Project description:Athough anti-TNF therapies can be used to treat colitis associated with inflammatory bowel disease, in mice the loss of the TNF receptor TNFR1 (Tnfrsf1a) in the Il10-/- spontaneous colitis background results in acceleration of disease onset. Whereas Il10-/- mice on the Bl/6 background are relatively protected from colitis throughout life, Il10-/- Tnfr1-/- mice develop colitis beginning at 4 wks of age. Their disease results in nearly 50% mortality by 12 wks of age. Strikingly, Tnfr1-/- mice (with functional IL-10) exhibit evidence of mucosal dysfunction at 4 and 12 wks of age. These mucosal abnormalities include loss of barrier integrity, increased epithelial cell proliferation, crypt malformations, and increased immune cell infiltrate. Because of the early onset of mucosal abnormalities in Tnfr1-/- mice, with or without IL-10 expression, we hypothesized that TNFR1 plays important roles in colonic mucosal function in early life, prior to weaning. To test this hypothesis, we profiled, using mRNA-Seq, the colonic transcriptomes from wildtype and Tnfr1-/- mice at 2 wks of age. The results demonstrate that Tnfr1-/- mice have important gene expression changes, including reduced expression of Il1b, a marker of the proinflammatory "weaning reaction" that is required for establishment of mucosal tolerance in later life. TNFR1 therefore has key roles in colonic mucosal homeostasis in early life.
Project description:The loss of TNFR1 (Tnfrsf1a) in the Il10-/- spontaneous mouse colitis background results in acceleration of disease onset. Whereas Il10-/- mice on the Bl/6 background are relatively protected from colitis throughout life, Il10-/- Tnfr1-/- mice develop colitis beginning at 4 wks of age. Their disease results in nearly 50% mortality by 12 wks of age. We hypothesized that this early-onset colitis was due to dysregulation of immune signals in early life, defining a key period known as the "weaning reaction" in which proinflammatory signals help induce mucosal tolerance of the microbiome. To test this hypothesis, we profiled, using mRNA-Seq, the colonic transcriptomes from Il10-/- and Il10-/- Tnfr1-/- mice at 2 wks of age. The results presented here show that Il10-/- Tnfr1-/- mice have reduced expression of cytokines at this early age, suggesting that they cannot amount an appropriate immune response. Thus, TNFR1 plays an important role in the weaning reaction and the acquisition of tolerance.
Project description:We have compared mRNA expression in full-thickness mouse colon between wildtype mice and mice with a genetic deletion in tumor necrosis factor receptor 1 (TNFR1, encoded by the Tnfrsf1a gene). This experiment was motivated by our observation that Il10-/- Tnfr1-/- double-knockout mice develop very-early-onset colitis at the time of weaning, significantly earlier than disease onset in Il10-/- single-knockout mice. This suggests that TNFR1 mediates protection from colitis. To understand these protective mechanisms at the transcript level in a non-inflammatory context, we performed transcriptome profiling (mRNA-Seq) on colons from 12-week-old Tnfr1-/- mice, which do not develop colitis, and wildtype littermates. These experiments revealed that an estimated 510 transcripts were upregulated and 377 downregulated in colonic tissue of Tnfr1-/- mice. We aggregated the transcript information to calculate gene expression and performed gene set enrichment analysis to identify signaling pathways altered in Tnfr1-/- mice. When queried against a high-confidence set of 50 signaling pathways, the Tnfr1-/- gene expression profile was associated with reduced mitosis and increased glycolysis, transforming growth factor beta signaling, DNA repair, and reactive oxygen species signaling. Gene ontological analysis classified some of the differentially expressed genes into cytokines, junctional proteins, and transcription factors, but within these groups there was no consensus on the direction of regulation. We also examined how differentially expressed transcripts (called the TNFR1-regulated transcriptome) compared to differentially expressed colonic transcripts from previously collected Tnfr2-/- animals (or the TNFR2-regulated