The mechanistic target of rapamycin mTORC1 is a key regulator of cell metabolism and autophagy. Despite widespread clinical use of mTOR inhibitors, the role of mTORC1 in renal tubular function and kidney homeostasis remains elusive. By utilizing constitutive and inducible deletion of conditional Raptor alleles in renal tubular epithelial cells, we discovered that mTORC1 deficiency caused a marked concentrating defect, loss of tubular cells and slowly progressive renal fibrosis. Transcriptional profiling revealed that mTORC1 maintains renal tubular homeostasis by controlling mitochondrial metabolism and biogenesis as well as transcellular transport processes involved in counter-current multiplication and urine concentration. Although mTORC2 partially compensated the loss of mTORC1, exposure to ischemia and reperfusion injury exaggerated the tubular damage in mTORC1-deficient mice, and caused pronounced apoptosis, diminished proliferation rates and delayed recovery. These findings identify mTORC1 as an essential regulator of tubular energy metabolism and as a crucial component of ischemic stress responses. Pharmacological inhibition of mTORC1 likely affects tubular homeostasis, and may be particularly deleterious if the kidney is exposed to acute injury. Furthermore, the combined inhibition of mTORC1 and mTORC2 may increase the susceptibility to renal damage.
mTORC1 maintains renal tubular homeostasis and is essential in response to ischemic stress.
Specimen part
View SamplesFetal liver of E14.5 RNaseh2b KOF and Rnaseh2b wild type embryos was isolated, RNA was extracted and microarray analysis using Affymetrix Mouse 430 2.0 gene chip was performed
Mammalian RNase H2 removes ribonucleotides from DNA to maintain genome integrity.
Specimen part
View SamplesThe experiment aimed at determing the influence of mast cell deficiency on the transcriptome of skin-infiltrating leukocytes in K14HPV16 mice at 2month and 6month of age. Overall design: Skin-inflitrating leucocytes were FACS-purified from mast cell proficient (Mcpt5-Cre-) and mast cell deficient (Mcpt5-Cre+) K14HPV16 mice. Mast cells (CD117 high, FCeR1 high) were excluded from the sorting gate. In order to control for minimal mast cell contamination during sorting from K14HPV16 Mcpt5-Cre- skin, mast cell signature transcripts were identified by comparing transcriptomes of samples fromK14HPV16 Mcpt5-Cre- mice in which mast cells were flow cytometrically included vs excluded.
Although Abundant in Tumor Tissue, Mast Cells Have No Effect on Immunological Micro-milieu or Growth of HPV-Induced or Transplanted Tumors.
Age, Specimen part, Subject
View SamplesRNA seq was used to compare the expression profile of macrophages in presence and absense of mast cells. MB49 cells were injected i.d. into Mcpt5-Cre+ R26DTA animals and cre-negative littermates. Macrophages were sorted at 20 d.p.i. Overall design: Macrophage RNA profiles of MB49 TAMs (tumor-associated macrophages), harvested at 20 d.p.i. in MC-Proficient and MC-deficient animals
Although Abundant in Tumor Tissue, Mast Cells Have No Effect on Immunological Micro-milieu or Growth of HPV-Induced or Transplanted Tumors.
Specimen part, Subject
View SamplesRetinitis Pigmentosa (RP) is a progressive retinal degeneration in which the retina loses nearly all of its photoreceptor cells and undergoes major structural changes. Little is known regarding the role the resident glia, the Mller glia, play in the progression of the disease. Here we define gene expression changes in Mller glial cells (MGCs) from two different mouse models of RP, the retinal degeneration 1 (rd1) and rhodopsin knock-out (Rhod-ko) models. The RNA repertoire of 28 single MGCs was comprehensively profiled, and a comparison was made between MGC from wild type (WT) and mutant retinas. Two time points were chosen for analysis, one at the peak of rod photoreceptor death and one during the period of cone photoreceptor death. MGCs have been shown to respond to retinal degeneration by undergoing gliosis, a process marked by the upregulation of GFAP. In this data, many additional transcripts were found to change. These can be placed into functional clusters, such as retinal remodeling, stress response, and immune related response. It is noteworthy that a high degree of heterogeneity among the individual cells was observed, possibly due to their different spatial proximities to dying cells, and/or inherent heterogeneity among MGCs.
Gene expression changes within Müller glial cells in retinitis pigmentosa.
Specimen part
View SamplesLarge numbers of ribonucleotides are incorporated into the eukaryotic nuclear genome during S-phase due to imperfect discrimination against ribonucleoside triphosphates by the replicative DNA polymerases. Ribonucleotides, by far the most common DNA lesion in replicating cells, destabilize the DNA, and an evolutionarily conserved DNA repair machinery, ribonucleotide excision repair (RER), ensures ribonucleotide removal. Complete lack of RER is embryonically lethal. Partial loss-of-function mutations in the genes encoding subunits of RNase H2, the enzyme essential for initiation of RER, cause the SLE-related type I interferonopathy Aicardi-Goutières syndrome. Here we establish that selective inactivation of RER in mouse epidermis results in spontaneous DNA damage, epidermal hyperproliferation associated with loss of hair follicle stem cells and hair follicle function. The animals develop keratinocyte intraepithelial neoplasia and invasive squamous cell carcinoma with complete penetrance, despite potent type I interferon production and skin inflammation. Compromised RER-mediated genome maintenance might represent an important tumor-promoting principle in human cancer. Overall design: CD45+ CD49f- cells were were isolated from skin cell suspensions by FACS. Total RNA was isolated using the RNeasy Micro Kit+ (Qiagen). mRNA libraries were prepared using a SMART protocol and subjected to deep sequencing on an Illumina®HiSeq 2500.
