Psoriatic skin differs distinctly from normal skin by its thickened epidermis. Most gene expression comparisons utilize full-thickness biopsies, with substantial amount of dermis. We assayed the ...transcriptomes of normal, lesional, and non-lesional psoriatic epidermis, sampled as split-thickness skin grafts, with 5'-end RNA sequencing. We found that psoriatic epidermis contains more mRNA per total RNA than controls, and took this into account in the bioinformatic analysis. The approach highlighted innate immunity-related pathways in psoriasis, including NOD-like receptor (NLR) signaling and inflammasome activation. We demonstrated that the NLR signaling genes NOD2, PYCARD, CARD6, and IFI16 are upregulated in psoriatic epidermis, and strengthened these findings by protein expression. Interestingly, PYCARD, the key component of the inflammasome, showed an altered expression pattern in the lesional epidermis. The profiling of non-lesional skin highlighted PSORS4 and mitochondrially encoded transcripts, suggesting that their gene expression is altered already before the development of lesions. Our data suggest that all components needed for the active inflammasome are present in the keratinocytes of psoriatic skin. The characterization of inflammasome pathways provides further opportunities for therapy. Complementing previous transcriptome studies, our approach gives deeper insight into the gene regulation in psoriatic epidermis.
CCHCR1 (Coiled-Coil α-Helical Rod protein 1) is a putative psoriasis candidate gene with the risk alleles CCHCR1*WWCC and *Iso3, the latter inhibiting the translation of isoform 1. CCHCR1 was ...recently shown to be a centrosomal protein, as well as a component of cytoplasmic processing bodies (P-bodies) that regulate mRNA turnover. The function of CCHCR1 has remained unsettled, partly because of the inconsistent findings; it has been shown to play a wide variety of roles in divergent processes, e.g., cell proliferation and steroidogenesis. Here we utilized RNA sequencing (RNAseq) using HEK293 cells overexpressing isoforms 1 or 3 (Iso1, Iso3 cells), in combination with the coding non-risk or risk (*WWCC) haplotype of CCHCR1. Our aim was to study the overall role of CCHCR1 and the effects of its variants.
The overexpression of CCHCR1 variants in HEK293 cells resulted in cell line-specific expression profiles though several similarities were observable. Overall the Iso1 and Iso3 cells showed a clear isoform-specific clustering as two separate groups, and the Non-risk and Risk cells often exhibited opposite effects. The RNAseq supported a role for CCHCR1 in the centrosomes and P-bodies; the most highlighted pathways included regulation of cytoskeleton, adherens and tight junctions, mRNA surveillance and RNA transport. Interestingly, both the RNAseq and immunofluorescent localization revealed variant-specific differences for CCHCR1 within the P-bodies.
CCHCR1 influenced a wide variety of signaling pathways, which could reflect its active role in the P-bodies and centrosomes that both are linked to the cytoskeleton; as a centrosomal P-body protein CCHCR1 may regulate diverse cytoskeleton-mediated functions, such as cell adhesion and -division. The present findings may explain the previous inconsistent observations about the functions of CCHCR1.
Desmoplakin (DSP) and Desmoglein 1 (DSG1) variants result in skin barrier defects leading to erythroderma, palmoplantar keratoderma and variable AQ4 other features. Some DSG1 variant carriers present ...with SAM syndrome (Severe dermatitis, multiple Allergies, Metabolic wasting) and a SAM-like phenotype has been reported in 4 subjects with different heterozygous DSP variants. We report here a patient with a novel DSP spectrin region (SR) 6 variant c.1756C>T, p.(His586Tyr), novel features of brain lesions and severe recurrent mucocutaneous herpes simplex virus infections, with a favourable response to ustekinumab. Through a review of reported cases of heterozygous variants in DSP SR6 (n = 15) and homozygous or compound heterozygous variants in DSG1 (n = 12) and SAM-like phenotype, we highlight phenotypic variability. Woolly hair, nail abnormalities and cardiomyopathy characterize patients with DSP variants, while elevated immunoglobulin E and food allergies are frequent in patients with DSG1 variants. Clinicians should be aware of the diverse manifestations of desmosomopathies.
