2 and Wip1) responsible for oscillations, and two antagonistic positive feedback loops (regulated by phosphatases Wip1 and PTEN) responsible for bistability. By means of bifurcation analysis of the deterministic approximation we capture the recurrent solutions (i.e., steady states and limit cycles) that delineate temporal responses of the stochastic system. Direct switching from the limit-cycle oscillations to the "apoptotic" steady state is enabled by the existence of a subcritical Neimark-Sacker bifurcation in which the limit cycle loses its stability by merging with an unstable invariant torus. Our analysis provides an explanation why cancer cell lines known to have vastly diverse expression levels of Wip1 and PTEN exhibit a broad spectrum of responses to DNA damage: from a fast transition to a high level of p53 killer (a p53 phosphoform which promotes commitment to apoptosis) in cells characterized by high PTEN and low Wip1 levels to long-lasting p53 level oscillations in cells having PTEN promoter methylated (as in, e.g., MCF-7 cell line).