transcriptome, available at the NCBI Gene Expression Omnibus under the accession GSE65408). The raw data were re-analyzed with the current pipeline to enable comparison. There was almost no correlation between TNFR1- and TNFR2-regulated transcripts. Only 30 (~3%) TNFR1-regulated transcripts were also TNFR2-regulated transcripts, and ~4% of the TNFR2-regulated genes were also TNFR1-regulated genes. Of the few co-regulated transcripts, there was a significant negative correlation in their direction of regulation in Tnfr1-/- versus Tnfr2-/- colons. Collectively these results indicate that TNFR1 and TNFR2 have mostly different and opposing effects on gene expression in the mouse colon. MANUSCRIPT ABSTRACT: BACKGROUND & AIMS: Very-early-onset inflammatory bowel disease (VEO-IBD) is a devastating disease beginning in early childhood, refractory to anti-tumor necrosis factor (anti-TNF) therapies, and associated with mutations in the interleukin 10 (IL-10) pathway. Contrary to mainstream clinical practice, cellular and animal studies have shown beneficial roles of TNF signaling in colitis, but how these roles are encoded through TNF’s receptors remains unknown. Here we examined the role of TNF receptor 1 (TNFR1, or p55) in modulating the onset and severity of colitis in the interleukin 10 (IL-10)-deficient mouse model. METHODS: Colitis severity was compared between Il10-/- Tnfr1-/- and Il10-/-- littermate mice at 2-12 weeks of age. To assess dysbiosis as a potential pathogenic mechanism, Il10-/- Tnfr1-/- mice were treated with neomycin and metronidazole and their cecal contents analyzed by 16S rRNA sequencing. Gene expression, barrier function, and epithelial proliferation and apoptosis were examined in adult colitis-free Tnfr1-/- wildtype littermates. RESULTS: In contrast to relatively healthy Il10-/- mice, Il10-/- Tnfr1-/- mice developed severe, antibiotic-treatable colitis shortly after weaning. Microbiotal composition was similar between Il10‑/- Tnfr1-/- mice and Il10-/- littermate controls. Tnfr1-/- mice expressed transcripts associated with reactive oxygen species and DNA repair pathways. Tnfr1-/- mice exhibited focal areas of crypt branching, higher colonic epithelial permeability, and hallmarks of DNA damage. CONCLUSIONS: TNFR1 promotes epithelial homeostasis and regulates commensal exposure. The lack of TNFR1 accelerates the onset and severity of IBD in the absence of tolerogenic signaling (i.e., lack of IL-10). Il10-/- Tnfr1-/- mice may serve as a valuable model of very-early-onset IBD (VEO-IBD).
Project description:Research shows that children who are reared in households with low socioeconomic status are more vulnerable to heart disease, respiratory infection, and some cancers when they reach adulthood. This study conducted transcriptional profiling of PBMC in healthy adults who were low vs. high in early-life SES to explore the long-lasting genomic effects of early experience. Keywords: life stress, gene expression, inflammation, socioeconomic status Samples from 30 adults with low early-life SES and 30 adults with high early-life SES
Project description:Death receptor-mediated hepatocyte apoptosis is implicated in a wide range of liver diseases including viral hepatitis, alcoholic hepatitis, ischemia/reperfusion injury, fulminant hepatic failure, cholestatic liver injury and cancer. Deletion of NF-ĸB essential modulator in hepatocytes (NemoΔhepa) causes the spontaneous development of hepatocellular carcinoma preceded by steatohepatitis in mice and thus serves as an excellent model for the progression from chronic hepatitis to liver cancer. In the present study we aimed to dissect the death-receptor mediated pathways that contribute to liver injury in NemoΔhepa mice. Therefore, we generated NemoΔhepa/TRAIL-/- and NemoΔhepa/TNFR1-/- animals and analyzed the progression of liver injury. NemoΔhepa/TRAIL-/- displayed a similar phenotype to NemoΔhepa mice characteristic of high apoptosis, infiltration of immune cells, hepatocyte proliferation and steatohepatitis. These pathophysiological features were significantly ameliorated in NemoΔhepa/TNFR1-/- livers. Hepatocyte apoptosis was increased in NemoΔhepa and NemoΔhepa/TRAIL-/- mice while NemoΔhepa/TNFR1-/- animals showed reduced cell death concomitant with a strong reduction in pJNK levels. Cell cycle parameters were significantly less activated in NemoΔhepa/TNFR1-/- livers. Additionally, markers of liver fibrosis and indicators of tumour progression were significantly decreased in these animals. The present data demonstrate that the death receptor TNFR1 but not TRAIL is important in determining progression of liver injury in hepatocyte-specific Nemo knockout mice. Expression profiling of livers from wild type, NEMO, NEMO-TRIAL, and NEMO-TNFR null mice
