Insights into the molecular pathogenesis of cardiospondylocarpofacial syndrome: MAP3K7 c.737-7A > G variant alters the TGFβ-mediated α-SMA cytoskeleton assembly and autophagy

A severe case of cardiospondylocarpofacial syndrome with a novel MAP3K7 variant

Cardiospondylocarpofacial syndrome (CSCFS) is a congenital malformation characterized by growth retardation, facial features, short toes with carpal and tarsal fusion, extensive posterior neck vertebral fusion, congenital heart disease, and deafness. Here, we report a severe case of CSCFS with a novel variant, p.Thr187Ile, in MAP3K7. Thr187 is the main phosphorylation site for TGF-beta-activated kinase 1 encoded by MAP3K7, and this variant may cause significant abnormalities in downstream signaling.

TGF-β and BMP Signaling Pathways in Skeletal Dysplasia with Short and Tall Stature

The transforming growth factor β (TGF-β) and bone morphogenetic protein (BMP) signaling pathways play a pivotal role in bone development and skeletal health. More than 30 different types of skeletal dysplasia are now known to be caused by pathogenic variants in genes that belong to the TGF-β superfamily and/or regulate TGF-β/BMP bioavailability. This review describes the latest advances in skeletal dysplasia that is due to impaired TGF-β/BMP signaling and results in short stature (acromelic dysplasia and cardiospondylocarpofacial syndrome) or tall stature (Marfan syndrome). We thoroughly describe the clinical features of the patients, the underlying genetic findings, and the pathomolecular mechanisms leading to disease, which have been investigated mainly using patient-derived skin fibroblasts and mouse models. Although no pharmacological treatment is yet available for skeletal dysplasia due to impaired TGF-β/BMP signaling, in recent years advances in the use of drugs targeting TGF-β have been made, and we also discuss these advances.

Roles of autophagy-related genes in the therapeutic effects of Xuanfei Pingchuan capsules on chronic obstructive pulmonary disease based on transcriptome sequencing analysis

Objective: Autophagy plays an important role in the occurrence and development of chronic obstructive pulmonary disease (COPD). We evaluated the effect of Xuanfei Pingchuan capsule (XFPC) on autophagy-related genes of COPD by a bioinformatics analysis and experimental verification. Methods: The best treatment duration was screened by CCK8 assays. HBE cells were divided into three groups: blank, CSE and XFPC. After intervened by XFPC, HBE cells were collected and sent to Shenzhen Huada Gene Company for transcriptome sequencing. Subsequently, differential expression analyses, target gene prediction, and function enrichment analyses were carried out. Expression changes were verified in HBE cells by real-time Quantitative PCR (RT-qPCR) and western blotting (WB). Results: The result of differential expression analysis displayed that 125 target genes of HBE cells were mainly related to mitogen-activated protein kinase (MKK) binding, interleukin 33 binding, 1-Pyrroline-5-carboxylate dehydrogenase activity, and the mitogen-activated protein kinase (MAPK) signal pathway. Among the target genes, the core genes related to autophagy obtained by maximum neighborhood component algorithm were CSF1, AREG, MAPK9, MAP3K7, and AKT3. RT-qPCR and WB methods were used to verify the result, it showed similar expression changes in CSF1, MAPK9, MAP3K7, and AKT3 in bronchial epithelial cells to those in the bioinformatics analysis. Conclusion: Through transcriptome sequencing and validation analysis, we predicted that CSF1, MAPK9, MAP3K7, and AKT3 may be the potential autophagy-related genes that play an important role in the pathogenesis of COPD. XFPC may regulate autophagy by down-regulating the expression of CSF1, MAPK9, MAP3K7, and AKT3, thus achieving the purpose of treating chronic obstructive pulmonary disease.

