Project description:Psoriasis is a common inflammatory disorder of the skin and other organs. We have determined that mutations in CARD14, encoding an NF-kB activator within skin epidermis, account for PSORS2. Here we describe fifteen additional rare, missense variants in CARD14, their distribution in seven psoriasis cohorts (>6,000 cases and >4,000 controls), and their effects on NF-kB activation and the transcriptome of keratinocytes. There was an excess of rare variants within CARD14 in cases versus controls (burden test p-value = 0.0015). Some variants were only seen in a single case and included putative pathogenic mutations (c.424G>A [p.Glu142Lys], c.425A>G [p.Glu142Gly]) and the generalized pustular psoriasis mutation, c.413A>C (p.Glu138Ala), that lie within the coiled-coil domain of CARD14. The c.349G>A (p.Gly117Ser) familial psoriasis mutation was present at a frequency of 0.0005 in cases of European ancestry. CARD14 variants led to a range of NF-kB activities, with putative pathogenic variants leading to levels >2.5-fold higher than wildtype CARD14. Two variants (c.511C>A [p.His171Asn] and c.536G>A [p.Arg179His]) required stimulation with TNF-a to achieve significant increases in NF-kB levels. Transcriptome profiling of wildtype and variant CARD14 transfectants in keratinocytes differentiated likely pathogenic mutations from neutral variants such as polymorphisms. Over 20 CARD14 polymorphisms were also genotyped and meta-analysis revealed association of psoriasis with rs11652075 (c.2458C>T/p.Arg820Trp; p-value = 2.1x10-6). In the two largest psoriasis cohorts, evidence for association increased when rs11652075 was conditioned on HLA-Cw*0602 (PSORS1). These studies contribute to our understanding of the genetic basis of psoriasis and illustrate the challenges faced in identifying pathogenic variants in common disease. Keratinocytes were transfected with wildtype Cardsh or one of 16 Card14 mutations (17 total samples). The cells were collected and RNA extracted to determine the effect of these mutations compared to wildtype Card14. No replicates are included.
Project description:Psoriasis is a common inflammatory disorder of the skin and other organs. We have determined that mutations in CARD14, encoding an NF-kB activator within skin epidermis, account for PSORS2. Here we describe fifteen additional rare, missense variants in CARD14, their distribution in seven psoriasis cohorts (>6,000 cases and >4,000 controls), and their effects on NF-kB activation and the transcriptome of keratinocytes. There was an excess of rare variants within CARD14 in cases versus controls (burden test p-value = 0.0015). Some variants were only seen in a single case and included putative pathogenic mutations (c.424G>A [p.Glu142Lys], c.425A>G [p.Glu142Gly]) and the generalized pustular psoriasis mutation, c.413A>C (p.Glu138Ala), that lie within the coiled-coil domain of CARD14. The c.349G>A (p.Gly117Ser) familial psoriasis mutation was present at a frequency of 0.0005 in cases of European ancestry. CARD14 variants led to a range of NF-kB activities, with putative pathogenic variants leading to levels >2.5-fold higher than wildtype CARD14. Two variants (c.511C>A [p.His171Asn] and c.536G>A [p.Arg179His]) required stimulation with TNF-a to achieve significant increases in NF-kB levels. Transcriptome profiling of wildtype and variant CARD14 transfectants in keratinocytes differentiated likely pathogenic mutations from neutral variants such as polymorphisms. Over 20 CARD14 polymorphisms were also genotyped and meta-analysis revealed association of psoriasis with rs11652075 (c.2458C>T/p.Arg820Trp; p-value = 2.1x10-6). In the two largest psoriasis cohorts, evidence for association increased when rs11652075 was conditioned on HLA-Cw*0602 (PSORS1). These studies contribute to our understanding of the genetic basis of psoriasis and illustrate the challenges faced in identifying pathogenic variants in common disease.