Epitranscriptomic modifications in RNA can dramatically alter the way our genetic code is deciphered. Cells utilize these modifications not only to maintain physiological processes, but also to ...respond to extracellular cues and various stressors. Most often, adenosine residues in RNA are targeted, and result in modifications including methylation and deamination. Such modified residues as
-6-methyl-adenosine (m
A) and inosine, respectively, have been associated with cardiovascular diseases, and contribute to disease pathologies. The Ischemic Heart Disease Epitranscriptomics and Biomarkers (IHD-EPITRAN) study aims to provide a more comprehensive understanding to their nature and role in cardiovascular pathology. The study hypothesis is that pathological features of IHD are mirrored in the blood epitranscriptome. The IHD-EPITRAN study focuses on m
A and A-to-I modifications of RNA. Patients are recruited from four cohorts: (I) patients with IHD and myocardial infarction undergoing urgent revascularization; (II) patients with stable IHD undergoing coronary artery bypass grafting; (III) controls without coronary obstructions undergoing valve replacement due to aortic stenosis and (IV) controls with healthy coronaries verified by computed tomography. The abundance and distribution of m
A and A-to-I modifications in blood RNA are charted by quantitative and qualitative methods. Selected other modified nucleosides as well as IHD candidate protein and metabolic biomarkers are measured for reference. The results of the IHD-EPITRAN study can be expected to enable identification of epitranscriptomic IHD biomarker candidates and potential drug targets.
CCHCR1 (Coiled-Coil α-Helical Rod protein 1), within the major psoriasis susceptibility locus PSORS1, is a plausible candidate gene with the psoriasis associated risk allele CCHCR1*WWCC. Although its ...expression pattern in psoriatic skin differs from healthy skin and its overexpression influences cell proliferation in transgenic mice, its role as a psoriasis effector gene has remained unsettled. The 5'-region of the gene contains a SNP (rs3130453) that controls a 5'-extended open reading frame and thus the translation of alternative isoforms. We have now compared the function of two CCHCR1 isoforms: the novel longer isoform 1 and the previously studied isoform 3. In samples of Finnish and Swedish families, the allele generating only isoform 3 shows association with psoriasis (P<10(-7)). Both isoforms localize at the centrosome, a cell organelle playing a role in cell division. In stably transfected cells the isoform 3 affects cell proliferation and with the CCHCR1*WWCC allele, also apoptosis. Furthermore, cells overexpressing CCHCR1 show isoform- and haplotype-specific influences in the cell size and shape and alterations in the organization and expression of the cytoskeletal proteins actin, vimentin, and cytokeratins. The isoform 1 with the non-risk allele induces the expression of keratin 17, a hallmark for psoriasis; the silencing of CCHCR1 reduces its expression in HEK293 cells. CCHCR1 also regulates EGF-induced STAT3 activation in an isoform-specific manner: the tyrosine phosphorylation of STAT3 is disturbed in isoform 3-transfected cells. The centrosomal localization of CCHCR1 provides a connection to the abnormal cell proliferation and offers a link to possible cellular pathways altered in psoriasis.
The macrophage scavenger receptor macrophage receptor with a collagenous structure (MARCO) is expressed in mice by the marginal zone macrophages of the spleen and by macrophages of the medullary ...cords of lymph nodes, as well as the peritoneal macrophages. MARCO is a relative of scavenger receptor A (SR-A), the more widely expressed prototypic member of the scavenger receptor family. In the present study, we found that genetic ablation of MARCO leads to changes in the organization of the splenic marginal zone, and causes a significant reduction in the size of the resident peritoneal macrophage population, possibly due to changes in adhesion and migration capacity. In mice lacking both MARCO and SR-A these effects are even more apparent. During ontogeny, the appearance and organization of the MARCO-expressing cells in the spleen precedes the appearance of other receptors on macrophages in the marginal zone, such as SIGNR1 and Siglec-1. In the absence of MARCO, a clear delay in the organization of the marginal zone was observed. Similar findings were seen when the reappearance of the various subsets from precursors was studied after depleting macrophages from the adult spleen by a liposome treatment. When challenged with a pneumococcal polysaccharide vaccine, a T-independent type 2 Ag for which an intact marginal zone is crucial, the knockout mice exhibited a clearly impaired response. These findings suggest that both MARCO and SR-A, in addition to being important scavenger receptors, could be involved in the positioning and differentiation of macrophages, possibly through interaction with endogenous ligands.
