A novel mutation in the cathepsin C (CTSC) gene in Iranian family with Papillon-Lefevre syndrome

Cathepsin C in health and disease: from structural insights to therapeutic prospects

Cathepsin C (CTSC) is a lysosomal cysteine protease constitutively expressed at high levels in the lung, kidney, liver, and spleen. It plays a key role in the activation of serine proteases in cytotoxic T cells, natural killer cells (granzymes A and B), mast cells (chymase and tryptase) and neutrophils (cathepsin G, neutrophil elastase, proteinase 3) underscoring its pivotal significance in immune and inflammatory defenses. Here, we comprehensively review the structural attributes, synthesis, and function of CTSC, with a focus on its variants implicated in the etiopathology of several syndromes associated with neutrophil serine proteases, including Papillon-Lefevre syndrome (PLS), Haim-Munk Syndrome (HMS), and aggressive periodontitis (AP). These syndromes are characterized by palmoplantar hyperkeratosis, and early-onset periodontitis (severe gum disease) resulting in premature tooth loss. Due to the critical role played by CTSC in these and several other conditions it is being explored as a potential therapeutic target for autoimmune and inflammatory disorders. The review also discusses in depth the gene variants of CTSC, and in particular their postulated association with chronic obstructive pulmonary disease (COPD), COVID-19, various cancers, anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, sudden cardiac death (SCD), atherosclerotic vascular disease, and neuroinflammatory disease. Finally, the therapeutic potential of CTSC across a range of human diseases is discussed.

Potential correlation between chronic periodontitis and Parkinson's disease

OBJECTIVES

This study aims to investigate possible hub genes, associated pathways, and transcription factors between chronic periodontitis (CP) and Parkinson's disease (PD).

METHODS

Gene expression profiles of CP (GSE16134, GSE23586, and GSE10334) and PD (GSE20141 and GSE49036) were downloaded from the gene expression omnibus (GEO) database for differential expression analysis and functional clustering analysis. The protein-protein interaction (PPI) network was constructed, and hub genes were screened by four topological analysis algorithms and modular segmentation. Functional clustering analysis was performed. The hub genes were validated by external datasets of CP and PD, and causal relation was further assessed by Mendelian randomization (MR).

RESULTS

After merging the data, 1 211 differentially expressed genes (DEGs) were screened in the CP datasets; of which, 551 were upregulated and 660 were downregulated. A total of 2 407 DEGs were screened in the PD dataset, of which, 1 438 were upregulated and 969 were downregulated. The PPI network included 145 nodes and 126 edges. Four hub genes (FCGR3B, PRF1, IL18, and CD33) and three transcription factors (HSF1, HSF2, and HSF4) were finally screened. The relevant pathway was predominantly natural killer (NK) cell-mediated toxic effects. The MR results suggest a possible positive causal relationship between CP and the risk of developing PD.

CONCLUSIONS

This study indicated the probably shared pathophysiology and possible causal relationship between CP and PD and may offer novel concepts and therapeutic targets for future mechanistic investigations.

The first case report of Haim Munk disease with neurological manifestations and literature review

HMS can have neurologic MS like manifestations. It is urgent to do more research and report probable unknown associations of HMS for its better management.

A novel mutation in the cathepsin C (CTSC) gene in Iranian family with Papillon-Lefevre syndrome

Objectives

In this study, we analyzed the whole exomes of CTSC gene in a family with history of PLS.

Materials and methods

Genomic DNA was extracted from peripheral blood and genotype analysis was performed. The mutated protein sequence was used to find the best possible tertiary structure for homology modeling. The homology modeling of the novel mutation was then performed using the online Swiss‐Prot server. The results were also analyzed for to verify its validity.

Results

The analysis of CTSC gene elucidated a novel insertion GAC. The novel mutation was proved by analyzing 50 healthy control volunteers. Modeling of the novel found mutation in CTSC gene revealed structural defects that may have caused the functional abnormalities.

Conclusions

The structural analysis of the mutated protein model identifies changes in the stereo‐chemical and the energy level of the mutated protein. Since this protein play a role in the activation of granule serine proteases from cytotoxic T lymphocytes, natural killer cells, mast cells, such structural defects may lead to its malfunction causing dysfunctioning of immune defense mechanisms.