Project description:In psoriasis lesions, a diverse mixture of cytokines is upregulated which influence each other generating a complex inflammatory situation. Although this is the case, the inhibition of Interleukin-17A (IL-17A) alone showed unprecedented clinical results in patients, indicating that IL-17A is a critical inducer of psoriasis pathogenesis. To elucidate IL-17A-driven keratinocyte-intrinsic signaling pathways, we treated monolayers of normal human epidermal keratinocytes in vitro with a mixture of 6 cytokines (IL-17A, TNF-a, IL-17C, IL-22, IL-36g and IFN-g) involved in psoriasis, to mimic the inflammatory milieu in psoriasis lesions. Microarray and gene set enrichment analysis revealed that this cytokine mixture induced similar gene expression changes with the previous transcriptome studies using psoriasis lesions. Importantly, we identified a set of IL-17A-regulated genes in keratinocytes, which recapitulate typical psoriasis genes exemplified by DEFB4A, S100A7, IL19 and CSF3, based on differences in the expression profiles of cells stimulated with 6 cytokines versus cells stimulated with only 5 cytokines lacking IL-17A. Furthermore a specific IL-17A-induced gene, NFKBIZ, which encodes IkappaB-zeta, a transcriptional regulator for NF-kappaB, was demonstrated to have a significant role for IL-17A-induced gene expression. Thus, we present novel in vitro data from normal human keratinocytes that would help elucidating the IL-17A-driven keratinocyte activation in psoriasis. Cytokine mixture-induced gene expression in primary normal human epidermal keratinocytes (NHEKs) was measured at 24 hours after exposure. NHEKs were exposed to the combination of selected six cytokines (IL-17A: 100 ng/ml, TNF-a: 10 ng/ml, IFN-g: 10 ng/ml, IL-17C: 100 ng/ml, IL-22: 100 ng/ml, IL-36g: 500 ng/ml) , or to the different combinations of five of the six cytokines (in total, 7 different treatments and one untreated control). No replicate experiments were conducted.
Project description:Psoriasis is a common, immune-mediated, genetic disorder of the skin associated with arthritis in approximately 30% of cases. Previously, we localized PSORS2 (psoriasis susceptibility locus 2) to chromosome 17q25.3-qter following a genome-wide linkage scan in a family of European origin with multiple cases of psoriasis and psoriatic arthritis. Linkage to PSORS2 was also observed in a multiply affected psoriasis family from Taiwan. With genomic capture and DNA sequencing, we identified unique gain-of-function mutations in caspase recruitment domain family, member 14 (CARD14) that segregated with psoriasis. The mutations, c.349G>A (p.Gly117Ser) and c.349+5G>A respectively, altered splicing between exons 3 and 4 of CARD14. A de novo mutation in CARD14, c.413A>C [p.Glu138Ala], was detected in a child with sporadic, early-onset, generalized pustular psoriasis. CARD14 activates nuclear factor kappa B (NF-kB), and the p.Gly117Ser and p.Glu138Ala substitutions were shown to lead to enhanced NF-kB activation and upregulation of a subset of psoriasis-associated genes in keratinocytes compared to wildtype CARD14. These included chemokine (C-C motif) ligand 20 (CCL20) and interleukin 8 (IL8). CARD14 is localized mainly in the basal and suprabasal layers of healthy skin epidermis, while in lesional psoriatic skin it is reduced in the basal layer and more diffusely upregulated in the suprabasal layers of the lesional epidermis. We propose that, following a triggering event that can include epidermal injury, rare gain-of-function mutations in CARD14 initiate a process that includes inflammatory cell recruitment by keratinocytes. This perpetuates a vicious cycle of epidermal inflammation and regeneration that is the hallmark of psoriasis. No replicates are included. Three sample sets. [1] Skin biopsies had RNA extracted for expression within target tissue. [2] HEK cells were transfected with different constructs (including wildtype) of CARD14 to determine the mutational effect in keratinocytes. [3] Keratinocytes derived from psoriasis patients with CARD14 mutations were cultured and compared with and without stimulation with TNFalpha.