The MAP3K7 gene: further delineation of clinical characteristics and genotype/phenotype correlations

Mitogen-Activated Protein 3 Kinase 7 (MAP3K7) encodes the ubiquitously expressed transforming growth factor β (TGF-β)-activated kinase 1 (TAK1), which plays a crucial role in many cellular processes. Mutationsin the MAP3K7 gene have been linked to 2 distinct disorders: frontometaphyseal dysplasia type 2 (FMD2) and cardiospondylocarpofacial syndrome (CSCF). The fact that different mutations can induce 2 distinct phenotypes suggests a phenotype/genotype correlation, but no side-by-side comparison has been done thus far to confirm this. Here we significantly expand the cohort and the description of clinical phenotypes for patients with CSCF and FMD2 who carry mutations in MAP3K7. Our findings support that in contrast to FMD2-causing mutations, CSCF-causing mutations in MAP3K7 have a loss-of-function effect. Additionally, patients with pathogenic mutations in MAP3K7 are at risk for (severe) cardiac disease, have symptoms associated with connective tissue disease and we show overlap in clinical phenotypes of CSCF with Noonan syndrome. Together, we confirm a molecular fingerprint of FMD2- versus CSCF-causing MAP3K7 mutations and conclude that mutations in MAP3K7 should be considered in the differential diagnosis of patients with syndromic congenital cardiac defects and/or cardiomyopathy, syndromic connective tissue disorders and in the differential diagnosis of Noonan syndrome. This article is protected by copyright. All rights reserved.

Loss-of-function variants in exon 4 of TAB2 cause a recognizable multisystem disorder with cardiovascular, facial, cutaneous, and musculoskeletal involvement

PURPOSE

This study aimed to describe a multisystemic disorder featuring cardiovascular, facial, musculoskeletal, and cutaneous anomalies caused by heterozygous loss-of-function variants in TAB2.

METHODS

Affected individuals were analyzed by next-generation technologies and genomic array. The presumed loss-of-function effect of identified variants was assessed by luciferase assay in cells transiently expressing TAB2 deleterious alleles. In available patients' fibroblasts, variant pathogenicity was further explored by immunoblot and osteoblast differentiation assays. The transcriptomic profile of fibroblasts was investigated by RNA sequencing.

RESULTS

A total of 11 individuals from 8 families were heterozygotes for a novel TAB2 variant. In total, 7 variants were predicted to be null alleles and 1 was a missense change. An additional subject was heterozygous for a 52 kb microdeletion involving TAB2 exons 1 to 3. Luciferase assay indicated a decreased transcriptional activation mediated by NF-κB signaling for all point variants. Immunoblot analysis showed a reduction of TAK1 phosphorylation while osteoblast differentiation was impaired. Transcriptomic analysis identified deregulation of multiple pleiotropic pathways, such as TGFβ-, Ras-MAPK-, and Wnt-signaling networks.

CONCLUSION

Our data defined a novel disorder associated with loss-of-function or, more rarely, hypomorphic alleles in a restricted linker region of TAB2. The pleiotropic manifestations in this disorder partly recapitulate the 6q25.1 (TAB2) microdeletion syndrome and deserve the definition of cardio-facial-cutaneous-articular syndrome.

Expanding the phenotypic spectrum of cardiospondylocarpofacial syndrome: From a detailed clinical and radiological observation of a boy with a novel missense variant in MAP3K7

Cardiospondylocarpofacial syndrome (CSCF; OMIM#157800) is characterized by growth impairment, failure to thrive in infancy, multiple valvular disease, carpal and tarsal fusions, vertebral fusions, and joint hypermobility. It is caused by pathogenic variants of MAP3K7, which encodes transforming growth factor-β activated kinase 1 (TAK1), a member of the mitogen-activated protein kinase kinase kinase family (MAPKKK). Only eight individuals with molecularly confirmed CSCF have been reported. Here, we report the first Asian CSCF male with a novel missense variant of MAP3K7 (NM_145331.3: c.467A > T: p.Asp156Val). We compared and reviewed the clinical and molecular findings in previously reported CSCF cases and the present case to better delineate the phenotype of CSCF. In addition to the main symptoms of CSCF, the present case had a mixed phenotype of Ehlers-Danlos syndrome (EDS) and Noonan syndrome. Taking this case together with the previously reported cases, CSCF may overlap with the phenotypes of EDS and Noonan syndrome, suggesting that this finding may contribute to diagnosing CSCF. Another major achievement of this research is to successfully capture the process of carpal fusion in a CSCF case radiographically. This work may expand the phenotypic spectrum of CSCF.