Diabetic Csf1op/op Mice Lacking Macrophages Are Protected Against the Development of Delayed Gastric Emptying

Background & AimsDiabetic gastroparesis is associated with changes in interstitial cells of Cajal (ICC), neurons, and smooth muscle cells in both animal models and humans. Macrophages appear to be critical to the development of cellular damage that leads to delayed gastric emptying (GE), but the mechanisms involved are not well understood. Csf1op/op (Op/Op) mice lack biologically active Csf1 (macrophage colony stimulating factor), resulting in the absence of Csf1-dependent tissue macrophages. We used Csf1op/op mice to determine the role of macrophages in the development of delayed GE.MethodsAnimals were injected with streptozotocin to make them diabetic. GE was determined weekly. Immunohistochemistry was used to identify macrophages and ICC networks in the gastric muscular layers. Oxidative stress was measured by serum malondialdehyde (MDA) levels. Quantitative reverse-transcription polymerase chain reaction was used to measure levels of mRNA.ResultsCsf1op/op mice had normal ICC. With onset of diabetes both Csf1op/op and wild-type Csf1+/+ mice developed increased levels of oxidative stress (75.8 ± 9.1 and 41.2 ± 13.6 nmol/mL MDA, respectively). Wild-type Csf1+/+ mice developed delayed GE after the onset of diabetes (4 of 13) whereas no diabetic Csf1op/op mouse developed delayed GE (0 of 15, P = .035). The ICC were disrupted in diabetic wild-type Csf1+/+ mice with delayed GE but remained normal in diabetic Csf1op/op mice.ConclusionsCellular injury and development of delayed GE in diabetes requires the presence of muscle layer macrophages. Targeting macrophages may be an effective therapeutic option to prevent cellular damage and development of delayed GE in diabetes

Transcriptomic signatures reveal immune dysregulation in human diabetic and idiopathic gastroparesis

Abstract Background Cellular changes described in human gastroparesis have revealed a role for immune dysregulation, however, a mechanistic understanding of human gastroparesis and the signaling pathways involved are still unclear. Methods Diabetic gastroparetics, diabetic non-gastroparetic controls, idiopathic gastroparetics and non-diabetic non-gastroparetic controls underwent full-thickness gastric body biopsies. Deep RNA sequencing was performed and pathway analysis of differentially expressed transcripts was done using Ingenuity®. A subset of differentially expressed genes in diabetic gastroparesis was validated in a separate cohort using QT-PCR. Results 111 genes were differentially expressed in diabetic gastroparesis and 181 in idiopathic gastroparesis with a log2fold difference of | ≥ 2| and false detection rate (FDR) < 5%. Top canonical pathways in diabetic gastroparesis included genes involved with macrophages, fibroblasts and endothelial cells in rheumatoid arthritis, osteoarthritis pathway and differential regulation of cytokine production in macrophages and T helper cells by IL-17A and IL-17F. Top canonical pathways in idiopathic gastroparesis included genes involved in granulocyte adhesion and diapedesis, agranulocyte adhesion and diapedesis, and role of macrophages, fibroblasts and endothelial cells in rheumatoid arthritis. Sixty-five differentially expressed genes (log2fold difference | ≥ 2|, FDR < 5%) were common in both diabetic and idiopathic gastroparesis with genes in the top 5 canonical pathways associated with immune signaling. 4/5 highly differentially expressed genes (SGK1, APOLD1, CXCR4, CXCL2, and FOS) in diabetic gastroparesis were validated in a separate cohort of patients using RT-PCR. Immune profile analysis revealed that genes associated with M1 (pro inflammatory) macrophages were enriched in tissues from idiopathic gastroparesis tissues compared to controls (p < 0.05). Conclusions Diabetic and idiopathic gastroparesis have both unique and overlapping transcriptomic signatures. Innate immune signaling likely plays a central role in pathogenesis of human gastroparesis.https://deepblue.lib.umich.edu/bitstream/2027.42/145193/1/12920_2018_Article_379.pd

Transcriptomic signatures reveal immune dysregulation in human diabetic and idiopathic gastroparesis