Project description:In psoriasis lesions, a diverse mixture of cytokines is upregulated which influence each other generating a complex inflammatory situation. Although this is the case, the inhibition of Interleukin-17A (IL-17A) alone showed unprecedented clinical results in patients, indicating that IL-17A is a critical inducer of psoriasis pathogenesis. To elucidate IL-17A-driven keratinocyte-intrinsic signaling pathways, we treated monolayers of normal human epidermal keratinocytes in vitro with a mixture of 6 cytokines (IL-17A, TNF-a, IL-17C, IL-22, IL-36g and IFN-g) involved in psoriasis, to mimic the inflammatory milieu in psoriasis lesions. Microarray and gene set enrichment analysis revealed that this cytokine mixture induced similar gene expression changes with the previous transcriptome studies using psoriasis lesions. Importantly, we identified a set of IL-17A-regulated genes in keratinocytes, which recapitulate typical psoriasis genes exemplified by DEFB4A, S100A7, IL19 and CSF3, based on differences in the expression profiles of cells stimulated with 6 cytokines versus cells stimulated with only 5 cytokines lacking IL-17A. Furthermore a specific IL-17A-induced gene, NFKBIZ, which encodes IkappaB-zeta, a transcriptional regulator for NF-kappaB, was demonstrated to have a significant role for IL-17A-induced gene expression. Thus, we present novel in vitro data from normal human keratinocytes that would help elucidating the IL-17A-driven keratinocyte activation in psoriasis.
Project description:Classical Hodgkin lymphoma (cHL) is one of the most common malignant lymphomas. It is characterized by the presence of rare Hodgkin and Reed/Sternberg (HRS) cells embedded in an extensive inflammatory infiltrate. Constitutive activation of nuclear factor-kappaB (NF-kappaB) in HRS cells which transcriptionally regulates expression of multiple anti-apoptotic factors and pro-inflammatory cytokines plays a central role in the pathogenesis of cHL (1, 2). In non-stimulated condition, NF-kappaB proteins are rendered inactive by binding to their inhibitors (IkappaB s), which sequester them in the cytoplasm. Stimulation of multiple receptors activates the IkappaB kinase (IKK) complex that phosphorylates IkappaB at two specific serine residues, followed by its ubiquitination and proteasomal degradation, thereby releasing NF-kappaB proteins and allowing their nuclear translocation (3). Recently, two studies provided further insights into the molecular mechanisms of IKK activation upon TNF stimulation (4, 5). Activation of the IKK complex and subsequent NF-kappaB activation requires Lys63 polyubiquitination of RIP1, a kinase which is recruited to the receptor upon TNF stimulation. IKK-gamma (NEMO), the regulatory subunit of the IKK complex, specifically recognizes these Lys63-linked polyubiquitins attached to RIP1 and thereby activates IKK and NF-kappaB (4, 5). A20 is an ubiquitin-modifying enzyme that inhibits NF-kappaB activation in succession of tumor necrosis factor (TNF) receptor and Toll-like receptor induced signals (6-8). This enzyme removes Lys63 linked ubiquitin chains from RIP1 and adds Lys48 polyubiquitins to RIP1, thereby targeting this factor for proteasomal degradation, thus explaining the molecular mechanism of NF-kappaB inhibition by A20 (6). A20 likely inhibits NF-kappaB acitivity also by additional means, including interaction with TRAF1 and TRAF2 (9).
Project description:Psoriasis is a common, immune-mediated, genetic disorder of the skin associated with arthritis in approximately 30% of cases. Previously, we localized PSORS2 (psoriasis susceptibility locus 2) to chromosome 17q25.3-qter following a genome-wide linkage scan in a family of European origin with multiple cases of psoriasis and psoriatic arthritis. Linkage to PSORS2 was also observed in a multiply affected psoriasis family from Taiwan. With genomic capture and DNA sequencing, we identified unique gain-of-function mutations in caspase recruitment domain family, member 14 (CARD14) that segregated with psoriasis. The mutations, c.349G>A (p.Gly117Ser) and c.349+5G>A respectively, altered splicing between exons 3 and 4 of CARD14. A de novo mutation in CARD14, c.413A>C [p.Glu138Ala], was detected in a child with sporadic, early-onset, generalized pustular psoriasis. CARD14 activates nuclear factor kappa B (NF-kB), and the p.Gly117Ser and p.Glu138Ala substitutions were shown to lead to enhanced NF-kB activation and upregulation of a subset of psoriasis-associated genes in keratinocytes compared to wildtype CARD14. These included chemokine (C-C motif) ligand 20 (CCL20) and interleukin 8 (IL8). CARD14 is localized mainly in the basal and suprabasal layers of healthy skin epidermis, while in lesional psoriatic skin it is reduced in the basal layer and more diffusely upregulated in the suprabasal layers of the lesional epidermis. We propose that, following a triggering event that can include epidermal injury, rare gain-of-function mutations in CARD14 initiate a process that includes inflammatory cell recruitment by keratinocytes. This perpetuates a vicious cycle of epidermal inflammation and regeneration that is the hallmark of psoriasis.