Project description:Research shows that children who are reared in households with low socioeconomic status are more vulnerable to heart disease, respiratory infection, and some cancers when they reach adulthood. This study conducted transcriptional profiling of PBMC in healthy adults who were low vs. high in early-life SES to explore the long-lasting genomic effects of early experience. Keywords: life stress, gene expression, inflammation, socioeconomic status
Project description:Death receptor-mediated hepatocyte apoptosis is implicated in a wide range of liver diseases including viral hepatitis, alcoholic hepatitis, ischemia/reperfusion injury, fulminant hepatic failure, cholestatic liver injury and cancer. Deletion of NF-ĸB essential modulator in hepatocytes (NemoΔhepa) causes the spontaneous development of hepatocellular carcinoma preceded by steatohepatitis in mice and thus serves as an excellent model for the progression from chronic hepatitis to liver cancer. In the present study we aimed to dissect the death-receptor mediated pathways that contribute to liver injury in NemoΔhepa mice. Therefore, we generated NemoΔhepa/TRAIL-/- and NemoΔhepa/TNFR1-/- animals and analyzed the progression of liver injury. NemoΔhepa/TRAIL-/- displayed a similar phenotype to NemoΔhepa mice characteristic of high apoptosis, infiltration of immune cells, hepatocyte proliferation and steatohepatitis. These pathophysiological features were significantly ameliorated in NemoΔhepa/TNFR1-/- livers. Hepatocyte apoptosis was increased in NemoΔhepa and NemoΔhepa/TRAIL-/- mice while NemoΔhepa/TNFR1-/- animals showed reduced cell death concomitant with a strong reduction in pJNK levels. Cell cycle parameters were significantly less activated in NemoΔhepa/TNFR1-/- livers. Additionally, markers of liver fibrosis and indicators of tumour progression were significantly decreased in these animals. The present data demonstrate that the death receptor TNFR1 but not TRAIL is important in determining progression of liver injury in hepatocyte-specific Nemo knockout mice.
Project description:Early life adversity has been linked to altered reproductive development in humans, including changes in the timing of pubertal onset and sexual activity. One common form of early life adversity is having limited access to resources. This form of early life adversity can be modeled in rodents using the limited bedding and nesting model (LBN), in which rat dams and pups are placed in a low resource environment from postnatal day (PND) 2 through 9. Our laboratory has previously shown that male rats raised in LBN conditions have elevated levels of plasma estradiol compared to control males. Female rats, on the other hand, show no effect of LBN on plasma hormone levels, pubertal timing, or estrous cycle duration in adulthood. Here, we find that LBN males also show changes in adult reproductive behaviors. LBN males acquired the suite of reproductive behaviors more quickly than their control counterparts over the course of 3 weeks of testing, showing shorter latencies to mount, intromit, and ejaculate compared to controls prior to the final week of testing. We also characterized LBN-induced gene transcription changes across sex in the medial preoptic area (mPOA) which underlies reproductive behaviors. Interestingly, there was no effect of LBN on puberty onset (as measured by preputial separation) or masculinization of the sexually dimorphic nucleus of the preoptic area (SDN/POA; as measured by calbindin immunoreactivity) in males, suggesting LBN may not exert effects on hormone-dependent measures until after puberty.