Ribonucleotide Excision Repair Is Essential to Prevent Squamous Cell Carcinoma of the Skin.
Specimen part, Subject
View SamplesLarge numbers of ribonucleotides are incorporated into the eukaryotic nuclear genome during S-phase due to imperfect discrimination against ribonucleoside triphosphates by the replicative DNA polymerases. Ribonucleotides, by far the most common DNA lesion in replicating cells, destabilize the DNA, and an evolutionarily conserved DNA repair machinery, ribonucleotide excision repair (RER), ensures ribonucleotide removal. Complete lack of RER is embryonically lethal. Partial loss-of-function mutations in the genes encoding subunits of RNase H2, the enzyme essential for initiation of RER, cause the SLE-related type I interferonopathy Aicardi-Goutières syndrome. Here we establish that selective inactivation of RER in mouse epidermis results in spontaneous DNA damage, epidermal hyperproliferation associated with loss of hair follicle stem cells and hair follicle function. The animals develop keratinocyte intraepithelial neoplasia and invasive squamous cell carcinoma with complete penetrance, despite potent type I interferon production and skin inflammation. Compromised RER-mediated genome maintenance might represent an important tumor-promoting principle in human cancer. Overall design: Keratinocytes (CD49f+) cells were isolated from skin cell suspensions by FACS. Total RNA was isolated using the RNeasy Mini Kit+ (Qiagen). mRNA libraries were prepared and subjected to deep sequencing on an Illumina®HiSeq.
Ribonucleotide Excision Repair Is Essential to Prevent Squamous Cell Carcinoma of the Skin.
Specimen part, Subject
View SamplesBiallelic defects of the gene encoding for the intracellular enzyme 3’ repair exonuclease (Trex)1 cause Aicardi-Goutières syndrome (AGS), a rare monogenic, lupus-like autoimmune disease, while heterozygous Trex1 loss of function alleles are associated with systemic lupus erythematosus (SLE). Trex1-/- mice develop lethal autoimmune multi-organ inflammation, which results from a chronic type I IFN response triggered by intracellular accumulation of a putative nucleic acid substrate of Trex1. This pathogenic nucleic acid is detected by the broadly, but not ubiquitously, expressed cytosolic DNA sensor cGAS, raising the question whether there are specific cell types that respond to Trex1 deficiency by production of IFN and induce autoimmunity. We generated mice with conditional knock out of the Trex1 gene and demonstrated that loss of Trex1 throughout the hematopoietic system and even selective loss in dendritic cells is sufficient to cause IFN release and autoimmunity. B cells showed no transcriptional response to Trex1 deficiency. Trex1-/- keratinocytes produced IFN but did not induce skin inflammation, whereas loss of Trex1 in cardiomyocytes triggered neither IFN response nor pathology. Trex1-deficient neurons and astrocytes did not release IFN in the CNS. In contrast, mice with selective inactivation of Trex1 in long-living CNS macrophages such as microglia locally produced IFN but did not reproduce the mild encephalitis seen in Trex1-/- mice. Collectively, individual cell types differentially respond to the loss of Trex1 and dendritic cells seem promising candidates for experiments addressing the molecular pathomechanism in Trex1 deficiency. Overall design: We sorted CD19-positive B cells from spleens of Trex1fl/fl CD19-Cre+ and Trex1fl/fl CD19-Cre- mice and isolated total RNA for library construction to perform mRNA deep sequencing.
Loss of Trex1 in Dendritic Cells Is Sufficient To Trigger Systemic Autoimmunity.
Specimen part, Subject
View SamplesTo elucidate responses of myeloid cells to SAMHD1 deficiency in the absence of exogenous viral infection, we performed global gene expression analysis of SAMHD1 deficient macrophages. Overall design: Peritoneal macrophages from 10 mutants and 10 controls were FACS sorted. Isolated RNA was subjected to next generation mRNA sequencing.
Mouse SAMHD1 has antiretroviral activity and suppresses a spontaneous cell-intrinsic antiviral response.
Sex, Age, Specimen part, Cell line
View SamplesTo investigate the contribution of type-1 IFN signalling to the upregulation of IFN- stimulated genes in SAMHD1-deficient cells, we performed global gene expression analysis of SAMHD1-deficient IFNAR-/- macrophages. Overall design: Peritoneal macrophages from ten SAMHD1-deficient IFNAR-/- and six SAMHD1-deficient controls were FACS sorted. RNA was subjected to next generation mRNA sequencing.
Mouse SAMHD1 has antiretroviral activity and suppresses a spontaneous cell-intrinsic antiviral response.
Sex, Age, Specimen part, Cell line, Subject
View Samples