Project description:Classical Hodgkin lymphoma (cHL) is one of the most common malignant lymphomas. It is characterized by the presence of rare Hodgkin and Reed/Sternberg (HRS) cells embedded in an extensive inflammatory infiltrate. Constitutive activation of nuclear factor-kappaB (NF-kappaB) in HRS cells which transcriptionally regulates expression of multiple anti-apoptotic factors and pro-inflammatory cytokines plays a central role in the pathogenesis of cHL (1, 2). In non-stimulated condition, NF-kappaB proteins are rendered inactive by binding to their inhibitors (IkappaB s), which sequester them in the cytoplasm. Stimulation of multiple receptors activates the IkappaB kinase (IKK) complex that phosphorylates IkappaB at two specific serine residues, followed by its ubiquitination and proteasomal degradation, thereby releasing NF-kappaB proteins and allowing their nuclear translocation (3). Recently, two studies provided further insights into the molecular mechanisms of IKK activation upon TNF stimulation (4, 5). Activation of the IKK complex and subsequent NF-kappaB activation requires Lys63 polyubiquitination of RIP1, a kinase which is recruited to the receptor upon TNF stimulation. IKK-ï§ï (NEMO), the regulatory subunit of the IKK complex, specifically recognizes these Lys63-linked polyubiquitins attached to RIP1 and thereby activates IKK and NF-kappaB (4, 5). A20 is an ubiquitin-modifying enzyme that inhibits NF-kappaB activation in succession of tumor necrosis factor (TNF) receptor and Toll-like receptor induced signals (6-8). This enzyme removes Lys63 linked ubiquitin chains from RIP1 and adds Lys48 polyubiquitins to RIP1, thereby targeting this factor for proteasomal degradation, thus explaining the molecular mechanism of NF-kappaB inhibition by A20 (6). A20 likely inhibits NF-kappaB acitivity also by additional means, including interaction with TRAF1 and TRAF2 (9). SNP 6.0 array (Affymetrix) analyses were performed according to the manufacturer's directions on DNA extracted from three Hodgkin cell lines (L1236, HDLM-2, U-HO1), HapMap samples included in the Genotyping Console Software 3.0 were used as references.
Project description:The efficacy of monoclonal antibodies against either interleukin (IL)-17 or the IL-17 receptor in psoriasis therapy provides strong evidence that IL-17 is the major inflammatory mediation in this disease. However, how IL-17 induces epidermal hyperplasia in psoriasis remains largely unknown. Here, we show that IL-17 actives NF-kB in keratinocytes and initiates the NF-kB-dependent transcription of microRNA-31 (miR-31), one of the most abundant microRNAs in the epidermis of lesional skin of psoriasis and two related mouse models. Similar to IL-17 deficiency (IL-17-/-), knocking out miR-31 (miR-31-/-) or targeting it by antagomir-31 prevents keratinocytes Ki67 expression and inhibits acanthosis and dermal inflammation in psoriasis mouse model. Moreover, PPP6c, a negative regulator restricting G0/G1 to G2/M phase progression in the cell cycle, is diminished in human psoriatic epidermis and is directly targeted by miR-31. Inhibition of ppp6c is functionally important for the biological effects of miR-31 in the development of epidermal hyperplasia. Thus, our data define IL-17-inducede miR-31 and its target ppp6c as critical factors for hyperproliferative epidermis in psoriasis. Epidermis samples from affected ears derived from 3 CD18hypo PL/J mice (DIS) or normal ears derived from 3 CD18hypo C57BL/6J mice(2128) were used for RNA extraction and hybridization on Affymetrix microarrays. We sought to compare miRNA expression of normal skin from control and lesional skin.