Abstract Background Cellular changes described in human gastroparesis have revealed a role for immune dysregulation, however, a mechanistic understanding of human gastroparesis and the signaling pathways involved are still unclear. Methods Diabetic gastroparetics, diabetic non-gastroparetic controls, idiopathic gastroparetics and non-diabetic non-gastroparetic controls underwent full-thickness gastric body biopsies. Deep RNA sequencing was performed and pathway analysis of differentially expressed transcripts was done using Ingenuity®. A subset of differentially expressed genes in diabetic gastroparesis was validated in a separate cohort using QT-PCR. Results 111 genes were differentially expressed in diabetic gastroparesis and 181 in idiopathic gastroparesis with a log2fold difference of | ≥ 2| and false detection rate (FDR) < 5%. Top canonical pathways in diabetic gastroparesis included genes involved with macrophages, fibroblasts and endothelial cells in rheumatoid arthritis, osteoarthritis pathway and differential regulation of cytokine production in macrophages and T helper cells by IL-17A and IL-17F. Top canonical pathways in idiopathic gastroparesis included genes involved in granulocyte adhesion and diapedesis, agranulocyte adhesion and diapedesis, and role of macrophages, fibroblasts and endothelial cells in rheumatoid arthritis. Sixty-five differentially expressed genes (log2fold difference | ≥ 2|, FDR < 5%) were common in both diabetic and idiopathic gastroparesis with genes in the top 5 canonical pathways associated with immune signaling. 4/5 highly differentially expressed genes (SGK1, APOLD1, CXCR4, CXCL2, and FOS) in diabetic gastroparesis were validated in a separate cohort of patients using RT-PCR. Immune profile analysis revealed that genes associated with M1 (pro inflammatory) macrophages were enriched in tissues from idiopathic gastroparesis tissues compared to controls (p < 0.05). Conclusions Diabetic and idiopathic gastroparesis have both unique and overlapping transcriptomic signatures. Innate immune signaling likely plays a central role in pathogenesis of human gastroparesis.https://deepblue.lib.umich.edu/bitstream/2027.42/145193/1/12920_2018_Article_379.pd

Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas

Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN

Distribution and Characterization of ANO10 in Mouse Small Intestine

Background: Anoctamin 10 (Ano10) belongs to the class of proteins that includes Ca2+ activated Cl-channels such as Ano1, which is expressed in interstitial cells of Cajal (ICC). Mutations in Ano10 lead to spinocerebellar ataxia and immunological defects. Evidence suggests that Ano10 is not a Ca2+ -activated Cl-channel but rather an intracellular protein that may regulate intracellular Ca2+. The aim of this study was to characterize the distribution of Ano10 in the mouse small intestine in order to determine the cell types in which Ano10 may contribute to cellular physiology. Methods: Small intestinal tissues from adult Balb/c (n=3) mice were obtained for both cryosections (10 μm thickness) and whole mount preparations. Tissues were immunolabeled using antibodies raised against Ano10 (rabbit polyclonal), a marker of ICC - Kit (goat polyclonal), a pan-neuronal marker - HuC/D (human, serum derived), and a macrophage marker - F4/80 (rat monoclonal). Secondary antibody controls were performed by exposing samples to secondary antibody in the absence of primary antibody to test for non-specific staining. Double labeling of Ano10 with other cell specific markers was performed on 5 cryosections and 2 whole mounts for each mouse. The distribution of immunoreactivity (IR) was determined by confocal microscopic imaging. Results: Ano10-IR was found to be present in neuronal cell bodies outside of the nucleus. Ano10-IR was present in 100% of HuC/D-positive neurons of the myenteric and submucosal plexuses. Ano10-IR was not found in ICC of the myenteric region; however, there was colocalization of Ano10-IR with Kit-IR on ICC of the deep muscularis plexus (ICC-DMP). Ano10-IR also colocalized with F4/80-IR present on resident macrophages in the region of the myenteric plexus. 100% of F4/80-IR colocalized with Ano10-IR. Conclusions: Immuno-reactivity for Ano10 is present in all types of myenteric and submucosal neurons and in all resident macrophages. Ano10-IR was present in a subset of ICC, specifically ICC-DMP but not ICC in the myenteric plexus. Given the putative role of Ano10 as a regulator of intracellular Ca2+, Ano10 may play a role both in regulation of gastrointestinal motility via neurons and ICC-DMP, as well as immunological responses via resident macrophages. Grant support: NIH DK057061, P01DK68055, and P30DK08456