Despite chronic inflammation, psoriatic lesions hardly ever progress to skin cancer. Aberrant function of the CCHCR1 gene (Coiled-Coil alpha-Helical Rod protein 1, HCR) within the PSORS1 locus may ...contribute to the onset of psoriasis. As CCHCR1 is expressed in certain cancers and regulates keratinocyte (KC) proliferation in a transgenic mouse model, we studied its relation to proliferation in cutaneous squamous cell cancer (SCC) cell lines by expression arrays and quantitative RT-PCR and in skin tumors by immunohistochemistry. CCHCR1 protein was detected in the pushing border of SCC and lining basal cell carcinoma islands. Different from psoriasis, Ki67 had a similar expression pattern as CCHCR1. The most intense CCHCR1 staining occurred in areas positive for epidermal growth factor receptor (EGFR). Expression of CCHCR1 mRNA was upregulated 30-80% in SCC lines when compared to normal KCs and correlated positively with Ki67 expression. The most aggressive and invasive tumor cell lines (RT3, FaDu) expressed CCHCR1 mRNA less than non-tumorigenic HaCaT cells. Moreover, the tumor promoters okadaic acid and menadione downregulated CCHCR1 mRNA. We conclude that both in psoriasis and the early stages of KC transformation, CCHCR1 may function as a negative regulator of proliferation, but beyond a certain point in oncogenesis cannot control this phenomenon any longer.
A novel murine plasma membrane protein has been identified in subpopulations of macrophages. It has an intracellular N-terminal domain, a transmembrane domain, and an extracellular region with a ...short spacer, an 89 Gly-Xaa-Yaa repeat-containing collagenous domain, and a C-terminal cysteine-rich domain. In situ hybridization and immunohistochemical staining have localized the protein to a subset of macrophages in the marginal zone of the spleen and the medullary cord of lymph nodes. No expression was observed in macrophages of liver or lung. Transfected COS cells synthesized a native trimeric plasma membrane protein that bound labeled bacteria and acetylated LDL, but not yeast or Ficoll. The results suggest that the novel protein is a macrophage-specific membrane receptor with a role in host defense, as it shows postnatal expression in macrophages, which are considered responsible for the binding of bacterial antigens and phagocytosis.
The scavenger receptors expressed by macrophages are thought to play an important role in the immune response against bacteria by mediating binding and phagocytosis. A novel member of the class A ...scavenger receptor family, macrophage receptor with collagenous structure (MARCO), has recently been identified. In this study we have generated a panel of mAbs with specificities for different domains of this receptor. Two of those reacting with the C-terminal cysteine-rich domain block ligand binding of MARCO. The in vivo expression of this murine receptor is normally restricted to distinct populations of macrophages in the spleen and lymph nodes. During bacillus Calmette-Guérin (BCG) infection, during bacterial sepsis, or after the injection of purified LPS, however, the expression of MARCO is rapidly induced on macrophages in other tissues, including Kupffer cells in the liver. Using the mouse macrophage cell line J774.2, it was shown that LPS stimulation up-regulates surface expression of MARCO in a dose- and time-dependent fashion. The proinflammatory cytokines IL-1, IL-6, TNF-alpha, and IFN-gamma had little or no effect. Using inhibitory mAbs, the relevance of MARCO for the clearance of circulating bacteria in vivo was determined. Although the overall elimination of live Escherichia coli and Staphylococcus aureus from the blood did not appear to be affected by treatment with these Abs, the capturing of heat-killed bacteria by macrophages in the marginal zone areas of the spleen was clearly inhibited. This study suggests a role for MARCO in the host antibacterial defense.
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